E t 50- a F 5 - International Joint Commission

1977 

Editors: H. SHEAR - A. f, I! WATSON

The statements and views presented in these proceedings are 

those of the authors and of the workshop participants, and do not 

necessarily represent the views or policies of the International Joint 

Commission, Research Advisory Board and Pollution from Land Use 

Activities Reference Group. Mention of trade names or commercial 

products does not constitute endorsement or recommendation for use. 

ii

1. 

2. 

3. 

k E S OF SEDIMUsr 

Natural Sheet and Channel Erosion of Unconsolidated Source 

Material (Geomorphic Control, Magnitude and Frequency of 

Transfer Mechanisms) 

D. E. Walling 

University of Exeter 

UNITED KINGDOH 

Influence of Land Use on Erosion and Transfer Process of 

Sediment 

T. Dickinson and G. Wall 

University of Guelph 

GUELPH. Ontario 

Anthropogenic Influences of Sediment Quality at a Source 

a) Pesticides and PCB's 

R. Miles 

Agriculture Canada 

LONM)N, Ontatio 

b) Nutrients: Carbon, Nitrogen and Phosphorus 

c) Metals 

M. Miller 


GUELPH, Ontario 

G. K. Rutherford 

Queen's University 

KINGSTON, Ontario 

R. Frank 

Ontario Ministry of 

Agriculture 6 Food 

GUELPH, Ontario 

PAGE 

1 

5 

11 

37 

69 

81 

95

4. Regional Overview of the Impact of Land Use on Water Quality 105 

CHAPTER 2 

TRANSFURT OF SEDIMENT 

A. D. McElroy 

Mdwest Research Institute 

KANSAS CITY, Mo. 

1. Influence of Flow Characteristics on Sediment Transport 

with Emphasis on Grain Size and Mineralogy 

J. Culbertson 

U.S. Geological Survey 

RESTON, Va. 

2. Sediment Storage and Remobilization Characteristics of 

Watersheds 

J. Knox 

University of Wisconsin 

MADISON, Wisconstn 

C. Nordin 

U.S. Geological Survey 

LAKEWOOD. Colorado 

3. Forms and Sediment Associations of Nutrients (C.N. and P.) 

Pesticides and Metals 

a) Nutrients - P 157 

H. L. Golterman 

Limnologisch Instituut 

NETHERLANDS 

b) Nutrients - N 181 

c) Pesticides 

T. Logan 

Ohio State University 

COLUMBUS. Ohio 

H. B. Pionke 

U.S. Department of Agriculture 

Agricultural Research Service 

UNIVERSITY PARK, Pennsylvania 

iv 

117 

137 

151 

T. Cahill 

Resource Management Associates 

WEST CHESTER, Pennsylvania 

199

d) Trace Metals 

Ulrich F6rstner 

University of Heidelberg 

4. Geochemistry of Sediment/Water Interactions of Nutrients, 

Pesticides and Metals, Including Observations on Availability 

a) Nutrients 

b) Pesticides 

c) Metals 

D. R. Bouldin 

Cornel1 University 

ITHACA, New York 

IWLICATIONS 

FOR TI-E GREAT LAKES 

1. Physical Processes 

2. Nutrients 

J. B. Weber 

North Carolina State University 

RALEIGH, North Carolina 

I. Jonasson 

Energy Mines and Resources 

OTTAWA, Ontario 

J. R. Vallentyne 

Environment Canada 

OTTAWA, Ontario 

G. H. DUKY 


MADISON, Wisconsin 

V 

PAGE 

219 

235 

245 

255 

275 

279 

285 

291

3. Pesticides 

4. Metals 

GwrER 5 

~KSHOP ORGANIZERS AND AITNDEES 

vi 

PAGE 

293 

295 

299

In April 1972 the United States and Canada signed the Great Lakes 

Water Quality Agreement. The responsibility for the implementation of this 

Agreement was assigned to the International Joint Commission. The International 

Joint Commission was established pursuant to the Boundary Waters Treaty of 

1909. Its operating concept assumes that solutions to boundary waters problems 

should be sought by joint deliberations of a permanent tribunal of three 

Canadians and three Americans. 

Under the terms of the Agreement a Research Advisory Board was 

established to advise the International Joint Commission on a continuing 

basis on matters relating to ongoing research and research needs related to 

Great Lakes Water Quality. Another group, with a defined lifespan of five 

years was also established - the International Reference Group on Great 

Lakes Pollution from Land Use Activities (PLUARG). The PLUARG was charged 

with answering the following questions: 

(1) Are the boundary waters of the Great Lakes System 

being polluted by land drainage (including ground and 

surface runoff and sediments) from agriculture, forestry, 

urban and industrial land development, recreational and 

park land development, utility and transportation systems 

and natural sources? 

(2) If the answer to the foregoing question is in the 

affirmative, to what extent, by what causes, and in what 

localities is the pollution taking place? 

(3) If the Commission should find that pollution of the 

character just referred to is taking place, what remedial 

measures would, in its judgement, be most practicable and 

what would be the probable cost thereof? 

The Commission is requested to consider the adequacy of existing 

programs and control measures, and the need for improvements thereto, 

relating to: 

(a) inputs of nutrients, pest control products, sediments, 

and other pollutants from the sources referred to above; 

(b) land use; 

(c) land fills, land dumping, and deep well disposal practices; 

1

(d) confined livestock feeding operations and other animal 

husbandry operations; and 

(e) pollution from other agricultural, forestry and land 

use sources. 

In carrying out its study the Commission should identify deficiencies 

in technology and recommend actions for their correction. 

The PLUARG, in its Study Plan of 1974 established a series of pilot 

watershed studies and other special land use studies in the United States 

and Canada to assess the impact of land on water use quality as related to 

river loadings to the Great Lakes. It was recognized that a variety of 

nutrients and contaminants are transported both by mineral and organic 

sediment. A better understanding of sediment-associated nutrient and 

contaminant transport in streams in time and space was needed to assess 

their impact on the Great Lakes. 

The PLUARG therefore referred this matter to the Research Advisory 

Board as the IJC's principal advisor on Great Lakes research. An evaluation 

was requested of the state-of-the-art of this topic together with recommendations 

for further research. The Board in turn decided to sponsor this workshop to 

synthesize current research and to identify research needs on nutrient and 

contaminant transport by sediment within fluvial systems. Clarification was 

sought on the interrelationships of source, in-channel storage, resuspension 

and transport mechanisms with long-term, seasonal and single-event flows, 

and including an examination of the interaction of sediment and water chemistry 

on key nutrients and contaminants. 

The Research Advisory Board anticipated positive recommendations 

from this workshop not only in terms of research needed, but of how the 

research that has been done can be put to use to solve Great Lakes water 

quality problems. These recommendations moreover, would be sufficiently 

succinct for clear-cut decisions by the Commission to advise appropriate 

Governmental action. 

It is intended that the recommendations in these proceedings will 

have an immediate effect on PLUARG studies and a longer term influence on 

the Great Lakes research community. 

2 

Dr. Harvey Shear 

Dr. Andrew E. P. Watson 

International Joint Commissio 

Great Lakes Regional Office 

100 Ouellette Avenue 

WINDSOR, Ontario

For the City of Kitchener: 

Mrs. Edith MacIntosh 

Mayor of Kitchener 

Good Morning. It is my pleasure to welcome you here today. I 

bring greetings on behalf of Kitchener to all of you who are involved, 

interested and concerned in this workshop on pollution from land use activities. 

I was looking over your program and I note that your purpose, and 

I am quoting, "is to synthesize current research and to identify research 

needs on nutrient and contaminant transport by sediment within fluvial 

systems". Further, you will be "clarifying the interrelationships of source, 

in-channel storage, resuspension and transport mechanisms with long term, 

seasonal and single-event flows, including an examination of the interaction 

of sediment and water chemistry on key nutrients and contaminants". I looked 

at that and I wondered what it all meant. Well, to me it meant, that, 

for instance, ten years ago at our cottage on the Bruce Penninsula, I could 

walk down to the shoreline, dip a pail into the and water take a drink. 

Today I can't do that. My hope is that with your expertise it will be 

possible in the not too distant future to drink Georgian Bay water again. 

I brought with me our latest report on the bacterial examination 

of drinking water and as I mentioned, ten years ago we could drink the water. 

Whenever we had it tested it came back A number 1. Today, it has a very 

high coliform bacteria count. It is rather disturbing. 

During my term as National President of the Consumer's Association 

of Canada, the soap bubble conditions in the Great Lakes was area a major 

issue. Canadian consumers fought for the ban on phosphorus in detergents in 

cooperation with the International Joint Commission. I have been told that 

this is still a problem. I understand that the Grand River watershed is 

one of the three major Canadian watersheds selected for intensive study 

under the PLUARG program. You, as invited experts, will be seeing first 

hand I hope, the work being done in the Grand. You may be wondering why I 

was carting around these two huge volumes. Here are 700 pages of the very 

latest information just tabled this week on what is being done in the Grand 

River Basin. 

Mr. Chairman, delegates, I would like to issue a very warm welcome 

to all of you. I know you have come from different countries and from 

across the province and from other provinces. I hope you have a very successful 

workshop here and we are glad you chose Kitchener. Again, welcome to 

everyone. 

5

For PLUARG 

Dr. R. L. Thorns 

Director 

Great Lakes Biolimnology Laboratory 

Department of Fisheries and the Environment 

Fisheries and Marine Service 

Canada Centre for Inland Waters 

Bur Zington, Ontario 

Thank you very much MKS. MacIntosh. A number of us present at 

this meeting, have recently returned from a symposium in Amsterdam on the 

interaction of sediment and fresh water. The organizer was Dr. Golterman 

who is going to talk to us later in this workshop on nutrients. The symposium 

was a significant event in limnological studies because it emphasized 

the fact that the role of sediments in the lacustrine environment is now 

starting to come to the fore. It is very gratifying to me personally 

and to many of us engaged on sediment studies at the Canada Centre for 

Inland Waters. The role and the significance of sediments is thus becoming 

very apparent, particularly with regard to toxic trace metals and persistent 

organic contaminants that are becoming all too apparent in our environment. 

The PLUARG which is charged with an assessment of the impact on 

the boundary waters of the Great Lakes of pollutants from diffuse sources, 

designed its programs to incorporate a significant number of sediment 

oriented studies. These studies are now in progress. Close to two years 

ago we decided to hold this workshop in order to bring together many of 

the internationally known experts in the field of fluvial sediment. We 

wanted to assure ourselves that the work we were doing was correct. We 

wanted an opportunity to discuss OUT problems; to assist in the interpretation 

of our data, and, if the experts have come up with new knowledge or techniques 

we want to know, so that we may, even at this stage, make modifications 

to OUK programs. Consequently, I feel that this is a highly significant 

workshop; to the reference group, to the International Joint Commission 

and to us participants and wish it every success in achieving its objectives. 

6

For the Research Advisory Board 

Dr. A. R. LeFeuvre 

Director 


BurZington, ktario 

I am very happy to be with you this morning at the beginning of 

this important workshop. As the Canadian chairman of the Research Advisory 

Board, I am very happy that we are able to lend our support and sponsorship 

to this workshop. 

I think that it is very timely, as Dr. Thomas has pointed out. 

The topic of the workshop is very important to our understanding of the 

several mechanisms that are at work in bringing pollutants and nutrients 

from the diffuse sources on the watershed into the river systems and then 

eventually into the boundary waters of the Great Lakes. This, of course, 

is why it is a reference under the International Joint Commission and 

provided for under the Canada-U.S. Water Quality Agreement. The Research 

Advisory Board, as you may know, is that part of the structure established 

under the Canada-U.S. Water Quality Agreement which has the responsibility 

for advising the Governments through the Commission on the needed research, 

and those research areas which could profitably be accomplished by joint 

effort, and provide this advice to the Governments in the of form annual 

reports and special reports. 

At our most recent reporting experience which was July, last 

the Research Advisory Board tabled a report on Research Needs. This was 

the compilation of identified research needs with priorities that identified 

for the Governments and their agencies those areas that required additional 

research effort and those areas which were of priority interest. All the 

workshops that are sponsored by the Research Advisory Board have of as one 

their objectives the identification of research needs. We hope that 

in your deliberations over the next several days you will be able to delineate 

and identify more precisely some of the continuing research needs 

in this important area. I think that we all realize that while we have 

learned a considerable amount about the processes involved, a great deal 

is still to be learned in this important area. We certainly encourage you 

to give conscious thought to the need for additional research as well as 

to the results of research that has already been undertaken. 

Please be conscious of the advice, guidance and recommendations 

that can come to the final report of PLUARG because of your deliberation 

here. You have a two fold task: one is to assist PLUARG in developing 

its recommendations with regard to pollution coming from land use activities.

It is important that you keep this in mind a as very positive and immediate 

output from your deliberations. The other point to consider is the identification 

of research needs that still exist and that may be addressed both 

through government research agencies and through university research. 

We are certainly very pleased to bring these words to you this 

morning and hope that in your deliberations you will have a very successful 

workshop in this important area, and we wish you the best of luck in your 

deliberations this morning and the days to follow.

BHiJFVEKl Q 

SOURCES OF SEDIMENT

INTRODUCTION 

Natural Sheet and Channel Erosion of Unconsolidated Source 

Material (Geomorophic Control, Magnitude and Frequency of 

Transfer Mechanisms) 

D. E. Walting 

This brief discussion of erosion processes and origins, the 

sources and delivery characteristics of sediment within the fluvial system 

aims to provide an introductory background some to of the questions associated 

with a discussion of sediment-associated contaminants and nutrients. 

It is concerned essentially with suspended sediment and more particularly 

the wash load portion of total sediment load, because fine grained sediment 

is in general the most chemically active. Consideration of the topic can 

be usefully structured under four headings: first, the general geomorphological 

context; secondly, the process mechanisms involved; thirdly, the 

integration of these processes into the watershed and the spatial characteristics 

of catchment response, and lastly, the resultant in terms of the 

temporal pattern of sediment delivery from a watershed. 

THE GENERAL GEWCRPKILOGICAL CONTEXT 

The magnitude of sediment flux within the fluvial system must 

reflect the general intensity of the denudation processes and in this 

respect it is useful to briefly consider the global pattern. Over the past 

twenty or more years, and particularly as a result of the impetus provided 

by the International Hydrological Decade (1965-74), measurements of the 

sediment yield of rivers in many parts of the world have become available.' 

Analysis of this information can provide an insight into the range of 

values exhibited at the world level and some indication of dominant controlling 

factors. The classic work by Langbein and Schumm,3 based on 

rivers in the United States, suggests that a global-scale relationship 

be established between annual precipitation and sediment yield and that the 

can 

form of the relationship can be accounted for in terms of the opposing 

influences of vegetation cover and precipitation energy (Figure 1). Maximum 

yields correspond to an optimum combination of these influences at a mean 

annual precipitation of 300 nun. A similar pattern was found by Douglas4 in 

an evaluation of the relationship between sediment yield and annual runoff 

at the global level, although the inclusion of information from tropical 

areas demonstrated a tendency for yields to increase again in areas of high 

runoff (Figure 1). These curves are inevitably very generalised as they 

take little or no account relief, of the environmental energy and other 

physiographic factors. Attempts have also been made to define the controls 

according to major vegetation types' and to develop multivariate equations.6 

In so far as it is possible to apply these general curves, we 

might expect sediment yields in the Great Lakes region to be relatively low 

and to amount to approximately 100 tonnesfkm'. This conforms to a 

11

Y 

L 

N' 800- A 

F 

-rc 

3 

- 

600- 

9 - / \ 

Q 

I \ 

~400- / \ \ 

Y 

L 

ry' 

F 

* 150- 

L 

9 - 

100- 

- 

c 

E 

i! 50- 

$ - 

0 500 lo00 1500 2000 

Effective Precipitation (mm) 

B 

@ 01 I 

I r 1 I 

0 Mean Annual 400 Runoff 800 (mm) 12 

Figure 1. 

General global relationships between sediment yield and annual 

precipitation and runoff proposed by Langbein and Schum (1958) 

and Douglas (1967). 

12

ecent Canadian survey7 which suggests that levels of 20-100 tonnes/km2 are 

characteristic of this area. The same survey provides an average value of 

mean suspended sediment concentration of 50-200 mg/l. (Figure 2). A U.S. 

Geological Survey compilation’ depicts the area of the United States tributary 

to the Great Lakes as exhibiting mean concentrations of less than 

300 mg/l (Figure 2) which, for an annual runoff of 300 mm corresponds to 

sediment yields of less than 90 tonnes/km2. In the geomorphological context, 

it can be inferred that the area under discussion is characterized by somewhat 

subdued erosion processes. Furthermore, it should be stressed that in 

such an area it will not always be immediately obvious precisely what 

processes are involved, and where the dominant sources of sediment are 

located. Generalized figure; on stream loads inevitably conceal considerable 

variations in sediment yield in both space and time and in order to 

appreciate these more fully, the processes involved must be discussed. 

EROSION F’ROCESSES 

In considering the processes involved in sediment detachment and 

entrainment, a useful distinction can be made between two major sediment 

sources, namely, the land surface and the channel system. The first 

reflects the action of rainsplash and surface runoff, often termed sheet 

erosion, and includes the development of rills where surface flow becomes 

concentrated. The second reflects the erosive power of concentrated channel 

flow and includes streambank scour, streambed degradation, and floodplain 

scour. Gully erosion is to some extent a link between the two in that it 

could be viewed as a development of sheet and rill erosion or a headward 

extension of channel erosion. 

Much work on sheet erosion has been carried out by agricultural 

engineers concerned with soil erosion and the influence of various cultivation 

practices and conservation measures, and the erosion plot and 

laboratory sprinkler have become well-used research tools. A distinction 

can usefully be made between the four major contributing processes, namely, 

splash detachment, splash transport, runoff detachment and runoff transport. 

Many empirical and theoretical relationshi s have been developed for 

total soil loss’ and for the component processes,Po based on rainfall and 

flow properties, topography and soil character (Tables 1 and 2). Soil 

erodibility has been related to various physical and chemical properties” 

and factors such as the particle size characteristics, structure, permeability, 

organic matter content, dispersion and cation exchange capacity 

must be taken into account. 

The Universal Soil Loss Equation” (U.S.L.E.) developed by the 

United States Department of Agriculture from over 10,000 plot years of 

records has been widely applied in many environments and its form provides 

a summary of the major controls on sheet erosion (Table 1). However, it 

should be recognized that the equation was developed from data collected 

from small plots and soil loss from a plot cannot necessarily be equated 

with sediment yield from a drainage basin. If sheet erosion or loss soil 

is to be estimated for individual events, rather than on a seasonal basis, 

detailed consideration of temporal variation in sediment availability both 

during storms and between events is required.’ Erodibility measures 

should then be thought of as dynamic rather than static indices and removal 

13

TABLE I 

Some examples of equations describing the Sheet Erosion Process. 47 

St = 

x 1.73 

. tan 1.35 B Kirkby (1969) 

A = E 1.35 

0.35 

s cs' sp - Ls . '30 

THE UNIVERSAL SOIL LOSS EQUATION (U.S.L.E.) 

E = R.K.L.S.C.P. 

DEVELDPMENTS OF THE U.S.L.E. 

b 

G = a(Q .q K.L.S.C.P. 

P 

A = (aA 

Where: 

St = 

*r 

+ bcQ. qp' ) K.L.S.C.P. 

Soil transport 

x = Slope length 

L = 

B = Slope gradient 

s = 

A = Soil loss 

c = 

E = 

S 

cs = 

Soil erodibility factor 

Soil cover factor 

P 

G 

= 

= 

s 

P 

Ls 

= Slope (per cent) 

= Slope length 

Q 

qp 

= 

= 

P - 

30 - 2 year 30 minute rainfall 

Ar = 

E = Soil loss 

A = 

R = Rainfall factor 

a,b = 

c = coefficient 

15 

1'75 Musgrave (1947) 

K = 

Wischmeier and Smith (1965) 

Williams (1975) 

Foster et a1 (1973) 

Soil erodibility factor 

Slope length factor 

Slope steepness factor 

Cropping factor 

Conservation factor 

Sediment yield 

Runoff volume 

Peak flow rate 

Drainage area 

Soil loss 

Weighting parameters

TABLE 2 

Some examples of equations describing various components of the 

Sheet Erosion Process.4g 

RAINFALL DETACHMENT 

Dr = Sdr. 

2 

Ai. 1 Meyer & Wischmeier (1969) 

Id = C.COs S (CosS.P2 - C,.d.P) Fleming & Fahmy (1973) 

2 

SS = f(KE. M . Vt ) 

Negev ( 1967) 

RUNOFF DETACHMENT 

Df = Sdf . Ai (SQ. Qp ) 

Rd = K. X.y.S 

TRANSPORT CAPACITY OF RAINFALL 

Meyer & Wischmeier (1969) 

Fleming & Fahmy (1973) 

T = St,. S I Meyer & Wischmeier (1969) 

It = T.P.Tan S Fleming & Fahmy (1973) 

TRANSWRT CAPACITY OF RUNOFF 

INTERRILL TRANSPORT CAPACITY 

T , = C . (Si + C ) W. L. (‘2.1) 

Cl s1 so 

Where: 

Dr = 

‘dr = 

Ai = 

I = 

I = 

d 

c = 

s = 

P = 

c1 = 

d = 

ss = 

Soil detached by rainfall 

Soil effect factor 

Area of increment 

Rainfall intensity 

Soil detachment rate 

Soil type parameter 

Angle of slope 

Rainfall intensity 

Soil parameter 

Particle size 

Soil splash 

Meyer & Wischmeier (1969) 

Bennett (1974) 

Foster & Meyer (1975) 

K = Soil parameter 

8 = Fluid specific gravity 

Y = Flow depth 

Tr = Splash transport capacity 

‘tr = 

Soil effect constant 

It = Impact transport rate 

T = Parameter 

T - 

f - 

s = 

tf 

Tc = 

Runoff transport capacity 

Soil effect constant 

Flow transport capacity 

so = Local bed slope 

ICE= Kinetic energy 

M = RaindroD .~ mass 

Vt = Terminal velocity of raindrops 

T . = Interrill transport capaci’ 

Cl 

C . = Soil tranSDOrtabilitv cosi 

efficient 

Si = Interrill slope steepness 

Df = Soil detached by runoff Cso = Transport capacity at zero 

Sdf = Soil effect constant 

U = 

slope 

Excess rainfall rate 

Q = 

Rd = 

Flow rate L 

Rate of soil detachment 

i 

c 

= 

= 

Interrill 

constant 

slope length 

16

of accumulated loose material must be distinguished from the inherent 

erodibility of the soil. Scope exists for replacement of the rainfall term 

in the U.S.L.E. with a runoff parameter,14 (Table 1) and research could be 

directed at providing an index of snowmelt runoff, in order to make the 

approach more applicable to spring melt conditions.” Results from erosion 

plots at Sherbrooke, Quebec,I6 Sandusky, Ohio,” and Guelph,” have referred 

to annual soil loss rates equivalent to up to 126, 280 and nearly 4,000 

tonnes/km2 respectively and demonstrate that these processes could be a 

significant sediment source in this region. 

Little attention is usually attached to subsurface erosion processes 

in terms of land surface sediment sources, but it should be recognized 

that water flow within the soil may carry clay particles and colloidal 

material. In this context it is difficult to distinguish between suspended 

and dissolved transport. PipingIg may also develop at horizons in the soil 

where throughflow is concentrated and where significant hydraulic gradients 

exist and this mechanism is doubtless significant for sediment removal, 

although little work has as yet been carried out on its relative importance. 

In contrast to sheet erosion, much less attention, both in terms 

of experimental measurement and theoretical analysis has been applied to 

processes of channel erosion and many of the mechanisms are poorly understood, 

Where channels are cut in non-cohesive materials, scour will occur 

along a reach if the transport capacity of the flow is not satisfied and 

equilibrium transport relationships and regime theory” could be employed 

to evaluate the extent of erosion. Several studies have focused on the 

factors influencing the erosion resistance of cohesive materials and the 

effect of moisture content” but there is considerable scope €or application 

to the field situation. A pioneering field investigation by Wolman 

in 1959,” pointed to various mechanisms of bank erosion. He found severe 

erosion in winter months when high flows attacked banks that were previously 

wet and he noted significant erosion from combinations of cold periods, wet 

hanks, frost action and rises in stage, and that freeze-thaw action also 

produced some erosion without a change of stage. Subsequent work has 

pointed to the importance of pre-conditioning of the banks, particularly by 

wetting, hcfore significant erosion occurs‘ and Carson &.” have 

developed a model of bank sediment entrainment for the spring flood in the 

Eaton Basin, Quebec. This is based on simulation of changes in bank erodibility, 

with sediment entrainment decreasing with increased duration of 

flow past a point and the rate of initial entrainment closely related to 

the time elapsed since that point was last submerged. 

Gully development is generally associated with an imbalance in 

the fluvial system such as occurs with a severe climatic event, improper 

land use or changes in base level. Their growth combines the action of 

concentrated surface water, alternate freeze-thaw of exposed banks and 

sides and sloughing due to undercutting and waterfall retreat. Several 

empirical studies of factors influencing gully growth have been carried 

out2* but in general the precise mechanics of gully development are poorly 

understood. 

THE WATERSHED RESPONSE TO EROSION PROCESSES 

In order to understand the sediment yield of a drainage basin, 

the processes outlined above must be integrated into the catchment and 

17

evaluated in terms of the overall drainage basin dynamics and hydrology. 

Not all the sediment eroded from a watershed will be transported out of the 

basin and the ratio of gross or total erosion (T) to sediment yield (Y) is 

Y 

generally referred to as the delivery ratio (D), i.e. D = 7, which is 

usually expressed as a percentage. The delivery ratio may vary in from 

excess of 90% to approaching zero and in a relatively homogeneous catchment 

it will tend to decrease with increasing basin area. Several workers have 

established quantitative relationshi s between the ratio and drainage area 

and other catchment characteristics,P6 and a generalized relationship 

between delivery ratio and catchment area based on such work is presented 

in Figure 3. Considerations of channel routing and in-channel and flood 

plain deposition and storage are involved in this characteristic of sediment 

delivery but little attention has been given to the precise process mechanisms 

involved. 

The relative efficacy of the various erosion processes in contributing 

to the sediment yield is also best evaluated at the basin level. 

Sheet erosion has primarily been studied on plots of bare or poorly vegetated 

soil, often under intense artificial rainfall, and the question of 

its importance under natural conditions in humid areas is closely related 

to discussion of the extent to which overland flow is a significant process 

in storm hydrograph production*’ and the relative importance of throughflow 

and surface runoff. Kirkby” demonstrated that rainfall intensities rarely 

exceed natural infiltration capacities in humid areas with good vegetation 

cover and suggested that throughflow is an important mechanism in storm 

hydrograph generation, with surface runoff only occurring from saturated 

areas near the slope base. The concept of widespread overland flow, resulting 

from rainfall intensity exceeding infiltration capacity, popularized by 

Horton” belongs essentially to semi-arid areas. 

Furthermore, the partial-area and variable source area models of 

storm runoff production, which have gained wide acceptance in years, recent 30 have very important implications for sediment source areas. If surface 

runoff is generated from a small portion of the basin close to the channel 

network, the area of the watershed significant for sediment yield will be 

limited to this contributing area, (Figure 4). The stream network must 

also be viewed as a dynamic element of the drainage basin and will in many 

cases expand and contract in response to variations in catchment moisture 

status and storm magnitude. 31 Acceptance of the dynamic character of both 

material erodibility and of the contributing area and drainage networks 

within a catchment necessarily means that sediment entrainment is very 

time-variant. 

The question of the precise sources of the sediment transported 

from a drainage basin is one that still requires detailed research. When a 

good vegetation cover is present and in the absence of direct evidence of 

overland flow, it is attractive to ascribe the dominant source to the 

channel system. Work by Kirkby3’ in an upland catchment in Scotland 

suggested that 93% of the sediment came from erosion of river bluffs and the 

study by Carson &. 33 of the Eaton Basin in the Quebec Appalachians 

concluded that the suspended sediment load originated primarily from scour 

of the banks of the channel network. However, calculation of sediment 

budgets can indicate that the rate of channel enlargement is totally inadequate 

to account for the volume of sediment represented by the sediment 

yield and alternative sources must be sought. Study of the clay mineralogy 

18

I- 

W 

. 

Based on: 

\ Roehl (1 962) 

Maner (1 958) 

Gottschalk and Brune (1950) 

2 100- 

Maner and Barnes (1 953) 

2 

t 50- 

E 

a 

20- 

*r, 10t 

F 5- 

$ 

@ 2- 

1 

0.0 1 

1 1 

0-05 0.1 

I I 

0.5 1.0 

I 

5 

I 

10 

1 I 

50 100 

I 

500 1000 

Drainage Area (Square miles) 

Figure 3. A generalized relationship between drainage area and sediment 

delivery ratio based on the findings of several U.S. workers.

N 

0 

2 Year Return Period 10 Year Return Period 

area 

Figure 4 . A hypothetical example of the variation of the storm runoff 

contributing area and the stream network within a catchment for 

flood events of different magnitude.

of sediments may provide information on source areas. " Techniques of 

'chemical fingerprinting' may also help to provide an answer and it is 

noteworthy that the increased attention recently being paid to the chemical 

quality of sediment may indirectly provide valuable evidence to as sediment 

sources. 

Despite some debate as to precise processes and source areas 

involved in sediment yield and their relation to storm runoff dynamics, 

several studies have successfully related catchment sediment yields to 

hydrometeorological variables, both on an annual and on a storm-period 

basis, 35 and to land use and other catchment characteristics. 36 Soil loss 

equations can also be adapted for catchment if use a routing algorithm is 

introduced. 3 7 Some researchers have, however, noted differences in the 

pattern of response to hydrometeorological conditions according to catchment 

size,3R with yields from plots and small catchments reflecting the 

seasonal distribution of rainfall energy and those from large catchments 

reflecting the runoff regime. Explanation of such contrasts must be 

sought in considerations of sediment routing, delivery ratios, and the 

partial-area concept. Following from the early work of Nege~,'~ progress 

has also been made in the field of computer simulation of erosion and 

sediment yields at the catchment level," although the dependence on 

existing runoff models and the use of optimized parameters can to call 

question the extent to which such models represent reality. Some attempts 

have been made to develop more deterministic models for individual hillslopes 

and small catchments," but progress must be limited until our 

knowledge of sediment processes and source areas improves and allows more 

realistic conceptual models to be formulated. 

TEMPORAL PATTERNS OF SEDIMENT I~LIVERY 

Temporal and spatial integration of the processes of erosion and 

sediment yield within a drainage basin result in a complex of pattern 

variation in sediment yield at the catchment outlet. A knowledge of the 

magnitude and timing of sediment concentration and loads is essential if 

the problems of sediment-associated contaminants and nutrients to are be 

evaluated. Sediment discharge (S) / streamflow ((1) or sediment concentration 

(C) / streamflow (Q) relationships or rating curves have been used 

by many workers to characterize the general range of variation of sediment 

transport rates and to demonstrate the tendency for increased concentrations 

or loads to be assoc'ated with high flows. In general a relationship of 

the form S or C = aQ' can be established (Figure 5). The close dependence 

of sediment concentration on discharge should not be viewed as indicative 

of a transport capacity effect, because the wash load is essentially a noncapacity 

load, but rather that the erosion processes causing sediment 

entrainment generally operate most effectively during periods of high flow. 

In most cases, considerable scatter about the simple rating relationship is 

apparent and this can be related to seasonal and hysteretic effects, the 

detailed timing of the concentration graph relative to the flow hydrograph, 

and an exhaustion effect operating both during a single event and through a 

series of events. '* An example from a British catchment of some of these 

controls and in particular the exhaustion effect is presented in Figure 6. 

Several researchers have suggested that the slope (b) and intercept (a) 

values of a rating relationship can be used to infer source areas and the 

general sediment dynamics of a catchment. 43 

21

1 000 

i 

\ 

9, 

E 

- - - . - - - 

Daily Mean Discharge (cfs) 

22

W 

N 

Figure 6. Variation of suspended sediment concentration during a series 

of storm runoff events on the River 

Dart, Devon, England (46 km’). This clearly demonstrates the complexity of the relationship 

between concentration and discharge.

The seasonal distribution of yield from a catchment will reflect 

the interaction of precipitation and flow regimes and sediment availability. 

In the Great Lakes region the seasonal yield pattern is dominated by the 

period of the spring melt, (Figure 7) and Dickinson &.'4 calculated that 

about 55% of the sediment load of rivers in southern Ontario is carried 

during March and April. Duration or frequency analysis can also be usefully 

employed to demonstrate that a large proportion of the sediment load 

of a river is carried during a short period of time. In small catchments 

in East Devon, England, for example, approximately 78 percent of the annual 

suspended sediment load was carried by flows which equalled or exceeded 1% 

of the time or within an overall duration equivalent to 3.5 days. Similar 

analysis for several rivers tributary to the Great Lakes is presented in 

Figure 8. In the case of the Cass River, Michigan, approximately 80 percent 

of the load was carried in 5 percent of the year. If the data available 

are sufficiently detailed, analysis can be extended to individual storms in 

order to evaluate the relative importance of storms of varying magnitude in 

sediment production. 'I5 Long periods of record will also enable relative 

importance of extreme events to be assessed and anlysis of the significance 

of events of varying return period could be usefully combined with an assessment 

of the extent and character of the associated contributing areas and 

of thresholds in hydrologic response. Techniques of measuring suspended 

sediment concentrations and loads are now well documented46 but careful 

evaluation of patterns of temporal variation in sediment transport is necessary 

if sampling programmes are to provide reliable estimates of sediment 

yield. 

Any statement of research needs depends closely on the perception 

of the purposes involved and on the subjective views of the writer. In the 

opinion of this writer, who is concerned with the geomorphological and hydrological 

background, future research on erosion processes, sediment sources 

and sediment yields should be focused on the drainage basin as a unit of 

study. Since the suspended load of a stream is primarily a non-capacity 

load, attention should be directed towards sediment sources and entrainment 

processes within the basin rather than channel transport hydraulics. Detailed 

evaluation of the erosion processes operating on a slope or a small plot 

may be of limited value if the eroded material does not enter a stream. The 

fate of the sediment as it is routed down the channel network remains another 

large area of uncertainty but this is outside the scope of this discussion. 

Worthwhile areas of study could include: 

1) In terms of process dynamics, detailed investigation of the 

mechanisms and significance of sediment entrainment by subsurface 

runoff and of bank erosion is required. Plot and reach studies will 

be necessary but the results should be integrated within the overall 

watershed response. 

2) Development of sediment budgets in order to demonstrate the 

relative importance of various processes. 

24

C 

4 30 

RIVER CASS (2196 km2) 

1966-70 

a < 30 

401 

x 

20 

$ 

5 10 

s 

P O 

BIG CREEK (591 km2) 

1967-73 

Figure 7. The average annual distribution of monthly sediment loads for 

several rivers draining to the Great Lakes. 

25

/ 

/ 

/ 

/ 

/ 

/ 

/ 

/ 

/ 

/ 

/ / 

/ 

/ 

/ 

/ 

/ 

/ 

I 1 I I I I I 1 I 1 I 1 I 1 

0.1 0.2 0.5 1 2 5 10 20 30 40 50 60 70 8C 

Cumulative Percentage of Time 

Figure 8. Duration characteristics of sediment yield from four catchments 

draining to the Great Lakes. Data from two other U.S. rivers 

are also included for comparative purposes. 

26

3) Delimitation of major source areas in order to evaluate the 

spatially distributed nature of erosion processes. 

4) Integration of source and budget studies with realistic 

concepts of storm runoff production, particularly the partial-area 

and variable source area concepts. 

5) Detailed monitoring of individual storm runoff events in order 

that the spatial and temporal integration of sediment dynamics can be 

understood. 

6) Development of physically-based models of erosion and sediment 

yield as a long term objective. 

LITERATURE CITED 

follow. 

1. 

2. 

3. 

4. 

5. 

6. 

7. 

8. 

References to elaborate points raised in the preceding discussion 

(Numbers refer to numbers in parentheses in the text) 

Task Committee on Preparation of Sedimentation Manual (1962). 

Sediment Transportation Mechanics: Introduction and Properties 

of Sediment, Proc. A.S.C.E. J. Hyd. Div. E, HY4, 77-107. 

For example: U.N.E.S.C.O., (1974). Gross Sediment Transport to 

the Oceans, U.N.E.S.C.O. Sc. 74lWSl33. 

Holeman, J. N., (1968). The Sediment Yield of Major Rivers of 

the World, Water Resources Research, 

4, 737-47. 

Langbein. W. B. and Schumm, S. A., (1958). Yield of Sediment in 

Relation to Mean Annual Precipitation, Trans. Amer. Geophys. Union, 

- 39, 1076-84. 

See also Wilson, L., (1973). Variations in Mean Annual Sediment 

Yield as a Function of Mean Annual. Precipitation, Amer. J. Sci. 

273, 335-349. 

Douglas, I., (1967). Man, Vegetation and the Sediment Yield of 

Rivers, Nature, 215, 925-8. 

Fleming, G., (1969). Design Curves for Suspended Load Estimation, 

Proc. Inst. Civ. Em., 9, 1-9. 

Jansen, J. M. L. and Painter, R. B., (1974). Predicting Sediment 

Yield from Climate and Topography, J. Hydrol. 11, 371-80. 

Stichling, W.. (1973). Sediment Loads in Canadian Rivers, in Fluvial 

Processes and Sedimentation, Proc. 9th Hydrology Symposium, Edmonton. 

Alberta, National Research Council, 39-72. 

Rainwater, F. H., (1962). Stream Composition in the Conterminous 

United States, U.S.G.S. Hydr. Inv. Atlas HA61. 

27

9. For example: Musgrave, G. W., (1947). The Quantitative Evaluation 

of Factors in Water Erosion, a First Approximation, J. Soil and 

Water Conservation 2, 133-8. 

Zingg, A. W. (1940) Degree and Length of Land Slope as it Affects 

Soil Loss in Runoff, Agricultural Engineering 

2, 59-64. 

Wischmeier, W. H. and Smith, D. D. (1958) Rainfall Energy and its 

Relation to Soil Loss, Trans. Amer. Geophys. Union, 2, (2). 285-91. 

Mirtskhoulava, T. E. (1974) Prediction of Erosion Intensification 

by Man, Int. Assoc. Hydr. Sci. Pub. 113, 78-82. 

10. For example: Meyer, L. D. and Wischmeier, W. H. (1969) 

Mathematical Simulation of the Processes of Soil Erosion by 

Water, Trans. Am. SOC. Ag. Engrs. 12, (6), 754-8, 762. 

Foster, G . R. and Meyer, L. D. (1975) Mathematical Simulation 

of Upland Erosion by Fundamental Erosion Mechanics, in Present 

and Prospective Technology for Predicting Sediment Yields and 

Sources, U.S.D.A. ARS-S-40 190-207 

Free, G. R. (1960) Erosion Characteristics of Rainfall, Ag. 

Engineering, 41, (7) 447-9, 455. 

Rowlison, D. L. and Martin, G. L. (1971) Rational Model Describing 

Slope Erosion, Proc. A.S.C.E. J. Irrig. Dr. Div. 97 (IRl), 39-50. 

Kiling, M. and Richardson, E. V. (1973) Mechanics of Soil Erosion 

from Overland Flow Generated by Simulated Rainfall, Colorado 

State University Hydrology Papers, 63. 

Carson, M. A. and Kirkby, M. J. (1972) Hillslope Form and Process 

Ch. 8., Surface Water Erosion. 

11. For example: Barnett, A. P. and Rogers, 3. S. (1966) Soil Physical 

Properties Related to Runoff and Erosion from Artificial Rainfall 

Trans. A.S.C.E. 2, 123 et al. 

Wischmeier, W. H. and Mannering, J. V. (1969) Relation of Soil 

Properties to its Erodibility, Proc. Soil Sci. SOC. America, 3, 

(1) , 131-37. 

Wischmeier, W. H. &. (1971) A Soil Erodibility Nomograph for 

Farmland and Construction Sites, J. Soil and Water Conservation 

- 26, 189-93. 

Bryan, R. B. (1969) The Development, Use and Efficiency of 

Indices of Soil Erodibility, Geoderma, 

2, (l), 5-25. 

12. Wischmeier, W. H. and Smith, D. D. (1965) Predicting Rainfall- 

Erosion Losses from Cropland East of the Rocky Mountains, 

Agriculture Handbook, 282, USDA, ARS.

13. 

14. 

15. 

16. 

17. 

18. 

1.9. 

20. 

21. 

22. 

For example: Emmett, W. W. (1970) The Hydraulics of Overland 

Flow on Hillslopes, U.S.G.S. Prof. Paper 662-A. 

Ellison, W. D. (1945) Some Effects of Raindrops and Surface 

Flow on Soil Erosion and Infiltration, Trans. Amer. Geophys. Union 

- 26, 415-29. 

Williams, J. R. (1975) Sediment Yield Prediction with Universal 

Equation Using Runoff Energy Factors, in Present and Prospective 

Technology for Predicting Sediment Yields and Sources, USDA, 

ARS-S-40, 244-52. 

Wigham, J. M. and Stolte, W. J. (1973) Sediment Yield Estimates 

from an Index of Potential Sediment Production, in Fluvial Processes 

and Sedimentation, Proc. 9th Hydrology Symposium, Edmonton, Alberta, 

208-16. 

Clement, P. and Gadbois, P. (1971) Comparison et Interpretation 

des Resultats de Deux Parcelles Experimentales d'Erosion 1969-70 

(Sherbrooke, Quebec). Proc. 2nd Guelph Symp. Geomorphol., 266-27 

Schwab, G. 0. et&., (1972) Chemical and Sediment Movement from 

Agricultural Land into Lake Erie Rept. Water Resources Center, 

Ohio State University. 

Ketcheson, J. K. &., (1973) Potential Contribution of 

Sediment from Agricultural Land, in Fluvial Processes and 

Sedimentation, Proc. 9th Hydrology Symposium, Edmonton, Alberta, 

208-16. 

Jones, A. (1971) Soil Piping and Stream Channel Initiation 

Water Resources Research, 1, 602-10. 

For example: Lane, E. W. (1955) The Importance of Fluvial 

Morphology in Hydraulic Engineering, Proc. A.S.C.E. 3. Hyd. Div., 

- 81, 1-17. 

Blench, T. (1957) Regime Behaviour of Canals and Rivers, 

Butterworths. 

For example: Smerdon, E. T. and Beasley, R. P. (1959) Tractive 

Force Theory Applied to Stability of Open Channels in Cohesive 

Soils. Research Bull. 715, Univ. Missouri Ag. Expt. Station, 

Columbia, Mo. 

Grissinger, E. H. (1966) Resistance of Selected Clay Systems 

to Erosion by Water, Water Resources Research, g,(l), 131-8. 

Partheniades, E. (1971) Erosion and Deposition of Cohesive 

Materials, in H. W. Shen (ed.) River Mechanics, 2.. 251-91. 

Wolman, M. G. (1959) Factors Influencing Erosion of a Cohesive 

River Bank, Amer. J. Sci., 257, 204-16. 

29

23. 

24. 

25. 

26. 

27. 

28. 

29. 

30. 

Knighton, A. D. (1973) Riverbank Erosion in Relation to Streamflow 

Conditions, River Bollin-Dean, Cheshire, East Midland Geographer, 

- 5, ( E), 416-26. 

Harrison, S. S. (1970) Note on the Importance of Frost Weathering 

in the Disintegration and Erosion of Till in East-Central Wisconsin, 

Bull. Geol. SOC. Am., 3, 3407-10. 

Carson, M. J., d., (1973) Sediment Production in a Small 

Appalachian Watershed During Spring Runoff: The Eaton Basin, 

1970-72, Canadian J. Earth Sciences, E, (12), 1707-34. 

For example: Thompson, J. R. (1964) Quantitative Effect of 

Watershed Variables on the Rate of Gully Head Advancement. Trans. 

Am. SOC. Ag. Engrs., 1, (I), 54-55. 

Beer. C. E. and Johnson, H. P. (1965) Factors Related to Gully 

Growth in the Deep Loess Area of Western Iowa, Proc. (1963) 

Federal Interagency Sedimentation Conference, USDA Misc. Pub. 

970. 37-43. 

Heede, B. H. (1974) Stages of Development of Gullies in the Western 

United States of America, Zeits. Geomorph.. 

Is, (3), 260-71. 

For example: Roehl, J. W. (1962) Sediment Source Areas, Delivery 

Ratios and Influencing Morphological Factors, Internat. Assoc. 

Hyd. Sci. Pub., 2, 202-13. 

Maner, S. B. (1958) Factors Affecting Sediment Delivery Rates 

in the Red Hills Physiographic Area, Trans. Amer. Geophys. Un., 

39, 669-75. 

- 

Renfro, G. W. (1975) Use of Erosion Equations and Sediment- 

Delivery Ratios for Predicting Sediment Yield, in Present and 

Prospective Technology for Predicting Sediment Yields and 

Sources, USDA, ARS-S-LO, 33-45. 

For example: Pierce, R. S. (1967) Evidence of Overland Flow 

on Forest Watersheds: and 

Hewlett, J. D. and Hibbert, A. R. (1967) Factors Affecting 

the Response of Small Watersheds ot Precipitation in Humid 

Areas, both in: 

Sopper, W. E. and Lull, H. W. (eds.) Int. Symp. Forest Hydrology 

(Pergarnon Press), 247-51 and 275-90. 

Kirkby, M. J. (1969) Infiltration, Throughflow and Overland Flow, 

in R. J. Chorley (ed.) Water Earth and Man, 215-28. 

Horton, R. E. (1933) The Role of Infiltration in the Hydrologic 

Cycle, Trans. Amer. Geophys. Un., 14 446-60. 

For example: Dunne, T. and Black, R. D. (1970) Partial Area 

Contributions to Storm Runoff in a Small New England Watershed, Water 

Resources Research, 5, 1269-1311. 

Ragan, R. M. (1967) An Experimental Investigation of Partial Area 

Contributors. Int. Assoc. Hyd. Sci. Pub., 3, 241-9. 

30

Nutter, W. L. and Hewlett, 3. D. (1971) Stormflow Production 

From Permeable Upland Basins, in Monke, E. J. (Ed.) Biological 

Effects in the Hydrological Cycle, Proc. Third Int. Seminar for 

Hydrology Professors, 248-58. 

Engman, W. T. (1974) Partial Area Hydrology and its Application 

to Water Resources, Water Resources Bulletin (3), 512-21. 

Dunne, T., Moore, T. R. and Taylor, C. R. (1975) Recognition 

and Prediction of Runoff-Producing Zones in 

Ass. Hyd. Sci. Bull. 0, 305-27. 

Humid Regions. Int. 

31. For example: Gregory, K. J. and Walling, D. E. (1968) The 

Variation of Drainage Density Within a Catchment. Int. 

Sci. Bull. 2, 61-8. 

Ass. Hyd. 

Blyth, K. and Rodda, J. C. (1973) A Stream Length Study. Water 

Resources Research 2, (5) 1454-61. 

32. Kirkby, M. J. (1967) Measurement and Theory of Soil Creep, 

J. Geol. 3, 359-78. 

33. Carson, M.J. gtt (1973) (see ref. 24). 

34. For example: Wall, G. J. and Wilding, L. P. (1976) Mineralogy 

and Related Parameters of Fluvial Suspended Sediments in Northwestern 

Ohio. J. Environ. Qual. 2, 168-73. 

Klages, M. G. and Hsieh, Y. P. (1975) Suspended Solids Carried 

by the Gallatin River of Southwestern Montana: 11. Using 

Mineralogy for Inferring Sources. J. Environ. Qual. 4. 68-73. 

35. For example: Dragoun, F. .J. (1962) Rainfall Energy as Related 

to Sediment Yield, J. Geophys. Research, 67, (4), 1495-1501. 

Williams, J. R. (1971) Prediction of Sediment Yields from 

Small Watersheds, Trans. Am. SOC. Ag. Engrs., E, (6), 1158-62. 

Guy, H. P. (1964) An Analysis of Some Storm Period Variables 

Affecting Stream Sediment Transport, U.S.G.S. Prof. Paper, 462E. 

Walling, D. E. (1974) Suspended Sediment and Solute Yields from 

a Small Catchment Prior to Urbanization, Inst. Br. Geogr. Spec. 

Pub. 6, 169-191. 

36. For example: Hindall, S. M. (1976) Prediction of Sediment 

Yield in Wisconsin streams. Proc. Third Federal Interagency 

Sedimentation Conference, 1205-18. 

Shown, L. M. (1970) Evaluation of a Method for Estimating Sediment 

Yield, U.S.G.S. Prof. Paper, 700-B, 245-9. 

Flaxman, E. M. (1972) Predicting Sediment Yield in the Western 

United States, Proc. A.S.C.E. J. Hyd. Div., 98. (HY12); 2073-85. 

31

37. 

38. 

39. 

40. 

41. 

42. 

43. 

44. 

Williams, J. R. (1975) Sediment Routing for Agricultural 

Watersheds. Water Resources Bulletin, 11. 965-74. 

McGuiness. J. L. & (1971) Relation of Rainfall Energy and 

Streamflow to Sediment Yield from Small and Large Watersheds, 

J. Soil and Water Cons., 26, 2087-98. 

Dickinson, W. T. g& (1975) Fluvial Sedimentation in Southern 

Ontario, Canadian J. Earth Sciences, 12, 1813-9. 

Negev, M. (1967) A Sediment Model on a Digital Computer. Rept. 

76, Stanford University, California. 

For example: Fleming, G. and Leytham, K. M. (1976) The 

Hydrologic and Sediment Processes in Natural Watershed Areas. 

Proc. Third Federal Interagency Sedimentation Conference, 1, 

233-46. 

Gupta, S. K. (1974) A Distributed Digital Model for Estimation 

of Flows and Scdiment Load from Large Ungauged Watersheds, Doctoral 

Thesis, University of Waterloo, Dept. Civil Engineering. 

For example: Foster, G. R. and Meyer, L. D. (1975) Mathematical 

Simulation of Upland Erosion by Fundamental Erosion Mechanics, in 

Present and Prospective Technology for Predicting Sediment Yields 

and Sources, USDA ARS-S-40, 190-207. 

Meyer, L. D. and Wischmeier, W. H. (1969) Mathematical Simulation 

of the Process of Soil Erosion by Water, Trans. Am. SOC. Ag. 

Engrs., 8, (4) 572-7, 580. 

Li Ruh-Ming 5 & (1976) Water and Sediment Routing from Small 

Watersheds, Proc. Third Federal Interagency Sedimentation Conference, 

- 1, 193-204 

Walling, D. E. and Teed, A. (1971) A Simple Pumping Sampler for 

Research into Suspended Sediment Transport in Small Catchments, 

J. Hydtol., z, 325-37. 

Porterfield, G . (1973) Computation of Fluvial-Sediment Discharge, 

U.S.G.S. Techniques of Water Resources Investigations, C3, (3). 

Bauer, L. and Tille, W. (1967) Regional Differentiations of the 

Suspended Sediment Transport in Thuringia and their Relation to 

Soil Erosion. Int. Ass. Hyd. Sci. Pub., 75, 367-77. 

Flaxman, E. M. (1975) The Use of Suspended Sediment Load 

Measurements and Equations for Evaluation of Sediment Yield in 

the West, in Present and Prospective Technology for Predicting 

Sediment Yields and Sources, USDA ARS-S-40, 46-56. 

Dickinson, W. T. eta2 (1975) Fluvial Sedimentation in Southern 

Ontario, Canadian Journal of Earth Sciences, 1 2, 1813-9. 

32

45. Piest, R. F. (1965) The Role of the Large Storm as a Sediment 

Contributor, Proc. (1963) Federal Interagency Sedimentation 

Conference, USDA Misc. Pub. 970, 97-108. 

46. For example: Guy, H. P. and Norman, V. W., (1970). Field Methods 

for Measurement of Fluvial Sediment, U.S.G.S. Techniques of 

Water Resource Investigations, g, (3). 

47. Kirkby, M. J. (1969) Erosion by Water on Hillslopes, in R. J. 

Chorley (ed.) Water, Earth and Man. 

Musgrave, G. W. (1947) Quantitative Evaluation of Factors in 

Water Erosion, a First Approximation, J. Soil and Water 

Conservation, 2, 133-8. 

Wischmeier, W. H. and Smith, D. D. (1965) Rainfall Erosion 

Losses from Cropland East of the Rocky Mountains, U.S.D.A. Agr. 

Handbook, 282. 

Williams, J. R., (1975). - See Ref. 14. 

Foster, G. R. 9 &. (1973) Erosion Equation Derived from 

Modelling Principles. ASAE Paper 73-2550. 

48. Meyer, L. D. and Wischmeier, W. H., (1969). See Ref. 41. 

Fleming, G. and Fahmy, M. (1973) Some Mathematical Concepts 

for Simulating the Water and Sediment Systems of Natural Water- 

shed Areas, Univ. Strathclyde Dept. Civ. Eng. Rept. H0-73-26. 

Negev, M. (1967). See Ref. 39. 

Bennett, J. P. (1974) Concepts of Mathematical Modelling of 

Sediment Yield, Water Resources Research, 

lo, 485-92. 

Foster, G. R. and Meyer, L. D., (1975). - See Ref. 41. 

33

DISCUSS ION 

Mr. T. CahiZZ: Dr. Walling, the application of partial area hydrology is 

complicated in parts of the Great Lakes Basin, especially in Lake Erie by 

the existence of extensive under-drainage systems in the agricultural 

regions. Do you know, or have you had any exposure to any work investigating 

partial area applications, or analysis in basins with heavy underdrainage 

networks? 

Dr. D. ValZing: I think the short answer to this is no. The concept of 

partial area and variable source area is rather complicated. It is difficult 

enough to get this working as a realistic deterministic model, let alone 

building in underdrainage. The two are obviously very closely linked. 

Dr. D. Baker: You used a figure showing three different storms with equal 

runoff but greatly differing sediment yields associated with those storms. 

I could not read the time base. To what extent might variations in source 

areas and ground cover affect the sediment yields at the outlet of your 

watershed, or is it washing out of accumulated sediments in the channel 

itself? What is the source of the variations? 

Dr. D. Wuv'aZv'aZing: The storms were over about a three day period. The watershed 

size is about 30 km'. The rainfall characteristics were essentially 

similar for those three storms. My own feeling is that one has got both 

storage in the channel and on the land surface, and one has got these 

important exhaustion effects. Once the first sediment is removed from the 

land surfare, you get back to the inherent erodibility of the soil and the 

sediment production rates then drop quite markedly. 

DrS. ?'. Uickinson: You made a comment with regard to the bank erosion that 

you called preconditioning. I might say that initial conditions are important. 

I suggest that in fact the initial conditions are important for any of the 

erosion processes and perhaps that is what you are saying and you are also 

saying source areas are important and the whole timing is important. I think 

there has been a fair bit of experience in the modelling exercises if that 

one can make a good guess at the initial conditions, soil conditions, moisture 

conditions, cropping conditions, or whatever, one be may able to make a 

reasonable estimate of what is going to come off, whether its the bank or the 

field or whatever. The major problem is making a good guess of how those 

conditions vary. Would you agree with that? 

35

Dr. D. Walling: Yes, entirely. One wants some continuous accounting process 

whereby one can watch the conditions as they vary through time. A very good 

point. 

Dr. E. &gley: I have one observation to make regarding what you have 

said. From the point of view of impact on such a large area as the Great 

Lakes, it is obviously not possible to do the kinds of detailed studies one 

would like to have for such a broad area other than in small areas to obtain 

a feeling for the variables involved or the intensity of the processes. I 

think one of the things we need to address ourselves to, perhaps in the 

working session, is how do we extend the knowledge that we can gain from 

small areas to assessing impact over broad areas. This is a major problem 

when you are looking at something the size of the Great Lakes area. 

36

Influence of Land Use on Erosion and Transfer Process 

of Sediment 

T. Dickinson and G. Wall 

The average sediment yield from the landscape and the condition of 

stream channels tend to change with advancing forms of man's land use activities, 

as summarized in Table 1. Land uses which can cause severe erosion 

and sediment problems (e.g. highway and urban construction, timber harvesting, 

strip mining operations) have been identified; and land uses which tend to 

stabilize the landscape (e.g. reforestation, permanent pastures, stabilized 

urban settings) have been noted in the literature. Yet it remains difficult 

to quantitatively estimate changes in erosion and/or sediment yield due to 

land use changes - even in regions where sediment data are available, let 

alone in areas where extrapolation is being attempted. 

Although persons have observed and measured soil erosion and de- 

position phenomena in nature and have ascribed general reasons for these 

occurrences, the interplay of the forces, causes and the boundary conditions 

pertaining to erosion and sediment movement are less obvious. 

An investigation of the influence of land use on erosion and transport 

processes (as indeed an investigation of the processes themselves) also 

reveals that apparent land use effects are closely related to the of scale 

the studies undertaken. The dominant forces and boundary conditions governing 

erosion and sediment transport vary with landscape scale (i.e. the 

processes predominant on a plot are quite different from those determining 

conditions on a large field). Although the matter of scale has been empirically 

handled by simple extrapolation and by means of the delivery ratio approach, 

the real influence of scale on the processes and on apparent land use effects 

is not well understood. 

In light of the present state of knowledge regarding erosion and 

transport processes and the part scale has played in affecting statements on 

land use effects, the following discussion is focused on approaches which 

have been taken on different landscape scales - identifying items learned and 

apparent gaps. 

PLOT SCALE 

Plot studies have been used extensively by agriculturalists and 

hydrologists to study soil and water losses under a variety of climatic, 

physiographic, land use, and soil management situations. Plots became the 

unit of experimentation in these studies since they provided a quick and 

37

inexpensive means of obtaining the needed data in a short period of time. 

The basic premise common to all plot studies has been that by locating plots 

in a similar environment, all variables can be controlled except the one to 

be studied. Differences in results are therefore attributed to the differences 

in treatments. Generally, all plot studies have assumed that results 

were applicable to a greater or lesser degree beyond the limits of the plot. 

A review of the literature has indicated that there is no standard 

design for plot equipment (Hayward, 1971). Plot sizes range from a few 

square feet in laboratory studies to several acres in field studies. The 

most common plot size was 1/40 to 1/50 of an acre. In general plots were 6, 

10, or 12 feet wide and 35, 70 or 72.6 ft. long. Plot width is often determined 

by drill size and tractor use within the plot. Plot length is usually 

determined by the local recommended terrace interval or the available length 

of uniform slope. Mutchler (1963) has given details of plot design and 

construction. 

The experimental design of soil loss plot experiments should permit 

the measurement of the difference between two or more treatments well as as 

furnish criteria by which the degree of confidence that can be placed in the 

result may be judged (Brandt, 1941). The two requisites of such a design are 

replication and randomisation. The purpose of replication is to increase 

precision and provide an estimate of error while randomisation ensures that 

the estimate of error is valid. It is significant to note that while the 

majority of plot studies reported in the literature did not replicate or 

randomize treatments, results are presented quantitatively (Hayward, 1971). 

The lack of proper design in these studies may mean that the results are 

either obscure or misleading (Brandt, 1941). 

Plot studies have been effectively employed to isolate factors 

which influence soil loss and runoff. Among the factors found to be most 

closely related to soil loss and runoff include: plant cover and mulches 

(Dickson, 1929); Kittredge. 1954; Duley. 1952). cropping practices and 

tillage (Van Doren and Bartelli, 1956; Meyer and Mannering, 1961), rainfall 

variables (Wischmeier, 1959; Rogers, &. , 1964) and slope parameters (Neale, 

1937; Zingg, 1940; Barnett and Rogers, 1966). In addition plot studies have 

been employed to evaluate the effectiveness of remedial measures proposed to 

reduce soil and water loss (Smith, 1941; Van Doren and Bartelli, 1956; Mannering 

and Meyer, 1961). However, there is an apparent lack of plot research in the 

literature that was designed to assess the importance of soil factors on 

erosion and runoff. Similarly, few studies have been conducted to study 

erosional processes. 

The findings from small plot studies have shown conclusively that a 

myriad of variables affect erosion. However, the extrapolation of plot data 

beyond the plot remains a problem. While many authors of plot research have 

freely assumed that their data had an application beyond the plot, it is 

generally admitted there is little evidence to support the direct aerial 

expansion of plot data. 

Several attempts have been made to relate plot data to field conditions 

through rational or empirical equations (Zingg, 1940; Musgrave, 1947; 

Smith, 1941; Van Doren and Bartelli, 1956). However, the universal soil loss 

equation (Wischmeier and Smith, 1965) is currently the empirical equation in 

38

LAND USE 

A. Natural forest 

or grassland 

B. Heavily grazed 

areas 

C. Cropping 

D. Retirement of land 

from cropping 

E. Urban construction 

F. Stabilization 

C. Stable urban 

TABLE 1. 

EFFECT OF LAND-USE SEQUENCE ON RELATIVE 

SEDIMENT YIELD AND CHANNEL STABILITY 

(after Guy, 1970 - a modification from Wolman, 1967) 

SEDIMENT YIELD 

Low 

Low to moderate 

Moderate to heavy 


Very heavy 

Moderate 


39 

CHANNEL STABILITY 

Relatively stable 

with some bank 

erosion 

Somewhat less 

stable than A 

Some aggradation and 

increased bank erosion 

Increasing stability 

Rapid aggradation and 

some bank erosion 

Degradation and severe 

bank erosion 

Relatively stable

greatest use. This statistical regression model was based upon soil loss 

records from test plots in U.S.A. the and takes the form A = RKLSCP where A 

is the average annual soil loss in tons per acre a specific from field, R is 

the rainfall factor, K is the soil erodibility factor, L is the slope length, 

S is the slope gradient, C is the cropping management factor and P is the 

existing conservation factor. 

The universal soil loss equation was designed to predict average 

annual soil losses from fields and construction sites by sheet and rill 

erosion. In order to obtain some estimate of the confidence limits of the 

equation, average annual soil losses were computed on 189 plots for which 

about 2300 plot years of records were available (Wischmeier, 1973). The plot 

predictions deviated from the corresponding measured soil losses by an 

average of 12% of the 11.3 ton overall average soil loss for the sample. 

The universal soil loss equation has been used for the prediction 

of watershed sediment yields but its capabilities and limitations for this 

use must be recognized (Shen, 1976). Universal soil loss equation predictions 

provide gross erosion levels and are not designed to predict deposition of 

sediments. It does not include sediment losses OK gains between the field 

and the stream OK reservoir. In order to use the universal soil loss equation 

to estimate sediment yield from a watershed it is necessary to introduce a 

weighted factor that takes into account deposition of eroded sediments. The 

sediment delivery ratio (defined as the change per unit area of downstream 

sediment movement from the source to any given measuring point) has been used 

for this purpose (Roehl 1962; Speraberry and Bowie, 1969; Renfro, 1972). 

Williams (1972) has modified the universal soil loss equation for predicting 

storm sediment yields by substituting the product of storm runoff amount and 

rate for the rainfall factor (R). 

Studies of erosion and sediment transport on watersheds have involved 

two approaches. On the one hand, sediment loads (primarily suspended 

solids) have been regularly sampled at the watershed outlet and inferences 

have been drawn regarding the sources of the sediment and the effects of land 

use. On the other hand, conceptual models of erosion and sedimentation 

processes have been hypothesized and used to estimate sediment yields at 

selected watershed outlet points. Where possible, these estimates have been 

compared with monitored results - OK monitored data have been used to "calibrate" 

the models. Each approach is considered below with regard to inherent 

strengths and weaknesses. 

(5) Sediment Load Monitoring 

Suspended sediment load data have been sparse in relation to those 

available for other hydrologic variables such as rainfall and streamflow. In 

Canada, it is only during the last two decades that continuous sampling of 

sediment loads for selected streams has been undertaken. Not only has 

sampling been sparse over area, but also it has been relatively infrequent in 

time . 

40

Although many of the sediment data have been carefully collected, 

and there have been pressing needs to make good use of this information, 

conclusions drawn from many of the monitored sediment load data regarding 

land use effects should be given careful consideration. Problems in this 

regard are noted below. 

Sediment load monitoring has customarily been time- rather than 

event-oriented (i.e. samples have been collected at regular time intervals 

rather than focused on storm events). As a consequence, peak concentrations 

and loads have not often been well defined. Since the loads occurring during 

peak flow periods account for the bulk of the total sediment load transported 

from a watershed (Dickinson, g., 1975) it is imperative that peak events 

be adequately sampled. 

Sediment samples taken during the year on a time-oriented base that 

misses many of the major sediment events do not provide either useful estimates 

of annual suspended loads or indices of such loads. Further, sample loads 

collected during periods of low flow, and land use effects inferred from low 

flow data, are not necessarily indicative of the annual suspended sediment 

load picture. This sampling problem poses a sufficient dilemma, that at the 

present time there is a need to examine the relative importance of peak flow 

events in order to design improved sampling schemes. 

In the northeastern United States and eastern Canada, the stream 

sediment load is controlled by source conditions rather than by downstream 

flow conditions. It is very difficult to "look upstream" from downstream 

data to identify important sources and land use effects without detailed 

information on source erosion and transport areas. 

(b) Watershed Models 

Watershed models of sediment yield have incorporated concepts 

whereby rainfall and runoff detach soil from field surfaces, transport it 

overland to drainageways, and move it downstream. One group of models 

applies the Universal Soil Loss Equation to land units (e.g. fields or groups 

oof fields) and routes the eroded material to other land and/or units downstream 

by means of empirical delivery ratios or transport factors (Kling and 

Olson, 1974; Frere, 1973). A second group couples erosion and sediment 

delivery concepts to deterministic hydrologic models (Negev, 1967; Fleming, 

1972; Simons &., 1975). Although some of the hydraulics-based aspects of 

these latter models are reasonably sophisticated, many of the concepts pertaining 

to the erosion of material and its transport are as simplistic and 

empirical as the delivery ratio approach. 

There is no doubt that* such models can be fitted to specific sets 

of input and output data, as numerous examples now illustrate. However, as 

the components and parameters are conceptual rather than physical in nature, 

it is extremely risky to apply the models to input conditions outside the 

range of conditions fitted - and to interpret model results in terms of 

land use effects. Predicted effects are not more meaningful than the individual 

and collective concepts included in the model. 

41

SWY NOTES 

1. 

2. 

3. 

4. 

5. 

6. 

Gaps in existing conceptual models include: 

lack of an adequate characterization of the dynamic development 

of the drainage system in a basin; 

lack of identification of the relative importance and physical 

significance of soil moisture storage concepts; 

lack of description of depositional processes in microdrainage 

systems; and 

insufficient emphasis on the role of large storms (year-to-year 

and storm-to-storm hydrologic differences often account for 

larger variations in sediment yield than most other factors!) 

Although plot studies have contributed information about factors 

influencing soil loss and runoff, the lack of statistical rigour 

in the design of these studies makes it difficult to interpret 

.ind/or use the results in a quantitative manner. 

?imple extrapolation of plot results to larger areas (often implied 

by the units used for reporting soil loss, i.e. tons/acre) is not 

valid. 

As plot data are of more qualitative than quantitative value, the 

use of them as a base for quantitative deterministic models of land 

use effects is questionable. 

Plot studies have not delineated sources of soil loss and associated 

land use effects. 

Land use effects inferred from time-oriented stream sediment sampling 

programs may be in error both qualitatively and quantitatively. 

lxisting watershed modelling approaches - although convenient - have 

not resolved our lack of understanding of erosion and transport 

processes, and of the effect of land use changes on these processes. 

Neither the plot nor the watershed approaches have addressed the 

problem of erosion sources or the problems of delivery and deposition 

between sources and downstream locations. In order to understand the processes 

and to draw meaningful conclusions about land use effects, focus must 

be given to sources and movement from sources to outlet. Event-oriented 

sampling studies from sources downstream, and @e application of dynamic 

contributing area concepts appear to be two of the most promising new approaches 

to the problem. 

Ackerman, W. C., and K. L. Corinth, (1962). An Empirical 

Equation for Reservoir Sedimentation. Publication 59, 

International Association of Scientific Hydrology, Commission 

of Land Erosion. pp. 359-366. 

42

Adams, J. E., R. C. Henderson, R. M. Smith, (1959). Interpretations of 

Runoff and Erosion from Field Scale Plots on Texas Blackland 

Soil. Soil Sei. x, pp. 232-238. 

American Society of Civil Engineering, (1975). Sedimentation 

Engineering. (ed.) V. A. Vanouri. ASCE, Manuals and Reports 

on Engineering Practice. No. 54. 

Anderson, H. W., (1949). Flood Frequencies and Sedimentation from 

Forest Watersheds. Transactions, American Geophysical Union, 

- 30, (4), Washington, D. C., pp. 567-583. 

Archer, R. J., (1960). Sediment Discharge of Ohio Streams During 

Floods of January-February 1959. Ohio Department of Natural 

Resources, Division of Water, Columbus, Ohio. 

Baird, R. W., (1964). Sediment Yields from Blackland Watersheds. 

Transactions, American Society of Agricultural Engineers, 1. 

(4), St. Joseph, Michigan, pp. 454-456. 

Barnett, A. P., J. S. Rogers, J. H. Holladay, A. E. Dooley, (1965). 

Soil Erodibility Factors for Selected Soils in Georgia and 

South Carolina. Trans. Am. SOC. Agric. Engr., 2, pp. 393-395. 

Barnett. A. P., J. S. Rogers, (1966). Soil Physical Properties 

Related to Runoff and Erosion from Artificial Rainfall. 

Ibid. 2, 123-125 and 128. 

Baver. L. D., (1937). Rainfall Characteristics of Missouri in Relation 

to Runoff and Erosion. Soil Sci. SOC. Am. Proc., ll, 533-536. 

w., 

Beale, 0. W., G. B. Nutt, T. C. Peele, (1955). The Effects of Mulch 

Tillage on Runoff, Erosion, Soil Properties and Crop Yields. 

19, 244-7. 

- 

Beer, C. E., and H. P. Johnson, (1965). Factors Related to Gully 

Growth in the Deep Loess Area of Western Iowa. Proceedings of 

the 1963 Federal Interagency Conference on Sedimentation, United 

States Department of Agriculture, Miscellaneous Publication 

970, pp. 37-43. 

Bennett, H. H., (1933). The Quantitative Study of Erosion Technique 

and Some Preliminary Results. Geogr. Rev., 2, pp. 423-432. 

Bethlahmy, N., W. J. Kidd, (1966). Controlling Soil Movement From 

Steep Road Fills. U. S. For. Serv. Res. Note I.N.T. 45. 

Blench, T., (1957). Regime Behavior of Canals and Rivers. Butteworth 

Scientific Publications, London, England. 

Blow, F., (1955). Quantity and Hydrological Characteristics of Litter 

Under Upland Oak Forests in Eastern Tennessee. J. For., 53 

190-195. 

Bonnard, D., and .I. Bruschin. Transports Solides en Suspension dans 

les Rivieres Suisses - Lonza, Grand-Eau, 1966-1969. Ecole 

Polytechnique Federale de Lausanne, Lausanne, Switzerland, (1970). 

Borland, W. M., (1961). Sediment Transport of Glacier-Fed Streams in 

Alaska. Journal of Geophysical Research, 66, (10). 

43

Borst, H. L., R. Woodburn, (1940). Rain Simulator Studies of the 

Effect of Slope on Erosion and Runoff. U.S. Dept. Agric. 

Soil Conserv. Serv. TP 36. 

Borst. H. L., R. Woodburn, (1942). The Effect of Mulching and Methods 

of Cultivation on Runoff and Erosion from Muskegon Silt Loam. 

Agric. Engng., St. Joseph, Mich., 3, pp. 19-22. 

Brandt, A. E., (1941). The Design of Plot Experiments for Measurement 

of Runoff and Erosion. 9. 2, pp. 429-432 and 436. 

Brice, J. C., (1966). Erosion and Deposition in the Loess-mantled 

Great Plains, Medicine Creek Drainage Basin, Nebraska. Professional 

Paper 352-H, United States Geological Survey, Washington, C. D. 

Brill, G. D., 0. R. Neal, (1950). Seasonal Occurrence of Runoff and 

Erosion from a Sandy Soil in Vegetable Production. Agron. 

J., 42, pp. 192-5. 

Brown, C. B., (1950). Sediment Transportation in Engineering 

Hydraulics, €I. Rouse (ed.) John Wiley and Sons, Inc., New 

York. N.Y., p. 771. 

Browning, G. M., C. L. Parish, J. Glass, (1947). A Method for 

Determining the Use and Limitations of Rotation and Conservation 

Practices in the Control of Soil Erosion in Iowa. J. Am. SOC. 

Agron., 3, pp. 65-73. 

Brune, G. B., (1948). Proceedings, Federal Interagency Conference on 

Sedimentation, Denver, Colo. 

Brune, G. B., (1953). Collection of Basin Data on Sedimentation, United 

States Department of Agriculture, Soil Conservation Service, 

Milwaukee, Wisc. 

Cameron, D. G.. (1952). Studies in Soil Conservation at Cowra Research 

Station 1941-45. J. Soil Conser. Serv. N.S.W., 5, pp. 158-168. 

Campbell, F. B., H. A. Bauder, (1940). A Rating Curve Method for 

Determining Silt Discharge of Streams. Transactions, American 

Geophysical Union, Part 2, Washington D. C., pp. 603-607. 

Carter, C. E., F. E. Dendy, C. W. Doty. (1966). Runoff and Soil 

Loss from Pastured Loess Soils in North Mississippi. Mississippi 

Water Resources Conference, Jackson, Miss. 

Carreker, J. R., (1946). Proper Cropping Practices Strengthen Terraces 

on Sloping Ground. Agric. Engng., St. Joseph, Mich., 27, pp. 311- 

312, 315. 

Carreker, J. R., (1948). Submission to Committee on Agricultural 

Hydrology. Am. SOC. Agric. Engr. w. (29), pp. 114-116. 

Carreker, J. R., (1954). The Effects of Rainfall, Land Slope and 

Cropping Practices on Runoff and Soil Losses. J. Soil Wat. Conserv., 

- 9, pp. 115-119. 

44

Carreker, J. R., A. P. Barnett, (1949). Runoff and Soil Loss 

Measurements by Cropping Periods. Agric. Engng., St. Joseph, 

Mich. 2. pp. 173-176. 

Clark, C. O., (1945). Storage and the Unit Hydrograph Transactions 

American Society of Civil Engineers, 

110, pp. 1419-1488. 

Colby, B. R., (1956). Relationship of Sediment Discharge of Strean- 

flow. U.S. Geol. Survey Open-file Report, 170 pp. 

Colby, B. R., (1963). Fluvial Sediments - A Summary of Source 

Transportation, Deposition and Measurement of Sediment Discharge. 

U.S. Geol. Survey Bull., 1181-A, 49 pp. 

Colby, B. R., and C. H. Hembree, (1955). Computations of Total 

Sediment Discharge, Niobrara River near Cody, Nebraska. Water- 

Supply Paper 1357, United States Geological Survey, Washington, 

D.C. 

Collier, C. R., (1963). Sediment Characteristics of Small Streams in 

Southern Wisconsin, 1954-1959. Water-Supply Paper 1669-B, 

United States Geological Survey, Washington, D. C. 

Collier, C. R., et&., (1964) Influences of Strip Mining on the 

Hydrologic Environment of Beaver Creek Basin, Kentucky, 1955- 

1959. Professional Paper 427-B. United States Geological 

Survey, Washington, D. C. 

Collier, C. R., personal communication, (1969). 

Collier, C. R., et&., (1971). Influence of Strip Mining on the 

Hydrologic Environment of Parts of Beaver Creek Basin, Kentucky, 

1955-1966. Professional Paper 427-C. United States Geological 

Survey, Washington, D. C. 

Conrey, G. W., E. M. Burrage, (1937). Soil Losses of Fertility 

Experiment Plots. Soil Sci. SOC. Am. Proc., 2, pp. 547-554. 

Costin, A. B., D. J. Wimbush, D. Kerr, (1960). Studies in Catchment 

Hydrology in the Australian Alps. I1 - Surface Runoff and Soil 

Loss. CSIRO Div. Pl., Ind. Tech. Pap. No. 14. 

Cox, R. K., (1950). The Land Use Factor in Wheat Land Erosion 

Control. J. Soil Conserv. Serv. NSW, 6, pp. 159-170. 

Crawford, N. H. and R. K. Linsley, (1966) Digital Simulation in 

Hydrology: Stanford Watershed Model IV. Tech. Rept., No. 39, 

Department of Civil Engineering, Stanford University, California. 

Curtis, W. F., J. K. Culbertson, E. B. Chase, (1973). Fluvial Sediment 

Discharge to the Oceans from the Conterminous United States. 

U.S. Geol. Survey Circular 67, 17 pp. 

Davis, W. W., (1937). A New Method for Measurement of Erosion from 

Experimental Plots. Soil Sci. SOC. Am. Proc., 2, pp. 579-583. 

45

Dawdy, D. R., (1967) Knowledge of Sedimentation in Urban EnVirOmentS. 

Journal of the Hydraulics Division, ASCE, 2, (HY6), Proc. Paper 

5595, pp. 235-254. 

Dawdy. D. R., R. W. Litchy, and J. M. Bergmann, (1972). A Rainfall- 

Runoff Simulation Model for Estimation of Flood Peaks for Small 

Drainage Basins. U.S. Geological Survey Professional Paper 506-B. 

Dickinson, R. E., (1929). The Results and Significance of the Spur 

(Texas) Runoff and Erosion Experiments. J. Am. SOC. Agron., 

- 21, pp. 415-422. 

Dickinson. W. T., A. Scott, and G. Wall, (1975). Fluvial Sediment- 

ation in Southern Ontario. Can. Jour. Earth Sciences, 12, 

(ll), pp. 1813-1819. 

Dickinson, W. T., and G. J. Wall, (1976). Temporal Pattern of Erosion 

and Fluvial Sedimentation in the Great Lakes Basin. Geoscience 

Canada, 3, pp. 158-163. 

Dils, R. E., Soil Loss Plots. Personal Communication. 

Diseker, E. G., and J. T. McGinnis, (1967). Evaluation of Climatic 

Slope and Site Factors on Erosion from Unprotected Roadbanks. 

Transactions, American Society of AgKiCUltUKd Engineering, 

- 10, pp. 9-14. 

Dodge, A. F., (1935). Measurement of Runoff as Influenced by Plant 

Cover Density, Symposia Commemorating Six Decades of the Modern 

Era in Botanical Science, (Iowa State College), 1. pp. 185-193. 

Dortignac, E. J., W. C. Hickey, (1963). Surface Runoff and Erosion 

as Affected by Soil Ripping. Proc. Fed. Interagency Sediment 

Conf. 1963. U.S. Dept. Agric. Misc. Publ. 970, pp. 156-165. 

Dragoun, F. J., (1962). Rainfall Energy as Related to Sediment Yield. 

Journal of Geophysical Research, American Geophysical Union, 

- 67, (4). Washington, D. C. 

Duley, F. L. and F. G. Ackerman, (1934). Runoff and Erosion from 

Plots of Different Lengths. Journal of Agricultural Research, 

- 48, (6). 

Duley, F. L., (1939). Surface Factors Affecting the Rate of Intake of 

Water by Soils. Soil Sci. SOC. Am. PKOC., fi, pp, 60-64. 

Duley, F. L., (1952). Relationship Between Surface Cover and Water 

Penetration, Runoff, and Soil Losses. Proc. Int. Grassld. 

Cong., 5, pp. 942-946. 

Duley, F. L., (1956). The Effect of Synthetic Soil Conditions (HPAN) 

on Intake Runoff and Erosion. Soil Sci. SOC. Am. PKOC., 0, 

pp. 420-421. 

Duley, F. L., F. G. Ackerman, (1934). Runoff and Erosion from Plots 

of Different Lengths. Agric. Res. Wash., 48, pp. 505-510. 

46

Duley, F. L., 0. E. Hays, (1932). The Effect of the Degree of 

Slope on Runoff and Soil Erosion. a. 65, pp. 349-360. 

Dunford, E. G., (1954). Surface Runoff and Erosion from Pine Grass- 

lands of the Colorado Front Range. J. For., 52, pp. 923-927. 

Einstein, H. A., (1950). The Bed Load Function for Sediment 

Transportation in Open Channel Flows. Technical Bulletin 

1026, United States Department of Agriculture, Soil 

Conservation Service. 

Feagon, W. T., J. Tedmond, (1955). Planning of Hydrology Experiments 

of Forested Catchments in Australia. Aust. N. 2. Ass. Adv. 

Sci., Sec. K., Melbourne. 

Fleming, G., (1968). The Stanford Sediment Model I: Translation. 

Bulletin International Association of Scientific Hydrology, 

XI1 e, Annee 2, pp. 108-125. 

Fleming, G., (1969). Design Curves for Suspended Load Estimation, 

Proceedings, Institution of Civil Engineers, Paper 7185, No. 

43, London, England, pp. 1-9. 

Fleming, G. (1972). Sediment Erosion-Transport-Deposition Simulation: 

State-of-the-art. Paper Presneted at the Sediment Yield Workshop, 

U.S.D.A. Sed. Lab., Oxford, Mississippi, November 28-30. 

Flint, R. F., (1972). Fluvial Sediment in Salem Fork Watershed West 

Virginia, U.S. Geol. Survey Water Supply Paper 1798-K. 

Forest Service, Fort Collins, Col., (1965). Notes on Sedimentation 

Activities, United States Bureau of Reclamation. 

Foster, G. R., and L. D. Meyer, (1975). Mathematical Simulation 

of Upland Erosion Using Fundamental Erosion Mechanics. 

Publication ARS-S-40, United States Department of Agriculture, 

Agricultural Research Service. 

Foster, G. R., and W. H. Wischmeier, (1973). Evaluating Irregular 

Slopes for Soil Loss Prediction. Paper 73-227, Presented at Meeting 

of American Society of Agricultural Engineers, Lexington, Kentucky. 

Free, G. R., (1960). Research Tells How Much Soil We Can Afford to 

Lose, Crops and Soils, 2, p. 21. 

Frere, M. H., (1973). "Adsorption - Transport of Agricultural Chemicals 

in Watersheds", Transactions of the ASAE, 

16, pp. 569-577. 

Garcia, G., W. C. Hickey, E. J. Dortignac, (1963). An Inexpensive 

Runoff Plots. U.S. For. Serv. Res. Note R.M. 12. 

Garde, L. E., C. A. Van Doren, (1949). Soil Losses as Affected by 

Cover Rainfall and Slope. Soil Sci. SOC. Am. Proc., 16, pp. 374-8. 

47

Geiger, A. F., and J. N. Holeman, (1959). Sedimentation of Lake 

Barcroft, Fairfax County, Va. SCS-TP-136, United States 

Department of Agriculture, Soil Conservation Service. 

George, J. R., (1963). Sedimentation in the Stony Brook Creek Basin, 

New Jersey, U.S. Geol. Survey Open File Report, 71 pp. 

Gilmore, D. A., (1965). Hydrological Investigations of Soil and 

Vegetation Types in the Lower Cotter Catchment. M. Ag. Sci. 

Thesis., Aust. Nat. Univ., Canberra. 

Glymph, L. M., (1951). Relation of Sedimentation to Accelerated Erosion 

in the Missouri River Basin. Technical Paper 102, United States 


Glymph, L. M. (1954). Studies of Sediment Yields from Watersheds. Publication 

No. 36 de L'Association International D'Hydrologie, 

International Union of Geodesy and Geophysics, pp. 178-191. 

Gottschalk, L. C., and G. M. Brune, (1950). Sediment Design Criteria 

for the Missouri Basin Loess Hills. SCS-TP-97, United States 


Gray, D. M.. (1968). Snow Hydrology of the Prairie Environment. 

Proceedings of the Workshop Seminar, Sponsored by the Canadian 

National Committee for the International Hydrologic Decade 

and the Univ. of N.B., Feb. 28 and 29. 

Grissinger, E. H., (1966). Resistance of Selected Clay Systems to 

Erosion by Water. Water Resources Research, 2, (1). 

Guy, H. P., (1964). An Anlysis of Some Storm-Period Variables Affecting 

Stream Sediment Transport. Professional Paper 462-E, United 

States Geological Survey, Washington, D. C. 

Guy, H. P., (1965). Residential Construction and Sedimentation at 

Kensington, Maryland, Proceedings of 1963 Federal Interagency 

Conference on Sedimentation, United States Dept. of Agriculture, 

Miscellaneous Publication 970. 

Guy, H. P., (1969). Laboratory Theory and Methods for Sediment Analysis: 

Techniques of Water Resources Investigations of the U.S. Geol. Survey, 

Book 5, Chapter C1. 

Guy, H. P., (1970). Fluvial Sediment Concepts: Techniques of Water 

Resources Investigations of the U.S. Geol. Survey, Book 3, Chapter 

Cl. 

Guy, H. P., (1970). Sediment Problems in Urban Areas: U.S. Geol. Survey 

Circular 601-E. 

Guy, H. P., and G. E. Ferguson, (1962). Sediment in Small Reservoirs 

due to Urbanization. Journal of the Hydraulics Division, ASCE, 

- 86, HY2, Proc. Paper 3070., pp. 27-37. 

40

Guy, G. P., and G. E. Ferguson, (1970). Stream Sediment: an Environment 

Problem: Jour. of Soil and Water Conservation, Soil 

Conservation Society of America, 5, (6), pp. 217-221. 

Guy, H. P., and W. Norman, (1970). Field Methods for Measurement of 

Fluvial Sediment: Techniques of Water Resources Investigation 

of the U.S. Geol. Survey, Book 3, Chapter C2. 

Happ, S. C., (1944). Effect of Sedimentation on Floods in the Kickapoo 

Valley, Wisconsin. Journal of Geology, G, (1). 

Happ, S. C., (1968). Valley Sedimentation in North-Central Mississippi. 

Proceedings of Third Mississippi Water Resources Conference, 

April 9-10. 

Happ, S. C., G. Rittenhouse, and G. C. Dobson, (1940). Some Principles 

of Accelerated Stream and Valley Sedimentation. Technical 

Bulletin 695, United States Dept. of Agriculture (original 

source, Rittenhouse, G ., and Holt, R. D. unpublished; copies 

in SCS and ARS libraries). 

Harley, B. M., F. E. Perkins, and P. S. Eagleson, (1970). A Modular 

Distributed Model of Catchment Dynamics. MIT, Dept. of Civil 

Engineering, Hydrodynamics Lab. Report No. 133. 

Hayward, J. A., (1971). A Review of Soil Loss Plot Studies, Unpublished 

paper obtained from author. Tussock Grasslands and Moutain 

Lands Institute, New Zealand. 

Heidel, S. S., (1956). The Progressive Lag of Sediment Concentration 

with Flood Waves. American Geophysical Union Transactions 37, 

(I), P. 56. 

Heineman, H. G. and R. F. Piest, (1975). Soil Erosion-Sediment Field 

Research in Progress. EOS-Trans AGU, 56, (3), pp. 

149-157. 

Henderson, F. M., (1966). Open Channel Flow. Macmillan, New York. 

Hill, A. L., (1965). Rates of Sediment Production in the Kansas River 

District. Report of Kansas City District, United States Corps 

of Engineers. 

Hickey, W. C., E. J. Dortignac, (undated). An Evaluation of Soil 

Ripping and Soil Pitting on Runoff and Erosion in the Semi 

Arid South West. Int. Assn. Scient. Hydrol., Publ. 65, pp. 

22-23. 

Holeman, J. N., (1968). The Sediment Yield of Major Rivers of the 

World. Water Resources Research, 5, (4), pp. 737-747. 

Holtan, H. N., N. C. Lopez, (1971). USDAHL-70 Model of Watershed 

Hydrology. USDA, Agricultural Research Service, Tech. Bulletin 

1435. 

49

Horton, R. E., (1938). An Interpretation and Application of Runoff 

Plot Experiments with Reference to Soil Erosion Problems. 

Soil Sci. SOC. Am. Proc., 2, pp. 340-349. 

Horner, G. M., (1960). Effect of Cropping Systems on Runoff, Erosion 

and Wheat Yields. Agron. J., 52, pp. 342-344. 

Homer, G. M., A. G. McCall, F. G. Bell, (1944). Investigations of 

Erosion Control and Reclamation of Eroded Land at the Palouse 

Conservation Experiment Station, Pullman, Wash. 1931-42. U.S. 

Dept. Agric. Tech. Bull. 860. 

Interagency Task Force, (1967). Upper Mississippi River Comprehensive 

Basin Study. Fluvial Sediment, Appendix G, United States Corps 

of Engineers. 

Ireland, H. A., C. F. Sharp, D. H. Eargle, (1939). Principles of 

Gully Erosion in the Piedmont of South Carolina. Technical 

Bulletin 633, United States Dept. of Agriculture. 

James, L. D., (1970). An Evaluation of Relationships Between Streamflow 

Patterns and Watershed Characteristics Through the Use Opset: of 

A Self-calibrating Version of the Stanford Watershed Model. Water 

Resources Institute Research Report 36, University of Kentucky, 

Lexington. 

Jansen, J. M. L., R. B. Pamter. (1974). Predicting Sediment Yield 

from Climate and Topography. Journ. of Am. SOC. of Civil Engr. 

Jour. of Hydrology, g, pp. 371-380. 

Jones, B. L., (1966). Effects of Agricultural Conservation Practices 

on the Hydrology of Corey Creek Basin, Pennsylvania, 1954-1960. 

Water-Supply Paper 1532-C, United States Geological Survey, 

Washington, D. C. 

Jones, H. R., (1961). Runoff and Soil Loss Studies at Wagga Research 

Station. J. Soil Conserv. Serv. NSW, 17 pp. 156-169. 

Kennedy, A. L., (1941). Equipment for Runoff Measurement. Agric. 

Engng, St. Joseph, Mich., 22, pp. 218 and 220. 

Ketcheson, J. W., W. T. Dickinson, P. S. Chisholm, (1973). 

Potential Contributions of Sediment from Agricultural Land. 

Proc. 9th Canadian Hydrology Symposium, Edmonton. 

Kilinc, M. Y., (1972). Mechanics of Soil Erosion from Overland Flow 

Generated by Simulated Rainfall. Dissertation, Submitted to 

the Dept. of Civil Engineering, Colorado State University, 

Fort Collins, Colorado. 

Kittredge, J., (1954). Influences of Pine and Grass on Surface Runoff 

and Erosion. J. Soil Wat. Conserv., 9, pp. 179-185, 193. 

Kling, G. F., G. W. Olson, (1974). "Sediment Transport Computer 

Model" Cornel1 Agronomy Mimeo, pp. 74-11. 

50

Krusekpof, H. H., (1943). The Effect of Slope on Soil Erosion. 

Missouri Agricultural Experiment Station Research Bulletin 

363. 

Krusekpof, H. H., (1958). Soils of Missouri--Genesis of Great Soil Groups. 

Soil Science, 3, pp. 19-27. 

Kulp, J. L., (1961). Geologic Time Scale. Soil Science, 133 

(3459), pp. 1105-1114. 

Kunkle, S. H. and G. H. Comer, (1972). Suspended, Bed, and Dissolved 

Sediment Loads in the Sleepers River, Vermont. ARS 41-188, 

United States Dept. of Agriculture, Agricultural Research 

Service. 

Lamb, J., G. R. Free, H. H. Wilson, (1944). The Seasonal Occurrence 

of Soil Erosion in New York as Related to Rainfall Intensities. 

J. Am. SOC. Agron., 36, pp. 37-45. 

Lamy, D. L., (1949). Some Effects of Summer Storms at Wagga Soil 

Conservation Research Station, 1947-48. J. Soil Conserv. Serv. 

NSE, 5, pp. 39-43. 

Lane, E. W., (1955). Design of Stable Channels. Transactions, ASCE, 

120, Paper No. 2776, pp. 1234-1260. 

Lane, E. W., (1955). The Importance of Fluvial Morphology in Hydraulic 

Engineering. Proceedings, ASCE, a, Paper No. 745. 

Lane, E. W., W. M. Borland, (1951). Estimating Bed Load. Transactions, 

American Geophysical Union, Washington, D. C. 

Langbein, W. B., S. A. Schumm, (1958). Yield of Sediment in 

Relation to Mean Annual Precipitation. Transactions, American 

Geophysical Union, 2, Washington, D. C., pp. 1076-1084. 

Leaf, C. F., (1970). Sediment Yield from Central Colorado Snow Zone. 

ASCE Jour. of Hydraulic Div., 95, pp. 87-93. 

Leopold, L. B., (1968). Hydrology for Urban Planning--a Guidebook 

on the Hydrological Effects of Urban Land Use. U.S. Geological 

Survey, Circular 554. 

Leopold, L. B., W. W. Emmett, R. M. Myrick, (1966). Channel and 

Hillslope Processes in a Semiarid area in New Mexico. Professional 

Paper 3524, United States Geological Survey, Washington, D. C. 

Leopold, L. B., T. Maddock, (1953). The Hydraulic Geometry of 

Stream Channels and Some Physiographic Implications. Professional 

Paper 252, United States Geological Survey, Washington, D. C. 

Leopold, L. B., M. G. Wolman, J. P. Miller, (1964). Fluvial Processes 

in Geomorphology, W. H. Freeman and Co., San Francisco, Calif. 

328 pp. 

51

Li, R. M., (1972). Sheet Flow Under Simulated Rainfall. Thesis 

Submitted to the Dept. of Civil Engineering, Colorado State 

University, Fort Collins, Colorado. 

Li, R. M., H. W. Shen, (1973). Effect of Tall Vegetation on Flow 

and Sediment. Journal of Hydraulics Division, American Society 

of Civil Engineers, 9, (HY5). Proc. Paper 9748, pp. 

793-814. 

Li. R. M., D. B. Simons, (1973). Discussion of "Sediment Yield 

Computed with Universal Equation" by J. R. Williams and H. D. 

Berndt. Journal of the Hydraulics Division, American Society 

of Civil Engineers, 99, (HYll), Proc. Paper 10109, 

pp. 2145-2147. 

Li, R. M., D. B. Simons, M. A. Stevens, (1975). Nonlinear Kinematic 

Wave Approximation for Water Routing. Water Resources Research, 

- 11, (2). pp. 245-252. 

Lillard, J. H., (1941). Effects of Crops and Slopes on Rates of Runoff 

and Total Soil Loss. Agric. Engng., St. Joseph, Hich., 22, 

pp. 396-398 and 406. 

Logan, J. M., (1960). Runoff and Soil Loss Studies at Wellington 

Research Station, Part I - Runoff. J. Soil Conserv. Serv. NSE, 

3, pp. 95-111. 

Logan, J. M., (1960). Runoff and Soil Loss Studies at Wellington Research 

Station, Part I1 - Soil Loss. u., 16, pp. 214-227. 

Longley, A. J., E. J. Bondy, (1963). Reducing Soil Loss in Kansas. 

Jour. Soil Wat. Conserv., e, pp. 160-161. 

Love, S. K., (1936). Suspended Matter in Several Small Streams. Trans- 

actions, 17th Annual Meeting, American Geophysical Union, 


Love, L. D., B. C. Goodell, (1960). Watershed Research on the Frazer 

Experimental Forest. J. For., 58, pp. 272-275. 

Lowdermilk, W. C., (1931). Studies of the Role of Forest Vegetation 

in Surficial Runoff and Soil Erosion. Agric. Engng, St. Joseph, 

Mich., 12, pp. 107-112. 

Lowdermilk, W. C., (1935). Certain Aspects of the Role of Vegetation 

in Erosion Control. Symposia Commemorating Six Decades of the 

Modern Era in Botanical Science (Iowa State College), 1, pp. 123-132. 

Lowdermilk, W. C., H. L. Sundling, (1950). Erosion Pavement to 

Formation and Significance. Trans. Am. Geophys. Un., 31, 

pp. 96-100. 

Lull, H. W., K. G. Reinhart, (1963). Logging and Erosion on Rough 

Terrain in the East. Proceedings of 1963 Federal Interagency 

Conference on Sedimentation, United States Dept. of Agriculture, 

Miscellaneous Publication 970, pp. 43-47. 

52

Lsuby, G. C., (1963). Causes of Variation in Runoff and Sediment Yield 

from Small Drainage Basins in Western Colorado. Miscellaneous 

Publication 970, U.S. Dept. of Agriculture. 

Lsuby, G. C., (1970). Hydrologic and Biota Effects of Grazing Versus Non- 

Grazing Near Grand Junction, Colorado. Professional Paper 

700-B, United States Geological Survey., Washington, D. C., pp. 

232-236. 

Lustig, L. K., (1965). Sediment Yield of the Castaic Watershed, 

Western Los Angeles County, California - A quantitative Geomorphic 

Approach. Professional Paper 422-F, U.S. Geological Survey, 


Mallory, C. W., J. J. Boland, (1970). A System Study of Storm 

Runoff Problems in a New Town. Water Resources Bull., 6, 

(6), pp. 980-89. 

Maner, S. B., (1958). Factors Affecting Sediment Delivery Rates in the 

Red Hills Physiographic Area, American Geophysical Union Trans- 

action, 3, (4). pp. 669-674. 

Maner, S. B., L. H. Barnes, (1953). Suggested Criteria for 

Estimating Gross Sheet Erosion and Sediment Delivery Rates 

for the Blackland Prairies Problem Area in Soil Conservation. 

U.S. Dept. of Agriculture, Soil Conservation Service 

Publication. 

Mannering, J. V., L. D. Meyer, (1961). The Effects of Different Methods 

of Corn Stalk Residue Management on Runoff and Erosion as Evaluated 

by Simulated Rainfall. Soil Sci. SOC. Am. Proc., 5, pp. 506-510. 

Mannering, J. V., (1963). The Effects of Various Rates of Surface Mulch on 

Infiltration and Erosion. Ibid. 27, pp. 84-86. 

Mansue, L. J., A. B. Commings, (1974). Sediment Transport by Streams 

Draining into the Delaware Estuary. U.S. Geol. Survey Water Supply 

Paper 1532-H. 

Marston, R. B., (1952). Ground Cover Requirements for Summer Storm Runoff 

Control on Aspen Sites in Northern Utah. J. For., x, pp. 303-7. 

McCully, W. G., W. J. Bowmer, (1969). Erosion Control on Roadsides 

in Texas. Research Report 67-8F, Texas Agricultural and Mechanical 

University, College Station, Tex. 

McKay, G. E., (1968). Problems of Measuring and Evaluating Snowcover; 

Proceedings of the Workshop Seminar. Canadian Nat. Comm. for 

Internat. Hydr. Decade and Univ. of N.B., Feb. 28-29. 

Menard, H. W., (1961). Some Rates of a Regional Erosion. Journal of 

Geology, 69, pp. 154-161. 

Meyer, L. D.. (1965). Mathematical Relationships Governing Soil 

Erosion by Water. Journal of Soil and Water Conservation, 

- 7-0, (4). 

53

Meyer, L. D. (1971). Soil Erosion by Water on Upland Areas. Chapter 27, 

Vol. 11, River Mechanics edited by H. W. Shen, Colorado State 

University, Fort Collins, Colorado. 

Meyer, L. D., G. R. Foster, M. J. M. Romkens, (1975). Sources of 

Soil Eroded by Water from Upland Slopes. Publication ARS-S-40, 

U.S. Dept. of Agriculture, Agricultural Research Service. 

Meyer, L. D., E. J. Monke, (1965). Mechanics of Soil Erosion by 

Rainfall and Overland Flow. Transactions, American Society of 

Agricultural Engineers, A, (4), St. Joseph, Michigan 

Meyer, L. D., L. A. Kramer, (1968). Relation Between Land-Slope 

Shape and Soil Erosion. Paper Presented at the 1968 Winter Meeting 

of ASAE, Chicago, Illinois. 

Meyer, L. D., E. J. Monke, W. H. Wischmeier, (1969). Mathematical 

Simulation of the Process of Soil Erosion by Water. Transactions, 

American Society of Agricultural Engineers, 12, St. Joseph, 

Michigan. 

Meyer, L. D., J. V. Mannering, (1961). Minimum Tillage for Corn: Its 

Effect on Infiltration and Erosion. Agric. Engng., St. Joseph, 

Michigan, 42, pp. 72-75, 86, 87. 

Miller, C. R., (1951). Analysis of Flow-Duration, Sediment-Rating Curve 

Method of Computing Sediment Yield. United States Bureau of 

Reclamation, Hydraulics Bureau. 

Miller, C. R., R. Woodburn, H. R. Turner, (1962). Upland Gully 

Sediment Production. International Association of Scientific 

Hydrology Publication No. 59. 

Moore, W. R., C. E. Smith, (1968). Erosion Control in Relation 

to Watershed Management. Am. SOC. of Civil Engineers, Proc. 

- 94, (IR3), pp. 321-331. 

Moldenhauer, W. C., W. H. Wischmeier, (1960). Soil and Water Losses 

and Infiltration Rates on Ida Silt Loam as Influenced by Cropping 

Systems, Tillage Practices and Rainfall Characteristics. Soil 

Sci. SOC. Am. Proc., 2, pp. 409-413. 

Mundroff, J. C., (1964). Fluvial Sediment in Kiowa Creek Basin, Colorado, 

U.S. Geol. Survey Water Supply Paper 1798-A. 

Murota, A., M. Hashino, (1969). Studies of a Stochastic Rainfall 

Model and its Application to Sediment Transportation. Tech, 

Rept., Osaka University, 9, pp. 231-247. 

Musgrave, G . W., (1947). The Quantitative Evaluation of Factors in Water 

Erosion, a First Approximation. Journal of Soil and Water 

Conservation, 2, pp. 133-138. 

Mutchler, C. K., (1963). Runoff Plot Design and Installation for 

Soil Erosion Studies. Agricultural Research Service Report 

NO. 41-79, U.S. Dept. of Agriculture. 

54

Neale, 0. R., (1937). The Effect of the Degree of Slope and Rainfall 

Characteristics on Runoff and Soil Erosion. Soil Sci. SOC. 

Am. Proc., 2, pp. 525-32. 

Neale, 0. R., (1939). Some Concurrent and Residual Effects of Organic 

Matter Additions on Surface Runoff. g. 5, pp. 420-25. 

Neal, J. H., (1945). Soil and Water Losses as Affected by Rainfall 

Characteristics. Agric. Engng., St. Joseph, Michigan, 3, 

pp. 463-464. 

Neal, 0. R., G. D. Brill, (1951). Conservation Effects of Crop 

Rotation on a Sandy Soil in Vegetable Production. J. Soil 

Wat. Conserv., 5, pp. 187-190 and 199. 

Neff, E. L., (1967). Discharge Frequency Compared to Long-Term Sediment 

Yields. Symposium on River Morphology, International Union of 

Geodesy and Geophysics, pp. 236-242. 

Negev, M., (1967). A Sediment Model on a Digital Computer. Technical 

Report 76, Stanford University, Stanford, California. 

Newman, J. E., (1970). Climate in the 1970's. Crops and Soils, 

- 

22, pp. 9-12. 

O'Loughlin, C. L. Private communication. 

Olson, T. C., W. H. Wischmeier, (1963). Soil Erodibility Evaluations 

for Soils on the Runoff and Erosion Stations. Soil Sci. Soc. 

Am. Proc., 27, pp. 590-592. 

Onstad, C. A., G. R. Foster, (1974). Erosion and Deposition 

Modeling on a Watershed. Scientific Journal Series 8537, 

Minnesota Agricultural Experiment Station. 

Packer, P. E., (1951). An Approach to Watershed Protection Criteria. 

J. For., 9. pp. 639-644. 

Parsons, D. A.. (1954). Coshocton-Type Runoff Samplers, Laboratory 

Investigations. SCS-TP-124. Soil Conservation Service, U.S. 

Dept. of Agriculture, Washington, D.C. 

Patric, J. H., (1959). Increasing Water Yield in Southern California 

Mountains. Jour. Am. Water Works Assoc., 51, pp. 474-480. 

Peel, T. C., (1937). The Relation of Certain Physical Characteristics 

to the Erodibility of Soils. Soil Sci. Soc. Am. Proc., 11, 

pp. 97-100. 

Peter, J. C., (1967). Effects on a Trout Stream of Sediment from 

Agricultural Practices. Journ. of Wildlife Management, 

- 31, (4). 

55

Piest, R. F., (1963). Long Term Sediment Yields from Small Watershed. 

International Association of Sci. Hydrology, General Assembly 

of Berkley, (1963), 11 (2) - Transport of sediment pp. 121-140. 

Piest, R. F., (1965). The Role of the Large Storm as a Sediment Contributor 

PKOC. of 1963 Federal Interagency Conference on Sedimentation, 

Miscellaneous Pub. 970. U.S. Dept. of Agriculture, pp. 97-108. 

Piest, R. F., H. G. Heineman, (1965). Experimental Watersheds 

Contribute Useful Sedimentation Facts. Internat. Assoc. of 

Sci. Hydr., 1. (2), p. 372. 

Piest, R. F., R. G. Spomer, (1968). Sheet and Gully Erosion in 

the Missouri Valley Loessial Region. Transactions, American 

Society of Agricultural Engineers, 11, St. Joseph, 

Michigan, pp. 850-853. 

Piest, R. F., J. M. Bradford, R. G. Spomer, (1975). Mechanisms of 

Erosion and Sediment Movement from Gullies. Publication ARS- 

S-40, Agricultural Research Service, U.S. Dept. of Agriculture. 

Piest, R. F., M. Bradford, G. M. Wyatt, (1975). Soil Erosion and 

Sediment Transport. ASCE Hydraulic Div., p. 65. 

Portfield. G., (1972). Computation of Fluvial Sediment Discharge 

Techniques of Water Resources Investigations of U.S. Geol. Survey, 

Book 3, Chapter C3. 

Rainwater, F. E., (1962). United States Geological Survey Hydrologic 

Investigations Atlas. HA-61. 

Rantz, S. E., (1964). Snowmelt Hydrology of a Sierra Nevada Stream. 

U.S. Geol. Survey Paper 1779-R. 

Reed, L. A., (1971). Hydrology and Sedimentation of Corey Creek and 

Elk Run Basins, North Central Pennsylvania, U.S. Geol. Survey 

Water Supply Paper 1532-E. 

Reed, L. A., (1976). Sediment Characteristics of Five Streams Near 

Harrisburg, Pennsylvania Before Highway Construction. USGS 

Water Supply Paper 1798”. 

Renard, K. G., (1969). Sediment Rating in Ephemeral Streams. 

ASAE Transaction, p. 80-85. 

Renard, K. G., L. J. Lane, (1972). Sediment Yield as Related to a 

Stochastic Model of Ephermeral Runoff. Paper Presented at the 

Sediment Yield Workshop, USDA Sed. Lab., Oxford, Mississippi. 

Rendon-Herrero, O., (1974). Estimation of Washload Produced on Certain 

Small Watersheds. Journal of the Hydraulics Div., American 

Society of Civil Engineers, 100, (HY7), PKOC. Paper 10638, 

pp. 835-848. 

56

Renfro, G. W., (1972). Use of Erosion Equations and Sediment Delivery 

Ratios for Predicting Sediment Yield, Paper Presented at the 

Sediment Yield Workshop, USDA Sed. Lab., Oxford, Mississippi. 

Renfro, G. W., J. W. Adair, (1968). Engineering and Watershed 

Planning Unit Technical Guide No. 12. Soil Conservation Service, 

U.S. Dept. of Agriculture, Fort Worth, Texas. 

Renfro, G. W., (1972). Use of Erosion Equations and Sediment Delivery 

Ratios for Predicting Sediment Yield. USDA Sed. Lab. Oxford, 

Mississippi. 

Rice, R. M., G. T. Foggin, (1971). Effect of High Intensity Storms 

on Soil Slippage on Mountanous Watersheds in South California. 

Water Resources Research, 1, (6). 

Ritter, J. R., (1974). The Effects of Hurricane Agnes Flood on Channel 

Geometry and Sediment Discharge of Selected Streams in Susquehanna 

River Basin, Pennsylvania. U.S. Geol. Survey Jour. of Research 

- 

2, (6), pp. 753-761. 

Rockwood, D. M., (1964). Program Description and Operating Instructions, 

Streamtlow Synthesis and Reservoir Regulation. Tech. Bulletin No. 

22, U.S. Army Engineering Uivision, North Pacific, Portland, Oregon. 

Rodriguez-Iturbe, I., C. F. Nordin, (1968). Time Series Analysis 

of Water and Sediment Discharges. IASH, 13, (2), 

pp. 69-86. 

Roehl, J. W., (1962). Sediment Source Areas, Delivery Ratios, and 

Influencing Morphological Factors. Publication 58, IASH, pp. 

202-203. 

Rogers, J. S., A. P. Barnett, C. Cobb, (1964). An Evaluation of Factors 

Affecting Runoff and Soil Loss from Simulated Rainfall. Trans. 

Am. SOC. Agric. Engr., I, pp. 457-459. 

Rosenbrock, H. H., (1960). An Automatic Method for Finding the Greatest 

or Least Value of a Function. The Computer Journal, 3, 

pp. 175-184. 

Rowlison, D. L., 6. L. Martin, (1971). Rational Model Describing 

Slope Erosion. Journal of the Irrigation and Drainage Division, 

ASCE, 97, (Irl), Proc. Paper 7981, pp. 39-50. 

Ruhe, R. V., R. B. Daniels, (1965). Landscape Erosion - Geologic 

and Historic. Journal of Soil and Water Conservation. 

Ruhe, R. V,, R. Meyer, W. H. Scholtes, (1957). Late Pleistocene 

Radiocarbon Chronology in Iowa. American Journal of Science, 

I 225, pp. 671-689. 

57

Sayre. W. W., H. P. Guy, A. R. Chamberlain, (1963). Uptake and 

Transport of Radionuclides by Stream Sediments. U.S. Geol. 

Survey Professional Paper 433-A. 

Scheidegger, A. E., (1961). Theoretical Geomorphology, Prentice- 

Hall, Inc., Englewood Cliffs, N.J. 

Schumm, S. A., (1956). The Role of Creep and Rainwash on the Retreat 

of Badland slopes. American Journal of Science, 254, 

pp. 693-706. 

Schumm, S. A., (1965). Quanternary Paleohydrology. The Quanternary 

of the United States. 

Searcy, J. K., (1959). Flow Duration Curves. Water Supply Paper 

1542-A, U.S. Geological Survey, Washington, 

D. C. 

Seginer, I., (1966). Gully Development and Sediment Yield. Research 

Report No. 13, The Israel Ministry of Agriculture, Soil Conser- 

vation Division. 

Shen, H. W., R. M. Li. (1973). Rainfall Effect on Sheet Flow Over 

Smooth Surface. Journal of the Hydraulics Division, American 

Society of Civil Engineers, E.. (HY5). Proc. Paper 9733. 

pp. 771-792. 

Shen, H. W., R. W. Li, (1976). Watershed Sediment Yield, 2, Stochastic 

Approaches to Water Resources. Edited and published by H. W. Shen 

for Collins Colorado. 

Simons, D. B., R. M. Li, M. A. Stevens, (1975). Development of 

Models for Predicting Water and Sediment Routing and Yield 

from Storms on Small Watershed. Colorado State Univ. Report 

CER74-75DBS-RML"AS24. Prepared for USDA Forest Service, Rocky 

Mountain Forest and Range Experimental Station, Flagstaff, Arizona. 

Smith, D. D., D. M. Whitt, (1948). Evaluating Soil Losses from Field 

Areas. E. 2, pp. 394-396 and 398. 

Smith, D. D., W. H. Wischmeier, (1957). Factors Affecting Sheet and 

Rill Erosion. Trans. Am. Geophys. Un., 38, pp. 889-896. 

Smith, D. D., (1962). Rainfall Erosion. Adv. Agron., 14, pp. 109-148. 

Smith, D. D., (1941). Interpretation of Soil Conservation Data for 

Field Use. Agricultural Engineering, 22, pp. 173-175. 

Smith, D. D., (1966). Broad Aspects of Erosion Research Presented at 

the 1966 American Society of Agricultural Engineers Winter meeting. 

Smith, D. D., D. M. Whitt. (1947). Estimating Soil Losses from 

Field Areas of Claypan Soils. Proceedings, Soil Science Society 

of America, 12, Madison, Wisc., pp. 485-490. 

Smith, D. D., W. H. Wischmeier, (1957). Factors Affecting Sheet 

and Rill Erosion. Trans. AGU, 3, pp. 889-896. 

Smith, D. D., W. H. Wischmeier. (1958). Evaluation of the Factors 

in Soil Loss Equation. Agricultural Engineer, 2, pp. 458- 

462. 

58

Smith, B. M., st. (1967). Renewal of Desurfaced Austin Clay. 

Soil Science, 103. 

Smith, R. M., W. L. Stamey, (1965). Determining the Range 

of Tolerable Erosion. Soil Science, 100, (6). 

Soil Conservation Service, United States Department of Agriculture, 

Procedures for Determining Rates of Land Damage, Land Depreciation, 

and Volume of Sediment Produced by Gully Erosion. Technical 

Release No. 32, Geology, July (1966). 

Soons, J. M., (1966). Some Observations of Microclimate and Erosion 

Processes in Cass Basin in the Southern Alps. Paper delivered N. Z. 

Hydrological Society Symposium on Precipitation and Erosion (1966). 

(cyclostyled). 

Speraberry, J. A., A. J. Bowie, (1969). Predicting Sediment Yields 

from Complex Watersheds. Trans. ASAE, 12, pp. 188, 201. 

Spomer, R. G., H. G. Heinemann, R. F. Piest, (1971). Consequences 

of Historic Rainfall on Western Iowa Farmland. Water Resources 

Research, L, (31, pp. 524-535. 

Springer, D. K., C. B. Breinig, M. E. Springer, (1963). Predicting Soil 

Losses in Tennessee. 3. Soil Wat. Conserv., 2, pp. 157-158. 

Stall, J. B., L. J. Bartelli, (1959). Correlation of Reservoir Sedimentation 

and Watershed Factors: Springfield Plains, Illinois, Illinois 

State Water Survey, Report of Investigations 37. 

Swanson, N. P., A. R. Dedrick, (1965). Protecting Soil Surfaces Against 

Water Erosion with Organic Mulches. Paper Delivered Am. Soc. 

Agron., Ohio, (1965). (cyclostyled). 

Swanson, N. P., A. R. Dedrick, H. E. Weakly, (1965). Soil Particles and 

Aggregates Transported in Runoff from Simulated Rainfall. Trans. 

Am. SOC. Agric. Engr., &, pp. 437-440. 

Swanson, N. P.. A. R. Dedrick, H. E. Weakly, H. R. Haise, (1965). 

Evaluation of Mulches for Water Erosion Control. w. 8, pp. 

438-440. 

Swanson, N. P., A. R. Dedrick, (1966). Simulation of Increased Slope 

Length on Small Runoff Plots. Paper Presented at Am. SOC. Agric. 

Engr. (cyclostyled). 

Taylor, R. E., 0. E. Hays, E. Bay, R. M. Dizon, (1964). Corn Stover 

Mulch for Control of Runoff and Erosion on Land Planted Corn after 

pp. 123-125. 

Corn. Soil Sci. SOC. Am. Proc., 8, 

Thompson, J. R., (1964). Quantitative Effect of Watershed Variables on 

the Rate of Gully Head Advancement. Transactions, American Society 

of Agricultural Engineers, 2, (A), St. Joseph, Michigan. 

pp. 54-55. 

59

Thoreson, A. S., J. K. Maddy, (1963). Using the Soil Loss Equation in 

Iowa. J. Soil Wat. Conserv., la, pp. 159-160. 

Todorovic, P., V. Yevjevich, (1969). Stochastic Process of 

Precipitation. Colorado State University Hydrology Paper 35. 

Turner, G. T., E. J. Dortignac, (1954). Infiltration Erosion and 

Herbage Production of Some Mountain Grasslands in Western 

Colorado. J. For., 52, pp. 858-860. 

Uhland, R. E., (1935). The Effect of Plant Cover on Soil and Water 

Losses. Symposia Commemorating Six Decades of the Modern 

Era in Biological Science (Iowa State College), 1, pp. 115-122. 

United States Department of Agriculture. Summary of Reservoir Sediment 

Disposition Surveys Made in the United States through 1970. 

Miscellaneous Publication 1226, Compiled Under the Auspices of 

the Sedimentation Committee, Water Resources Council, (1973). 

United States Geological Survey, National Reference List of Water 

Quality Stations, Water Year 1971, Water Resources Division, 

Washington, D. C., (1971). 

United States Geological Survey Water Supply Papers. Quality of 

Surface Water of the United States, (published) and annual 

summaries (unpublished) Washington, D. C., (1959-1967). 

University of Missouri, Agricultural Experiment Station, (1962). 

Missouri Soil and Water Conservation Needs Inventory. 

Ursic, S. J., F. E. Dendy, (1965). Sediment Yields from Small Watersheds 

Under Various Land Uses and Forest Covers. Proceedings of 

(1963) Federal Interagency Conference on Sedimentation, Miscellaneous 

Publication 970, United States Dept. of Agriculture, pp. 47-52. 

USBR., (1960). Investigation of Meyer-Peter, Muller Bedload Formulas. 

Sedimentation Section, Hydrology Branch, Division of Project 

Investigation, U.S. Dept. of the Interior, Bureau of Reclamation. 

U.S. Dept. of Agriculture, (1975). Erosion and Sedimentation. Soil 

Conservation Service, Great Lakes Commission, Appen. 18. 

U.S. Dept. of Housing and Urban Development, (1970). Proceedings of the 

National Conference on Sediment Control, Washington, D. C. 

September 14-16, 1969, May 1970. 

U.S. Environmental Protection Agency, (1975). Control of Water Pollution 

from Cropland. Vol. 1, USDA ARS H-S-1 and EPA 600/2-75-0269. 

Van Doren, C. A., R. S. Stauffer, E. H. Kidder, (1950). Effect of 

Contour Fanning onSsoil Loss and Runoff. Soil Sci. SOC. Am. 

Proc., 2, pp. 413-417. 

Van Doren, C. A., L. J. Bartelli, (1956). A Method for Forecasting 

Soil Losses. Agricultural Engineering, x, pp. 335-341. 

60

Van Vliet, L. J. P., G. J. Wall, W. T. Dickinson. The Effect 

of Agricultural Land Use on Sheet Erosion Losses in Southern 

Ontario. Can. Jour. Soil Science (in press). 

Vice, R. B., G. E. Ferguson, H. P. Guy, (1968). Erosion from 

Suburban Highway Construction. Journal of the Hydraulics 

Division, ASCE, 94. (HY l), Proc. Paper 5742, pp. 347-348. 

Vice, R. B., H. P. Guy, G. E. Ferguson, (1969). Sedimentation Movement 

in an Area of Suburban Highway Construction, Scott Run Basin, 

Fairfax County, Virginia, 1961-64. U.S. Geol. Survey Water Supply 

Paper 1591-E. 

Walker, P. H., (1966). Postglacial Environments in Relation to Landscape 

and Soils on the Cary Drift, Iowa. Agriculture and Home Economics 

Experiment Station Bulletin 549, Iowa State University. 

Whitaker, F. D. H. G. Heinemann. The Effects of Soil Management 

Variables on Soil Losses (to be published in University of Missouri 

Experiment Station Bulletin). 

Whitaker, F. D., V. C. Jameson, V. F. Thornton, (1961). Runoff and Erosion 

Losses from Mexico Silt Loam in Relation to Fertilization and 

Other Management Practices. Soil Sci. SOC. Am. Proc., 2, pp. 401-403. 

Williams, J. R., (1972). Sediment Yield Prediction with Universal Equation 

Using Runoff Energy Factor. Paper Presented at the Sediment Yield 

Workshop, USDA Sed. Lab., Oxford Mississippi. 

Williams, J. R., (1975). Sediment Routing for Agricultural Watershed. 

Water Resources Bulletin, 11, (5), pp. 965-970. 

Williams, J. R., H. D. Berndt, (1972). Sediment Yield Computed with 

Universal Equation. Journal of Hydraulics Division, American 

Society of Civil Engineers, 98, (HYlZ), Proc. Paper 

9426, pp. 2087-2098. 

Williams, J. R., H. D. Berndt, (1972). Sediment Yield Computed with 

Universal Equation. Journal of the Hydraulics Division, ASCE, 

- 98, (HYlZ), Proc. Paper 9426. pp. 2087-2098 

Wilson, L., (1972). Seasonal Sediment Yield Pattern of U.S. Rivers, 

Water Resources Research, 8 (6), pp. 1470. 

Wilson, L., (1973). Variation in Mean Annual Sediment Yield as a Function 

of Mean Annual Precipitation, Am. Jour. of Sci. (in Press). 

273, (4). pp. 334-349. 

61

Wiltshire, C. R., (1947). Runoff Plots and Standard Runoff and Soil 

Loss Measuring Equipment Used by the New South Wales Soil 

Conservation Service. J. Soil Conserv. Serv. N.S.W., 3, 

pp. 171-178. 

Wiltshire, C. R., (1948). The Measurement of Runoff and Soil Loss from Plot 

Experiments. u. ft, pp. 40-44. 

Wischmeier, W. H., (1960). Cropping-Management Factor Evaluations for 

a Universal Soil Loss Equation. Soil Sci. SOC. Am. Proc., 26, 

pp. 322-326. 

Wischmeier, W. H., (1959). A Rainfall Erosion Index for a Universal 

Soil Loss Equation. Soil Sci. SOC. Am. Proc., 2, pp. 246-249. 

Wischmeier, W. H., (1966). Relation of Field-Plot Runoff to Management and 

Physical Factors. H. 2, pp. 272-277. 

Wischmeier, W. H., D. D. Smith, (1958). Rainfall Energy and its 

Relationship to Soil Loss. Trans. Am. Geophys. Un., 3, pp. 

285-291. 

Wischrneier, W. H., D. D. Smith, R. E. Uhland, (1958). Evaluation of 

Factors in the Soil Lose Equation. Agric. Engng., St. Joseph 

Michigan, 2, pp. 458-462 and 474. 

Wischmeier, W. H., (1962). Storms and Soil Conservation, Jour. of Soil 

and Water Conservation. x, (2). 

Wischmeier, W. H., (1962). Rainfall Erosion Potential, Agric. Engineerinl 

- 43, (4). pp. 212. 

Wischmeier, W. H., (1972). Estimating the Cover and Management Factor 

for Undisturbed Areas. Paper Presented at the Sediment Yield 

Workshop, USDA Sed. Lab. Oxford, Mississippi. 

Wischmeier, W. H., D. D. Smith, (1958). Rainfall Energy and its 

Relationship to Soil Loss, Am. Geophys. Union Trans., 3, 

- 2, pp. 285. 

Wischmeier, W. H., D. D. Smith, R. E. Uhland, (1958). Evaluation of 

Factors in the Soil-Loss Equation, Jour. of Agric. Engineering. 

Wischmeier, W. H., D. D. Smith, (1960). A Universal Soil-Loss Equation 

to Guide Conservation Farm Planning. 7th International Congress 

of Soil Science, Madison, Wisconsin. 

Wischmeier, W. H., D. D. Smith, (1965). Predicting Rainfall-Erosion 

Losses from Cropland East of the Rocky Mountains. Agriculture 

Handbook 282, U.S. Dept. of Agriculture, Agricultural Research 

Service. 

62

Wischmeier, W. H., C. B. Johnson, B. V. Cross, (1971). A Soil- 

Erodibility Nomograph for Farmland and Construction Sites. 

Journal of Soil and Water Consevation, a, (5), pp. 

189-193. 

Wischmeier, W. H., (1973). Upslope Erosion Analysis in River Mechanics, 

111, H. W. Shen (ed.) 

Woodburn, R., (1945). A Comparison of Erosion Losses After Turning 

Under Legumes and Non Legumes. Agric. Engng., St. Joseph, 

Michigan, 26, pp. 247-240. 

Wolman, M. G., (1964). Problems Posed by Sediment Derived from Construction 

Activities in Maryland. Report to Maryland Water 

Pollution Control Commission, Annapolis. 

Wolman, M. G., J. P. Miller, (1960). Magnitude and Frequency of 

Forces in Geomorphic Processes. Journal of Geology, 68. 

Wolman, M. G., A. P. Schick, (1967). Effect of Construction on 

Fluvial Sedimentation in Urban and Suburban Areas in Maryland. 

Water Resources Research, 3, (2). 

Woolhiser. D. A., P. H. Blinco, (1972). Watershed Sediment Yield- 

A Stochastic Approch. Paper Presented at Sediment Yield Work- 

shop, USDA Sed. Lab., Oxford, Mississippi. 

Woolhiser, D. A.. P. Todorovic, (1974). A Stochastic Model for 

Sediment Yield for Ephemeral Streams. Proc. International 

Association for Statistics in Physical Science, Symposium of 

Hydrology, Tuscon, Arizona, August 29-September 2, 1971, USDA 

Misc. Publication 1275, pp. 295-308. 

Yen, B. C., H. G. Wenzel, Jr., (1970). Dynamic Equations for Steady 

Spatially Varied Flow. Journal of the Hydraulics Division, 

American Society of Civil Engineers, 96, (HY3), pp. 

801-814. 

Yoon, N. Y., (1970). The Effect of Rainfall on the Mechanics of Steady 

Spatially Varied Sheet Flow a on Hydraulically Smooth Boundary. 

Ph.D. Thesis, Dept. of Civil Engineering, University of Illinois. 

Urbana, Illinois. 

Yorke, T. H., (1975). Effects of Sediment Control on Sediment Transport 

in the Northwest Branch Anacostia River Basin, Montgomery County, 

Maryland, U.S. Geol. Survey, Journ. of Research, 2,(4), 

pp. 487-494. 

Yorke, T. H., W. J. Davis, (1971). Effect of Urbanization on Sediment 

Transport in Bel Pre Creek Basin, Maryland; U.S. Geol. Survey 

Prof. Paper 750-B. 

Yorke, T. H.. (1972). Sediment Yield of Urban Construction Sources, 

Montgomery County, Maryland; Progress Report Rock Creek Anacostia 

River Basin, U.S. Geol. Survey Open file Report, p. 39. 

63

Young, R. A., C. K. Mutchler, W. H. Wischmeier, (1964). Influence of 

Row Direction and Type of Vegetal Cover on the Slope-Soil Loss 

Relationship. Trans. Am. SOC. Agric. Engr., 2, pp. 316-317 and 320. 

Young, R. A., C. K. Mutchler, (1969). Soil Movement on Irregular 

Slopes, Water Resources Research, 5(5), pp. 1084-1089. 

Young, R. A., J. L. Wiesrner, (1973). The Role of Rainfall in Soil 

Detachment and Transport. Water Resources Research, 9(6), 

pp. 1629. 

Ziemnicki, S ., C. Jozefaciuk, (1965). Soil Erosion and its Control. 

Translated from Erozja, Panstwowe Wydawnictwo Rolnicze i 

Lesne, Warszawa. 

Zingg, A. W., (1940). Degree and Length of Land Slope as it Affects 

Soil Loss in Runoff. Agricultural Engineering, 3, pp. 

59-64. 

Zingg, A. W., (1941). Soil Movement Within the Surface Profile of Terraced 

Lands Unpublished report, U.S. Dept. of Agriculture, Soil 

Conservation Service. 

64

DISCUSSION 

Dr. C. Nordin: I have a comment on your remarks about sediment monitoring. 

About forty years ago the Federal Agencies in the United States set up the 

interagency sedimentation group to look at sampling problems and to standardize 

the methodology in the equipment. The geological survey was quite 

heavily involved in this. Paul Benedict, and Bruce Colby in particular 

did very extensive work back in the 30's and 40's. At that time they recognized 

that sediment sampling had to be event-based; that most of the sediment 

could be carried in a single event during the year or at very irregular 

intervals. They developed equipment to sample this and methodologies that 

give you a very good sample. Now people are not monitoring sediment properly. 

It is for one of two reasons: either they don't know what they are doing 

and they are unwilling to read the literature, or they are unwilling to 

spend the money to do it right. But these things have been known for four or 

five decades. 

Dr. T. Dickinson: Well, I can only agree with you Carl. I think it is a 

good point. Some of these things have been known for years and years, but I 

only know that, for instance in Canada, we have not been sampling sediment 

for very long. The measurement techniques are known and they are used. In 

many cases they are not used well. Now, whether it is because people are not 

taking the time to use them well or don't know the appropriate mechanism, I 

am not sure. I don't want to go into the detail, but I agree with you that 

some of that methodology, or much of is it, already known if we just make 

good use of it. I suggest that particularly in small watershed studies 

where the events can be very, very short, people are not making the best 

use of it and I must say too, that in the International Joint Commission 

studies, there is a lot of experimentation in doing it and trying to a do 

better job. I am not openly criticizing all studies, but I do say many of 

the data we have on some of the basins need to be interpreted carefully. 

If one looks at the sampling frequency and looks at how they were taken, we 

better acknowledge just how that was done and interpret the results accordingly, 

and very often the sampling frequency in just time is not anywhere 

near where it has to be to give us meaningful results. 

Dr. D. Wazling: Just a general comment that concerns the possibility of 

using turbidity measurements for documenting sediment output from drainage 

basins. One of the traditional views is to dismiss these immediately 

and say they have got far too many problems associated with them, I have but 

in fact experimented with these in England, and if one uses them for specific 

catchment and carries out detailed calibration procedures it seems to me 

that they will work and they do provide a very useful means of getting a 

continuous record of sediment concentration. The point I really want to 

get at is that if one takes that continuous record as being a worthwhile 

continuous record, it is extremely interesting to compare individual sampling 

programs with a continuous record. When you start to work out error 

functions of what individual programs would give compared to what a continuous 

record would give, then is it absolutely staggering the errors that 

could be creeping in. And I really want to support your point, you could be 

4 or 500% out with the figures when you compare them with the continuous 

record. 

65

Dr. T. Pickinson: Two comments. One: we have taken a look at this. 

We have been able to find no good relationship on the basins we are 

working on right now between turbidity and suspended load that we could 

use in a quantitative way. But I quite agree with you that it is a convenient 

way. One thing we found convenient about it is that it may be a 

way of identifying sources. In other words you can set them up and run them 

continously in a number of places in a basin, and at least begin to identify 

when there is load coming out of particular areas versus when there is no 

load coming out of certain areas; even if we can't say how much load is 

coming from here versus how much is coming from there. We have real difficulty 

making that step because we have done this in where places we got 

measurements. Certainly as an index of helping us sort out sources, we are 

finding it very convenient in a couple of the basins. 

Dr. D. Simons: I would simply like to make the point in addition to what 

has been stated that as we monitor small watersheds, plots, large watersheds; 

the data collection, the instrumentation, so and forth require a lot 

of time, a lot of amendments of effort. It is expensive and I do think that 

it is probably timely to mention that we should take every opportunity to 

utilize the physically-based models to determine what the data needs are. I 

think in many instances where we are going out and instrumenting watersheds 

and plots, we may be gathering data that are trivial OK we may be gathering 

during times when they are not important. By utilizing these models and 

carrying out sensitivity analyses, I think we can in the future better design 

to meet our real data needs to do a better job; get more back for the money 

spent in the effort. 

Dr. T. Lsickinson: I would certainly agree. I think that the models can be 

a great help and play a great learning part and it may be a way of efficiently 

spending the dollars we have to try and reach some of the problems faster. 

Dr. L. HetZing: Following your talk and the subsequent discussion, I see 

three different areas where additional study or research resources could be 

put: 

1. Modeling and process development including laboratory and/or 

field studies directed to the understanding of actual processes. 

2. Field measurements over a variety of watersheds directed towards 

increasing OUT data base on actual sediment movement. 

3. Development of measurement techniques directed towards improving 

accuracy and lowering cost. The annual cost of a sediment measurement 

station is now $10,000 to $15,000. 

Which of these three areas, given $10,000 or $100,000 or $1 million, 

would be the best investment considering the present state of the art. 

66

Dr. T. Dickinson: I think that is one of the purposes of this workshop. I 

think we have got to do them all and I agree you can not do them all on one 

particular basin. But hopefully in some of these broader projects like the 

IJC one, there is room for some to be done on each one to try to learn from 

each one, to complement the other. I think that is the stage we are at. I 

don't think we are at the stage where we can say "let's put all our money in 

one bag". That begs the question, but I think that is where we are, because 

we must have more data to make sense, but on the other hand we have got to 

look at some of the processes. I guess the problem I have, is that in terms 

of processes 1 think we may have to study them in the field, and in particular 

field conditions. At least I think in some cases we have got to do more of 

that before we can even go into the laboratory to model them because I am 

not sure we even know quite how to set up the laboratory model for the field 

situation we want to model. I think that in the laboratory the time scale 

we can use is one of the advantages, but we had better find out really what 

is the time scale of changes in the field before we go into the laboratory 

to try to sort some of that out. I think we have got to do a little bit of 

all of it and hopefully in looking at all the resources in the area as a 

pool we can come up with a balance that is meaningful, and avoid some of 

the pressures that suggest haste and "so and so down the road is doing that". 

In fact if "so and so down the road is doing that", we better do something 

else and learn in that way. 

Dr. E. &gley: I have to draw this session to a close as far as my participation 

is concerned. I wish to offer one comment which I would like a 

number of you who I know have been working on the relationships between 

specific kinds of land use and their effects upon water quality to consider. 

If I synthesize correctly what you have said Trevor (Dickinson), in general 

our ability to use existing data generating techniques is not sufficiently 

discriminatory to enable a distinction to be made amongst various land uses. 

I know at least two of you, and I am sure there are many more in this room. 

who have done very specific work on attempting to discriminate in terms of 

water quality and up-stream land uses, and I would like you to think about 

this because it is a question that is going to come out in the working sessions. 

67

INTRODUCTION 

Anthropogenic Influences of Sediment Quality at a Source. 

Pesticides and PCBs 

R. Miles 

Environmental studies at the London, Ontario, Research Institute of 

Agriculture Canada have included investigations of the pollution of streams 

and water systems by insecticides used in agriculture. We have analysed 

soils in the stream basins, water, suspended sediment, bed load, bed material 

and fish for insecticide residue content. In this report I shall discuss the 

concentrations of insecticides found in soil and on the various sediments, 

the conversion of DDT to its metabolites on sediments, and the relation of 

water solubility to insecticide adsorption onto sediments. We studied Big 

Creek, Norfolk County, Ontario, which drains 280 square miles including an 

important tobacco growing area, and the water system draining the 7,500 acre 

Holland Marsh; an intensively cultivated vegetable muck area about 30 miles 

north of Toronto. To compare insecticide residues from the two areas in: (a) 

soil, (b) suspended sediment, and (c) bed material, samples from Big Creek 

contained 4.0, 0.11, and 0.026 ppm DDT, respectively; while corresponding 

values from Holland Marsh were 8.0, 29, and 0.30 ppm. 

DISCUSSION OF RESULTS 

An important sediment is the bed load - the shifting mass of sediment 

and detritus which we sampled using a Bogardi Bed Load Sampler. Residues of 

total DDT, dieldrin and endosulfan (Thiodan) found in bed material and bed 

load of Big Creek in 1973 are listed in Table 1. With one exception (August 

14th) the concentrations on the bed load were several times greater than the 

concentrations in the bed material. This means that benthic fish and crustaceans 

may be exposed to much mre insecticide residue than would be indicated 

by analysis of bed material alone. 

DDT converts to its metabolite DDE by splitting off HC1. This 

conversion to DDE is generally associated with enzyme dehydrochlorination in 

insects, mammals and fish. DDT conversion to another metabolite DDD is a 

reductive dechlorination and is reported to be favoured by anaerobic conditions. 

The ratio of metabolite to parent DDT is a measure of the degradation 

of the insecticide residue. In Holland Marsh bed material DDE/DDT 

increased from 0.2 (April) to 0.8 (September) in 1972 and from 0.2 (April) to 

1.4 (September) in 1973. DDD/DDT increased from 1.6 (April) to 6.7 (September) 

in 1972 and from 2.6 (April) to 13.0 (October) 1973. Water is pumped from 

the marsh drainage ditch depending on water levels, and very little pumping 

occurs during the summer after June. It would appear from the above results 

that in the quiet water of the drainage ditch the microorganisms are able to 

convert DDT to its metabolites during the period from spring through to 

69

autumn. Both DDD and DDE are much less toxic to mammals than the parent DDT 

(acute oral LD50 to male rats > 4,000, 880 and 200 mg/kg respectively) so 

the above degradation is a lessening of overall toxicity of DDT residues 

although DDE is blamed for the thin eggshell syndrome in birds. 

Sediment must require considerable time to move along the of a bed 

stream from source to mouth and we theorized that microorganisms would be 

able to convert some DDT to its metabolites during the time the sediment 

moved downstream in Big Creek, a distance of about 30 miles. We sampled bed 

material at 6 locations on the same day over this distance in 1972 and DDE/ 

DDT increased from 0.2 (upstream) to 1.5 (stream mouth), while DDD/DDT 

increased from 0.1 (upstream) to 2.0 (stream mouth). Thus the ratio DDD/DDT 

in residues in the bottom sediment increased 20 times in samples from upstream 

to the stream mouth! A similar study in 1973 produced the same trend but not 

to as significant a degree. Again this represents a considerable reduction 

in overall DDT mammalian toxicity. 

In analysing water samples for insecticide residue content it is 

our normal practice to analyse the whole water sample including suspended 

sediment. To determine the amount of insecticide adsorbed on suspended 

sediment we filter companion samples and analyse the filtered sediment. 

Averaging a large number of samples from Big Creek and Holland Marsh we found 

the per cent of the whole warer analysis which was adsorbed on the sediment 

to be 61% average for DDT (30-93% range) and 15% average for dieldrin (3-42% 

range). These values are in agreement with the water solubility of these 

compounds (0.0012 ppm for DDT and 0.186 ppm for dieldrin). In the Holland 

Marsh water samples, diazinon (an organophosphorus insecticide) was present 

at concentrations greater than the dieldrin but no diazinon was found adsorbed 

onto the sediment. These data also agree with the water solubility value (40 

ppm) for diazinon. Our laboratory adsorption experiments verify these findings, 

i.e. that the more water soluble the chemical, the less it is adsorbed onto 

the sediments. 

In summary, we have found significantly different insecticide 

residue concentrations in soil, suspended sediment, bed load and bed material. 

We have noted the conversion on sediment of DDT to its less toxic metabolite 

DDD and also to DDE. And we suggest that we might have quite different 

environmental pollution with insecticides in the future - the sedimentassociated 

organochlorine insecticides settle into the bed material of bays 

when a stream enters the receiving lake, but the water-soluble organophosphorus 

insecticides which persist will continue on with the water to become widely 

distributed in the lake. 

70

1973 

June 26 

July 10 

August 14 

September 15 

October 2 

TABLE 1. 

INSECTICIDE RESIDUES IN BED MATERIAL AND BED LOAD, 

BIG CREEK, NORFOLK COUNTY, ONTARIO (PARTS PER BILLION) 

Total - DDT 

Bed Mat. Bed Load 

30 198 

26 45 

27 21 

35 100 

18 30 

Dieldrin 

Bed Mat. Bed Load 

1 6 

1 4 

2 1 

1 8 

1 2 

18 62 October 16

INTRODUCTION 


Pesticides and PCBs 

R. Frank 

Between 1974 and 1976 samples of suspended solids were collected 

at the river mouths of those watercourses on the Canadian side of the Great 

Lakes that del.ivered at least 0.5% of the water contributed to that lake by 

Canadian land drainage. The suspended solids were removed from stream water 

during the high flows in spring by centrifugation and freeze drying. The 

field work was carried out by staff of the Canada Centre for Inland Waters, 

under PLUARG study Task D. Many suspended solids have still to be 

analysed and the findings given herein must be treated as preliminary. 

RESULTS 

Around Lake Ontario 34 of 53 streams sampled were analysed for 

pesticides; along Lakes Erie and St. Clair the number was 14 of 24 streams; 

along Lake Huron it was 9 of 21 streams (1974), and 5 of 48 streams (1975), 

and along Lake Superior it was 5 of 45 streams. 

DDT and/or its metabolites were present in all samples. Mean 

residues in 1974 were 138 and 160 ppm in suspended solids entering Lakes 

Ontario and Huron, while in 1975 residues were considerably lower at 34.0, 

2.9 and 2.3 ppb, respectively, on suspended soljds entering Lakes Erie, St. 

Clair, Huron and Superior, In 1974 the largest component in the CDDT was the 

parent compound DDT, but in 1975 the largest component was DDE. 

Dieldrin was present in 50 and 9% of samples collected at river 

mouths along Lakes Ontario and Huron in 1974; these contained mean residues 

of 1.5 and 0.2 ppb respectively. All suspended solids entering Lakes Erie- 

St. Clair (1975) contained dieldrin; the mean residue being 3.6 ppb. Mean 

residues were 0.4 and 0.2 ppb dieldrin in solids entering Lakes Huron and 

Superior and were detected in 80% of samples. 

Endosulfan was present in 19% of suspended solids entering Lake 

Ontario (mean residue 2.3 ppb) but none entered Lake Huron in 1974. In 1975, 

endosulfan was present on 79%, 80% and 40% of suspended solids entering Lakes 

Erie - St. Clair, Huron and Superior; at the respective mean concentrations 

of 5.5, 0.8 and 0.4 ppb. 

Heptachlor epoxide and chlordane were not detected on suspended 

solids entering Lake Ontario or Lake Huron in 1974 to a limit of 0.5 ppb. 

Heptachlor epoxide was present in 50%, 40% and 20%, respectively, of suspended 

solids entering Lakes Erie - St. Clair, Huron and Superior in 1975. The 

respective mean residues were 1.2, 0.2 and

Organophosphorus insecticides were not found in any suspended 

solids over the two year period to a limit of 1-10 ppb. 

PCBs were present in all suspended solids over the 2-year period. 

The highest concentrations were in those entering Lake Ontario (194 ppb) and 

Lake Huron (84 ppb) in 1974. Mean concentrations were 60, 20 and 20 ppb, 

respectively, in 1975 in solids entering Lakes - Erie St. Clair, Huron and 

Superior. 

A few samples were analysed for HCB in 1974. Two of nine samples 

entering Lake Ontario contained HCB at 5 ppb. No HCB was found in two 

samples analysed from streams flowing into Lake Huron. 

There were enough samples in 1974 to analyse suspended solids 

entering Lake Ontario and Lake Huron for s-triazines. None of those streams 

flowing into Lake Huron contained s-triazines and 3 only of 34 contained 

detectable levels of s-triazines entering Lake Ontario. The mean residue 

of the 3 samples was 510 ppb. There was insufficient sample in 1975 to do 

s-triazine analyses and more sample is being obtained. 

A few streams in Lakes Ontario and Erie - St. Clair were sampled at 

monthly intervals throughout the year. Both IDDT and PCB varied greatly trom 

month-to-month. This was especially the case among suspended solids from 

streams entering Lake Ontario (1974). On the other hand the same parameters 

showed only small differences in 1975 from Lakes - St. Erie Clair and Huron. 

CONCLUSION CCMNTS 

This report is intended to be only preliminary and a more exact 

interpretation will have to await completion of analysis and calculations of 

actual amounts of pesticide and pollutants being carried to the Great Lakes 

by streams. 

14

U 

VI 

Table 1. Pesticides in Suspended Solids Collected at the Mouths of Rivers and Streams on the Canadian Side 

of the Great Lakes 

Contaminant 1 

Samples 

Analysed 

ZMT 

Dieldrin 

Endosulfan 

Hept. Epox. 

Chlordane 

PCB 

Ontario 

(1974) 

53 

34 

34 

138 

2-2380 

18 

1.5 

0-6 

6 

2.3 

0-35 

0 

0 

34 

194 

2-1800 

Erie 6 St. 

Lakes 

Clair Huron 

Superior 

(1975) 

(1974) (1975) (19 

24 

14 

14 

34 

1.1-115 

14 

3.6 

0.5-13.8 

11 

5.5 

0.0-18.3 

7 

1.2 

0.0-3.6 

12 

2.9 

0.0-20.0 

14 

60 

10-330 

21 

9 

8 

160 

0-1330 

1 

0.2 

0.0-2.0 

0 

- 

- 

0 

0 

9 

84 

20-370 

48 

5 

5 

2.9 

1.4-5.2 

4 

0.4 

0.0-1.5 

4 

0.8 

0-4.3 

2 

0.2 

0.0-0.6 

4 

0.8 

0.0-1.0 

'No organophosphorus insecticides found in any suspended solids. 

HCB present in 2 of 9 samples from L. Ontario - mean 1.1 ppb, range 0-5 ppb, absent in 2 samples from L. Huron. 

Atrazine in 3 of 34 samples in L. Ontario - mean 45 ppb, range 0-1110 ppb. No atrazine in 9 samples from L. Huron (1974). 

5 

20 

8-30 

5 

5 

2.3 

1.0-4.1 

4 

0.2 

0.0-0.4 

2 

0.4 

0.0-2.0 

1 

I 

TABLE 2. 

Lakes DDE TDE 

Lake Ontario (1974) 

Lake Huron (1974) 

Lake Huron (1975) 

COMPONENTS OF CDDT FOUND IN SUSPENDED SOLIDS COLLECTED 

AT THE MOUTHS OF RIVERS AND STREAMS ON THE CANADIAN SIDE OF THE 

GREAT LAKES 

Lakes Erie & St. Clair (1975) 

Lake Superior (1975) 

54 

38 

8.0 

1.4 

1.7 

76 

Content in suspended solids (ppb) 

20 

14 

6.4 

0.6 

0.5 

” 

OPDDT I P~DDT I CDDT

DISCUSSION 

Mr. J. CuZbertson: On the first half of the discussion, one of the tables 

indicated 59 and 62% of the insecticide was found on the sediment. How much 

sediment was this on? Did you determine the mass or surface area or Of Size 

these sediments? 

Dr. R. Miles: These are very low sediments, all less than 100 milligrams 

per litre. Some of them are very small, around 10 milligrams per litre. Does 

that answer your question? 

Mr. J. CuIbertson: The major point was, what was the mass of the material 

associated with this percent? 

Dr. R. Miles: I think I had that on one of the first slides, where we had 

parts per billion level of DDT on the suspended sediment, and I as say this 

suspended sediment was in the very low milligrams per litre. Now that table 

you asked about was the percent of the insecticide of whole the water sample 

that was absorbed on the sediment. We used the whole water sample in correlation 

with flow data that we have from Water of Survey Canada, and we 

actually measured the pounds of DDT. We calculated them out in weekly progression 

through the season and we have a paper on that with nutrients and 

insecticides from Big Creek that is in press. The weights are in grams per 

year, even some of the insecticides. It does not sound very dramatic, but 

the concentrations in the water in the streams are still greater than the 

recommendations by the EPA in the States. We have quantified them on the 

basis of the whole water samples or with the flow-data. 

Dr. E. GngZey: On the table where you showed the downstream increasing 

conversion of DDT to DDE and DDD this is, as I understand it, taken on the 

bed load or on the suspended solids fraction? I was not quite sure about 

that. 

Dr. I?. Miles: It was on the title as "Bed Material". That was bed material 

which we figured would take a considerable time work to down. It probably 

only gets moved during storm events, say, but we figured that the microorganisms 

in the bed material would have a longer period of work time on to 

the substrate as it moved downstream. 

Dr. E. Ongtey: Would it be correct to say that most of this would be asso- 

ciated with the fine fraction 

- the clay sized fraction? 

Dr. R. Miles: In Big Creek there is no real clay. Mostly gravel 1111 sand. 

The clay would come up in the Holland Marsh where there is a hea\ Idy

underlay under the bed material. It is a little difficult to characterize up 

there. The bottom mud does not get incorporated down with the clay. It 

forms its own bed material, the solid mass as opposed to the shifting bed 

load above that. 

Dr. E. Ongley: In your opinion we should not then perhaps restrict ourselves 

to looking at merely the fine sediment fraction, if we are looking at sediment 

quality, which is a statement that has been made earlier. 

Dr. R. Miles: Maybe I didn't make that point clear. The point of the bed 

load analyses was that the benthic fish and crustaceans are exposed to a 

higher concentration than you would appraise from a bed material analysis 

of the more permanent bed material. I think you can see, however, that there 

is a,considerable degradation and dilution from concentrations found in the 

soil. Also, with the large number of insecticides found in the soil, we are 

only finding a small proportion of them in the sediments. 

Dr. J. Weber: I have a comment. A lot of the grains of sand and coarser 

material are coated with fine clay particles and with fine organic substances. 

You can't really separate them. You may get a lot of the finer material 

associated with the coarser material in surface coverage. 

The question I have is that the analysis was on atrazine. 

This suggests that there is a lot of corn production. I was wondering if 

there was any soyabean production, if and so, had you analyzed for dinitroanilins? 

Dr. R. Frank: The only anilin that we have looked for is Arochlor. 

Dr. J. Weber: Arochlor would be an acid analid. I mean Trifluralin. 

Dr. R. Frank: No. 

Dr. J. Weber: The reason I ask is because I was also curious as to whether 

you had analyzed any of the sediments for some nitrosamine contaminants that 

have been found. 

Dr. R. Frank: One of the problems that we have been facing is that we only 

have five grams of sediment. Our first analysis is for the organochlorine 

group. If any sample is left we go to the triazine group. If any sample 

is still left we go to any other group. By then we have usually exhausted 

our sample. 

This is one of the problems we are up against. We need a 

system to obtain more sample. I understand that one would have to sit at the 

mouth of some of these streams for a month to get enough sample to do all the 

analyses. Perhaps Dr. Thomas could elaborate on this. 

70

Dr. H. Thomas: In order to investigate some of the points raised in this 

discussion, I should explain our procedures. We have gone up to the mouth of 

the Grand River with our sampling equipment. We sat there for eight hours, 

pumped some 4600 litres of water and recovered the solids. We have good 

recoveries of the solids in four size fractions. We have the associated 

water samples that we can supply for analysis. 

It is our intention to do more of this type of work. We want 

to fill in those samples where Dr. Frank did not have enough material. We 

intend to sample next spring (1977). 

The point that should be made is that we are not really 

discussing loadings in this context. We are having a look at concentrations 

of these materials, as they appear at the interface of the Lakes and rivers 

themselves. 

I think it is rather interesting if one looks at the organochlorines. 

We have done analyses on most of the residual samples from past 

sampling in the Great Lakes (Lake Erie, Lake St. Clair, Lake Ontario and 

presently Lake Huron. Lake Superior is yet to be done). This represents 

an enormous amount of work. 

Once you look at something that equates to a mass balance 

coming into, for example Lake Erie, one gets some shocks. Ralph Miles mentioned 

that in certain cases insecticides coming from these watersheds are 

in the grammes or kilogrammes range. Yet the amounts of these materials that 

are depositing in the open waters of the lakes are much higher and cannot be 

accounted for from these watersheds. When one looks at Lake Erie, the major 

impact is from the Detroit River. We know that there are not many pesticides 

or PCBs in Lake St. Clair. Yet once one looks at Western Lake Erie, the 

sediments are in terrible shape. Something is happening in that stretch of 

river that we have to investigate. It is a massive impact compared to a more 

minor impact from the watersheds themselves. 

Dr. R. Frank: I might just comment, that in the agricultural watersheds we 

are looking at a much wider range of parameters. We are not only doing that, 

but we are carrying field surveys to determine exactly how much material is 

going onto the land surface. Where we have a watershed that has got a big 

use of Trifluralin, we go back and look at the water in that watershed, 

instead of looking at it as monitoring and trying a to handle get on what is 

going on out there in the field and then trying to determine what is present. 

This is being done. 

Dr. J. Weber: If you took samples of the bottom deposits, has anyone sampled 

the concentration of the chemicals in the deposits with depth? You say DDT 

is decreasing with time, surely then, that means DDT the found deeper might 

be in higher concentrations, unless it is degraded and in that case you would 

find metabolites. 

Dr. R. Thomas: Well I think that is a function of the ability to sub-sample 

a sediment core with the resolution you are talking about. For example, in 

many lakes one centimetre would represent approximately 10 years of accumulation. 

You have to wait a long time to see any decline. But if you go back up 

through a core looking for PCBs, we have quite a nice picture in Lake Erie. 

It starts to appear quite strongly around 1955. 

79

Dr. H. Pionka: Were these sediments primarily organic? Were they very high 

in organic matter? 

Dr. I?. Thomas: We have measured total organic carbon in the suspended samples 

and I must confess I was very surprised indeed. I was anticipating high 

organic content. This is not the case. We are running up to orders of 7% 

organic carbon which is not high if you look in the Bay of Quinte in the Great 

Lakes. You are up over 20% organic carbon in samples from that area, so these 

are very low in organic matter. 

80

INTRODUCTION 

Anthropogenic Influences of Sediment Quality at a Source 

Nutrients: Carbon, Nitrogen and Phosphorus 

M. Miller 

Crop production practices have a marked influence on the amount of 

sediment eroding from farm fields. They may also have a marked influence on 

the nutrient concentration on the sediment either by altering the physical 

characteristics of the sediment or by altering the nutrient content of surface 

soil and hence of sediment. 

ALTERATIONS IN PHYSICAL CHARACTERISTICS OF SEDIMENT 

The erosion process is selective that in sediment generally contains 

a larger proportion of finer particles and organic matter than does the 

source soil. The nutrients carbon, nitrogen and phosphorus are in higher 

concentrations in the finer particles. This is demonstrated for phosphorus 

in Figure 1 in which the ratio of the phosphorus content of soil fractions to 

that of the total soil (P enrichment ratio) is related to the maximum particle 

size included in the fraction. The fact that the phosphorus enrichment 

in runoff sediment is related to enrichment in clay and organic matter content 

is also demonstrated in Table 1. 

Any management practice which tends to reduce the carrying capacity 

of the runoff water will tend to reduce the mean particle size of the sediment 

and hence will tend to increase the nutrient concentration on the sediment. 

Tillage practices can affect the runoff velocity through its effect on surface 

roughness, degree of incorporation of plant residues etc. Table 2 illustrates 

the effect of three tillage practices on the nutrient concentration in the 

sediment from simulated rainfall. 

Romkens, &. , (1973) states that "differences in the N and P 

concentrations in runoff sediment between tillage systems are primarily due 

to selective soil erosion.... Ridges across slope and/or corn residue on the 

soil surface act as sediment traps and natural barriers to surface runoff". 

Thus management practices which reduce sediment loss probably will 

not reduce the nutrient loss proportionately. 

ALTERATIONS IN NUTRIENT CONTENT OF SIRFACE SOIL AND HENCE OF SEDIMNT 

Carbon 

Crop production generally reduces the organic matter content of the 

surface soil. Because organic matter is critical in maintaining stable soil 

structure, a reduction leads to increased sediment loads in runoff from 

agricultural lands. 

81 

t

a2 

0 

m 

N 

Ln 

0 

N 

0

I 

Dependent Variable I 

TABLE 1 

PHOSPHORUS ENRICHMENT OF SEDIMENT FROM RUNOFF PLOTS 

AT GUELPH, ONTARIO AS A FUNCTION OF ENRICHMENT IN 

CLAY AND ORGANIC MATTER 

(6 EVENTS FROM 6 PLOTS - 1973-1975) 

Independent Variables I R2 

P Enrichment Clay Enrichment 

(Cl. Enrich. ) 

Org. Mat. Enrichment 

(Org. Mat. Enrich. ) 

0.61* 

0.64 

0.69 

0.70 

* R' - proportion of the variability in P enrichment accounted by for 

regression including this independent variable and all others 

preceding it in the table. 

Tillage 

Chisel 

Coulter 

Conventional 

TABLE 2 

EFFECT OF TILLAGE SYSTEM ON RUNOFF AND NUTRIENT 

CONTENT OF SEDIMENT 

(FROM ROMKENS. NELSON AND MANNERING, 1973) 

Runoff 

( cm) 

3.81 

4.39 

5.56 

1.68 

1.87 

24.74 

83 

I 1147 

2022 

1278 

616 

387 

308

Although it is difficult to increase the organic matter content of 

the surface soil on a sustained basis, temporary increases may occur from 

heavy applications of manure or sewage sludge, if they are not incorporated. 

Runoff from such fields would have a markedly higher carbon content, both in 

solution and in suspended particles during initial runoff events following 

application. Later runoff events would exhibit much lower differences as 

illustrated by the data in Table 3. 

Nitrogen 

Because nitrogen in soil is, for the most part, associated with the 

organic matter, the nitrogen and carbon contents of sediment will be closely 

related. Applications of fertilizer, manure or sewage sludge will temporarily 

increase the nitrogen content of surface soil. If these materials are applied 

to the soil surface during the late or fall winter and are not incorporated, 

the spring runoff will be appreciably higher in both dissolved and particulate 

nitrogen. If they are added at the times and rates most effective for crop 

production, there should be little increase in the nitrogen content of the 

runoff . 

Phosphorus 

The phosphorus content of the surface soil is modified by crop 

production practices to a much greater extent than either carbon or nitrogen. 

Most soils in the natural state are deficient in available phosphorus. 

Sustained production of high yielding crops requires that phosphorus be added 

to the soil to increase the available phosphorus level. This increases the 

total phosphorus content of the sediment and, perhaps more importantly it 

increases the labile phosphorus in particular. The influence of fertilizer 

phosphorus addition on the "extractable P" content of a soil is illustrated 

by the data in Table 4. 

Because phosphorus reacts in the soil to form only slightly soluble 

compounds, phosphorus applied to the surface is retained in the surface 1 to 

2 cm. thus increasing the available phosphorus content of this portion of the 

soil to a much greater extent than if the phosphorus were mixed throughout 

the plow layer (Table 5). 

The increase in "Extractable P" in the surface soil results in a 

similar increase in the "Extractable P" of the sediment and in the dissolved 

P concentration in the runoff water as illustrated by the data in 6, Tables 7 

and 8. 

The relation between dissolved P in runoff and the "Extractable P" 

in the sediment can be demonstrated €urther by data from runoff at plots 

Cuelph. For six runoff events from each of six plots during 1973-1975, 

"Extractable P" (0.5 N NaHC03) accounted for 55% of the variability in 

dissolved ortho-P in runoff. The data are plotted in Figure 2. It is 

apparent from Figure 2 that when manure is present on the surface, there is 

no relation between dissolved P and extractable P content on the sediment. 

However, in the absence of surface manure, the relationship is reasonably 

good. 

a4

I 

TABLE 3 

ORGANIC CARBON CONTENT OF SURFACE SOIL (0-1 CM) 

AND OF SEDIMENT FROM RUNOFF PLOTS AT GUELPH, ONTARIO 

%C 

Treatment Soil (0-1 cm) Sediment* 

No manure 1.78 2.52 

Manure** - on surface 1.98 2.77 

* Average of 9 runoff events 1973-1975 

** Applied each year since 1968 without incorporation 

TABLE 4 

THE INFLUENCE OF FERTILIZER P ADDITION ON "EXTRACTABLE P" 

CONTENT OF AN ONTARIO SOIL 

Fertilizer P Added 

(kg Plha17 yr) 

0 

75 

150 

300 

600 

* Extractable with 0.5N NaHCO 3' 

85 

"Extractable* P" 

(Pi? PIP) 

7 

9 

11 

20 

44

Depth 

( cm) 

0- 1 

1-2 

2- 3 

3- 4 

4-5 

5-7 

7-9 

9-11 

11-13 

13-15 

TABLE 5 

"EXTRACTABLE P" IN AN ONTARIO SOIL FOLLOWING 

YEARLY MANURE APPLICATIONS FOR 8 YEARS 

Manured 

Not incorporated 

110 

105 

95 

17 

63 

45 

31 

18 

17 

15 

* Extractable with 0.5 N NaHC03. 

TABLE 6 

Extractable P* 

Manured 

Plowed 

(Pg PIP) 

58 

52 

55 

47 

63 

68 

55 

65 

55 

45 

"EXTRACTABLE P" IN SOIL AND SEDIMENT AND DISSOLVED 

ORTHOPHOSPHATE CONTENT OF RUNOFF FROM PLOTS 

AT GUELPH, ONTARIO 

No 

Manure 

"Extractable P*" 

Soil (0-1 cm) Sediment** Dissolved** 

Ortho P in 

Treatment Range 

"-(~p/g) "- 

Manured - not incorporated 108 100-200 140 

Manured - plowed 57 50-95 63 

No manure 28 44-90 62 

* Extractable with 0.5 N NaHC03 

** Six storms 1973-1975. 

86 

(mgll) 

1.38 

0.56 

0.51 

28

I 

TABLE 7 

THE EFFECT OF PHOSPHORUS FERTILIZER APPLICATION ON 

"EXTRACTABLE P" IN SEDIMENT AND ON DISSOLVED ORTHOPHOSPHATE 

IN RUNOFF. (FROM ROMKENS AND NELSON - 1974) 

Extractable P* Dissolved Ortho P 

Fertilizer P Applied in Runoff in Sediment 

(kg/ha) (dg) 

(mg/U 

0 

56 

113 

14.6 

35.4 

57.6 

* Extractable by Bray P.l test (.03 N NHrF + .025 N HC1) 

TABLE 8 

0.07 

0.24 

0.44 

INFLUENCE OF METHOD OF FERTILIZER APPLICATION ON 

"EXTRACTABLE P" IN SEDIMENT (TIMMONS, BURWELL AND HOLT - 1973) 

Method of Application "Extractable PI'* in Sediment 

(VdP) 

No Fertilizer 

20 

Fertilized, plowed and disced 

20 

Plowed, fertilized and disced 

30 

85 Plowed, disced and fertilized 

* Extractable with Bray P. 1 test (.03 N NH4F + .025 N HC1) 

a7 

1

m 

2.0 

1.8 

1.6 

EL 

a - 1.2 

LC 

’c 

0 

c 

I 

.- 

c 0.8 

n. 

V 

al 

- 

2 0.4 

.- 

n 

0 

0. / 

a6b 

10 

0 

0 

0 

. 

1 

40 80 100 160 200 

Extractable P content of sediment 

(ppd 

0 

0 Surface Manure 

y = 0.029786~ - 0.000098~~ - 0.881201 

(r2 = 0.55) 

Figure 2: Relationship between NaHCO -extractable P of the sediment and dissolved P 

in the runoff at the exper?rnental plots in Guelph. 

0

From the above discussion it is apparent that application of 

phosphorus to soil will increase the labile P of the eroded sediment and also 

the dissolved orthophosphate of runoff water. However, when one attempts to 

relate dissolved orthophosphate in runoff to the Extractable P in the soil, 

the relationship is much less clear. The data presented in Figure 3 are from 

samples of runoff collected from farm fields in small two Ontario watersheds. 

The area in the field from which the runoff occurred was sampled and the 

"Extractable P" was determined. The data illustrates the marked effect of 

surface manure on the dissolved P levels. There is, however, no apparent 

relationship between dissolved P and extractable P in the soil, even when the 

samples from the manured fields are excluded. This is probably due, at least 

in part, to the variation from one runoff event to another in the degree of 

selectivity in the erosion process. The extractable P content will be greater 

in the finer soil particles. The degree of enrichment in clay and hence the 

enrichment of extractable P in the sediment will vary from one event to 

another as well as with management practices, it thus is not possible at this 

time to predict dissolved P in runoff directly from the extractable P level 

in surface soils. 

Profitable crop production requires that the available phosphorus 

level be increased in most soils which have not previously been fertilized. 

rhere is a level, however, above which no further economic increases in yield 

fill be obtained. This level varies from crop to crop. Generally, it is 

ligher for vegetable crops such as potatoes, and tomatoes, than for field 

:KO~S such as corn or barley. Thus soils that are used for vegetable crop 

xoduction are likely to have a higher available phosphorus content than are 

rhose used for field crop production. This is illustrated by data in Table 

3. 

There are a number of soil tests that can be used to determine the 

available phosphorus content of the soil and hence the fertilizer required 

€01- most profitable yield levels. They provide an effective tool to maintain 

the available phosphorus content of the soil at, but not above, the optimum 

level. This will assure continued production of high yielding crops while 

ninimizing the dissolved and total phosphorus content of runoff from agricultural 

fields. 

We must accept the fact that applications of nitrogen and phosphorus 

are essential to sustained production of profitable yeilds. To minimize the 

effects of these applications on the nitrogen and phosphorus content of 

runoff water we must improve our understanding of the nitrogen and phosphorus 

requirement of major crops and of fate the of nitrogen, particularly. when 

applied to the soil. This would allow us to better match the nutrient content 

of the soil to the needs of the crop, thus avoiding unnecessary levels 

in the soil and in runoff. 

We must also develop management systems which permit incorporation 

of manure and fertilizer into the soil rather than leaving them on the surface 

where they are much more subject to the erosional processes. 

a9

90 

w 1- 

I: 

00 

N U 

x c 

" C 

0 2 P 

0 

" C 

n a 

m a 

u 3 

L L m 

I 

al 

0 

0 

M O L 

I 

0 

0 % c 

r a 

a x 

U 

V I L 

c 

0 

- + .- c 

o m 

'c 

0 

0 

al 

a 

C 

m 

r 

al 

U 

m 

'c 

L 

3 

m

TABLE 9 

"EXTRACTABLE P"* LEVELS IN ONTARIO SOILS 

IN RELATION TO CROP GROWN 

Crop Optimum Extractable P** 

Average Extractable P*** 

Mixed grain 

Corn 

Tobacco 

Potatoes 

Soybeans 

Tomatoes 

(Llg/g) (ug/g) 

14 

20 

115 

60 

15 

60 

1 1 

* Extractable with 0.5 N NaHCO 3 

** Test beyond which no further P required 

*** Samples submitted to Ontario Soil Testing Laboratory. July 1, 1974 - 

June 30, 1975 

91 

I 

12 

18 

64 

41 

18 

34

I, TTEM TUHE Cl TED 

Romkens, M. J. M., D. W. Nelson and J. V. Mannering, 1973. 

Nitrogen and Phosphorus Composition of Surface Runoff as 

Affected by Tillage Method, J. Envir. Qual., 2, 292-295. 

Romkens, M. J. M., and D. W. Nelson, 1974. Phosphorus Relation- 

ships in Runoff from Fertilized Soils, J. Envir. Qual., 

- 3, 10-13. 

Timmons, D. R., R. E. Burwell and R. F. Holt, 1973. Nitrogen 

and Phosphorus Losses in Surface Runoff from Agricultural 

Land as Influenced by Placement of Broadcast Fertilizer, 

Water Res. Research, 9, 658-667. 

92

DISCUSSION 

DP. 7'. Logan: I would like to make a comment. The comment is that I think 

we have to be very careful about the emphasis we on put soluble phosphorus 

values coming off small watersheds or plots. We have to keep in mind that 

the adsorption reaction of phosphorus on sediment is a very rapid process. 

I have been doing some thinking on this regarding some of those soils that 

are high in available phosphorus. There are some possibilities that may 

be happening. One possibility is that on those soils that have appreciable 

available phosphorus, we might be seeing for example dicalcium phosphate 

that will be dissolved as we get a dilution during the runoff process. 

This will produce some of the soluble phosphorus that you are seeing. On 

looking downstream, you may see a readsorption phenomenon. 

Dr. 7'. Dickinson: You mentioned looking ahead to suggestions for remedial 

work, that one might be able to improve communication systems to get people 

to use better fertilizer amounts on their fields. 

Carrying this a step further, might it be realistic that 

in situations where one is applying manure or sludge, things that release 

nutrients more rapidly into surface runoff water, that it may be that in 

certain parts of watersheds there may be fields that are not very directly 

connected to the drainage and microdrainage system. There are fields that 

for only brief periods of the year might have runoff going into the drainage 

systems. In areas like that it might be very safe to carry on certain kinds 

of practices. There might be more opportunities to use a variety of management 

practices to be safer. On the other hand there may be parts of a 

drainage system near the main channel or very close to connected drainage 

systems where the management practices that would be allowable would be 

very restricted. In other words, one would have to be much more restrictive 

there. We mentioned that when you start differentiating between management 

practices on a watershed basis rather than just on a crop basis, there are 

going to be some problems telling the farmer over here that he can do these 

things and the farmer over here that he cannot. I see that as a possible 

way of looking to remedial measures not on just a crop basis or a soil 

basis, but even on a watershed basis and how that watershed may be receiving 

things downstream. 

Dr. M. MiZZer: Certainly in terms of fertilizer use we do use and apparently 

need to use much more phosphorus on some crops. We have to build the soil 

phosphate level up to much higher levels on some crops than others. If you 

could control the production of crops to those certain areas, it would help. 

I think that will be a major undertaking. 

93


Metals 

G. K. Rutherford 

Erosion and sedimentation are natural, usually gentle, processes 

releasing controlled amounts of sediments to receiving waterbodies. Anthropogenic 

activities have burst into this process and caused far-reaching and 

mostly detrimental environmental changes, the extent of which has not yet 

been fully appreciated. 

Whereas the soluble ionic transport of chemicals is perhaps the 

most insidious and dangerous, the object of this paper is show to the myriads 

of ways in which sediment transported materials are damaging to our of way 

life. In particular I will emphasize the so-called heavy metals. 

BASIC ~TERIALS 

As most suspended particles have been soil materials in the 

immediate past, it would seem appropriate to consider some of the basic 

properties of soil materials. 

Soils consist of: (i) skeleton grains which form the virtually 

stable skeleton and are generally immobile and unreactive; (ii) plasma 

or the fine reactive and mobile parts; (iii) voids or the holes in the 

soil and (iv) water and e. Although plasma is considered to be the 

only solid material which moves intact through soil, the both plasma and 

skeleton may be elements in sediment transportation. 

The plasma is generally considered to consist of particles less 

than 2u in minimum dimension the and skeleton greater than 2U but in reality 

the upper size is about lop. In other words the plasma consists mainly of 

COLLOIDAL MATERIALS or materials possessing the properties of colloids - 

i.e. HAVING SURFACE CHARGES, usually negative. Not only the INORGANIC 

materials derived from rocks but also ORGANIC materials derived from the 

destructive microbial breakdown of formerly living organisms exhibit these 

properties. Virtually all finely comminuted materials of colloidal size 

possess, to some degree, this electric charge and strangely enough, 

amorphous materials both organic and inorganic appear to have the highest 

charges. The total charge, usually measured as ability to hold positively 

charged cations, is known as the CATION EXCHANGE CAPACITY and is this a 

specific property of each known compound and of major importance in the 

understanding of heavy metal transport in suspension. 

Soil materials, measured using conventional methods, exhibit a 

marked total positive electric charge although it has long been known that 

negative anions may be held or ADSORBED by soil materials. During the 

last 125 years many theories to explain this phenomenon have been put 

95

forward. Since about 1940, the theoretical background to anion holding 

processes has been modestly researched but since 1960 and particularly 

1970 the anion adsorbing powers of soils is attracting a wider circle of 

interested workers and a new pattern of thinking appears to be developing. 

Soil materials art said to have the property of IONIC EXCHANGE: 

in other words the adsorbed ions may be exchanged by other ions and there 

appear to be three major criteria determining if an ion will be held or 

exchanged on a colloidal body. Most heavy metals go into solution as 

individual cations, complex anions, or cations in a variety of forms. 

These parameters are generally considered to be: ionic charge, ionic radius 

and degree of hydration. Thus, in soils, cations tend to be bonded by van 

der Waals-type forces to the "parent" colloid whilst anions generally are 

more labile and move through and out of the soil body with drainage waters. 

The concentrations of POb, SOq, NOJ and C1 in lake and other water bodies, 

the causes of eutrophication, are a direct result of this. 

SOIL FORMING PFWESSES 

If, indeed, sediments have passed through a soil stage it is 

then appropriate to examine briefly the ramifications of soil forming 

processes for sedimentary reactions. Amongst other things, the soil 

forming processes tend to: 

(a) produce finer inorganic and organic particles - i.e. more 

colloids; 

(b) form neoformations. 

(i) Inorganic. These are formed by the association of ions in solution 

to form a new insoluble material: 

2M + xSi + yo -f [M Six OY]- gives new silicate minerals or 

z J 

more simply Mg + Ca + Cor + CaMgC03. 

If these new formations are of colloidal dimensions they will acquire a 

negative charge. However there is a very important exception to this and 

that is the sesquioxides: 

Fe + OH [Fe(OH) 31' 

or A1 + OH 

4 

(Al(0H) 31' 

4 

and there are all manner of variations over the above theme inasmuch as 

the final product may have a very variable composition. The same process 

involves such elements as Mn, Cr and V. These neoformations, particularly 

in the case of Fe, give soil its characteristic range of colours from the 

tropics to the Arctic. The sesquioxide neoformations are characteristically 

POSITIVELY charged and amorphous in nature when formed. With the passage 

of time, these become crystalline and change their charge slowly to negative 

and may become quite strongly negatively charged. The origin of this 

negative charge in soils is thoroughly explored and known. The process of 

positive adsorption on to silicate colloids is still largely speculative. 

96

(ii) Organic. The soil forming processes tend to destroy recently dead 

plant and animal tissue and form, amongst other things, strongly complexed 

compounds with metallic cations. The chelates with EDTA* are perhaps the 

best known and understood and occur in ionic and colloidal dimensions. 

These compounds commonly enhance the passage of elements such as Zn, Cu, 

Fe through soils and are said to SEQUESTER these elements. When these 

organic compounds are broken down by microbial attack the metals become 

available for recomplexing or precipitation. In the sequestering process 

the metal may simply be enmeshed or surrounded by the rest of the longchain 

molecule(s). 

(iii) Weak combination bonding. In the generation of neoformations some 

metal cations by virtue of size, charge or hydration may be "dragged" 

(seduced?) into a loose association with another compound such as iron 

hydroxide (oxide). Although this bonding may be loose, the heavy metal 

elements are strongly occluded into the newly formed compound. Our colleagues 

in exploration geochemistry called this SCAVENGING. Whereas the 

process is by no means as simple as I have implied, it is extremely 

important in the concentration of many elements in compounds of other 

elements. The examples of Cr and Co although at different ends of the 

scale are essentially similar. The concentration of Cr in laterites is 

thought to be due to this process. 

In order to understand the concern about heavy metals, reference 

must be made to the nutrition of animals and plants. N, P, K are known as 

MACRONUTRIENTS and must be fed to plants at the rate kg/ha; of 1 Ca, and 

Mg are intermediate whilst Zn, Co, Cu, I, F, B, etc., are the so called 

trace or MICRONUTRIENTS and are fed to plants as g/ha. The heavy metals 

fall in the micronutrient category and many of these are essential for 

plant, animal and human growth. What is one group's food is another group's 

poison. Some trace elements are essential for plant growth in general whilst 

these may not all be essential for human growth and vice versa. Na is a 

good example of one of these. The trace (heavy) metals are essential for 

one or many metabolic functions in plants and/or animals. Fe is essential 

for blood formation, Mg is needed for chlorophyll, is V part of cholesterol 

synthesis and Cr is needed for glucose synthesis. Deficiency in B causes 

cauliflower to malform and deficiency of Mo inhibits the nitrogen fixing 

bacteria, causes white muscle disease in fowls and probably plays a role 

in multiple sclerosis in humans. 

It is a common understanding that deficiency diseases are a 

function of a lack of a nutrient in the growth medium, however, it is 

equally likely to be a function of ION ANTAGONISM by which process the 

excess of one element may cause a deficiency of another. Zn appears to be 

antagonistic (and vice versa) to Ca, Cu, Se and Cd so that excess amounts 

of this element in industrial waste waters will cause deficiency diseases 

associated with the other elements. Vegetables in British Columbia in the 

same area showed differences of element content of 500 up to times, showing 

extreme differences in microenvironmental conditions. 

* Ethylene diamine tetra-acetate

Low pH in soils may cause AI, which is normally very stable 

geochemically, to go into solution. At a pH less than 3 one is measuring 

pAl rather than pH. A1 is extremely poisonous to plants and animals as 

witnessed by the failure of jute in Guyana. 

If heavy metals are transported by sediments and deposited by 

irrigation waters, as flood waters, in channel and stream bottoms, it is 

not unlikely that the new environment may give rise to conditions which 

divorce the element from its parent sediment and allow it to circulate in 

soil or plant nutrient solution where its ramifications and mischief may 

be far-reaching. 

ANTHROPOGENIC SCURCES OF HEAVY METALS (AND PROCESSES AFFECTING THEIR 

DISTRIBUTION IN SEDIMENT TRANSPORT) 

Some of the major sources of pollutants and their relationship 

to sediment transport will now be briefly discussed. The role of the 

transport medium and the special influence of the source will be brought 

out. The following man-sponsored sources of environmental pollution are 

perhaps the best known. 

Sewage, sludge and effluent. (Human metabolic processes) 

Animal metabolic processes. 

Domestic waste disposal. 

Industrial waste disposal. 

Agricultural plant protection + fertilization. 

Urban expansion. 

Industrial extraction processes; Smelting and Mining. 

Precipitation. 

Automobiles. 

Case study - Mercury. 

Human metabolic processes. The greatest uptake of heavy metals in 

the human intestine occurs at the end of the alimentary tract. The 

metabolic need for these is quite low hence human feces tend to concen- 

trate these elements. In the sewage disposal process the more soluble 

elements (geochemically) such as N, P and K tend to be in solution in ' 

urine and the heavy metals attached as finely adsorbed organic colloids. 

In a secondary treatment plant much of this material and a of portion the 

soluble materials is precipitated out by the use of electrolytes. This 

SLUDGE is removed and not uncommonly used on agricultural land, primarily 

as a source of organic matter and P. In an untreated sewage system it is 

abundantly clear how effective sediment is in concentrating and carrying 

heavy metals. 

Sewage sludge has been shown to have many admirable properties 

for plant growth - a common limiting factor is the plugging of voids in 

the soil and the consequent increase in runoff which in turn results in 

re-entry to the waterways with sediment-borne pollutants. 

98

(b) Animal metabolic processes. The many stomach forms of the different 

domestic animals result in slight variations of the same effects as in 

(a) above but in general the same tendencies hold. The soil, and particularly 

soils with well developed A horizons have an admirable ability to 

adsorb and process animal manures of a carrying capacity 200 up times to 

that of common mixed-agriculture. However feed-lot agriculture is based 

on carrying capacities far higher than these. Many if not most feed lots 

are sited along or close to waterways. The surface soils soon become 

trodden and impermeable so that virtually all runoff from the lot empties 

into the waterway. Well fermented cattle manure from the ruminant stomach 

must provide about the best imaginable source of transportable sedimentborne 

heavy mineral pollutants. Most of the recorded fish kills are 

likely primarily and indirectly a function of excess dissolved nutrients. 

(c) Domestic waste disposal. Most domestic waste is still entered in the 

soil: in the case of incineration pyrolysis and other "refining" processes 

a treated product is still placed in earth materials. The many studies 

which have been done on the composition of municipal garbage show the 

extreme range of composition from place to place and even from day to day. 

However a great amount of heavy metals, in an unsuspected variety of 

forms, from additives to paper, tires and paint, through the agencies of 

microorganisms and decomposition processes may come into solution as 

simple or complex ions and gain access to the groundwater and become 

potential hazards. However, the passage and transport of these ions is 

affected by sediment transport under only two conditions: 

(i) when the entombing material is very coarse so that water may 

move relatively unimpeded through it, and 

(ii) during the process of infilling when the spoil material may 

be washed by rain or runoff, by sediment transport may remove 

certain heavy metal cations particularly in readily available 

form such as battery acid and metal pickling solutions. 

(d) Industrial waste disposal. Industrial waste disposal concerns industries 

which discard waste in: (i) liquid form or (ii) solid form. In 

general the same factors play their role in breakdown and transport as 

has been described above. Any industrial waste which carries finely 

divided materials, be it silicates or iron filings, will operate more or 

less as a colloidal system. The nature of the colloidal "host" will be 

the determining factor in how long and how effectively the heavy metal 

element is bound in sediment or is liberated. Host colloids which are 

broken down by organisms either in an oxidizing or reducing environment 

will liberate the heavy metal in a potentially hazardous form at an earlier 

stage than otherwise. 

Two host colloids worthy of note in this connection are: (i) 

tailings from ore refining processes and crushed products of coal, cement 

and (ii) fertilizer industries, although the same conditions will be 

obtained in any refining process which uses finely comminuted material. 

At Sudbury, for instance, The International Nickel Company 

produces some 35,000 tons of tailings per day which are fed into large 

tailings lakes. The average size of these tailings is about 3011 and thus

would have insignificant colloidal properties. Although the tailings are 

relatively high in some heavy metals they would not constitute a solution 

hazard should they accidently get into waterways. The surface mining of 

coal and indeed the crushing of deep-mined coal produces quantities of 

colloidal-sized, chemically neutral materials which are not uncommonly 

exposed to surface runoff waters. Not uncommonly, rock minerals in associated 

strata contain sulphides of Zn and other heavy metals. It is not inconceivable 

that the host colloidal materials may partake in the transport of heavy 

metals to some degree. Whereas there is an increasing volume of literature 

on the ionic solution of heavy metals from such sites, there is, at least 

to this author virtually no known literary material on the sediment transport 

of heavy metals from such areas. 

(e) Agricultural plant protection and fertilization. Most biocides are 

soluble and sprayed as solutions or, in fact, with colloidal suspensions 

such as oil or clay as the host colloids. .Those biocides which have a heavy 

metal as the primary killing agent or a host for a series of chlorohydrocarbons 

(anion), will be transported in erosional processes in the same manner 

as has been outlined earlier for other sources. The ease of microbial breakdown 

releasing the heavy metal will determine the degree of environmental 

hazard. Exchange relationships on inorganic colloids will be a similar 

deciding factor. 

Although N, P and K are the primary nutrients used in agriculture 

a series of "tailor-made" fertilizers are produced for many crops. Those 

fertilizers in which heavy metals are concentrated either intentionally or 

accidently during the manufacturing process will present potential hazards 

for waterways as a result of erosional activities. 

(f) Urban expansion. It has been convincingly shown that in many environments 

urban construction including highways, airports, etc., is the greatest 

source of sediment in waterways. As the A and B horizons are the major 

soil horizons exposed to erosion and as much of the land used for urban 

expansion has been prime agricultural land it is not unlikely that the 

eroded sediments carry significant amounts of adsorbed heavy metal cations 

bound to both organic and inorganic host colloids. As these sojl horizons 

are highest in potentially electropositive colloids it can be surmised 

that these sediments are highest in both complex and simple anions of 

heavy metals. 

As the area of urban roofs and asphalt parking lots steadily 

increases so must the colloid content of storm water runoff. In arid 

regions and in dry parts of the year in humid areas the fine dust content 

of cities increases strikingly. At the same time our affluent society 

has more careless spills of oils and solids which provide sources of heavy 

metals. 

(9) Industrial extraction processes. The smelting process if unchecked 

puts into the atmosphere SOz, N02, other similar gases and the stable 

oxides and sulphides of heavy metals as particulates. The latter fall to 

the soil surfaces or are swept down in the smoke plume at greater or 

lesser distances. For example, the concentration of these near the old 

smelter at Coniston is high, whilst the concentration from the 400 m new 

stack at neighbouring Sudbury is spread out a greater distance. Modern 

100

smelting methods helped by modern legislation have seemed to reduce the 

access of active particles to colloids for transport. The future danger 

will be more from dissolved ionic materials than from transported materials. 

However, in the past, the smoke plumes and precipitation killed vegetation 

and have bared the soil surface so that active erosion could take place. 

The less refined pollutants landing on the surface would be adsorbed first 

to organic colloids and transported by waterways. Cation exchange processes 

may then obtain and cause heavy metal cations to become available as 

poisons or growth inhibitors. 

(h) Precipitatg. Although precipitation has long been known to be far 

from pure near cities and industrial areas it only is recently that detailed 

studies of the amounts of metals being deposited have been undertaken. It 

is perhaps in Norway that the most prolific information is available. In 

recent years, pollution from rainfall has driven salmon and trout from 

most rivers in the south of the country. The primary effects of this 

precipitation in most places in North America will be found in solution in 

rivers and streams and in vegetation changes. This factor, although 

important, will have little apparent influence on sediment transportation. 

However in more arid regions with marked dry seasons, this precipitation 

factor may play an important if not critical role due to heavy metal 

transpcrtatior, ty sediments. 

(i) Automobiles. The addition of lead tetraethyl as an antiknock compound 

in gasoline has occurred since the early 1930's. A great deal of research 

has been done on soils and vegetation along highways. Most of the research 

has produced a self-evident result -- the soils are high in adsorbed lead. 

Notwithstanding the possible high lead contents of vegetables, this lead 

has remained rather stable. Only when road extensions and widening take 

place does erosion remove the lead adsorbed on colloids. Two other previously 

unconsidered elements are Cd and Zn in automobile tires: both elements have 

been found in conspicuously high amounts near highways. The extensive use 

of de-icing salts may cause cation exchange reactions which liberate, temporarily 

at least, these three elements in ionic form. Lubrication oils have 

also been found to have significant amounts of both Cd Zn. and 

FUTURE RESEARCH NEEDS 

Naturally my suggestions will be chauvanistic. However in 

addition to the present data collecting research efforts which must continue, 

I would submit that the following are worthy of support. 

1. The nature, species and charge properties of suspension 

transported colloids. 

2. Phase relationships between adsorbed and solution ions in stream 

channels. 

3. The nature of the heavy metals and all ions being transported 

by sediments. 

4. Laboratory studies on negative (anionic) adsorption. 

101

May I, finally, have the temerity to suggest two future events are 

worthy of your interest which may affect your research efforts: 

1. Climatic change. There is a considerable volume of evidence to 

suggest that we may be approaching a period where almost violent climatic 

fluctuations may be the norm rather than the exception. This will present 

a whole new range of demands on the knowledge and experience of our sedimentologists. 

?.. How much longer can the strained soil colloids surrounding commercial, 

industrial and domestic garbage dumps continue with their life saving 

ionic exchange without being totally clogged? Many of these dumps are 

perched precariously near water bodies. 

REFERENCE LIST 

- A. Some Appropriate Texts 

Soil Conditions and Plant Growth, E. W. Russell, 10th Edition 

Longmans, London, (1973). 

Non-Agricultural Applications of Soil Surveys, R. W. Simonson, 

Elsevier, (1974). 

Trace Elements in the Environment, E. ,L. Kothny, American Chemical 

Society, (1973). 

Cleaning Our Environment - The Chemical Basis for Action, 

F. A. Long, American Chemical Society, (1969). 

The Natural Environment: Wastes and Control, R. F. Christian 

4.. Goodyear Pub. Co., Pacific Palisades California, 

(1973). 

Micronutrients in Agriculture, J. J. Mortvedc &., American 

Society of Agronomy, (1972). 

Organic Substances in the Environment I & 11, M. Schnitzel, 

Marcel Dekker, N. Y., (1972). 

Cleaning Our Environment - The Chemical Basis for Action, (ed.), 

F. A. Long, American Chemical Society, (1969). 

Vaxtekologi, M. G. Stalfelt, Svenske Bokforlaget, Stockholm. 

- B. Symposia and Conferences 

Trace Substances in Environmental Health, University of Missouri 

I (1967) 

I1 (1968) 

111 (1969) 

IV (1970) 

Agricultural Pollution of the Great Lakes Basin, - Water EPA Quality 

Office, 13028-C7/71, US Govt. Printer 

102

'The Chemical Investigation of Recent Lake Sediments from Wisconsin 

and their Interpretation, US EPA Water Pollution Control Series, 

16010EHR03/71. 

Second Research and Applied Technology Symposium on Mined-land 

Reclamation, National Coal Board, Kentucky, (1974). 

Environmental Protection in Surface Mining of Coal, US EPA 

Environmental Protection, Technology Series, EPA - 

670/2/74-093. 

Processes, Procedures and Methods to Control Pollution from 

Mining Activities, US EPA, 430/9.73.011. 

Land For Waste Management, (ed.), B.P. Warkentin, National Research 

Council, Ottawa, (1974). 

Municipal Waste Disposal - Problem or Opportunity, Ontario Economic 

Council, Toronto, (1971). 

Solid W&tes - 11, (ed.)., S. S. Miller, American Chemical Society, 

(1973). 

Wastes - Solids, Liquids and Gases, Chemical Publishing Co., 

N.Y., (1974). 

Canada - Ontario Agreement on Great Lakes Water Quality: 

Research Report No. 2 Sludge Handling and Disposal Seminar, (1974) 

3 High Quality Effluents Seminar, (1976). 

28 Removal of Phosphates and Metals from 

Sewage Sludge, (1973). 

30 Heavy Metals in Agricultural Lands Receiving 

Chemical Sewage Sludges, (1975). 

33 The Removal and Recovery of Metals from 

Sludge and Sludge Incinerator Ash, (1976). 

35 Land Disposal of Sewage Sludge, Vol. 111, 

(1976). 

38 The Harvest of Biological Production as a 

Means of Improving Effluents from Sewage 

Lagoons, (1976). 

Subsurface of Disposal of Waste in Canada 111, R. 0. van Everdingen, 

Environment Canada Technical Bulletin 82, (1974). 

Soils in Environmental Protection, B. C. Dept. of Agriculture, 5th 

B. C. Soil Science Workshop Report, (1975). 

First Symposium on Mine and Preparation Plant Refuse Disposal, 

Coal and the Environment Technical Conference, Kentucky, (1974). 

Sediment in a Michigan Trout Stream, USDA Forest Service 

NC-59, (1971). 

Fish Kills Caused by Pollution In 1972, US EPA 440/9-73-001, 

(1973). 

103

Analyse av organiske mikroforurensninger i nedbdr, G. Lunde og 

Jdrgen Gether, SNSF Project, (ed.), F Braekke, Oslo, (1974). 

Avsyring av sure vann, A. Henriksen og M. Johannessen, SNSF 

Project IR5/75, (1975). (A literary review of acid precipitation). 

104

INTRODUCTION 

Regional Overview of the Impact of Land on Use Water Quality 

A. 1). MeEZroy 

Midwest Research Institute was given the task in mid 1974 of 

conducting a national assessment of nonpoint source pollution for the 

U.S. Environmental Protection Agency. The program had two phases. In 

Phase I, loading functions for estimation of nonpoint pollution loadings 

were developed. In Phase 11, these functions were employed to calculate 

pollutant loadings on a national basis. The loadings were calculated 

and reported for minor basins, major basins, the 48 states, and the 

continental United States. In addition, loadings were aggregated for 

each of the 10 federal (EPA) regions. 

We were asked to develop loading functions based on "available" 

data. This meant generally that the more sophisticated models under 

development were not appropriate, since these usually require very 

detailed information which is not available to the user. Further, such 

models require a sophistication in use which usually is beyond the 

capabilities of the personnel involved in nonpoint planning and to whom 

the functions were directed. 

A further constraint consisted of, in most cases, steering clear 

of determining the impacts of nonpoint pollution on water quality. We 

thus estimated delivered loads, but did not estimate the resultant impacts 

on water quality. It goes without saying that this represents a major 

void which must be fiiled if we are to develop a good picture of the 

impacts oE nonpoint pollution. 

PROGRAM DESCRIPTION 

The program included analysis of natural background nonpoint pollution, 

i.e., pollution obtained in the absence of modern man's influences. 

One can readily appreciate that such a state is not to easy define, nor is 

it a simple matter to develop natural or background loadings which can be 

rigorously defended. Nevertheless, activities in this area have yielded 

results which are interesting and one of the most informative comparisons 

involves background and the present disturbed state. 

The loading functions developed and used on the program relied 

heavily on soil loss from erosion as a building block. Soil loss can 

be described and estimated with reasonable accuracy by existing equations, 

for which a large body of data is in existence. If one assumes that bulk 

loadings (or total loadings) of nitrogen, phosphorus, and organic matter 

can be relatcd simply to soil concentrations of these pollutants, then 

105

one has a fairly powerful tool for calculating loads of ROD, total 

nitrogen, and total phosphorus from major nonpoint sources. This approach 

begins to fail (or lw less accurate) when eroded sediment is relatively 

minor, as in well managed forests or grasslands, particularly for soluble 

forms of nitrogen. The soil loss equations are also a powerful tool for 

estimating loads of heavy metals delivered in sediments. 

Other approarhes are required for numerous other sources, snch as 

feedlot runoff, leachnte from solid waste disposal, mine drainage, irrign- 

t ion return flow, and urban runoff. The paper will briefly present the 

approaches which were taken for such cases. 

I'he paper will, however, deal principally with thr results of 

the assessment, rather than on methods for calculating loads. As indicated 

above, the assessment was made for minor basins, major basins, and tlle 

48 sL:ites. :md has been summarized by region. Data will be presented 

which depict land use hy state and pollutant loads by state. Similar 

presentations will also be made for land 

10 federal regions. 

use and pollutant loads by the 

DISCUSSION OF RESULTS 

Onr of the most usrtul comparisons involves loads from an acre of a 

particular source. Some comparisons follow. Acre load of phosphorus from 

a background condition, averaged for the 10 regions, vary from about 0.2 

lb/acre/year to about 6 lb/acre/year. Loads from forests are about the 

same as background in regions which were heavily forested in the naturcil 

state, and are as little as about 15% of hackground in regions which we're 

sparsely forested in the natural state. Acre loads of phosphorus f1om 

cropland range from about L to 20 times tuckground with the greatest 

relative increases occt~rring in regions heavily forested in Lhe nat~~ral 

state. In arid and semi-arid regions where cropland is chiefly irrigdtt'd, 

cropland represents an improvement over background. Pasture and range 

acre loads are 1.5 to 2 times background in Regions VI-IX, and 3 tll 20 

times background in Regions I-V and X. Feedlots (no control assumed) 

give calculated acre loads ranging from about 20 to 2,000 times back$l,round. 

Uncontrolled feedlots are clearly less of an insult in both relativv md 

absolute terms in semi-arid regions of the country. Urban runoff c

impacts occur when a natural condition in a high rainfall area is 

extensively disturbed (as in construction) and that the same activity can 

have a small relative impact in arid and semi-arid regions. 

CONCLUSIONS 

Conclusions generally supported by the results are as follows: 

* It is immediately apparent that loads of sediment, nutrient 

elements, and BOD are proportional, as one might predict, to 

the extent that land has been converted from its natural 

state to a highly disturbed state. Agriculture is the 

predominant "disturbed" state, and thus in gross or overall 

terms is the predominant influence on nonpoint source emissions. 

X Comparisons of background loadings with as-is loadings show 

clearly that the greatest relative impact of man's activities 

occurs in parts of the country which were relatively nonpclluting 

in the natural state due to the existence of an 

excellent ground cover of grasses and forests, but which are 

by reason of climate and terrain highly productive agricultural 

lands. The corn belt accordingly has suffered the greatest 

__- relative increase in nonpoint pollution compared to background. 

This overall effect would appear to reflect the relatively high 

overall complex of man's activities in such regions, i.e., 

urbanization and industrialization as well as utilization for 

agriculture. 

* Total loadings tend to be high in regions which are extensively 

committed to agriculture even though rainfall requirements for 

agriculture are somewhat marginal, i.e., the Great Plains, but 

the relative impact of man's activities (increase over background) 

is less in such regions because the "natural" state is 

more polluting than the natural state in higher rainfall areas. 

* As one proceeds to the arid- semi-arid regions (the West and 

Southwest) man's activities tend to have a positive effect 

(excluding secondary effects such as salinity in irrigation 

return flows), since these activities involve augmentation of 

rainfall and generation of improved ground cover conditions. 

'< While silviculture is a major land use, pollutant loadings 

on an overall basis are substantially less than for the other 

major land use--agriculture--because major land disturbances 

in silviculture are relatively minor in extent at any one 

time. However, the pollutant loadings from disturbed forest 

lands are high, and transitory local impacts are accordingly 

also high. 

* Construction, surface mining, small feedlots, and terrestrial 

disposal also turn out to be relatively minor in the overall 

sense, and the impacts would thus appear to be significant 

chiefly when viewed as localized impacts, which again can be 

quite high. 

107

+ National 

* Particularly noteworthy are regions in which man has endeavored 

to "use" land which has moderate to high rainfall and poor 

terrain. This effect is pronounced in the states such as 

Kentucky and Tennessee. 

* An i formative set of results was obtained in a study for 

P 

NCWQ in which effectiveness of pollution control in agriculture 

was estimated. The results demonstrate clearly that a relatively 

small proportion of land in agriculture is responsible 

for a significant fraction of the total load, and that benefits 

measured in terms of pollution reduction are fairly startling 

if this land is converted to uses which are judged to be "adequate" 

from a soil conservation standpoint. These results, together 

with other observations noted above, indicate that marginal 

land use is particularly critical from the environmental 

nonpoint source point of view. 

* Heavy metal loads delivered in eroded surficial soils and 

sediments are calculated to be major in quantity rather than 

"trace" as one might intuitively expect. We are not certain 

what lessons can be learned or what conclusions can be drawn. 

It is clearly evident that large quantities of heavy metals are 

delivered to surface waters, either from the natural or mandisturbed 

states of rural lands, and that these constitute a high 

background against which loads,from point sources should be 

viewed and interpreted. 

* The overall results of the assessment are rather crudely 

interpretable in terms of the basic physical/chemical characteristics 

of the land and water, and of climate. Perhaps the 

simplest example is mine drainage, which is a function of both 

the capacity of a region to generate acid and its capacity to 

neutralize the acid--the western coal mining regions have a 

high neutralizing capacity, while the eastern regions do not. 

Similarly, relationships between delivered loads of nutrients 

and BOD, and observed burdens of these same pollutants indicate 

that surface waters differ across the country in assimilative/ 

use capacities. The relative proportions of these pollutants 

further indicate that eutrophication processes can be expected 

to follow a fairly systematic trend one as proceeds from low 

rainfall to high rainfall regions. 

* Finally, it is usually true that nonpoint loads of pollutants 

are substantially in excess of in-stream burdens. One concludes 

that it is imperative that a better understanding be developed 

of the nature of assimilation of these pollutants, including 

adsorption on sediments or trapping out in sediments, equilibria 

between sediments and water, chemical and biology processes, 

and transport processes. 

Committee on Water Quality. 

108

U,S, EPA REGIONS 

I. Maine, Vermont, New Hampshire, Massachusetts, Connecticut, Rhode 

Island. 

11. New ‘fork, New Jersey 

111. Pennsylvania, Delaware, Virginia, West Virginia, Maryland 

IV. Kentucky, Tennessee, North and South Carolina, Georgia, Mississippi, 

Alabama, Florida 

V. Ohio, Illinois, Indiana, Michigan, Wisconsin, Minnesota 

VI. Arkansas, Louisiana, Oklahoma, Texas, New Mexico 

VII. Iowa, Kansas, Missouri, Nebraska 

VIII.Colorado, Montana, North and South Dakota, Utah, Wyoming 

IX. Arizona, California, Hawaii, Nevada 

X. Alaska, Idaho, Oregon, Washington 

109

DISCUSSION 

Dr. D. Huff: One of the things that I have been interested in, particularly 

in some of the earlier discussions this morning, is the direction that I heard 

people taking from the larger to the smaller process oriented kinds of studies. 

Certainly there is a lot of detail involved in those things, but in effect 

what you have done is to go the other way; trying to summarize on the basis of 

existing information what one can say about a very large area and, in particular, 

your last comments about things like coefficients for metabolism; say 

organic materials in the stream. On a large scale this may be something you 

might comment on. Perhaps you could be a little more specific about the 

kinds of things that you saw as needs at that scale. 

Dr. A. McEZroy: Well, I don't know that those particular needs are unique to 

a large scale. I think they apply to whatever scale you happen to be working 

at. I think we have probably seen some rather gross manifestations of what 

these problems are, that is differences between burdens and loads, one that 

does not account for very readily. We probably just illustrated or manifested 

these questions, and I would think for the large areas you have essentially 

the same need for this kind of information you as do for small areas. You 

need much more specific information, I suspect, for small areas because you 

are dealing with a much more specific situation which you want to monitor 

precisely, and you don't necessarily need the kind of detail that you would 

need if you were analyzing a larger area. 

Mr. J. CuZbertson: Please explain to me what an acre burden is. You have 

thrown in this term burden. I can't qujte understand that in the terms you 

have used. 

Dr. A. McEZroy: I should have defined it earlier. We define a burden as it 

relates to the actual quantity of a pollutant which is in a stream. We 

define that as a burden rather than a load for our purposes. In a sense it 

is not different from a load, but we made that distinction because, in what we 

call the stream-to-source methods, you start with what is a burden, or load 

if you wish to call it that, in the stream and you try to work backward to 

the source. When it got along the way we found that the loads that we 

calculated going from a source to a stream method were considerably larger, 

so we simply developed this distinction between a burden and a load. Burden 

refers to that quantity which actually exists in the stream as detected by 

sampling the water. In this case, we call it an acre burden. It is a quantity 

of pollutant which exists in a stream which we attribute to an acre of source, 

as opposed to an acre load which is that quantity which is delivered to a 

stream from an acre of source. 

111

Dr. D. Baker: For all of your loading calculations you use a delivery ratio, 

and I am wondering to what point you are delivering these loads when you are 

adding up data for counties, states or regions. 

Dr. A. MeElroy: We developed a delivery factor which is based on stream 

densities and upon soil textures and these delivery factors were developed on 

a land resource area. In other words, we did not develop delivery factors 

which were specific to a county; rather, we assigned a delivery factor for a 

big region to a county. We are reluctant to publish our county loads you 

might say, or to pass them out because they have values assigned to them in 

a number of cases which are typical of the region, but not necessarily 

specific to the county. 

Dr. D. Baker: As I recall your delivery ratio graphs, they are not a function 

of area anyway. They are more related to drainage density, which is area 

independent. I can't see how you can come up with a delivery ratio that isn't 

related to the area of the watershed. 

Dr. A. MeEZroy: Well, I'll see if I understand your question. If you happen 

to have the drainage density any in particular county, and the number of 

miles of stream per square mile for example, this essentially is a drainage 

density. If you have that figure for the county, then this would be essentially 

a drainage density which would in effect depict you for the average 

distance to the nearest permanent stream for that county. I should think 

in that case that it would be specific for that area. 

Dr. D. Huff: I think that what he is asking is "did you look at the total 

load delivered say at the outlet, wherever that is for the whole region, 

and then normalize that?" In other words, to get a per unit area you had to 

have an area to divide by. 

Dr.. A. McEZroy: Well as I said our basic unit for making the calculations 

was the county, however, we did use for specific sources, the acreages of the 

various categories of land use in that area. We would apply our delivery 

factor to whatever acreage we happened to come up with. I have a feeling you 

are not quite satisfied yet. 

Dr. 5'. Yaksieh: I notice you reported some of your data to 8 about significant 

figures. Do you really have that much confidence in it? 

UP. A. McElroy: It is hard to teach the computer to do otherwise. Heavens, 

no ! 

Dr. S. Yaksich: What type of error estimates would you place on the numbers 

you are producing? 

112

at2. (1. hI,-!'~rY,'~t; EPA asked us to develop error analysis for our loadings. 

We asked some of our people to do this and they said there were not enough 

statistics available. We did it and if you want to consider all the possible 

errors, they are quite large; say 50% if you want to consider enough factors. 

However, I think that without being able to prove it, generally we are 

talking about perhaps 202, and one of the reasons is that we are dealing 

with fairly large areas with a considerable amount of statistics which have 

been generated for these areas and I would rate them at about 20-25%. Now 

that is going to vary. For some of OUT pollutants from feed lots, for 

example, we used ranges of concentrations of pollutants in feed lot runoff 

which would range all the way from very nearly zero up to a couple of thousand, 

so pick a number in the middle of them. We had to For this kind of 

study. 

Dr. S. Yuksich: The reason why I asked is some of your loading functions 

were used by another study done by the National Commission on Water Quality 

in the Lake Erie drainage basin by Dalton, Dalton & Little. Some comparisons 

of the loadings that they got of total phosphorus coming into Lake Erie in 

comparison to the type of numbers that we generated from a stream sampling 

program at about 600 samples during the course of a year for each stream, 

showed their estimates were about double ours coming out of the streams. 

Dr. A. McBZroy: I guess I wouldn't expect the error to be that bad. You 

have to bear in mind that these are average numbers that we are using and any 

one particular year can be very much in deviation from an average year. This 

is one thing you need to take into consideration. I think that if you were 

to accept these loading functions in a sense that they are the average and if 

you are looking for an average condition, then probably they should for the 

most part be reasonably good. If you were to consider the deviation year to 

year and try to use an average number you might find out they would be 

considerably in error for a particular year.

Influence of Flow Characteristics on Sediment Transport 

with Emphasis on Grain Size and Mineralogy 

J. Culbertson 

The transport of sediment by water has been studied and documented 

since at least 1808 (Inter-Agency Committee on Water Resources, 1940). 

Although not documented, canal builders in India, Afghanistan, and other 

countries must have learned much about the subject (see Bibliography). 

All of those early studies were aimed at learning processes of sediment 

transport that related to the engineering aspects; that is, related to the 

building of structures and water-conveyance systems. Objectives wLre 

related mostly to determination and prediction of the volume of sediment 

being deposited in or removed from channel beds, or transported into 

reservoirs. Theoretical studies were related to the mass and volume of 

mineral sediments -- those sands and gravels that continuously to act 

change and modify river systems. 

Also, during the nineteenth century other engineers were studying 

the sanitary aspects of sedimentation as a result of demands for clear 

water piped to homes and sanitary sewer systems piped from homes. Their 

needs for knowledge also related more to mass and volume than anything 

else; however, they recognized that sediments were not all mineral. 

Environmental concerns over the past decade particularly, have made 

us more aware of the problem related to the sorption and transport of chemical 

constituents on sediments. With the recognition of this fact, sediment, very 

quickly was 1-abeled a pollutant. We now find that water chemists, aquatic 

biologists, sanitary engineers, geomorphologists, and sediment engineers 

must talk to each other - the one individual who can understand all of these 

different specialists calls himself or herself an environmentalist, or 

perhaps an ecologist. The purpose of this paper to is present a brief 

description of the processes that govern the transport of sediment by 

water. 

The term sediment must be defined in terms of current needs. 

Sediments (fluvial) are solid materials that have a specific gravity greater 

than 1.00 that will settle in a column of quiescent water due to the gravitational 

force. Sediments found in the fluvial environment can be either 

mineral or organic materials. Table 1 defines the kinds of materials, 

physical sizes of materials, and their general mode of transport in a 

flowing stream. 

11 7

TABLE 1 

KINDS OF MATERIALS 

Sediment Size Class Mode of Transport 

Boulders Larger than 256 m Bedload 

Cobbles 64-256 mm Bedload 

Gravel 2-64 TDUI Bedload 

Sand 0.062-2 UIU Bedload or Suspended 

Silt 0.004-0.062 UUU Suspended 

Clay 0.0002-0.004 TDUI Suspended 

Organic detritus 

Includes leaves, trees, 

biological remains, etc. 

Bedload or Suspended 

Biota Bedload or 

Includes bottom dwelling 

organisms 

NOTE: The size classes of mineral sediments shown are based on the 

Wentworth scale (Lane 5 &.. 1947). 

118

The mass of sediment being transported in suspension is called 

suspended load. The mass of sediment being transported in virtually 

continuous contact with the streambed is called bed load. The transport 

rate of suspended load is the suspended-sediment discharge, and the transport 

is expressed in terms of mass per unit time of (kilograms per second, 

megagrams per day, etc.). The range in size and specific gravity of 

sediments transported for both modes of transport is tremendous. 

The environmentalist faces a real problem in sorting out the 

definitions of terms that have been coined by the various disciplines over 

the years. Suspended sediment also is called suspended solids, nonfilterable 

solids, silt, turbidity, etc. Bedload materials are called bed material, 

bottom material, deposited sediment, benthic material. substrate, etc., 

depending on the background of the individual. The definition of "solution" 

also enters the picture. Solution is defined by most water chemists as 

the liquid that passes through a 0.45 Dm (micrometre) filter. By this 

definition, a solution can include particles that the engineering profession 

classifies as fine clay and colloids. 

Another problem that relates to measurement and definition of 

fluvial sediments is that there is a continuous interchange of some 

sizes of sediment between the streambed and &he streamflow. Sediments in 

suspension may settle into the bed mve and for some period of time as 

bed load, or they may remain at rest until moved back into suspension 

for another period of time. Even the very fine silts and clays are 

involved in this process, particularly in reaches of sand bedded streams 

where there is a loss of flow from the stream to the ground water system. 

Zn this situation, fine materials can infitrate the sand bed to a considerable 

depth. 

In order to standardize analytical methods, sedimentologists have 

related particle size of sediments to quartz spheres (Figure 1). One reason 

is that most mineral sediments carried by streamflow consist of roughly 92-98 

percent of particles having an average specific gravity 2.65. of Therefore 

2.65 is used to represent all sediment carried when computing sediment discharge. 

Sedimentation diameters are used to define size classes for fine sediments 

because of the relative ease of analytical techniques. Size, shape, specific 

gravity, and viscosity of the water effect the sedimentation rate, and a 

small, heavy grain may have the same mass and fall velocity as a larger quartz 

grain. 

Figure 2 illustrates the basic principles of sediment transport. 

The velocity with depth in the general case is illustrated. The resistance 

at the bed is caused by the drag of the liquid over the particles, and that 

drag and turbulence of the flow causes the bed materials to move along the 

bed or to jump into suspension for unpredictable periods. The upward velocity 

vector must overcome the gravitational force on a particle in order for it 

to remain in suspension. Turbulence is greatest near the bed; therefore, the 

coarsest particles are carried near the bed. Finer sediments, generally finer 

than 62 Dm (silt and clay size by definition), require little turbulence 

to maintain them in suspension, and therefore, are transported throughout 

the depth of flow in about the same concentration. Concentration is the term 

used to mean the mass of sediment per unit volume of the water-sediment mixture. 

The discharge rate of suspended sediment varies generally with depth as 

illustrated by the concentration variation with depth. 

119

In any given fluid at any temperature 

VfP VfP Vf s 

If SGp = SGs and VIP = VIS 

then D = SEDIMENTATION DIAMETER of particle. 

If in distilled water at 24°C. 

9 Tq P D 

then D ~ STANDARD SEDIMENTATION DIAMETER. 

vfpl vlp2 vlp3 VIS 

1- . I 

If Vfpl, Vfp2, Vfp3 7 VfS = STANDARD FALL VELOCITY 

then D = STANDARD FALL DIAMETER 

Figure 1. Relating standard sediment dimeters 

to diameter of quartz spheres. 

120

' I . 

Depth Velocity 

of 

Figure 2. Schematic diagram of velocity and suspended-sediment 

concentration distribution in a stream vertical 

121

122

c1 

N 

w 

mg/ 1 at surface = 880 935 910 91 5 91 0 860 

mean in vertical = 941 930 942 920 932 907 

DISTANCE. IN FEET 

Water discharge = 1280 cubic feet per second 

Mean velocity = 4.41 feet per second 

Median diameter of bed materlal = 0 33 rnm 

Figure 4. Distribution of silt and clay (finer than 0.062 mm) in cross 

section of Rio Crande conveyance channel near Bernardo, 

New Mexico

I- 

* 

N 

c 

W 

w 

LL 

z 

x 

I- 

a 

W 

0 

C mg/ 1 at surface = 640 770 690 880 660 350 

mean in vertical = 1220 1350 1400 1600 1420 1190 

DISTANCE, IN FEET

Figure 2 also illustrates the sampling problem. Currently available 

suspended-sediment samplers sample only to a point from about 0.3 to 0.5 feet 

above the bed. It is evident that these samplers do not sample that part of 

the flow carrying the greatest concentration of coarse particles. 

Figures 3, 4, and 5 illustrate data based on actual field measurements 

of velocity and suspended sediment made in the Rio Grande conveyance 

channel near Bernardo, New Mexico (Culbertson 5 &., 1972). The conveyance 

channel is straight and uniform for several thousand feet. Point 

velocities and point suspended-sediment samples were obtained at five 

points in each of six verticals in order to define the isovels and zones 

of equal concentration of various size classes of sediment. Concentration 

values shown are in mg/l (milligrams per litre). 

Velocity distribution (Figure 3 ) was found to be quite variable 

because of the roughness caused by the dune bed conflguration. Note the 

four distinct cells of high velocity in the cross section. Also, note 

the slower velocity along the right bank. 

The finer sediments (silts and clays) were distributed almost 

uniformly throughout the cross section (Figure 4 ). Concentrations of 

samples collected at the surface were almost the same as the mean concentration 

in each vertical; therefore, within the limits of accuracy 

obtainable in most laboratories, a sample collected almost anywhere in 

this cross section would be considered representative for this size 

range. 

Figure 5 illustrates the distribution of the coarse suspended 

sediment (sand). It is obvious that the sampling problem in this case is 

real. If one wishes to analyze a sample of the streamflow to determine 

either the mass of sediment being transported or the amount of sorbed 

constituents on the sediments, one must have a representative sample that 

contains representative masses of each size class of material. 

The preceding discussion has related only to the general case, 

and the instantaneous steady uniform flow condition. Time variation of 

sediment transport presents another problem. Figure 6 illustrates the 

general relation between water discharge and suspended-sediment discharge. 

For a given site, it is not uncommon to find a variation in suspendedsediment 

discharge of about 1.5 log units for any given water discharge. 

This variation is caused mostly by: (1) seasonal variations in availability 

of sediment; (2) snowmelt runoff versus thunderstorm runoff; (3) period 

between floods; (4) and the difference between turbulence characteristics 

on rising and falling stages. 

Figure 7 shows the typical variation of sediment concentration 

with time and discharge. The differences in concentrations for a given 

gage height (discharge) between the rising and falling stages can be 

noted. 

In summary, the variation in transport rates of sediment in streams 

is dependent upon the turbulent characteristics of the flow and the avail- 

ability, size, and specific gravity of sediment in the system. Sediments 

125

1 O( 

la 

1.0 

0.1 

WATER DISCHARGE (cfs) 

Figure 6. Direct runoff versus sediment discharge, by day, Pigeon Roost 

Creek Watershed 5, .January 1957-December 1960. After Piest 

(in Proceedings, 1963, p. 102).

can be transported either in suspension or as bed load; however, there can 

be a continuous interchange between the streamflow and the channel bed. 

The coarser sediments require more turbulence to maintain in them suspension, 

and therefore, are found in greater concentrations near the 

stream bed. Much greater care is required when sampling streams carrying 

coarse sediments (sands) in order to obtain a sample that represents the 

streamflow. 

The variability of sediment concentration with water discharge is 

great, and many samples may be required to define the suspended-sediment 

discharge during floods. Variability with time also is great, and 

samples must be obtained throughout the year to define sediment discharge 

variation due to changes in land use (availability) and seasonal effects. 

SELECTE3 LITERATURE 

Abbett, R. W., (1956). American Civil Engineering Practice. V.1, 

sec. 2(John Wiley). 

An Appraisal of Water Pollution in the Lake Superior Basin. FWPCA 

Great Lakes Adm.. April 1969. 

Anderscn, A. G., (1942). Distribution of Suspended Sediment in a 

Natural Stream, Am. Geophys. Union Trans., 2, (Pt. 21, 

678-683. 

A.S.T.M. Designation: C136-38T, (1938). Tentative Method of Test 

for Sieve Analysis of Fine and Coarse Aggregates, Proc., 

- 38-1, 808-810. 

Bagnold, R. A.. (1956). The Flow of Cohesionless Grains in Fluids, 

Royal So. (London) Philos. Trans., 249, 235-297. 

Bagnold, R. A., (1966). An Approach to the Sediment Transport Problem from 

General Physics, U.S. Geol. Survey Prof. Paper 422-1. 37 pp. 

Barthel, J. C., (1969). Pesticide Residues in Sediments of the Lower 

Mississippi River and its Tributaries. In: Pesticides Monitoring 

Jour., 3, (l), 8-66 

Barton, J. R., and Lin, Pin-Nam, (1955). A Study of the Sediment 

Transport in Alluvial Channels. Civil Eng. Dept., Colorado 

State Univ., Fort Collins, Colo.. 43 pp.. 21 figs., and appendix. 

Benedict. P. C.. Albertson, M. L., and Matejka, D. Q., (1955). 

Total Sediment Measurement in Turbulence Flume. Amer. SOC. 

Civil Engineers Trans., 120, 457-484. 

Bondurant, D. C., (1955). Report on Reservoir Delta Reconnaissance, 

Corps of Engineers, Missouri River Division Sediment Series 

Pub. No. 6. 

Borland, W. H.. and Miller, C. R.. (1958). Distribution of Sediment 

in Large Reservoirs, Am. SOC. Civil Engr.. Jour. Hyd. Div.. 

84, 1587. 

- 

128

Bormann, F. H., Likens, G. E., Eaton. J. S.. (1969). Biotic Regulation 

of Particulate and Solution Losses from a Forest Ecosystem. 

Bioscience, 19. (7), 600-610. 

Brown, H. E., Hansen, E. A., and Champagne, N. E., Jr., (1970). 

A System for Measuring Total-Sediment Yield from Small Water- 

sheds, Water Resources Research, 5, (31, 818-826. 

Burrell, G. N., (1951). Constant-Factor Method Aids Computation of 

Reservoir Sediment, Civil Engineering, 21. (7), 51-52 

Chia-Shun Shih, and Gloyne, E. F., (1969). Influence of Sediments 

on Transport of Solutes, Jour. Hyd. Div., 95. (HY4). 

Colby, B. R., and Hembree, C. H.. (1955). Computation of Total 

Sediment Discharge, Niobrara River near Cody, Nebr., U.S. 

Geol. Survey Water-Supply Paper 1357. 

Colby, B. R., (1956). Relationship of Sediment Discharge to Stream- 

flow, U.S. Geol. Survey, Open-File Report. 

Colby, B. R., (1957). Relationship of Unmeasured Sediment Discharge to 

Mean Velocity, her. Geophys. Union Trans., 2, (5), 

708-717. 

Colby, B. R., (1961). Effect of Depkh of Flow on Discharge of Bed Material. 

U.S. Geol. Survey Water-Supply Paper 1498-D. 12 pp. 

Colby, B. R., (1964). Discharge of Sands and Mean-Velocity Relationships 

in Sand-Bed Streams, U.S. Geol. Survey Prof. Paper 462-A, 

47 PP. 

Cook, H. L., (1935). Outline of the Energetics of Stream-Transporation 

of Solids, Am. Geophys. Union Trans., 16, (2), 456-463. 

Corps of Engineers, U.S. Army, (1961). Reservoir Sedimentation Invest- 

igations Program, Engineering Manual 1110-2-4000. 

Culbertson, J. K., Scott, C. H., and Bennett, J. P., (1972). Summary 

of Alluvial-Channel Data from Rio Grande Conveyance Channel, 

N. Mex., U.S. Geol. Survey Prof. Paper 562-.I., 49 pp. 

David, C., (1969). Sediment Radioactivity in the Columbia River Estuary, 

In Selected Water Resources Abs., 2, October 1, 1969, 32 pp. 

Davis, Foote, and Kelly, (1966). Surveying: Theory and Practice. 

Fifth edition, Chap. 30 (McGraw-Hill). 

Davis, Foote, and Kelly, (1964). Special Surveys: Dept. of Army Tech. Manual 

5-235. 

Dendy, F . E., and Champion, W. A ., (1969). Summary of Reservoir 

Sediment Deposition Surveys Made in the United States 'Illrough 

1965, USDA Misc. Pub. 1143.

fhkin, If. M. (rev. Brown, C. B.), (1939). Silting of Reservoirs, 

U.S. Dept. Agr. Tech. Bull. 524, 168 pp. 

Einstein, H. S., and Chien, Ning, (1953). Can the Rate of Wash Load 

be Predicted from the Bed-Load Function?, Am. Geophys. Union 

Trcllls. , E, 867-882. 

Einstein, H. S., (1950). The Bed-Load Function for Sediment Trans- 

portation in Open Channel Flows, U.S. Dept. Agr. Tech. 

Bull. 1026, 70 pp. 

Einstein, H. S., (1954). Second Approximation to the Solution of the 

Suspended Load theory, U.S. Corps Engineers, Missouri River Div. Sediment 

Ser. 3, 30 pp., 12 figs. 

Flammer, G. H., (1962). Ultrasonic Mmeasurement of Suspended Sediment, 

U.S. Geol. Survey Bull. 1141-A, 48 pp. 

Gilbert, G. K., (1914). Transportation of Debris by Running Water, 

U.S. Geol. Survey Prof. Paper 86, 263 pp. 

Gleason, 6. R., and Ohlmacher, F. J., (1965). A Core Sampler for 

In-Situ Freezing of Benthic Sediments, Ocean Science and Ocean 

Engineering, Joint Conference Marine Tech. Soc. and Amer. SOC. 

Lim. and Ocean, Washington, D. C., Trans., L, 737-741. 

Gottschalk, L. C., (1951). Measurement of Sedimentation in Small 

Reservoirs, Am. SOC. Civil Engr., Proc. Hyd. Div., 77. 

Guy, H. P., (1968). Quality Control of Adjustment Coefficients in 

Geological Survey Research 1968, U.S. Geol. Survey Prof. Paper 

600-B, pp. B165-Bl68. 

Guy, H . P., (1969). Laboratory Theory and Methods for Sediment Analysis, 

U.S. Geol. Survey Techniques Water-Resources Inv., Book 5, 

Chap. C1, 58 pp. 

Guy, H. P., (1970). Fluvial Sediment Concepts, U.S. Geol. Survey 

Techniques W-R Inv., Book 3, Chap. C1, 58 pp. 

Guy, H. P., and Norman, V. W., (1970). Field Methods for Measurement 

of Fluvial Sediment, U.S. Geol. Survey Techniques W-R Inv., 

Book 3, Chap. C2, 59 pp. 

Hubbell, D. W., (1964). Apparatus and Techniques for Measuring 

Bed Load, U.S. Geol. Survey Water-Supply Paper 1748, 74 pp. 

Hubbell, D. W., and Matejka, D. Q., (1959). Investigations of 

Sediment Transporation. Middle Loup River at Dunning, Nebr., 

U.S. Geol. Survey Water-Supply Paper 1476, 123 pp. 

Inter-Agency Committee on Water Resources, (1940). A Study of Methods 

Used in Measurement and Analysis of Sediment Loads in Streams: 

Field Practice and Equipment Used in Sampling Suspended Sediment, 

Report No. 1. 

130

Inter-Agency Committee on Water Resources, (1940). Equipment for 

Sampling Bed Load and Bed Material, Report No. 2. 

Inter-Agency Committee on Water Resources, (1941). A Study of 

Methods Used in Measurement and Analysis of Sediment Loads in 

Streams: Methods of Analyzing Sediment Samples, Report No. 4 

Inter-Agency Committee on Water Resources, (1941). A Study of 

Methods Used in Measurement and Analysis of Sediment Loads in 

Streams: Laboratory Investigation of Suspended-Sediment 

Samplers, Report No. 5. 

Inter-Agency Committee on Water Resources, (1943). A Study of New 

Methods for Size Analysis of Suspended-Sediment Samples, Report 

No. 7. 

Inter-Agency Committee on Water Resources, (1952). The Design of 

Improved Types of Suspended Sediment Samplers, Report No. 6. 

Inter-Agency Committee on Water Resources, (1953). Accuracy of 

Sediment Size Analysis Made by the Bottom-Withdrawal-Tube 

Method, Report No. 10. 

Inter-Agency Committee on Water Resources, (1957). The Development 

and Calibration of the Suspended-Accumulation Tube. Report No. 11. 

Inter-Agency Committee on Water Resources, (1957). Some Fundamentals 

of Particle-Size Analysis, Report No. 12. 



Operation and Maintenance of U.S. BM-54 Bed-Material Sampler, 

Report M. 

Inter-Agency Committee on Water Resources, (1959). Sedimentation 

Instruments and Reports, Report AA. 



Determination of Fluvial Sediment Discharge, Report No. 14. 

Ismail, H. M., (1952). Turbulent Transfer Mechanism and Suspended 

Sediment in Closed Channels, Am. SOC. Civil Engineers, Trans., 

- 1 I 7, 409-446. 

Jackson, H . W., (1970. A Controlled-Depth Volumetric Bottom Sampler, 

The Progressive Fish Culturist, 

2 (2). 

Kennedy, J. F., (1961). Further Laboratory Studies of the Roughrle~,~ 

and Suspended Load of Alluvial Streams, California lnst. ‘1ecI1nology, 

W. M. Keck Lab. Rept. KH-R-3. 

Keulcgm, C. H., (1938). Laws of Turbulent Flow in Open Channels, 

U.S. Natl. Bur. Standards, Jour. Research, 21, ( f~), 

707-741. 

l,i\i’sev, K. H., (1970). The Role Sediments Play ill lk~trrmining the 

((u:llity of Water, U.S. Army Corps of Engr., ilm.tl~n [list. 

131

McCain, E. H., (1957). Measurement of Sedimentation in TVA Reservoirs, 

Am. SOC. Civil Engr., Jour. Hyd. Div., g, (HY3), Paper 1277. 

McCain, E. H., (1965). Operation Manual for Radioactive Sediment Density 

Probe, Corps of Engineers, Omaha District. 

Meyrr-Peter. E., and Muller, R., (1948). Formulas for Bed-Load 

Transport, Int. Assoc. of Hydraulic Structures Research, 

2nd Mtg., Stockholm, Sweden, 39-64. 

Proceedings of the Federal Inter-Agency Sedimentation Conference, 

(1948), 314 pp. 

Proceedings of the Federal Inter-Agency Sedimentation Conference, 

(1963). U.S.D.A. Misc. Pub. No. 970, 933 pp. 

Proceedings of the Third Federal Inter-Agency Sedimentation 

Conference, (1976). Sedimentation Committee of the Water 

Resources Council. 

Prych, E. A., and Hubbell. D. W., (1966). A Sampler for Collecting 

Sediments in Rivers and Estuaries, Geol. SOC. America Bull., 

- 77, 549-556. 

Ritter. J. R.. and Helley, E. J.. (1969). Optical Method for 

Determining Particle Sizes of Coarse Sediment, U.S. Geol. 

Survey Techniques of Water Resources Inv., Book 5 , Chap. 

c3, 33 pp. 

Sayre, W. W., and Chang, F. M., (1968). A Laboratory Investigation 

of Open-Channel Dispersion Processes for Dissolved, Suspended, 

and Floating Dispersants, U.S. Geol. Survey Prof. Paper 433-E, 

71 PP. 

Sayre, W. W., and Hubbell, D. W., (1965). Transport and Dispersion of 

Labelled Bed Material, North Loup River, Nebr., U.S. Geol. 

Survey Prof. Paper. 433-C, 48 pp. 

Sellers, B., Papodopoulos, T., and Ziegler, C., (1966). Radioisotope 

Gage for Monitoring Suspended Sediment Concentration in Rivers 

and Streams, U.S. Atomic Energy Comm. 

Simons, D. B., Richardson, E. V., and Albertson, M. L., (1961). 

Flume Studies Using Medium Sand (0.45 nun), U.S. Geol. Survey 

Water-Supply Paper 1498-A, 76 pp. 

Sooky, A. A., (1969). Longitudinal Dispersion in Open Channels, 

Jour. Hyd. Div., 95, (HY4). 

Task Force on Bed Forms in Alluvial Channels of the Committee on 

Sedimentation, ASCE, (1966). Jour. Hyd. Div., 92, (HY3). 

51-64. 

U.S. Army, Corps of Engineers, Omaha District, (1952). Sediment 

Transport Characteristics Study of Missouri River at Omaha. 

Nebr. Unpublished Report.

U.S. Bureau of Reclamation, (1958). Interim Report, Total Sediment 

Transport Program, Lower Colorado River Basin: Sedimentation 

Sec., Hydrology Br., Div. Prof. Inv., 175 pp. 

U.S. Waterways Experiment Station, (1935). Studies of River Bed 

Materials and Their Movement, with Special Reference to the 

Lower Mississippi River, U.S. Waterways Expt. Sta., Paper 17, 

161 pp. 

Vanoni, V. A., (1975). Sedimentation Engineering, Am. SOC. Civil 

Engr., Manuals and Reports on Engineering Practice - No. 54, 

745 pp. 

Vanoni, V. A., and Brooks. H. H., (1957). Laboratory Studies of the 

Roughness and Suspended Load of Alluvial Streams, California 

Inst. Technology, Report No. E-68. 

Wolman, M. C., (1954). A Method of Sampling Coarse River Bed Elaterial, 

Am. Geophys. Union Trans., 21, (6). 951 pp. 

133

DISCUSSION 

Dr. E. ihgley: We are all aware of the fact that the relationship between 

sediment discharge and flow is generally non-linear when we are looking at 

total sediment. I am wondering, do you have any feeling for the relationship 

between the finer than 62 p fraction with flow? Is it because it is 

not depth dependent? Is it really a simple function of flow? 

Mr. J. 'iciiw2*tsmI; No. The fine material is that material finer than 62 

micron5 and I might mention that Hydro Comp has a model out where they stop 

at 50 microns. Why they selected that I don't know. This fine material 

has been called wash load. There is no relation between the concentration 

or load of wash load with the hydraulics. It is not velocity- and depth 

dependent. The sands do relate well with velocity-depth relations but the 

fine material, no. This is a real problem because vou cannot predict the 

fine material or washload. 

135

INTRODUCTION 

Sediment Storage and Remobilization Characteristics 

of Watersheds 

.I. Knox 

Accuracy in estimating long term sediment yields depends to a 

large degree on understanding the natural variability of the magnitude and 

frequency of surface runoff. Although the magnitude and frequency characteristics 

of surface runoff are normally presumed to display random 

variation over time, this presumption is often not fulfilled. Long hydrologic 

records spanning many decades and proxies of surface runoff that 

extend to century time scales indicate that natural departures from the long 

term average often occur in clustered sequences. Because many hydrologic 

records span only short periods of time, a condition which is especially 

true for sediment yield records in many small watersheds, it is important 

that observed erosion and sediment transport rates be calibrated to reflect 

the range of both short term and long term variations. Significant changes 

in erosion and sediment transport often occur when an existing balance 

between land cover and climate is disrupted. Disruption may occur naturallv 

in response to climatic change, or it may be produced in response to changes 

of land use. The responses of sediment yield to changes of climate or land 

use are mostly related to changes in the magnitude and frequency characteristics 

of surface runoff. It is also apparent that changes in magnitude and 

frequency of surface runoff, in turn, cause changes both in the functional 

relationship between sediment yield and water yield and in the sediment 

delivery ratio. Nearly all of the techniques currently in practice for 

estimating long term sediment yields of watersheds involve an assumption of 

temporal uniformity (stationarity) in the time series of variables that 

relate to either precipitation or runoff. Over the time span of several 

decades and longer, the assumption of stationarity may not be met because of 

changes in either climate or land use or both. 

THE MOVEPENT OF SEDIMENT THROU;H K~TERSHEDS 

Long term changes in the magnitude and frequency of surface runoff 

can alter the long term rate of movement of sediment through a watershed by 

causing changes in the rate of upland erosion and/or in the volume of sediment 

that is stored in the watershed as colluvium and alluvium. The volume of 

upland erosion is largely related to storms and surface runoff of events 

moderate magnitude and frequent occurrence. For example, Wischmeier (1962) 

found that three-fourths of the soil losses from small, cultivated, singlecover 

plots in the United States were caused an by average of about four 

storms per year. Piest (1965, p. 101) concluded that, on the average, more 

than one-half of the annual soil losses from 72 small watersheds from 17 

states was related to storms that occur more often that once per year. 

137

Altllougll the data of Wischmeier and Piest make it clear that most upland 

sediment loss is related to meteorological events that recur relatively 

frequently, the actual total number of events is relatively small. For 

rxdmplc, Knox et al. (1975, p. 42) found that, for small Iowa watersheds 

draining less than 10 square miles (16 km2), the suspended sediment yield of 

only eight to ten davs normally accounted for more than 90 percent of the 

annual yield. The actual number of days per year that are associated with 

relatively high magnitude suspended sediment yields increases slightly as 

drainage area increases (Figure 1). It may be concluded that the hulk of 

erosion and transportation of sediments from upland sites is related to a 

very small number of hydrologic events, whose occurrence is dependent upon 

the development of specific meteorological conditions. The importance of a 

small numher of climatic events makes climate variation critical to the 

explanation of long term variations of the mobility and storage of sediments 

in watersheds. A modest change in an expected seasonal location of a storm 

track or air mass boundary affects the number of occurrences of days with 

high mngnitude sediment yields. Climate changes of this type explain most 

of bottt the short and long term variations of upland sediment yields. 

Long term variations in the magnitude and frequency of surface 

runoff also affect the balance between sediment that is eroded and transported 

versus sediment that is stored as colluvium and alluvium (sediment 

delivery ratio). Millenia scale episodes of channel alluviation and channel 

degradation have been documented as occurring over wide regions (Starkel, 

1966, 1972; Haynes, 1968, 1976; Klimek and Starkel, 1974; 1NQUA Holocene 

Symposium, 1975; Knox, 1976; and Johnson, 1976). The regional synchroneity 

of many documented alluvial episodes provides evidence that the sediment 

delivery ratio is subject to change on long term time scales. Current 

estimates of long term average sediment delivery ratios have suggested that 

the ratio varies inversely with drainage area raised to the 0.125-0.20 power 

(Piest, Miller, and Vanomi, 1975, pp. 462-463; EPA, 1973, p. 58). Year to 

year variability in surface runoff may cause large departures from the 

expected average sediment delivery. For example, when land cover is held 

constant, the magnitude of the sediment delivery ratio increases with 

increasing runoff (Piest, Kramer, and Heinemann, 1975, p. 132; Elutchler and 

Bowie, 1976, p. 1-21). If. over the long term, vegetative cover improves to 

better protect the land surface from erosion and acts as a friction factor 

to reduce the rate of surface runoff, then sediment delivery percentages 

will decline (PiesL, K~dme~, and Heinemann, 1975, pp. 139-140). On the other 

hand, if changes in runoff are associated with highly variable flood flows 

with relatively frequent recurrence of large floods, then stream channels 

are likely to become unstable and floodplain erosion may follow (Schumm and 

Lichty, 1963, pp. 74-76; Stevens et 4.. 1975; and Knox, 1976, pp. 182-186). 

In summary, the amount of transportation and/or storage of sediment 

in watersheds is dominated by a relatively small number of hydrologic 

events that tend to occur each year. The actual frequency and the character- 

istics of the critical hydrologic events is strongly dependent on the 

prevailing climate and land use characteristics. 

IMPACT OF LONG TEW VPRIATICNS OF CLIMATE 

The importance of climate as a variable influencing short term 

variations of sediment yields is generally accepted, but many, if not most, 

investigaLors assume that climate variations are essentially random in 

relation to time scales than span several decades or longer. The assumption 

138

___ 

FIGURE 1 

The relationship between days of occurrence of relatively 

high magnitude suspended sediment yield and drainage area. 

The equation explains seventy-six percent of the variance 

of high sediment yield days and is significant at 0.01 the 

probability level. High yield days, as defined here, 

accounted for an average of eighty-five or more percent of 

annual sediment yields in watersheds draining 500 square 

miles (1300 krn'). Only about sixty percent of the total 

annual suspended sediment yields were represented by the 

high yield days when the drainage area increased to about 

5000 square miles (13000 h2). The data utilized in the 

above equation provide quantitative documentation that a 

very large fraction of the total annual yield of suspended 

sediment from a watershed is related to hydrologic events 

which occur on only a small number of days during the year. 

The specific magnitude and frequency characteristics of 

the critical hydrologic events are in turn highly 

sensitive to variations in the dominant climatic regimes. 

139

nt randomness is frequently not supported by long historical records of 

climntc nor by proxies of long climate records (e.g., tree ring character- 

istics) (Lamb, 1966, pp. 56-112). 

Climate circulation regimes are often characterized by positive 

and negative feedback mechanisms that lead to persistence of anomalous 

conditions. Persistence of certain "preferred" circulation regimes, in 

turn, contribute to persistence in characteristics of hydrologic events. 

Persistence occurs on many time scales. For example, an analysis by this 

author revealed that, for the years 1941-1969, frequencies of floods in 29 

Upper Mississippi Valley watersheds displayed patterns of departure from 

,average that were strongly persistent on approximately a decadal time scale 

(Figures 2 and 3). The number of "runs" of consecutive occurrences of flood 

frequencies, expressed as five-year running averages in Figure 2, was nearly 

four standard deviations below the expected mean number for a statistically 

random arr'iv. I t was estimntrd that departures, of the above decadal scale, 

wtart' rt,sponsihle for four ((1 -,t~vt~n-told v.iriations in tht: average short term 

sediment yields. 

An example of how surface runoff can vary between climatically 

different years is prcvided in Figure 4 which represents thv Rickapoo Kiver 

"Strahler" 

St ream 

Order 

TABLE 1* 

Estimated Suspended Sediment Yields for 

Average Drainage Areas of Stream Orders 

in the Kickapoo Watershed Upstream of 

LaFarge, Wisconsin 

Average Sediment Yield (tonslmi') 

Drainage "wet"* "dry"* "average" 

Area (mi') 

1965 1963 

.016 

.07 

.33 

1.55 

6.65 

30.50 

~ 

2450 475 14 30 

2025 390 1180 

1640 310 945 

1320 250 760 

1100 2 10 630 

88 5 170 520 

*The sediment yield data were generated from seasonally calibrated sediment 

rating curves derived from U.S. Geological Survey sediment data collected 

for the Kickapoo River near LaFarge, Wit;consin. For further information 

see Knox aJ., 1975, pp. 50-57. 

141

Decadal scale variation in flood frequencies. A listing of the 

gaging stations and other descriptive characteristics of the

FIGURE 3 

Total Floods -Partial Duration Series 

29 Basins 

per Mississippi Valley 

Month 

- 1941 - I949 

"" I*Io-lv5v 

IVbO- I969 

Decadal scale variation in seasonal concentrations of 

flood occurrences (After Knox et al., 1975, pp. 10, " 

17, 30-40). 

FIGURE 4 

Hydrographs - Kickapoo River LaFarge, Wisconsin 

Climatic influence on runoff. Data from U.S. Geological 

Survey. After Knox et al., 1975, p. 51. 

143

FIGURE 5 

. , .. 

Annual flood series, Mississippi River at Keokuk, Iowa. 

Data from U.S. Geological Survey, After box - et _. a1 3 

1975, p. 7. 

1. 

FIGURE 6 

Minimum Stagor of th. Nil. Rivor at Cairo, Egypt 

Progressive 50-year average stages of Nile River. 

Redrawn from Stevens' Fig. 9 closure to paper by 

Jarvis (1935, p. 1048). 

144

to reflect probable climatic trends. If long term estimates of the mobility 

and storage of sediments are to extend to century and longer time scales, 

then probabilistic interpretations of duration curves based on long records 

represent "best available" approximations. Planning for long term mobility 

and storage of sediments in watersheds should probably be viewed in relation 

to scenarios of possible conditions of climate influence. 

IWACT OF LONG TERM VARIATIONS OF [AND USE 

The long term mobility and storage of sediment in watersheds is 

influenced by land use in a way that is analogous to climate changes, because 

both involve disturbance of the relationships amongst precipitation, land 

cover, and runoff. The influence of land use on sediment yield has been 

investigated extensively (e.g., Federal Inter-Agency Sedimentation Conferences: 

1947, 1963 and 1976; U.S. Environment

Environmental Protection Agency (EPA), 1973. Methods for Identifying 

and Evaluating the Nature and Extent of Non-Point Sources of 

Pollutants: EPA - 430/9-73-014, Washington, 261 pp. 

HLIPP, S . C., Rittenhouse, C., and Dobson, C. C., 1940, Some 

principles of accelerated stream and valley sedimentation: 

U.S. Department of Agriculture, Tech. Bull. 695. 

Havrlt.s, (1, V., 1968, Geochronology of late-Quanternary alluvium: 

In - Means of Correlation of Quaternary Successions (R.B. 

Morrison .rnd II. E. Wright, Eds.) pp. 591-631, Vol. 8. Proceedings 

VI1 INQUA Congress, Univ. of Utah Press, Salt Lake City. 

International Association of Hydrological Sciences, 1974, Effects 

of Man on the Intrrtace of the Hydrological Cycle with the Physical 

".~"I_ 

Environment: IAHS I'ublication No. 113, 157 pp. 

~" 

"_ . 

INQUA Holocene Symposium, 1975, Weogeographical Changes of Valley 

Floors in the Holocene: Biuletyn of Genlogiczny, Vol. 19, 

Warsaw University Press, Warszawa. 

.I.trvis. C. S., 1935, Flood-stage records of the river Nile: Trans. 

American Society of Civil Engineers, Paper No. 1944, pp. 

1012-1070. 

Johnson, W. C.. 1976, The impact OF environmental change on €luvial 

systems: Kivkapoo River, Wisconsin: Unpublished Pt1.D. disserat.ion, 

University o i Wisconhin, Department of Geography. 

Klimek, K., and Starkel, L., 1974. History and actual tendency 

of floodplain development at the border of the Polish Carpathians: 

In: Report OF the Commission on Present-day Processes (H. Poser, 

Ed.), pp. 185-196, International Geographical Union, Vandenhoeck 

and Kuprecht, Gottingen. 

box, .1. C., 1976, Concept of the graded stream: In - Theories 

of Landform Developms, R. Flemal and W. Melhorn, Eds., Sixth 

Annual Geomorphology Symposium. Binghamton, NY, pp. 169-198. 

Knox, J. C., Bartlein, P. J., Hirschboek, K. K., and Muckenhirn, 

R. J., 1975. The response of floods and sediment yields to 

climatic variation and land use in the Upper Mississippi 

Valley: University o€ Wisconsin Institute for Environmental 

Studies Report No. 52, 76 pp. 

Lamh, H. H.. 1974, The current trends of world climate--a report 

on the early 1970's and a perspective: University of East 

Anglia, Norwich, Climatic Research Unit Research Publication 

No. 3, 28 pp. 

Lamb, H. H.. 1966, On the nature of certain climatic epochs which 

differed from the modern (1900-1939) normal: In: The Changing 

Climate (H. H. Lamb). pp. 58-112, Methuen and Co., Ltd., 

London. 

Mutchler, C. K., and Bowie. A. J., 1976, Effect of land use on 

sediment delivery ratios: In - Proceedings of the Third Federal 

Inter-Agency Sedimentation Conference, Water Resources Council, 

Washington, pp. 1-11. 1-21. 

146

Piest, R. F., 1965. The role of the large storm as a sediment contributor: 

Proceedings of 1963 Federal Interagency Conference on Sedimentation, 

Misc. Pub. 970, U.S. Department of Agriculture. 

Piest, R. F., Kramer, L. A., and Heinemann, H. G., 1975, Sediment 

movement from loessial watersheds: In - Present and Prospective 

Technology for Predicting Sediment Yields and Sources, U.S. 

Department of Agriculture, Agricultural Research Service Report 

ARS-S-40., pp. 130-141. 

Piest, R. F., Miller, C. R., and Vanomi, V., 1975, Chapter Iv - 

Sediment sources and sediment yields: In - Sedimentation 

Engineering, V. Vanomi, Ed., American Sor. Civil Engineers Task 

Committee on Sedimentation, NY, pp. 437-493. 

Renfro, G. W., 1975, Use of erosion equations and sediment-delivery 

ratios for predicting sediment yield: In - Present and 

~ _" ~ 

Prospective Technology for Predicting Sediment Yields and 

__- Sources, U.S. Dept. of Agriculture, Agricultural Research 

Service, Publication ARS-S-40, pp. 33-45. 

Schumm. S. A., and Lichty, K. W., 1963, Channel widening and tlood- 

plain construrtion along Cimarron River in Southwestern Kansas: 

U.S. Geological Survey Prof. Paper 352-D, pp. 71-88. 

Starkel, I,., 1966, Post-glacial climate and the moulding of European 

relief: In - World Climate from 8000 to 0 B.C., Royal 

Meteorological Society, London, pp. 15-33. 

Starkel, L., 1972, Trends of development of valley floors of mountain 

areas and submontane depressions in the Holocene: Studia 

Geomorphologica Carpatho-Balcanica, Vol. 6, pp. 121-133. 

Stevens, M. A., Simons, D. B., and Richardson, E. V., 1975. 

Nonequilibrium river form: Proceedings American Society 

Civil Engineers, Journal Hyd. Division, HY5, V. 101, PP. 

551-566. 

Trimble, S. W., 1975, A volumetric estimate of man-induced soil 

erosion on the southern piedmont plateau: In - Present 

and Prospective Technology for Predicting Sediment Yields 

and Sources, U.S. Dept. of Agric., Agric. Research Service, 

Publication ARS-S-40, pp. 142-154. 

Trimble, S . W., 1976, Sedimentation in Coon Creek Valley, Wisconsin: 

In - Proceedings of the Third Federal Inter-Agency Sedimentation 

Conference, Washington, pp. 5-100, 5-112. 

U.S. Department of Agriculture. 1965, Proceedings of the Federal 

Inter Agency Sedimentation Conference, 1963: U.S. Government 

Printing Office, Washington, 933 pp. 

U.S. Department of Agriculture, 1975, Present and Prospective 

Technology for Predicting Sediment Yields and Sources: 

Agricultural Research Service Publication ARS-S-40, pp. 285 

147

DISCUSSION 

Dr. 0. Bouldin: One of the problems we always run into is that we have got 

to make estimates based on imperfect knowledge. Now I see nothing particularly 

wrong with that, but what really bothers me is that most of the time 

we have no way to estimate how sure we are about, or put confidence intervals 

on, those estimates, particularly sediment loads. What kinds of handles can 

we put on this problem? In other words how do we make an estimate of a 

coniidence interval 

years of data? 

for a sediment load that may be derived from two or three 

Dr. J. Kwxt Well, again I am sure this probably varies regionally. The 

situation that I am familiar with in the upper midwest is that we do see 

frequently decadal scale persistence in the records, and we can look at 

longer term records of climate or climate proxies. In this case we have 

records of temperature that we can take back to 1820 or so. In the case of 

Canada, the Hudson Bay Company has some nice records that go hack iarther. 

I think what we need to ds is look at these kinds of records and see to what 

degree the probabilities of recurrence of certain kinds of critical events 

that transport sediment might have varied within those records. Now, this, 

I think, is preferable, at least from my point of view, in estimating what is 

likely to happen, say over the next 10 years than just assuming pure randomness. 

I think you come up with a better figure, but again I think because we do not 

have the capability of perfect prediction, even very good prediction right 

now, that probably the scenario approach is still a requirement. You have to 

look at it in terms of what is possible and I think those probability figures 

are pretty good in telling you what is possible, perhaps even what is reasonably 

probable. We see right now, at least occuring since about 1950, a 

return to circulation patterns that seem to have characterized many years in 

the previous century, recurred with much greater frequency. Now whether 

that is going to continue to happen, I have no way cf knowing, but it is 

interesting that some of the patterns we have now apparently are similar to 

ones that occurred over long periods of time. Much of the first half of the 

20th century had recurrence frequencies of circulation patterns, preciptation 

characteristics and runoff that may be a little bit unusual over the long 

term scale of the last 200 years or so. Now, if that is true and we are 

working from duration curve extrapolations and we weight our data relative to 

the record, that is not really representative of what is going to occur in the 

next decade or so; then we are in trouble. 

149

INTRODUCTION 

Sediment Storage and Remobilization Characteristics 

of Watersheds 

C. Nordin 

The movement in a watershed of a sediment particle from its 

position of weathering and erosion to its point of ultimate deposition is 

a complex process developing in time under random influences. By definition 

(Cramir, 1964), this movement is a stochastic process. 

Most of what we know about sediment movement and sediment 

storage in watersheds comes from empirical observations, and despite the 

fact that sedimentary processes have been observed for many decades, only 

a few generalizations can be drawn from the extensive data accumulated. 

This discussion deals with the following generalizations: (1) the relation 

of sediment yield to drainage area and its implication in of terms sediment 

storage in watersheds; (2) the random nature of daily and annual sediment 

loads; (3) short-term in-channel storage of sediment; and finally (4) a 

stochastic model of sediment movement and its limitations. 

SEDIMENT YIELD AND DRAINAGE AREA 

Sediment yield usually is determined one of three ways: (1) 

from small experimental plots where artificial precipitation is controlled 

and all runoff and sediment can be measured; (2) from periodic surveys 

of sediment collected in reservoirs; and (3) from sampling sediment loads 

of streams. Auxilliary methods involving remote sensing, topographic 

mapping or cross sectional valley and channel surveys also are used. 

The relations of sediment yield to drainage area vary from arid 

to humid regions, but the general trend is for the unit sediment yield to 

decrease with increasing drainage area. The implications are clear; the 

movement of eroded sediment is not continuous, and the larger the drainage 

area, the more chances there are for storage of eroded material. The 

major unresolved problems with respect to sediment yield are those re- 

lating to storage. If all the sediment eroded from the headwater areas 

of watersheds is not transported out of the basin, where does this sediment 

go, what is its residence time while in storage, and what are the factors 

that control its movement and deposition? Despite the tremendous amount 

of empirical data collected to determine sediment yield from small watersheds, 

it has not been possible to draw sufficient generalizations to 

permit answering these sorts of questions. 

Most of the reliable data on sediment yield are from watersheds 

with drainage areas less than about 10 square kilometres, while most 

stream sediment discharge records are for basins with drainage areas 

greater than 200 square kilometres. Very little information is available 

for basins in the range 10 of to 200 square kilometres drainage area. 

151

DAILY AND ANNUAL SEDIMENT LOADS 

The sediment yield from large watersheds and sediment discharge 

to the oceans are determined from measurements of sediment discharge at 

gauging stations. These records are considered fairly reliable because: 

(1) the flow and transported sediment are confined generally a single to 

channel where measurements are relatively simple and standardized; and 

(2) many of these stations have been operated for years so that the 

stochastic properties of the time series of flow and sediment discharge 

are well-defined. 

A common method of displaying sediment loads is to plot them 

against water discharge. Generally, there is a fair correlation with an 

increasing trend of sediment load with water discharge, indicating that 

the same variables affect both runoff and sediment yield, and almost 

always there is considerable scatter about a mean line relating sediment 

discharge to water discharge. Typically, the sediment discharges from 

arid and semi arid regions are several Orders of magnitude higher a for 

given water discharge than those from more humid basins, and at low 

flows, the scatter in sediment load for arid regions is five or six 

orders of magnitude compared to about an order of magnitude for the humid 

regions. Part of this scatter is seasonal variation, but even after 

integrating over the annual cycle, there is considerable scatter in the 

relation of annual sediment load to annual streamflow. 

Land use has substantial impact on sediment yield, and most 

activities such as road building, urbanization, timbering, and strip 

mining, if not subjected to careful controls, can increase substantially 

the sediment yield of a specific area. The rate of rehabilitation of a 

disturbed area is generally rapid in urban areas and decreases with 

decreasing annual precipitation in rural areas. 

IN-CHANNEL STORAGE AND REENTRAIN" 

In-channel storage and reentrainment of sediment may a be longterm 

phenomenon associated with the building of point bars and flood 

plains with concurrent lateral migration of channels, or it may a be 

seasonal or shorter-term phenomenon related to hydrologic and hydraulic 

properties of the flow. There is little basis today other than projection 

of historical data for predicting rates of lateral migration of channels, 

but short-term changes related to stream hydrology OK to hydraulic sorting 

can be modelled with reasonable success if sufficient data are available 

to establish initial conditions, boundary conditions, and inputs. The 

two general approaches to modelling these processes are: (1) to construct 

stochastic models of the time series of water discharge and sediment 

discharge (Rodriguez and Nordin, 1968); or (2) to employ computational 

hydraulics as described by Bennett (1974). 

152

STOCHASTIC M~DELS OF PARTICLE M~VEMENT 

-L 

Mathematically, the position vector X(t) of a particle at time 

t is given by 

* 

where the initial position X(o) = o at time t = 0. The velocity 0, 

O.t 

is a random function of position and time so X also is a random function 

of position and time. 

ft 

Equation 1 says simply that a particle's position is the integral 

over its velocity and the description is precise whether the movement is 

continuous or discontinuous. From a practical point of view, though, the 

utility of equation 1 is restricted to some few cases where the particle 

velocity can be specified or where the distributions of particle step 

lengths and rest periods are known; so the applications are limited 

mostly to the hydraulic problems of predicting dispersion of fine particles 

or bedload transport under conditions of steady uniform flow. Considerable 

progress has been made in recent years on these particular stochastic 

models, but there still exist some disturbing departures of empirical 

observations from the theoretical models (Nordin, 1975), so the problems 

can hardly be considered solved. Nonetheless, it is encouraging that at 

least certain aspects of the sediment transport processes can be approached 

on a fairly rigorous mathematical basis. 

Although equation 1 is an exact description of particle movement, 

there are practical limitations in its applications. The first restriction 

requires the process be stationary; that is, the parameters describing 

the distributions in the process should not vary with time. A second 

restriction, one that is even more critical, is that the model is kinematic; 

so for predictive purposes, it is necessary to relate the parameters of 

the model to the dynamic forces of the flow. This can be done for steady 

uniform Flow over a flat bed. For this case, the particle steps,

Todorovic and Nordin (1975) generalize the wst important 

theoretical results of various stochastic models that have been proposed 

and derive expressions for the errors involved in the approximations in 

equation 2. 

Probably the most critical research need today is to compile 

and generalize existing empirical data to permit interpolation and extrapolation 

to areas where no field data have been collected. Such generalization 

would also serve as a rational basis for network design to collect 

additional field data where it is needed. Further development of mathematical 

and stochastic models should be undertaken, with particular 

attention to methods for treating non-steady or non-stationary processes. 


Bennett, J. P., (1974) Concepts of Mathematical Modelling of Sediment 

Yield Water Resources Research, lo. (3). 485-492. 

Cram&, Harald, (1964). Model Building With the Aid of Stochastic 

Processes Technometrics, 5, (2), 133-159. 

Nordin, Carl, (1976). Simulation of Velocity Distribution and Mass 

Transfer Stochastic Approaches to Water Resources (ea. H. W. 

Shen), P. 0. Box 606, Fort Collins, CO., V. 11, chap. 22, 24 p. 

Rodriguez-Iturbe, I., and Nordin, C. F., (1968), Time Series Analysis 

of Water and Sediment Discharges Int. Assoc. for Scientific 

Hydrology, 13, (2), 69-86. 

Todorovic, Petar, and Nordin, C. F., Jr., (19751, Evaluation of Stochastic 

Models Describing Movement of Sediment Particles on Riverbeds 

U.S. Geol. Survey Journ. of Research, 3, (5), 513-517. 

154

DISCUSSION 

Dr. E. Ongley: 1 am wondering, if you have any feeling for whether there is 

an inverse relationship between particle size and the residence time in 

transport? Would you suspect that? 

Dr. C. Nordin: I have evidence that says that there is under steady uniform 

flow conditions. Experimental evidence in a laboratory flume shows that the 

rest period duration, or a distribution of rest periods of a particle is a 

function of the particle size. Once you get into a natural condition where 

you do not have steady, uniform flow, where you have particles depositing 

some place and picked up somewhere else, it is hard to say. One typical 

storage problem that you would run into is in most natural channels where 

you have material eroded from the outside of a bed being deposited on the 

next bar downstream. This material might be stored in that bar for centuries 

until the meander sweeps on downstream. So what is the rest period of particles 

there? They take a few hops along the channel and rest in that bar deposit 

for a couple of decades or a couple of centuries until the meander sweeps on 

downstream and picks them up. This is important in terms of nutrients and 

contaminants because there is a possibility for contaminants to be deposited 

in a flood plain and then be re-exposed a at later time on a fairly uniform 

basis. So you may never get these things out of the channel. 

Ur. J. Knor: Carl (Nordin), what time scale are you applying a randomness 

on? The reason I ask is that on certain time scales, things are certainly not 

very random; they are very episodic. 

Vr. C. Nordin: I do not think that the concept of persistence is in conflict 

with the ideas of randomness if you look at the work that Mandelbroth and 

Hurst have done, or even the work that G. I. Taylor did in introducing the 

correlation function to statisticians. There is a persistence, and until 

that correlation dies out this persistence determines the movement. 

Dr. .J. Knox: The point is really how much energy do you want to expend to 

make something that appears random at one scale really deterministic at 

another scale? 

155

Dr. C. Nordin: Well as an engineer I am perfectly contented to work with 

design lives. Most engineers are willing to work with 50 years or 100 years 

because if they design something, they are going to be gone by the time it 

fails. The time scales are very different. I agree with you that there 

are episodes of very low flow and very high flow of very intense activity 

and I don't know how you handle these. 

Dr. J. Knox: One thing that we did to improve the level of explained variance 

between water yield and sediment yield was to calibrate for the various kinds 

of events within a given physiographic area and given land use region. The 

explained variance rose and then you could interpret your records Over a 

longer term of events by looking at the stream flow from which you usually 

have longer records. It is a matter of calibrating over shorter periods of 

time, for particular times of events and then getting a long equation with 

dummy variable type inputs where a 1 OK a 0 is ahead of the calibration 

coefficient. If that event occurred in that period, it had a 1 and multiplied 

it in. If it did not it cancelled it out. That gives pretty reasonable 

results. It explains most of the variance but it takes a lot of time and much 

effort, but it can be a significant improvement. 

Dr. C. Nordin: I think I would also agree with your suggestion that when you 

start simulating or trying to predict these things through simulation you 

have to look at a large variety of scenarios or you have to run a lot of 

realizations of your stochastic process and get some distribution of these. 

156

I NTRODUCT I ON 

Forms and Sediment Associations of Nutrients (C.N. b p.) 


Nutrients - P 

H. L. Golterman 

As most of the Dutch lakes are situated in the deltas of the Rhine 

and Meuse, they receive large amounts of nutrients from this source. 

In total they receive 6 g m-', y-l; about 50% from the Rhine. The 

Rhine carries about 70,000 tonnes of PO+-P per year, of which 80% is 

transported into the North Sea. Of the remaining 15,000 tonnes about 

50 - 60% is accumulating in the Dutch lakes, which receive an annual 

load of about 6 g per m2 per year. 

ESTIWTES OF RIVERINE PHOSPHATE 

Sources 

Three different sources of riverine phosphate - and thus of the 

Rhine - can be distinguished: 

1) natural erosion; 

2) human waste; 

3) agricultural runoff. 

Global Phosphate Resources 

A first estimate of the erosion can be made with a global mean value. 

Phosphate occurs in rocks as calcium apatite, in the range between 0.07 - 

0.13%. Van Wazer (1961) estimated the total amount of phosphate in the 

lithosphere to be 1.1 x loz5 g of which lo" g is present in the sea 

in the dissolved state, while loz1 g is buried in marine sediments. (Only 

3 x 10l6 g is considered to be mineable). 

Erosion-derived Phosphate 

During chemical weathering the major part of this amount is converted 

into a "lattice bound clay" phosphate. In unpolluted clays the phosphate 

phosphorus is about 0.1%. 

Following Meybeck's (1976) estimate for total solid riverine transport 

(2 x 10l6 g per year, = 5 x the dissolved transport) we arrive at a figure 

for erosion for PO~-P of 2 x 1013 g per year. 

157

For specific calculations we use Meybeck's figures for erosion of: 

- 500 tonnes per km2 for small alpine rivers; 

- 200 tonnes per km2 for middle sized basins (A= about 100,000 km2) and 

- 140 tonnes per km2 for large basins (A > 400,000 km2), 

while rivers in a low relief area have values about 10 times lower. With 

this kind of calculation we arrive at a value for the mine of about 4,000 

tonnes. 

Silicate - Phosphate Ratio6 

A second calculation makes use of the ratio Si02-Si/POs-P, which we 

found to be around 100/1 in many unpolluted rivers in Africa and Southern 

France. This calculation gives a POh-P load in the Rhine of about 

10,000 tonnes. Human waste can be estimated to be around 50,000 tonnes 

per year, based on an annual POs-P production 1.5 of kg per year per 

person. 

Agricultural Phosphate 

Agricultural runoff can be estimated at 1,000 - 10,000 tonnes per 

year assuming a runoff of 0.05-0.5 kg per ha per year. The total of these 

three fractions is about 65,000 - 70,000 tonnes per year, not far from 

the measured value. 

Phosphate Availability - Algal Bioassays 

Availability of sediment phosphate was studied by algal bio-assays, 

using Scenedemus as a test organism. All sediment yielded a good algal 

growth, although not all the phosphate appeared to be available. It seems 

that the phosphate bound into the clay lattice (the "natural" clay phosphate) 

is not available for algae, although it is readily available for agricultural 

crops. Phosphate freshly adsorbed onto clay is easily available to algal 

cultures. 

Phosphate Availability - Chemical (NTA) Desorption 

It was found that with NTA (nitrilotriacetic acid) an amount of phosphate 

could be extracted equal to that used by algae. Iron bound phosphate is 

entirely available, while the availability of apatite depends on the 

crystal size. Whether this potential availability can indeed be used in 

the real lake situation depends largely of course on the hydrodynamics 

of the system. 

158

Long Term Studies 

Experiments in an artificial pond (enclosure type) supported the 

results of the bioassays. In half a year's experiment well over 1 g. per 

m2 of POq-P was released by the sediments. The NTA extractable phosphate 

fraction decreased in the same period 50%. by 

A Sediment Phosphate Model 

A schematic model discussed relates to the importance of sediment 

phosphate to the general phosphate cycle. 

Colterman, H. L., 1973. Natural phosphate sources in relation to 

phosphate budgets. Water Research 7, 3-17. 

Golterman, H. L., 1977. Sediments as a source of phosphate for algal 

growth (In press. Proceedings of a symposium, held in Amsterdam 

September 1976. Interactions between sediments and freshwater) 

Junk/Pudoc, The Netherlands. 

Meybeck, M ., 1976. Total mineral dissolved transport by world major 

rivers. Hydrological Sciences-Bulletin-des Sciences Hydrologiques 

XXI, 2 611976. 

Van Wazer, J R., (ed), 1961. "Phosphorus and its Compounds," 2 Vols., 

Vol. 2, Interscience, New York". 

159

DISCUSSION 

Dr. D. BouZdin: Does the soil in the agar disc undergo reduction during the 

assay or does it remain oxidized? 

Dr. H. Goltermun: It remains oxidized. 

Dr. ,J. Shapiro: What concentrations of NTA do you use for extracting? 

Dr. H. Golteman: 0.01 molar, pH about 7-8. 

L%. d. Shupiro: Do you think the concentrations that would normally be 

expected from use of NTA in detergents could have any effect? 

Dr. H. I;olteman: No, this is about a thousand times as much. 

161

I NTRODKT I ON 

Forms and Sediment Associations of Nutrients (C.N. & P.) 


Nutrients - P 

T. CahiZZ 

The purpose of this discussion is to summarize current knowledge 

of phosphate transport, particularly as developed during the past four 

years. Prior to 1972, measurement of both orthophosphate and total phosphate 

in natural river systems was done on a grab sampling basis, usually 

without corresponding stream flow measurement. The inclusion of total 

phosphate as a regular water quality parameter was actually not widespread 

prior to the mid-l960's, so that the historical record is both short and 

largely qualitative. A typical record of this type is shown in Figure 1. 

The absolute variability of concentration over time can be estimated from 

such records, but any projection of mass flux rate or annual mass transport 

is fraught with error. 

A number of studies conducted during 1972, 1973 and 1974, (e.g. 

Baker and Kramer, 1973; Cahillg &. 1974) have been based on sampling 

procedures utilizing synchronous measurement of storm flow and chemistry, 

with particular emphasis upon storm events. This research has yielded 

several facts regarding the behaviour of phosphate loadings. 

The concentration of total phosphate increases with stream 

discharge, so that the phosphate chemograph closely parallels 

the hydrograph. 

Soluble phosphate behaves quite differently from total phosphate. 

Strong correlations are often found between total phosphate 

and suspended solids concentrations. 

Mass transport during storms tends to comprise very a large 

proportion of total annual phosphate loadings. 

Past methods of estimating long term phosphate loadings on the 

basis of average concentrations have severely underestimated 

annual mass transport. 

More recent studies have continued to build on this knowledge. I 

The present discussion is based on the findings of three such investigations: 

1) analysis of Lake Erie tributaries in the LEWMS' project (COE', 

1975); 2) the Maumee River Basin Study conducted for the GLBC3 (GLBC, 

1976); and 3 ) recent analysis of data for Honey Creek in the Sandusky River 

Basin of northwest Ohio. Honey Creek has served as a pilot study area in 

the continuation of the LEWMS project and thus has been the of focus 

considerable water quality analysis. (See Figure 2 ) 

' Lake Erie Wastewater Management Study 

* United States Army Corps of Engineers 

Great Lakes Basin Commission 

163

"""" 4 

"I 

i: 

4 

""- 

0 """ 

"""- -I=I____ 

P 

"" 

n 

s 1 

""- " 

I

165

Increased knowledge of the mechanisms whereby phosphorus is 

released from insoluble forms has suggested that the proper focus of 

attention in lake eutrophication studies is total phosphate, rather than 

soluble phosphate or orthophosphate alone. Analysis of the behaviour of 

total phosphate in river systems has been limited primarily to examination 

of relationships with discharge. In the Lake Erie basin, the strongest 

positive relationships with discharge are found in the western tributaries 

such as the Maumee (Figure 3); the weakest associations occur in the eastern 

basins such as the Cattaraugus (Figure 4). Prior studies in the Brandywine 

basin of southeastern Pennsylvania have also indicated relatively poor 

relationships (Figure 5 ). 

Analysis of total phosphate is complicated by the fact that 

different sources and transport mechanisms are dominant under different 

flow conditions. Loadings at high flow consist very largely of insoluble 

sediment-associated phosphate derived from nonpoint sources. During lowflow 

conditions, soluble phosphate from point sources is likely to predominate, 

although nonpoint sources such as agriculture and on-site disposal 

of domestic waste may also be important. The behaviour of total 

phosphate concentrations over time is therefore likely to reflect the mix 

of sources present in a watershed. 

A convenient step in analyzing conventional water quality records 

is to partition total phosphate into two components: orthophosphate, and 

total minus ortho phosphate. The latter is treated as an estimate of 

particulate phosphate, although it is known to be only approximate. 

(Investigators must of course acknowledge that phosphate delivered to a 

river system in soluble form may adsorb to particulate material in while 

transport). Separate analysis of these phosphate components will not 

necessarily establish the relative importance of specific pollutant sources, 

but can be very helpful in clarifying the nature of loading mechanisms. 

Ideally, such studies should include detailed chemical/hydrologic modeling 

of river basins. An intermediate level of empirical analysis is possible, 

however, which goes beyond simplistic plotting of the data without attempting 

to specify explicitly all the causal linkages responsible for observed 

loadings. The Honey Creek findings discussed below represent the outcome 

of this type of intermediate analysis. 

ORTHOPHOSPHATE 

Unlike total phosphate, orthophosphate concentrations have not 

been found to bear a positive association with stream discharge in most 

river studies, and may in fact be inversely related to discharge over the 

lower flow range. Such an inverse relationship may be linked to dilution 

of point source effluents. In the Brandywine Creek studies,'orthophosphate 

concentrations have been found to obey relationships of the following form: 

166

16 7 

1/9W ‘d lt1101 

c d d 4 0 0 0 0 

ID 0 Lo 0 ID 0 ID 0 

P 

N 0 

In N 0 c: L”

1.5 - 

1.2 - 

0.9 - 

0.6 -I 

0.3 - + 

' 

. 

. 

H"H+H 

0 41 

DISCHRRGE IN CFS 

Figure 4. Cattaraugus Creek at Gowanda, New York 

Spring 1975 Sampling Period, From LEWMS, 1976

L 

- 

= 

2000- 

$i 

In 

E 

c! 

2 

5 1500 

E 

W 

!z 

X 

v) 

e 1000- 

n 

d 

4 

I- 

O 

I- 

500 

0 

I I I I I I 

4000 8000 12000 16000 

FLOW cubic feet per second 

Figure 5. Composite of Storm Samples, 1973 

Chadds Ford 

169

C Cws + ~QP (C - Cms) 

Q 

where: C = orthophosphate concentration; 

CWs = orthophosphate concentration from nonpoint sources; 

Qp = discharge from point source "P"; 

C = orthophosphate concentration in effluent from point 

P source "P"; 

Q = stream discharge. 

The quantity Cms represents a base-level orthophosphate concen- 

tration which is related to the land use characteristics and natural features 

of the watershed. In the Lake Erie basin, values of Cms appear to range from 

100-200 pg/l in the heavily-impacted western tributaries such as the Portage, 

to 10-20 pg/l in the eastern watersheds. Loss of orthophosphate due to adsorption 

during transport may affect these relationships, although the influence 

of this factor is undetermined. 

Somewhat different findings have been obtained for Honey Creek, 

a basin which was chosen as a test area partly because of its agricultural 

nature and absence of major point sources. The orthophosphate concentration 

in Honey Creek appears to be positively related to discharge--but only during 

certain periods of the year. Analysis of Honey Creek data has been conducted 

by partitioning streamflow into two components; direct runoff, and groundwater 

outflow. The former consists of surface runoff from rainfall and snowmelt 

events, plus a portion of infiltrated water which passes rapidly to the tile 

drains underlying agricultural land. Flow separation has been accomplished 

solely on the basis of discharge records at the watershed mouth; experimentation 

indicates that the methodology utilized is not critical. The analysis of 

orthophosphate has then been based on the assumption that each observed 

concentration represents a weighted average of orthophosphate concentrations 

in the two flow components. That is, 

where: CD = 

CG = 

Q,, Q, = 

orthophosphate concentration in direct runoff; 

orthophosphate concentration in groundwater outflow; 

streamflow due to direct runoff and groundwater 

outflow, respectively; 

The imputed orthophosphate concentrations CD and CG have been 

estimated by regression analysis, utilizing the 1976 record for Honey Creek 

which spanned 7 months and contained more than 300 observations. Values of 

C and C were allowed to vary among different portions of the sampling 

D G 

period (through the use of dumy variables yielding the interesting results 

shown in Figure 6). Both of the imputed concentrations followed a similar 

pattern, falling from moderate levels in mid-winter to low values in April, 

then rising to high levels in June and July. The seasonal variation was 

more pronounced for the imputed orthophosphate Concentration in direct runoff; 

and this quantity was generally higher than the imputed groundwater concentration. 

170

0.200 0.200- - 

"1 " 

' DIRECT RUN OFF 

I 

I 

I 

I 

I 

I 

0.160 0.160- - 

I 

I 

-I 

3 

z_ 

z 0.120 0~120-"~"""""g - 

1""""""g 

P 

t a 

+ 

z 

w 

y 0.08 - 

y 0.08- 

0 

0 

0.04 - 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

r""-d 

r""-d 

I 

p m " l 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

GROUNDWATER 

OUTFLOW 

Figure 6. Imputed Orthophosphate Concentrations in Direct Runoff and Groundwater 

Outflow 

Honey Creek Watershed, 1976

The rise in concentrations from April to June is believed to be 

related to fertilizer application on agricultural land. This finding, if 

verified in other watersheds, could provide an important index of the 

agricultural contribution to phosphate loadings. The decline in concentrations 

from January to April could represent exhaustion of the soluble 

phosphate available from agricultural activities in the previous year. The 

mid-February decline in the direct runoff concentration could also be 

related to another factor. Discharge during the previous period was caused 

primarily by snowmelt, and contained unusually low suspended solids concentrations 

(see discussion below). The rate of phosphate adsorption during 

transport could therefore have been relatively low, due to lack of available 

sites. The decline in orthophosphate concentrations which followed the 

major rainstorm in February 16 could thus represent, in part, simply a 

return to more normal circumstances with regard to phosphate transformation. 

In any case, linkage of orthophosphate concentration to the crop production 

cycle appears to be the only plausible explanation for the overall patterns 

shown in Figure 6. 

The two-compartment approach utilized here for analysis of orthophosphate 

could easily be expanded to a three-compartment approach by 

incorporation of the point source equation given earlier. This of mode 

analysis is considered promising in cases where full-scale chemical/ 

hydrologic modelling is not feasible. 

PARTICUATE PHDSPHATE 

There is little question that most of the total phosphate in 

transport during storm flow conditions is occurring in association with 

particulate matter, as measured by suspended solids. The overall correlation 

between total phosphate and suspended solids is good for most, but 

not all of the Lake Erie basins, (Figure 7). Linear regressions can be fitted 

to these data and take the form of y = mx+b, as in the Maumee; 

TP (ug/l)=l. 32(SSmg/1)+153 (Maumee at Waterville, 1975). 

The Brandywine Basin Data also found a good relationship between 

total phosphate and solids, but used "Residue on Evaporation" (ROE) rather 

than suspended solids. bThose data showed the best curve (r' fit = 0.86) to 

be the power curve y=ax 

, yielding; 

Total Phosphate (pg/l) = 1.48 (ROE) 0.975 

Of course, the ROE measurement includes both suspended and 

dissolved solids, and would not be suitable for basins with relatively high 

dissolved solids, such as the Maumee. 

Recognizing that the bulk of phosphate transport occurs with 

particulates, it is of interest to take that portion of the total phosphate 

which is non-soluble, defined as TP (TP - OP = TP ), and compare its ratio 

P P 

to suspended solids as the concentration changes over a hydrograph. The 

linkage of total minus ortho phosphate to suspended solids concentration is 

extremely strong. In the statistical analysis of Honey Creek data, the 

only additional factor needed to explain total minus ortho P concentrations 

172

173 

N N 4 

LD 0 v) 

9 Y 9 

4 0 0 

1/9W 'd ltJ101

was stream discharge (which had a very low estimated exponent). By combining 

and rearranging the predictive relationships for total minus ortho 

and suspended solids, an expression has been obtained for the of ratio the 

former to the latter, as a function of discharge, seasonality, and time 

since start of storm. This predictive equation for the phosphorus-tosediment 

ratio (excluding orthophosphate) is depicted graphically in Figure 

8. The curves in Figure 8 relate to storm periods in the spring; summer 

conditions would differ slightly. The phosphorus-to-sediment ratio is 

found to be linked positively to time since start of storm, which is plotted 

on the horizontal axis, and negatively to discharge. 

Both of these associations are probably related to systematic 

differences in the composition of the suspended load carried by the stream 

during different flow conditions. In the early stages of storm events, and 

during periods of high discharge generally, a large proportion of the 

suspended load may consist of coarse grained materials which are relatively 

low in phosphorus content. Since these are the materials most likely to be 

lost from storm water during storage and transport, the sediment load at 

other times tends to be limited primarily to fine colloidal particles, 

which are relatively high in phosphorus. Although additional studies are 

needed to provide fuller understanding of these relationships, it is clear 

that the phosphorus-to-sediment ratio is fairly stable across storm events. 

During non-storm periods, the ratio tends to be somewhat higher than the 

values shown in Figure 8 (due in part to the more prominent role played by 

soluble orthophosphate). 

CHANNEL SCOUR AND I~POSITICN 

An issue which has been the subject of some discussion is the 

role of the stream channel in sediment transport, i.e., the extent to which 

observed suspended solids concentrations reflect SCOUK and deposition 

processes in the channel system. The Honey Creek data for the February 

snowmelt/thaw period provide an interesting perspective on this issue. In 

the four-day period from February 10 to 14, high discharges occurred entirely 

as a result of snowmelt and thawing of the soil surface. Suspended solids 

concentrations at Melmore would thus reflect channel scour, and land erosion 

due to surface flow, rather than raindrop impact. The low concentrations 

observed suggest that channel scour tends to be of relatively minor importance. 

The following table compares the February snowmelt period with a 

four-day storm period in March, which involved a somewhat higher peak 

discharge but similar total runoff. Both of these periods occurred approx- 

imately two weeks after a major storm; initial discharge in each case was 

90 cfs. 

Suspended Solids 

Peak 

Discharge in cfs Load in concentration 

Period Duration Peak Average metric tons (md1) 

Feb. 10-14 4.0 days 947 820 

March 3-7 4.0 days 1279 805 

174 

522 104.1 

1950 506.5

.0030 

.Ei .0020 

c, 

a 

a: 

w 

0 

a, 

2 .0015 

m 

> 

.OOlO 

- 

Q= 50 

.0025 - Q=i50 

Q=1100 

- 

- 

I I I I 

0 1 2 3 4 

Time Since Storm Start, in Days 

Figure 8. 

Values of the Phosphorus-to-Sediment Ratio (Excluding 

Orthophosphate) by Time Since Storm Start and Discharge 

(Q) Honey Creek Watershed, 1976. 

175

The total suspended solids loading was nearly four times as great 

in the March storm as in the February snowmelt period; and the peak concentration 

was five times as great. There appears to be no reason, other than 

the somewhat lower peak discharge, why net channel scour should be less in 

the February period than in the March period. Scour should perhaps be greater, 

due to the low utilization of transport capacity by sediment from the land 

surface. Thus, if these figures can be regarded as representative, one 

might conclude that channel scour is responsible for no more than 25% about 

of the total suspended solids load in a moderate storm (and possibly much 

less, in view of the other potential sources of sediment during snowmelt/thaw 

periods). The implication would be that the bulk of suspended solids and 

phosphorus loadings from small basins such as Honey Creek tend to originate 

from the land during the same storm period which in they are observed. 

Hydrologic Response 

A great deal of analysis has been done (LEWMS, 1975) which considers 

the variation in concentration of total phosphate with hydrologic response 

in different watersheds, showing the seasonality, storm duration mag- and 

nitude effects. Several multipeaked hydrographs have also been analyzed, 

and demonstrated the "hysteresis" effect. The conclusion drawn from these 

data is that a rigorous analysis of individual events in a watershed is 

necessary to understand the generation of diffuse pollutants, and any 

application of "annual loading factors" is misleading at best. Of particular 

interest in the data analyzed was the large variability in mass 

transport produced with different storms. It was seen that any estimate of 

load contributed per unit area of watershed (kg/ha) would depend entirely 

upon the period sampled, and thus we can begin to understand why the literature 

shows such a great variability when different sets of data are compared 

in this way. Expressed quite simply, there is no such thing as "average" 

mass flux produced in a watershed, but rather the diffuse pollutant transport 

which occurs is entirely a function of the hydrologic response of the 

basin, and the mechanisms which generate the response determine the pathways 

by which pollutants are brought into suspension or solution and pass 

through the system. The fact that greater storms produce greater transport 

per "unit area" could be interpreted to mean that an increased percentage 

of the basin land area was having pollutants removed form its surface, as 

"partial area" hydrology would suggest (Dunne, 1973). Dunne and others 

have suggested that the hydrologic response a of basin does not occur a on 

uniform basis, but that incident precipitation on certain areas produces 

the immediate hydrograph rise. These partial areas are flat, impervious 

soils with high water table, usually contiguous to the drainage channels. 

Since diffuse pollutant transport occurs in association with this runoff, 

the management implication is that only a small portion of a total watershed 

need be regulated to reduce the production of these pollutants. 

TOTAL PHOSPHATE - (~GANIC (COD) TRANSPORT 

One might question the possibility that much of the total phos- 

phate measured with storm transport is occurring in organic matter, or 

detritus, rather than in association with inorganic matter or soil particles. 

176

Everything from decaying vegetation to macroinvertebrates are flushed from 

a river bottom or land surface and of course contain phosphorus. The only 

parameter measured over hydrographs which might express the organic transport 

has been Chemical Oxygen Demand (COD). It has been observed that 

there is a very great increase in concentration of COD during runoff, 

reaching values averaging 40 mg/l and peaks of over 100 mg/l. This represents 

an organic transport which, in many basins, far exceeds the input 

from point sources. 

As far as the relationship between total phosphorus and COD goes 

however, it is very poor; that is, while both materials are in transport 

during a runoff event, they do not seem to occur in association with each 

other. While these data is far from conclusive, they do not support the 

"organic phosphorus" source possibility. 

PHOSP~DRUS TRANSPORT THROUGH ESTUARIES 

A key question pertaining to the storm transport of phosphorus 

out of river basins into a lake such as Lake Erie, is just how much phosphorus 

actually gets flushed through the estuary and reaches the lake. Knowing 

the nature of these estuaries, the tremendous dredging required to maintain 

the shipping channels and the sediment-associated nature of most of the 

total phosphorus, one might speculate that we have exaggerated the loading 

problem, and in actuality only a fraction of a tributary basin's nutrients 

actually reach the lake. However, synchronous sampling of riverine and 

estuarine stations in both the Maumee and Cuyahoga basins during several 

spring storms in 1975 strongly suggest, although not conclusively, that 

most if not all of the sediment-associated phosphate is flushed through the 

estuary during a large storm. A great deal more work, however, is necessary 

to answer this question satisfactorily. 

BIOLOGICAL UPTAKE DURING NON-STORM CONDITIONS 

One final question pertains to the phosphate which is discharged 

from treatment plants and either taken up by aquatic vegetation or precipitated 

by calcium ions to settle on the stream bottom. These mechanisms 

are significant in many basins, especially during summer, (TMACOG', 1976). 

This "point source residual" can accumulate in a stream, and subsequently 

may be scoured during storm runoff. However, a continuous mass balance 

analysis for several watersheds with large point source inputs, such as the 

Portage basin, demonstrated that only a minor portion of the total mass 

transport of phosphate during storms can be accounted for by this residual. 

SEARCH NEEDS 

In an effort to better guide the management strategies which are 

evolving with respect to the reduction and control of diffuse or non-point 

sources in the Great Lakes, some general knowledge gaps can be identified 

' Toledo Metropolitan Area Council of Governments 

177

egarding phosphate which have broad applicability to other pollutants. 

Because of the immediate need for this information, these deficiencies receive 

a higher priority than some of the long term research needs. These knowledge 

gaps can be filled by four general programs carried out jointly by the various 

agencies operating in the Great Lakes. They as are follows: 

(1) Evaluate the effectiveness of land management techniques, 

especially agricultural, for nutrient load reduction; 

(2) Analyze storm transported phosphate to determine long 

term bioavailability; 

(3) Develop hydrologic response models which more accurately 

simulate pollutant production and transport mechanisms, and 

(4) Evaluate both the positive and negative aspects of widespread 

acceptance of tillage modification techniques, such as no-till. 

While a great wealth of water quality data has been developed 

throughout the Great Lakes Basin, is it likely that additional sampling 

will be required for selected watersheds to accomplish the first three 

programs. Other important research questions should not be neglected, 

including a reevaluation of erosion loss analysis techniques (USLE) as 

applied to watersheds, modelling particulate transport during storms, lake 

bottom release rates and tile drainage effects, to mention only a few. 

However, the primary objectives of research during the next to two five 

years should centre on land management techniques which will actually 

reduce diffuse pollutants and the evaluation of present erosion control 

techniques to determine if they will accomplish the necessary reduction. 


Baker, D. B. and Kramer, J. W., (1973). Phosphorus Sources and 

Transport in an Agricultural River Basin of Lake Erie, 

Proc. 16th Conf. Great Lakes Res. 

Bowen, D. H. M., (1970). The Great Phosphorus Controversy, Environmental 

Science and Technology, 6, 725-726. 

Cahill, T. H., P. Imperato and F. H. Verhoff, (1974). Evaluation of 

Phosphorus Dynamics in a Watershed, Journal of the 

Environmental Engineering Division, ASCE, April 

100, (EEZ), Proc. Paper 10445. 

- 

Cahill, T. H., J. Adam and D. Baker, (1976). The Importance 

of Diffuse Pollutants in River Chemistry, Presented at the 19th 

Conference on Great Lakes Research, May 1976. 

Cahill, T. H., P. Imperato, P. K. Nebel and F. H. Verhoff, (1975). 

Phosphorus Dynamics In A Natural River System, in WATER- 

1974, 145, 71, A.I.Ch.E., New York. 

Cleaves, E. T., Godfrey, A. E. and 0. P. Brinker, (1970). Geochemical Balance 

of a Small Watershed and its Geomorphic Implications, Geological 

Society of America Bulletin, e, 3015. 

178

Connell, C. H., (1965). Phosphates in Texas Rivers and Reservoirs, Water 

Research News No. 73, Southwest Water Research Council, 

Fort Worth Tex. 

Deevy, E. S., Jr., (1970). Mineral Cycles, Scientific American, 223, 

(3), 149-158. 

Dunne, T., and Black R. D., (1970). Partial Area Contributions to Storm 

Runoff in a Small New England Watershed, Water Resources 

Research, 6, 1269. 

Hammer, Thomas, H., (1976). Interim Report; Urban Land/Water 

Relationships, U.S.E.P.A., Cont. No. 68-01-3551, June 1976. 

Hutchinson, G. E., (1969). Eutrophication, Past and Present, Eutrophication: 

Causes, Consequences, Correctives, National Academy of Sciences, 

Washington, D. C., pp. 17-26. 

Johnson, N. M., g., (1969). A Working Model for the Variation in 

Stream Water Chemistry at the Hubbard Brook Experimental Forest, New 

Hampshire, Water Resources Research, 1, 1353. 

Keup, L. E., (1968). Phosphorus in Flowing Streams, Water Research, 

- 

2, 373. 

Lee, 6. F., (1969). Analytical Chemistry of Plant Nutrients, Water and 

Sewage Works, 116, R-38. 

Logan, T. J. and G. 0. Schwab, (1976). Nutrient and Sediment Character- 

istics of Tile Effluent in Ohio, Journal of Soil and Water 

Conservation, 2, (1). 

Mackenthun, K. M., (1965). Nitrogen and Phosphorus in Water, An Annotated 

United States Selected Bibliography of Their Biological Effects, 

Publication 1305. United States Department of Health, Education 

and Welfare, Division of Water Supply and Polution Control, 

pp. 1-112. 

Mackenthun, K. M., (1968). The Phosphorus Problem, Journal of the Water 

Works Association, 60, 1047-1053. 

McKee, 6. D., &, (1970). Sediment-Water Nutrient Relationships, Part 2, 

Water and Sewage Works, 177, 246. 

National Assessment of Trends in Water Quality, Environmental Control, 

Inc., National Technical Information Service, Springfield, 

Va., June, 1972. 

Rendon-Herrero, 0. J., (1974). Estimation of Washload Produced on Certain 

Small Watersheds, Journal of Hydraulics Division, ASCE, 100, 835. 

Rigler, R. H., (1956). A Tracer Study of the 

Water, Ecology, x, 550-562. 

179 

Phosphorus Cycle in Lake

Sandoval, M. T., T. H. Cahill, and F. H. Verhoff, (1975). Mathematical 

Modellings of Nutrient Cycling in Rivers, Div. of Env. Chem. 

ACS., Phila., Pa., April 6, 1975. 

Wang, W. C. and Evans, R. L., (1970). Dynamics of Nutrient Concentrations 

in the Illinois River, Journal Water Pollution Control Federation, 

- 42, 2117. 

Wolman, M. G., (1971). The Nation's Rivers, Science, 174, 905. 

180




Nutrients - N 

T. Logan 

Nitrogen along with phosphorus are nutrients that are required by 

most organisms in large quantities. These organisms range from the 

smallest bacteria to algae and also higher plants used by man for food. 

Many authors have cited nitrogen and phosphorus as the nutrient 

elements limiting productivity in waters (Mackenthun &., 1967; 

Hasler, 1970). Keeney indicated that N may be more important than P 

in limiting growth in eutrophic lakes, especially those high P in 

(Keeney, 1972). 

This review will consider: 

1. The forms of nitrogen involved in fluvial transport with emphasis 

on sediment N. 

2. The relative sources of nitrogen entering fluvial systems. 

3. The microbiological and chemical transformations of nitrogen 

involved in sediment-aquatic environments. 

4. The role of the C/N ratio in nitrogen transformations. 

5. Identification of research problems and knowledge gaps. 

1, FORMS OF NITROGEN 

Nitrate-N 

Ions 

- NO-3 

Ammonium-N NH+u 

Nitrite-N NO-2 

181 

soluble anion; product of 

nitrification; used by most 

organisms; not retained in 

soil, leaches readily. 

soluble cation; product of 

decomposition of organic 

materials; utilized by most 

organisms; retained on neg- 

atively charged clay particle. 

soluble anion; product of 

biological oxidation; toxic 

to higher plants; does not 

usually occur in high concentrations; 

will accumulate in 

soil or sediment at high pH 

and under anaerobic conditions.

Ammonia-N 

Nitrous oxide 

Nitrogen 

PARTICULATE FORMS 

Gases 

product of biological 

decomposition; toxic; 

evolved when pH is high 

or under dry soil conditions. 

product of denitrification; 

constituent of atmosphere; 

product of denitrification. 

Many attempts have been made to identify the mostly organic forms 

of nitrogen In biological systems. In addition to the biologically viable 

compounds in fauna and flora tissue including protein, amino acids, and 

nucleic acids. there are the complex N forms found in decomposed organic 

materials. This organic matter, also called humus is the product of 

primarily microbiological decomposition. Brenmer (1967) summarized the 

extensive work in soil organic nitrogen characterization. Based on this 

work, soil organic nitrogen may be divided into several categories (Table 

1). Much of the soil organic N remains unidentified and may include amino 

acids other than those previously identified and heterocyclic nitrogen 

compounds (Bremner, 1967). 

+ 

The small amount of fixed MI, is primarily a consequence of the 

+ 

physiochemical entrapment of NHI, ions between the internal surfaces of 

expandable clays such as illite (Figure 1). The degree of fixation will 

vary with expandable clay content and the extent of interlayer weathering. 

The bioavailability of particulate N has concerned agronomists 

for years and is also of interest to ecologists studying the impact of 

tributary loadings on lake water quality. Attempts to correlate N 

bioavailability with a particular fraction or fractions has been unsuccessful. 

In recent years, more attention has been given to direct bioavailability 

and mineralization tests (Stanford, 1968) and correlations 

between chemical extraction and N released by incubation (Stanford and 

Smith, 1976). These tests show some promise in estimating potential N 

mineralization in soil but have not been extended to aquatic systems. 

2, SOURCES OF NITFKIGEN ENTERING FLUVIAL SYSTEMS 

a) Runoff and Erosion - the main product of runoff and erosion is 

surface soil and some crop residue, leaves and other debris. Some 

soluble Nos-N and N1k-N is transported during runoff; however, 

if erosion is significant the organic soil N contribution 

will be much greater (Armstrong et&., 1974). Runoff sediment 

is enriched with nitrogen, i.e. the total N content of the 

sediment is higher than the soil from which it originated. 

Hensler and Attoe (1970) found that total N enrichment was 

2.7 to 5 fold. This is due to selective clay transport and 

also the lower density of some organic matter. The total 

particulate N content of sediment can be estimated 

from a knowledge of the soils from which it was derived. 

182

TABLE 1. 

FORMS OF PARTICULATE N IN SOILS 

Form X of total N 

Amino - N 20-40 

Hexosamine 5-10 

Purines and pyrimidines -1 

Unidentified forms 30-50 

Fixed NH4 3-8 

TABLE 2. 

CHARACTERISTICS OF WASTEWATER EFFLUENTS 

Primary Trickling Secondary Ponds 

Activated 

Sludge 

”----% 1- 

Total N 31 16 23 23 

NO 3-N 0.3 6.3 3.9 0.7 

NH4-N 23 5.9 17.0 a. o 

183

CI 

0 

0 

0 

0 

0 

0 

0 

0 0

Jenny (1941) in his classic thesis on soil formation indicated 

that soil N increased with increasing rainfall and showed that 

soils developed under grasses contained higher N levels than 

under forest vegetation (Figure 2). For most of the Great 

Lakes basins, the total N of virgin soils would be about 0.1 

- 0.25%. Cultivation has resulted in substantial mineralization 

of soil N (Figure 3) and present levels are about 60-70% of the 

virgin soil N. Further net soil N loss is quite low and crop 

residue management and adequate N fertlization can maintain 

soil N levels. 

b) Tile Drainage and Seepage - this source will contain mostly 

nitrate; low concentrations of NHb-N and dissolved organic -N 

may be found in tile drainage (Armstrong et&., 1974). 

c) Precipitation - varying amounts of N (5-50 kg/ha) can be added 

in rainfall; made up of both nitrate and ammonia. 

d) Sewage - the major source of N from domestic sewage is that 

discharged as secondary treated effluent. Pound and Crites 

(1973) indicated that depending on the method of treatment (Table 

Z), effluent will contain varying amounts of N forms with 

organic N as the major constituent. The organic N is quite 

stable and resistant to further mineralization. Septic tank 

leakage can be a major component N of loading in some watersheds, 

but this source is difficult to quantify. Most input 

would be as nitrate. 

e) Livestock Wastes - Improper disposal of livestock wastes due 

to inadequate storage facilities or because of excessive 

application to soil can result in significant N additions to 

streams. Livestock wastes are highly variable in their 

characteristics depending on livestock type and the degree of 

decomposition of the manure. Runoff of fresh manure from 

barnlots or feedlots can result in high BOD and NH3 loadings 

which can have disastrous effects on downstream aquatic 

habitat. Leaching of NO,-N from excessively manured land will 

mean increased N loading. Livestock wastes vary in total N 

content (Table 3) and the percentage of the total N that is 

subject to mineralization. In general, about 50% of the total 

N is mineral ( NHJ + NO3) and about 25-50% of the organic N is 

mineralizable in the first year. 

f) Processing Wastes - may be high in both NHk-N and organic N. 

BOD levels are usually high. A localized problem. 

g) Overall Sources of N to Great Lakes - Various estimates of 

point and nonpoint sources of nitrogen would indicate that about 

30-50% of the total N loadings are from point sources, particularly 

wastewater effluents. Loadings of N to Lake Erie 

from various tributaries (Table 4) indicate that most of the N 

is in the form N03-N of with smaller amounts of organic and 

NH4-N. If we assume an annual mineralization of 3% for the 

organic N (based on rates for soil N), then it would appear that 

sediment N is relatively insignificant as a source N of loading 

to Lake Erie. 

185

c 

C 

0, 

0 

C 

0 

C 

al 

0) 

2 4- .- 

0.300 

- 0 Grassland soils 

- 

8 Grassland soils (averages) 

- t Forest soils 

- + Forest soils (averages) 

- 

- 

- 

$J 0.200 - 

a 

- - 

.- 

5: 

- 

LC - 

0 - - 

C 

0, 

c - 

- 

- 

- 

- Q 

E 0.100 - 

Humidity factor (N.S.Q.) 

+ 

New Jersey 

Figure 2. Effect of rainfall on soil N content (Jenny, 1941) 

+

18 7 

I 

0 

0 

0.. 

0 

0

Stream 

Cuyahoga 

Sandusky 

Black 

Huron 

Portage 

TABLE 3. 

CHARACTERISTICS OF LIVESTOCK WASTES 

Dairy Cow 3.9 

Beef Feeder 4.9 

Swine Feeder 7.5 

Total N (Percent of total Solids) 

Sheep Feeder 4.5 

Poultry Layer 5.4 

Poultry Broiler 6.8 

Horse 2.9 

TABLE 4. 

TRANSPORT OF NITROGEN FROM STREAMS DRAINING INTO LAKE ERIE 

(1974-1975) LAKE ERIE WASTEWATER MANAGEMENT STUDY 

Sediment 

mt/yr x lo3 

1222 

483 

270 

136 

71 

48 

* Percent of total Kjeldahl-N 

~_______ 

N03-N + N02-N 

mtlyr % * 

34700 594 

2020 120 

5170 85 2 

3520 297 

1180 317 

2100 808 

18 8 

Ammonia-N 

mt/yK % 

966 16.5 

476 20.3 

213 35.1 

338 28.5 

46 12.4 

57 21.9 

Organic-N 

mt/yK % 

5174 88.6 

1200 71.4 

394 64.9 

847 71.5 

326 87.6 

203 78.0 

Kjeldahlmtlyr 

5840 

1680 

607 

1185 

372 

260

3. BIOLOGICAL NITROGEN TRANSFONTIONS IN SEDIENT/WATER SYSTEMS 

The important sediment-nitrogen reactions are visualized 

in Figure 4 (Keeney, 1972). 

a) Nitrogen Fixation - primarily by blue-green algae (Cyanophyceae). 

Some fixation by anaerobic heterotrophs has been reported but 

N fixation in sediments is probably of only minor importance 

(Brezonik, 1971). 

b) Immobilization - also termed assimilation. In aquatic systems, 

+ 

NHs-N assimilation is probably more significant than N03-N. 

Whereas, in terrestial systems (soils) bacteria and fungi are 

dominant in N assimilation, in aquatic systems the phytoplankton 

and herbivorous zooplankton are more important because of their 

numbers and capacity to assimilate organic materials. Bacteria 

play an important role in the decay of these organisms. Bacteria 

may aLso be very important in utilizing organic N secreted by 

zooplankton and converting it to mineral N (Keeney, 1972). 

c) Mineralization - Ammonification - Decomposition of organic 

materials by heterotrophic bacteria results in the release of 

mineral N as NH;. N regeneration, i.e. net N release, is 

determined by the stability of organic forms and the ability 

of the bacteria to convert organic C to cellular C (Foree 

" et al., 1971). Net mineralization appears to be less efficient 

under anoxic conditions than when the system is aerated. The 

degree of mineralization of organic N in sediments will depend 

on the extent to which the organic material is humified (Bremner, 

1967). Recent organic deposits will be mineralized to a greater 

extent than organic N from soils. In addition, there is some 

degree of stability imparted by the interaction of organic compounds 

with clay minerals. Zooplankton are involved in ammonification by 

excreting NH3 and amino acids which they gain by feeding on 

phytoplankton + detritus. Johannes (1968) believes this 

to be the dominant mechanism of ammonification in surface 

waters. Direct autolysis after cell death may account for 

30-50% of N released from plant and animal material. Bacterial 

decomposition is considered to be of minor importance in N 

mineralization in shallow lakes except where sewage contributes 

large amounts of organic matter. In sediment systems, however, 

bacterial and fungal mineralization is the dominant process. 

d) Nitrification - Biological oxidation of nitrogen to nitrite and 

nitrate is performed by heterotrophs including bacteria, fungi 

and algae; however, these are of limited importance compared with 

the autotrophic bacteria. The net nitrification is given as: 

N H + ~ 20; -f NO; + H ~ + O ZH+ + energy 

Nitrite, NO;, is an intermediate oxidation product, but is rzrely 

present in significant concentrations because the rate NOz of + 

oxfdation is much faster than the initial oxidation NHr of to 

N02. 

189

ATMOSPHERE 

WATER NO,-, NH,', Organic N 

SEDIMENT ~,y 

{ Rainwater 3 

External Sources 

Particulate organic N-NH,' 

[-I - NH,' (Soluble 

(Nitrification) 

Exchangeable) 

9 

NO,- in Groundwater 

Figure 4. Generalized nitrogen cycle in waterlsediment system (Keeney, 1972)

The conditions for nitrification are favourable in fluvial Systems 

above 1 O C and there is evidence to indicate that nitrification 

will also proceed in bottom sediments if they are stirred and pH 

buffered (Keeney, 1972). 

e) Denitrification - The biological reduction of nitrate to gaseous 

N (NO, NzO, N2). This is a significant reaction in streams and 

lakes, leading to loss of nitrogen from the system. Bacteria 

responsible for denitrification include species of the genera 

Pseudomonas, Alcaligenes, Achromobacter, Bacillus and Micrococcus. 

Denitrification occurs in the absence 0,, of induced by 0, 

consumption during decomposition of organic material (BOD) and 

by the limitation of O2 diffusion in quiescent water. Denitrification 

is limited by temperature (optimum at 60-65°C 

and considerable activity above 20°C) and pH (optimum at pH's 

near 7). Denitrifiers require a readily available source of 

organic carbon. Denitrification will be high in high BOD stream 

sections, especially where the organic carbon is easily decomposable. 

Denitrification - nitrification can occur simultaneously (Keeney, 

1972) and this process is responsible for much of the disappearance 

of NOB-N from lakes. The role of denitrification in fluvial N03-N 

balance has not been studied extensively; however, it would appear 

that conditions for denitrification would be optimum during low 

flow summer periods if sufficient carbo? is present. Reddy 

al. (1976) have recently shown that NHs in the anoxic zone 

of sediment can be denitrified NH,, + as diffuses into the oxic 

zone and is nitrified. The nitrate then diffuses down into the 

anoxic zone where it is decitrified. 

4, THE F~LE OF THE CARBON/NITROGEN RATIO IN NITROGEN TRANSFORNITIONS 

All organisms have a characteristic C/N ratio, depending on 

the relative amounts of protein in their biomass. Higher plants 

may range from as high as 1OO:l for some straw residues to as low 

as 2O:l for some of the legumes (Brady, 1974). Bacteria and other 

microorganisms have a ratio of about 9:l. During the heterotrophic 

decomposition of organic materials, mineral N (N03-N) may be assimilated 

or released depending on the C/N ratio of the mineral being decomposed 

(Figure 5). Much of the N assimilated by the heterotrophs will be 

mineralized as these organisms themselves die and are decomposed. The 

N not mineralized becomes part of the solid phase (soil or sediment) 

as organic matter with a C/N ratio of about 10-12:l. This nitrogen 

is quite resistant to further decay. The C/N ratio of decomposable 

material in transport will determine if there is a net gain or loss 

of N from the system due to microbiological transformations. 

5. SEDIPENT-NITROGEN TRANSFORMATIONS DURING FLUVIAL TRANSPORT 

a) During Storm Runoff - during periods of maximum transport in the 

early spring, biological nitrogen transformations will be minimal 

due to the short transport intervals and cooler temperatures. 

191

192

Sediment nitrogen will closely reflect source materials (eroded 

soil, resuspended bottom sediments). These sediments are likely 

to have C/N ratios of about 10-12:l to and be quite stable. 

Low Flow Winter Runoff - this is a period of minimum sediment 

transport. Most of the nitrogen transported will be NOS-N from 

seepage and tile flow with some NHq-N from point discharges. 

There will be a minimum of biological activity. 

Low Flow Summer Runoff - during this period, sediment transported 

will be low; nitrogen transport will be minimal and confined to 

point sources. Biological activity will be high. Sediment-water 

phase reactions involving biological nitrogen transformations 

will be operating under optimum conditions. Nitrate will be 

removed from the water phase by assimilation and denitritifation. 

The net addition or removal of N frpm the system will depend 

on the environmental conditions determined by stream characteristics. 

Sediment acts to buffer the transport of nitrogen as it 

does for phosphate. The multitude and complexity of biological 

N transformations make N transport a very dynamic process and 

makes estimation of delivery ratios to streams difficult (McElroy 

" et al., 1976). 

6, GAPS IN CURRENT WWLEDGE 

Most of the available literature pertains to terrestial or lake 

systems. In-stream nitrogen transformations involving sediment 

nitrogen have not been studied extensively. 

The extent of microbial and algal N fixation in streams not is 

known. 

A satisfactory model for N transformation during fluvial transport 

is needed; this is especially true of in-stream assimilation and 

denitrification. 

The extent of transport of N in organic materials (crop residues, 

leaf litter, detached aquatic vegetation and zooplankton) needs 

to be further elucidated. 

Analytical methods to determine bioavailability of suspended 

sediment nitrogen should be developed. 

The effect of estuaries on nitrogen loadings to the lake is not 

known. 

In summary, the processes of nitrogen cycling and interchange 

in sediments are complicated and poorly understood. The mechanisms whereby 

nitrogen is exchanged between water and sediments are probably known, 

and in some cases qualitative rankings can be given to their importance. 

However, almost no information is available to establish the in situ 

rates and controlling factors for these processes (Brezonik, 1971). 

193


Armstrong, D. E., K. W. Lee, P. D. Uttomark, D. R. Keeney, and R. F. 

Harris, (1974). Land Use/Water Quality Relationships in the 

U.S. Great Lakes Basin. Task A6: Nutrients. PLUARG, IJC, 

Windsor. Ontario. 

Brady. N. C., (1974). The Nature and Properties of Soils, 8th Edition, 

Macmillan, New York. 

Brewer, J. M., (1967). Nitrogenous Compounds. In Soil Biochemistry, 

A. D. McLaren and G. H. Petersen, Eds., Marcel Dekker, N. Y., pp. 

19-66. 

Brezonik. P. L., (1971). Nitrogen: Sources and Transformations in 

Natural Waters. Presented at American Chemical Society, Los 

Angeles, California. 

Foree, E. G., W. J. Jewel1 and P. L. McCarty, (1971). The Extent of 

Nitrogen and Phosphorus Regeneration from Decomposing Algae. 

Water Research, I (27).1-15. 

Hasler, A. D., (1970). Man-Induced Eutrophication of Lakes. Global 

Effects of Environmental Pollution, S. F. Singer, Ed. Springer- 

Verlag, N. Y., pp. 110-125. 

Hensler, R. F. and 0. J. Attoe. (1970). Rural Sources of Nitrates 

in Water. Proc. 12th Sanit. Eng. Conf., Nitrate and Water Supply, 

Source and Control, Univ. Illinois. Bull., %,(2),86-98. 

Jenny, H., (1941). Factors of Soil Formation. McGraw-Hill, New York. 

Johannes, R. E., (1968). Nutrient Regeneration in Lakes and Oceans. 

Adv. Microbiol. Sea., 1,203-212. 

Keeney, D. R.. (1972). The Fate of Nitrogen in Aquatic Ecosystems. 

Eutrophication Information Program, University of Wisconsin, 

Madison, Wisc. 

McElroy, A. D., S. Y. Chiu, J. W. Nebgen, A. Aleti and F. W. Bennett, 

(1976). Loading Functions for Assessment of Water Pollution from 

Nonpoint Sources. Midwest Research Institute, EPA-600/2-76 151. 

Mackenthun, K. M. and W. I. Ingram, (1967). Biological Associated 

Problems in Freshwater Environments - U.S. Dept. Interior, FWPCA, 


Nomnik, H.. (1965). Ammonium Fixation and Other Reactions Involving a 

Nonenzymatic Immobilization of Mineral Nitrogen in Soil. In 

Soil Nitrogen, Amer. SOC. Agron. Monograph No. 10. 

Pound, C. E. and R. W. Crites, (1973). Characteristics of Municipal 

Effluents. Proc. Joint Conf. Recycling Municipal Sludges and 

Effluents on Land, Champaign, Ill. 

Reddy, K. R., W. H. Patrick, Jr. and R. E. Phillips, (1976). 

Ammonium Diffusion as a Factor in Nitrogen Loss from Flooded 

Soils. Soil Sci. SOC. her. Journ., 3,528-533. 

194

Stanford, G., (1968). Extractable Organic Nitrogen and Nitrogen 

Mineralization in Soil. Soil Sci., 106,345-351. 

Stanford, 6. and S. 3. Smith, (1976). Estimating Potentially 

Mineralizable Soil Nitrogen from a Chemical Index of Soil 

Nitrogen Availability. Soil Sci., =,71-76. 

ADDITIONAL LITERATURE 

Likens. G. E., (1972). Nutrients and Eutrophication: The Limiting- 

Nutrient Controversy, Symposium. American Society of Limnology 

and Oceanography, Allen Press, Lawrence, Kansas. 

Allen, H. E. and J. R. Kramer, (1972). Nutrients in Natural Waters. 

Environmental Science and Technology Series, Wiley-Interscience, 

John Wiley and Sons, New York. 

195

DISCUSSION 

Dr. R. Swank: Relative to your problem on nitrogen balances in marshes or 

the ability of marshlands and wetlands to attenuate the nitrogen loads, 

there is a large study going on now, sponsored by the Smithsonian Institute 

in the Chesapeake Bay area in Maryland, in which I understand, they are 

focusing primarly on nitrogen, phosphorus and carbon in wetlands. This is 

in both salt water marshes and freshwater marshland. We hope to get some 

useful data out of that. The laboratory where I work (U.S. EPA, Athens, 

Georgia) is also sponsoring some work at the Westpoint Military Reservation 

where there are rather extensive small freshwater marshes driven almost 

entirely by sub-surface flow, intermittent flows and runoff from primarily 

forested and pasture type land use. There are no pasturing animals on it, 

just grassland. That might also be very useful for this purpose. We are 

focusing on that area with regard to some modelling studies. It is a major 

plus because the data so far suggest that marshes are particularly effective 

in absorbing nitrogen - i.e. denitrification. They appear to be great sinks 

for nitrogen of all forms, less so for phosphorus and the carbon situation 

is unclear. Frankly, there apparently seems to be an equilibrium in the 

marshes, but there are a lot of data being generated there lot and of a 

research interest in that domain as well. 

With regard to the nitrogen sources there is some work that 

was done by EPA in the agricultural runoff model. We are taking a very 

close look at the runoff forms of nitrogen by continuous simulation, but 

it is a process model. It is essentially a marriage of the lump parameter 

hydrology model with a process nitrogen model. We are doing a lot of calibration 

of that model or testing it, as well as calibration of parameters in 

various locations around the U.S. We have four years of data at Watkinsville 

which is in Piedmont, Georgia, near the location of my laboratory. Those 

data are about to be published and should be of great interest both from 

pesticides, sediment, water yield and nitrogen yield for agronomic crop growth 

operations. There are about four different watersheds, a variety of practices, 

a variety of crops and a variety of management practices. 

We have extended that study rather comprehensively to Iowa 

State University on Four Mile Creek. Iowa State, Purdue and EPA are involved 

in that one as well. We are looking at in-stream processes there, trying to 

make some kind of rational judgements about the kinds of nitrogen work you 

are talking about as a data gap. We recognize it also as a severe data gap. 

We hope to have some data out of that, in of terms sediment movements in streams, 

loading and dynamic loading. Continuous simulation is the approach we are 

taking. We have extended that further to do some regionalization based on 

197

the Smithsonian Institution's work primarily in the Chesapeake Bay area. We 

are participating in that study again with the of idea calibrating on a 

regional basis the R model with this kind of concept. The U.S. Department 

of Agriculture is involved in that with some of their continuous simulation 

approaches. I think they are going to look at ACMO and some of the other new 

models they have developed recently. So we again are hoping to "piggy-back" 

onto many researchers for this kind of work. I just wont to indicate that 

there is a lot of work underway in some of these data gap areas that may 

directly relate to the problems of the Great Lakes, even though they are not 

in fact being done in assocation with any of the Great Lakes programs. 

198




Pesticides 

H. 8. Pionke 

It is my intention to assist in the PLUARG endeavour by identifying 

significant gaps in current knowledge and to define associated research 

needs relative to specific problems of the Great Lakes Basin. The emphasis 

is on: (1) determining the impact of land use activities on boundary waters 

rather than upstreams areas; (2) defining pesticide research needs to answer 

specific problems or to meet needs of the Great Lakes Basin rather than to 

answer general issues in pesticide research; and (3) developing practical 

remedial measures for correcting the identified problems. The last two needs 

imply a sufficiently good forecasting and inventory capability to establish 

present pesticide use and near-future trends. 

Because the impact of a pesticide in boundary or upstream waters 

is going to be related to pesticidal bioactivity in some phase such as the 

sediment, aqueous, or vegetative phases, the planner's objective is to 

estimate or determine this bioactive concentration. The bioactive concentration 

depends on the pesticidal concentration and its toxicity. In turn, 

the pesticide concentration observed in a phase at a downstream point 

depends on upstream use, persistence, the characteristic pesticide distribution 

between phases, and the resultant hydrologic dilution. Relatedly, 

the expected toxicity may be abnormally reduced by adsorption or incorporation 

of the pesticide or abnormally increased to some target species by 

the presence of other pesticides or chemicals (i.e. synergism). 

The title of this paper "Forms and Sediment Associations of 

Pesticides" defines an important part of the environmental system that 

exerts controls on pesticidal toxicity and concentration in selected phases. 

For example, pesticidal persistence, toxicity and concentration of the 

pesticide distributed between phases can be substantially altered by sediment 

during loss, transport and in the impact area. However, it is the author's 

opinion that environmentally-oriented, future pesticide research must first 

be considered in the context of the total system before one component of 

this system, i.e., the adsorbed and sediment-associated phase can be isolated 

and considered separately. The current gaps in present knowledge relative 

to this workshop's objectives are still at a system rather than a component 

scale. Thus, the pesticide-sediment interaction will not be discussed 

separately but within the context of the dominant environmental and pesticide 

properties controlling the pesticide bioactivity in a phase. 

199

In order to usefully answer the three questions posed by IJC the 

in term of this assignment and the workshop objectives. a more appropriate 

set of questions needs to be asked. Basically, these are: "Which pesticides 

have potentially the greatest impact?" and "For those pesticides selected 

as having potentially the greatest impact, what are the dominant environmental 

conditions reasonably occurring in the Great Lakes that substantially 

alter the expected downstream environmental hazard?" Specific answers to 

these two questions would likely place research emphasis on a select few 

pesticides and the dominant environmental conditions. 

My paper will refine and expand these two questions into a philosophy 

to select pesticides and their key environmental interrelationships 

for special research emphasis. This is followed by several specific recommendations 

most of which are aimed at improving the selection process. 

The selection process is described by answering the questions which are 

subdivided and mare clearly defined for purposes of better organizing the 

folloving discussion. 

They are: (1) Which pesticides are and will be applied in large 

quantities to major watersheds within the Great Lakes Basin? (2) Of these, 

which pesticides have the basic properties that alone or in combination 

create a potential environmental hazard under a reasonably selected standard 

set of environmental conditions? and (3) What known or expected environmental 

changes in subunits of the watershed could substantially alter the potential 

environmental hazard of pesticides earlier identified by answering the 

previous two questions? Generally, the text will follow the flow chart 

(Figure 1). 

Which pesticides are and will be applied in large quantities to 

major watersheds in the Great Lakes Basin? This is the most important 

information need for selecting pesticide research. To do this adequately, 

annual surveys by specific pesticide according to subwatersheds are needed. 

This will tie time and area distributions of application together. To 

date, this information is not available for the Great Lakes Basin. Best 

current sources of information are the periodic surveys (1964. 1966, 1971) 

by the Economic Research Service, USDA, which are presented according to 

combined State rather than watershed boundaries and by the Ontario Ministry 

of Agriculture and Food publication, which more closely coincides with 

watershed boundaries. However, the latter is still not current, the latest 

year of publication being 1973. The Great Lakes states (Michigan, Minnesota 

and Wisconsin) were chosen for comparison because this grouping had the 

highest percentage of land area draining into the Great Lakes of Basin any 

state grouping. This was approximately one-half the total land area of 

these three states. 

Note that by using these data to designate present use and to 

establish use trends in selected Great Lakes states and Ontario (Table l), 

it is apparent that the organochlorine insecticide use has decreased 

dramatically. Increased use of methoxychlor, chlordane and the relatively 

stable usage of toxaphene in the U.S. contradict this overall trend. The 

200

FIGURE 1 A FLOW DIAGRAP: FOR IDENTIFYING PESTICIDE RESEARCH PRIORITIES IN 

THE GREAT LAKES BASIN 

\ 

(Toxic, persistent 

and adsorbed) 

(intermediate 

icology and/or persistence) 

I 

tox- t 

RESEARCH AUTOPIA- 

TICALLY CONSIDERED 

FOR ENVIR- COMMON 

ONMENTL CONDITIOMS 

PEST IC IDES 7 PERT I NENT ENV I RONMENTAL 

EXCLUDED (Toxicity PROPERTIES THAT SUBSTAN- 

FRY; STUDY ~ ~ ~ { ~ ~ c TIALLY ~ e rALTER - TOXICITY, 

greatly 

reduced) 

PERSISTENCE OR ADSORP- 

TIVITY (NON STANDARD BUT 

EXPECTED ENVIRONMENTAL 

CONDITIONS) 

I 

(Toxicity andfor 

persistence. adsorptivity 

greatly increased) 

4 

INDICATE WHICH PESTI- 

CIDES SHOULD BE STUD- t 

IED AND IN WHAT CONTEXT 

201 

I

N 

0, 

Table 1. Quantities of Organochlorine Insecticides (1000 lb units active ingredients) used in Lake States 

(Michigan, Wisconsin and Minnesota) for 1964, 1966 and 1971 and in Ontario, Canada for 1968-1973. 

Lakes State- 

11 

Ontario, Canada- 21 

Insecticide 1964 1966 1971 Trend 1968 1970 1969 1973' 

- - 

Aldrin 761 717 93 Greatly decreased 3263 27 

Chlordane - 154 225 Increase (8)- 41 

(74) 82 (105) 

DDD 104 108 1 Greatly decreased 296 85 463 - 

DDT 511 430 2 

I, 

Dieldrin 69 97 - 0.3 0.8 - 

Endosulfan - 32 2 Stable U U U 

Endrin 12 - - Decrease (3) (3) (0.2) 

Heptachlor 105 48 10 Greatly decreased U U U - 

Lindane 24 58 1 Decrease (2) (2) 6 (3) 

Methoxychlor - 5 76 Increase U U U 3 

Toxaphene 53 111 40 Stable U U U - 

" - none reported U = unknown 

'/ Farmers Use of Pesticides, 1964, 1966, 1971 - Quantities, Economic Research Service, USDA, Agricultural 

Economic Reports Nos. 131, 179, 252. 

2/ Agricultural Pollution of the Great Lakes Basin, (1971). Environmental Protection Agency, Water Quality Office 

Publication 13020---07/71. 

Roller, Nick F. Survey of Pesticide Use in Ontario, 1973. Economics Branch, Ontario Ministry of Agriculture 

and Food Parliament Buildings, Toronto, Ontario. M7A 1B6, October 1975. Total amount applied determined by 

summing specific use categories in Appendix IV. 

Parenthetical statements are average annual quantities calculated from the total sale records over the following 

two year periods: 1968-1969, 1970-1971 and 1972-1973. Frank, R.; Smith, E. H.; Braun, H. E.; Holdrinet, 

M.; and Wade, J. W. (1975), Organochlorine Insecticides and Industrial Pollutants in the Milk Supply of the 

CA..+.L"" n- , ~ I 79 

C 

- 

15

use of carbamates has increased substantially whereas total organophosphate 

insecticide usage has remained essentially stable. However, the trends in 

these data must also be interpreted relative to regulatory actions which 

have severely prohibited the use of organochlorine pesticides (Table 2, in 

particular note chlordane and toxaphene). The present applications of 

such pesticides have either declined to near insignificance or are in 

imminent danger of being severely restricted for agricultural use. Thus, 

in the context of research leading to future remedial programs that are 

directed toward land use effects on pollution in the Great Lakes, research 

into the organochlorine insecticides should be severely downgraded if not 

dropped from consideration. The most recently available pesticide usage 

and use trends are summarized in Tables 3 and 4. 

For trend analysis, results of any survey need to be supplemented 

with a knowledge of imminent or recently instituted Provincial, State or 

Federal regulatory actions. This should include the projected effect of 

new pesticide introductions. In the context of applying remedial measures, 

it may take 5-10 or more years to develop a research idea to the level of 

an effective watershed-scale remedial program. Thus, if successful implementation 

of remedial measures depends on prior research, long-term pesticide 

use projections will have to become part of the research planning process. 

The pesticides listed on Tables 3 and 4 in addition to methoxychlor 

and toxaphene were used to construct Table 5. The fungicides were not 

included because they were applied in much smaller quantitites were than 

the insecticides and herbicides. Table 5 incorporates some basic pesticidal 

properties, determined under select conditions, which serve as the base 

information for the next step. 

Of these, which pesticides have the basic properties that or alone 

in combination create a potential environmental hazard under a reasonably 

selected standard set of environmental conditions? The three basic pesticidal 

properties considered here to be of primary importance in the Great Lakes 

are: persistence; toxicity; and the basic pesticide distribution between 

phases, e.g., water, sediment and vegetative phases. Considerable information 

exists and much of it is already available for guidance on making 

some of the most basic decisions regarding research emphasis. 

On the basis of trend data presented earlier, the shift in pesticide 

consumption has been from the persistent insecticides of relatively low 

mammalian toxicity to those of much less persistence but often greater 

toxicity. 

The persistence times of the most commonly used pesticides are 

presented in Table 5. The persistence categories of low (C6.0 months), 

intermediate (6-18 months) and high (218 months) were chosen according to 

time required to dissipate an accumulated 10 year residue once application 

had stopped according to a first order disappearance rate (Tables 6 7). and 

Unless the pesticide degrades to substantially longer-lived phytotoxic 

daughter-products, the impact of the short-lived pesticides ($6 months onehalf 

life) is expected to be upstream or on watersheds rather than in 

boundary waters. Thus, the impact of the short-lived compound is probabilistic, 

i.e., based on the probability of a selected rainfall event or 

series occurring within a certain period after application, which will 

cause the pesticide concentration in some phase downstream to exceed a 

203

Table 2. Major regulatory action limiting agricultural use of Organochlorine 

Insecticides in Ontario. Canada and the U. S. 

Aldrin 

BHC 

Chlordane 

Dieldrin 

DDD 

DDT 

Endrin 

Heptachlor 

Hept. Epox. 

Lindane 

Methoxychlor 

Mirex 

Toxaphene 

~~~ ~~ 

Ontario, Canade 

11 

United States- 

21 

Action- 

31 

Date Act ion- 

31 

Date 

Restricted 1969 

Cancelled 

Never registered for 

agricultural use 

- 

To be reviewed 

Being reviewed at 1976 

Federal level 

Suspended 

Restricted 1969 Cancelled 

Restricted 1970 Cancelled 

Restricted 1970 Major restrictions 

Cancelled 

Restricted 1972 To be reviewed 

Restricted 1969 

Suspended 

Never registered - 

Suspended 

No restriction - 

To be reviewed 

No restriction - 

No restriction 

Never registered - 

Restricted to non 

food crops (intent 

to ban) 

Restricted at 1972 No restriction 

Federal level 

1972 

1976 

1975 

1972 

1971 

1969 

1972 

1976 

1975 

1975 

"Agricultural Pollution of the Great Lakes Basin, Combined Report of Canada and 

the United States, 1971. Environmental Protection Agency, Water Quality 

Office Publication 13020-"07171. Also private communication from Dr. R. Frank 

Ontario Ministry of Agriculture and Food, University of Guelph, Guelph, Ontario 

1976 

- 

?/The Pesticide Review by D. L. Fowler and J. N. Mahan. Agricultural Stabilization 

and Conservation Service. USDA, 1968 to 1975 (annual publication). Also 

private communication from J. Ellenberger, Regulatory Entomologist, EPA, 


"Statement may not be legally correct but essentially so based on impact on 

agricultural use. 

Cancel. = No application allowed. 

Suspension = No manufacture allowed. 

Review = Initiate process that can lead to suspension or cancellation. 

Restrict = Restricted to non agricultural uses. 

204 

1971 

-

Table 3. Top six ranking insecticides according to amount applied with use 

trends in parentheses. 

I 

Lakes States (1971) Ontario (1973) 

Carbaryl (stable) 

Bux (stable) 

Carbofuran (greatly increasing) 

Diazinon (stable) 

Phorate (greatly increasing) 

Azinphosmethyl (stable) 

Carbaryl 

(unknown) 

Chlordane (unknown) 

Dursban (unknown) 

Carbofuran (unknown) 

Phorate (unknown) 

Phosvel (unknown) 

Table 4. Top six ranking herbicides according to amount applied with use 

4, 

trends in parentheses. 

1 

2 

3 

4 

5 

6 

Lakes States (1971) 

Atrazine (greatly increasing) 

Propachlor (greatly increasing) 

2,4-D (stable) 

EPTC-vernolate (greatly increasing) 

Amiben (greatly increasing) 

Alachlor (greatly increasing) 

Used mostly in combination with Atrazine. 

See Table 1 for references. 

205 

Ontario (1973) 

Atrazine (unknown) 

* 

Butylate (unknown) 

Alachlor (unknown) 

2.4-D (unknown) 

Amiben (unknown) 

* 

Cyanazine (unknown)

206

207

0 

N 

m 

li = llllknow~: L = Laboratory Study; F - Field Study; S - Sediment predominant node of transport; W - Water. 

*~’er~l~~cci~~ is the experimentally dvtermined ~ lme required for the original pesticide concentration in soil to he reduced to 

one-ll,?tf. is the concentretlcln lethal to 50% of the population exposed for a given number of hours. Hours are in 

pazenLllrtlcr1 statement. Kd is ~lle equilibrium concentration adsorbed on the soil or organic carbon (OC) divided by that in 

5010210n. 

i/il.maher, .I. W. 1972. Decomposition: quantitative Aspects, Chapter 4 In Organic Chemicals in the Soil Environment: Vol. 1 

Harcal Lkkker. New Kork. 

?/Edwards, C. A. 1972. Insecticides. Chapter 8 Organic Chemicals in the Soil Environment: Vol. 1. Uarcel Dekker. 

E(eu Yurk. 

J’l~lmentcl, I). 1971. Ecological Effects of Pesticides on Non-Target Species. Executive Office of the President. Office of 

Srlcncc and Technnlogy. GPO Stock No. lalob-0029. 

d’Becaose no experimentally determined values available, approximate values based on relative rnohilities are provided (see 

C2irlr 8). 

~~ll.~m.aker, .I. W. and J. M. Tllompson. 1972. Adsorption, Chapter 2 Organic Chemicals in the Soil Environment: Vol. 1. 

H~r~el Dekker. New Yurk. 

fi’St

critical concentration established according to some criteria. Pesticides 

originally selected according to use and use trends that disappeared from 

soil at approximately first order rates with half-lives in excess 18 of 

months, were considered persistent and automatically worthy of further 

research consideration. The remaining pesticides or resulting phytotoxic 

daughter-products, with half-lives intermediate between the short-lived and 

persistent compounds, would require further examination; particularly for 

c.onditions in which the half-life may be extended under reasonably changed 

environmental conditions to more than an 18 month half-life. These were 

defined as following approximate first order kinetics with half-lives 

between 6 and 18 months under normal soil conditions. 

The second property, toxicity, should be operationally defined as 

a critical concentration exceeding some tolerance level for chosen indicator 

organisms. In this case (Table 5), the Rainbow Trout was used as the indicator 

organism to group pesticides into low, intermediate, and high acute toxicity 

levels because of the general availability of the data for the pesticides 

of interest. There is no intent on the author's part in suggesting Rainbow 

Trout should be the only test organism considered. Chronic toxicity levels, 

i.e., 96 or more hours exposure, which should be considered were not included 

for purposes of this discussion. Testing for increased toxicity due to 

possible synergistic effects among pesticides should be considered provided 

that the pesticides are applied both in quantity in and proximity to each 

other as determined from survey data. 

The third pesticidal property following persistence and toxicology 

is the adsorptivity. Numerous references are available on how adsorptivity 

will increase persistence and reduce bioactivity of the compound. Sometimes 

a portion of the pesticide is irreversibly sorbed and may be essentially 

removed from the system. Furthermore, adsorption may provide the mechanism 

for transport and accumulation in selected phases of the stream and lake 

environment. Determined under standard conditions, the K or distribution 

d 

coefficient of the pesticide between phases may be a useful indicator. 

These values are expressed on both the soil and organic matter basis (Table 

5). Because these are not available for many pesticides, a rough correlation 

was observed between Kd and the relative mobility of pesticides in soils 

(Table 8) which was used to approximate missing data in Table 5. This 

relationship was observed by Gerber and Guth (1973)'. Also, the phases may 

include vegetation and fish in addition to sediment and water. These biotic 

phases often concentrate pesticides by an order or several orders of magnitude 

above that found in sediments. The K is expected to be useful for: a) 

estimating zones of accumulation or pisticide distribution among phases; b) 

identifying primary transport mechanisms for modelling purposes; or c) 

indicating which pesticides are most susceptible to irreversible sorption 

or most likely to exhibit increased persistence and reduced toxicity upon 

adsorption. 

The K between water and sediment may be especially useful for 

d 

making some rough cut decisions regarding erosion and fluvial transport of 

selected pesticides (Figure 2). This figure shows how Kd influences the % 

total pesticide load carried by the sediment fraction relative to the suspended 

sediment concentration. 

' Short Theory, Techniques and Practical Importance of Leaching and Adsorption 

Studies, Proc. Eur. Weed Res. Coun. Symp., Herbicides-Soil, pp. 51-69, 1973. 

209

N 

0 

SEDIMENT DILUTION AND EFFECT ON THE X PESTICIDE LOAD TRANSPORTED IN THE SEDIMENT RUSE 

100 

80 

60 

40 

20 

0 

DILUTION FACTOR 

loox lox 4x 2x 0 

SEDIMENT CONCENTRATION k /L)

Table 6. Accumulated pesticide residue (kg/ha) resulting from annual applica- 

tions of 2 kg/ha active ingredients (calculated according to C = Coe-kt). 

Years of Persistence in Half Lives 

Application 3 mo 6 mo 1 yr 2 yr 4 yr 8 yr 12 yr 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

.125 0.50 1.00 

.133 0.63 1.50 

.134 0.66 1.75 

.134 0.67 1.88 

.134 0.67 1.94 

.134 0.67 1.97 

.134 0.67 1.99 

.134 0.67 2.00 

.134 0.67 2.01 

.134 0.67 2.01 

1.41 1.70 

2.41 3.13 

3.12 4.35 

3.62 5.38 

3.98 6.26 

4.23 7.00 

4.40 7.63 

4.49 8.17 

4.55 8.62 

4.60 9.00 

1.83 

3.51 

5.05 

6.46 

7.76 

8.95 

10.05 

11.05 

11.97 

12.80 

Table 7. Remaining pesticide residue (kg/ha) after application-free interim 

periods of 1-5, 10, 15 and 20 years following 10 years of sequential annual 

application of 2 kg/ha active ingredients (calculated according to 

-kt 

C=Ce ). 

1.89 

3.67 

5.35 

6.94 

8.44 

9.86 

11.19 

12.45 

13.64 

14.80 

Lapsed Time 

Following Final 

Persistence in Half Lives 

Application (yrs) 3 mo 6 mo 1 yr 2 yr 4 yr 8 yr 12 yr 

0 

1 

2 

3 

4 

5 

10 

15 

20 

0.134 

0.01 

9.0 

0.0 

0.0 

0.0 

0.0 

0.0 

0.0 

0.67 

0.17 

0.04 

0.0 

0.3 

0.0 

0.0 

0.0 

0.0 

211 

2.01 4.60 9.0 12.8 14.8 

1.00 3.25 7.6 11.7 14.0 

0.50 2.30 - - - 

0.25 1.63 - - - 

0.12 1.15 - - - 

0.06 0.81 3.8 8.3 11.0 

0.00 0.14 1.6 5.4 8.3 

0.00 0.03 0.67 3.5 6.2 

0.00 0.00 0.28 2.3 4.7

* 

Table 8. Relative mobility of pesticides in soils 

594 

TCA+ 

Dalapon 

2,3,6-TBA 

Tricamba 

Dicamba (0.0) 

Chloramben (0.3) 

Picloram (0.45) 

Fenac 

Pyrichlor 

MCPA 

Amitrole 

2,4-D (1.6) 

Dinoseb 

Bromacil 

Propachlor 

Fenuron (1.0) 

Prometone (13) 

Naptalam 

2,4,5-T (1.0) 

Terbacil 

Propham 

F luome t uron 

Norea 

Diphenamid 

Thionazin 

** 

Mobility Class (decreasing mobility 

3 

Endothall 

Monuron (33) 

Atratone 

WL 19805 

Atrazine (25) 

Simazine (15) 

Ipazine 

Alachlor 

Ametryne 

Propazine (25) 

Trietazine 

2 

Siduron 

Bensulide 

Prometryne (55) 

Terbutryn 

Propanil 

Diuron (196) 

Linuron (147) 

Pyrazon 

Molinate 

EPTC 

Chlorthiamid 

Dichlobenil 

Vernolate 

Pebulate 

Chlorprouham 

Azinphosmethyl 

Diazinon 

1 

Neburon 

Cloroxuron 

DCPA 

Lindane (321) 

Phorate 

Parathion 

Disulfoton 

Diquat 

Chlorphenamidine 

Dichlormate 

Ethion 

Zineb 

Nitralin 

C-6989 

ACNQ 

Morestan 

Isodrin 

Benomyl 

Dieldrin 

Chloroneb 

Paraquat 

Trifluralin 

Benef in 

Heptachlor 

Endrin 

Aldrin 

Chlordane 

Toxaphene 

DDT (10,000) 

Helling, C. S., Kearney, P. C., and Alexander, M., 1971. Belwviour of Pesticides in Soils. Adv. Agron. 

- 23,147-240. 

** 

Class 5 compounds (very mobile) to Class 1 compounds (immobile); in each class pesticides are ranked in 

estimated decreasing order of mobility. Underlines designate the most commonly used pesticides by survey. 

Parentheses enclose average Kd's from Hamaker, J. W. and J. M. Thompson, (1972),Adsorption. Chapter 2 & 

Organic Chemicals in the Environment, Vol. I. Marcel Dekker, N. Y., 440 pp.

Washoff losses of pesticides are likely to be predominantly 

associated with the eroded rather than the aqueous phase at or above relatively 

low Kds, e.g., 100. However, once eroded, the initial transport 

will be heavily weighted toward the aqueous phase unless the 1000 Kd or is 

more with reasonably high sediment concentration, i.e., 500 over mg/l for 

the larger Great Lakes tributaries. Further transport downstream increases 

the likelihood of dilution by other water exhibiting lower sediment concentration. 

From Figure 2, hydrologic dilution of the pesticide by 10 times 

substantially shifts the pesticide load to the aqueous phase unless the Kd 

equals or exceeds 10,000. The dilution factor has to be very large, e.g., 

100 times or greater to significantly shift the load from the adsorbed to 

aqueous phase if the Kd is this high. Furthermore, if a dynamic equil- 

ibrium exists between fluvial sediment and the aqueous phase, and the Kd 

is large, substantial and perhaps rapid pesticide losses may occur because 

of pesticide adsorption on exposed stream banks and bottoms and associated 

vegetation within relatively short travel distances. Usually the Kd for 

most pesticides used today is 1000 or less, thus weighting the load transported 

to the aqueous rather than adsorbed phase (Figure 2). However, 

adsorptivity or oganic matter may be 10 to 1000 times greater than that for 

soil (Table 5). Thus, in situations where organic soils, organic sediments 

or transported organic materials predominate, transport may be heavily 

weighted toward a sediment fraction of low density. Such highly adsorptive 

systems are usually primary candidates for investigation related to irreversible 

adsorption, increased persistence and decreased bioactivity due to 

adsorption. The same consideration would apply to highly polluted stream 

sediment to which the pesticide distribution could be greatly altered. 

Table 9 summarizes these three properties for the pesticides originally 

chosen according to the survey. 

From this table, both chlordane and toxaphene potentially provide 

both upstream impact (toxicity) and downstream impact (persistence), being 

primarily lost by erosion and transported in both the aqueous and sediment 

phase. Azinphosmethyl, phorate and diazinon potentially provide upstream 

impact only, because although they are toxic they lack persistence. They 

are lost primarily by erosion but transported primarily in the aqueous 

phase. Thus, hydrologic dilution likely dominates the concentration of 

this material downstream and this concentration dissipates rapidly. Dursban 

does potentially provide upstream impact and is transported primarily in 

the aqueous phase. The persistence was not known. The impact of phosvel 

and carbofuran is limited to upstream areas because of low persistence. 

The persistence for bux is unknown. The remaining compounds are not likely 

to be of concern. 

Thus, this whole approach provides some guidelines for research: 

Firstly, these compounds which are important on the basis of use; secondly, 

the identification of the important pesticidal properties and how they might 

indicate particular research needs and provide research emphasis assuming 

normal environmental conditions. This kind of approach not only attempts 

to direct attention to the most environmentally hazardous properties of 

a compound but also points out weak or missing data needed to make of some 

these basic assessments and perhaps provide some insight. However, this 

213

Table 9. Selected pesticides grouped according to combinations of properties. 

Pesticide 

Chlordane 

Toxaphene 

Azinphosmethyl 

Phorate 

Phosvel 

Dursban 

Methoxychlor 

Diazinon 

Bux 

Carbofuran 

Atrazine 

Cyanazine 

EPTC 

Vernolate 

Carbaryl 

Butylate 

Amiben 

2,4-D 

Alachlor 

Propachlor 

Group Ranking for each Property 

Toxicity Persistence Adsorptivity 

I I I 

I I I 

I I11 I1 

I I11 I1 

I 111 U 

I U I11 

I U U 

I, I1 I11 I1 

I1 U U 

I1 I11 U 

I11 I1 I11 

I11 I1 I11 

I11 I11 I1 

I11 I11 I1 

I11 I11 I11 

I11 I11 U 

I11 I11 I11 

I11 111 I11 

I11 I11 I11 

I11 I11 111 

I = Toxicity (0.003 - .05 mg/l, LC50 over 24 48 to hour for Rainbow Trout), 

OK persistence 5 18 months (observed time for one-half the original 

concentration to disappear from soil) OK adsorptivity 2 1000 Kd (Kd = 

concentration on sediment (x/m) versus that in solution (C at equilibrium 

from Freundlich relationship n=l). at 

ed 

I1 = Toxicity (0.052 - 0.3 mg/l ditto) or 6 months < persistence < 18 months 

OK 100 5 Kd < 1000. 

I11 = Toxicity (1.0 - 20, mg/l ditto) or persistence 5 6 months or Kd < 100. 

U = Unknown. 

214

has as yet only treated properties under standard or a selected set of 

environmental conditions. This is often not the case. 

What known or expected environmental changes in subunits of the 

watershed could substantially alter the potential environmental hazard of 

those pesticides earlier identified by answering the previous two questions? 

Answering this third question assumes that the dominant local stream and 

lake environments on a seasonal or annual basis are known. Then those 

dominant, yet nonstandard environmental conditions which substantially 

extend pesticidal persistence beyond the middle-range persistence OK bias 

the distribution of pesticide among phases causing a potentially hazardous 

environmental level, can be identified and their impact researched. This 

investigation would apply to those pesticides of intermediate persistence 

or toxicity as determined from answering questions 1 and 2. These could 

include the effect of: pH changes from field to stream to lake (persistence 

and redistribution between phases of pH-dependent charged pesticides); 

chemical reducing conditions on persistence; temperature on persistence; 

exposure to sediment associated with industrial type pollutants, e.g., 

petroleum products mixed with sediment, on persistence and selective distribution 

of pesticides in this phase; exposure to organic soils and 

sediments on toxicity, persistence and adsorptivity, etc. Obviously, the 

criterion of reasonability should be followed regarding the likelihood of 

these conditions existing and their severity. The test conditions chosen 

should not be extreme or unreasonable relative to the expected in range 

pertinent environmental conditions. 

CONCLUSION 

In summary, if a pesticide is used extensively or in increasingly 

larger amounts, is known to be toxic to selected aquatic organisms, and is 

either persistent or has an intermediate half-life that may be extended by 

adsorption and/or abnormal environmental conditions that are known to occur 

within the area, then these should be the primary subject of research 

emphasis. 

RECOWMIATIONS 

1. 

2. 

' 3. 

Better surveys of individual pesticide usage on an annual basis are 

needed in order to establish present usage and trends in usage. This 

should be assembled by the IJC according to subwatershed divisions 

within the Great Lakes Basin. 

The organochlorine insecticides should not be the subject of new 

research unless justified on the basis of present and projected 

use in the Great Lakes Basin. 

The pesticides selected on a usage or use trend basis should be 

further evaluated according to persistence, toxicity, and adsorptivity 

under some set of standard conditions. Synergistic effects on selected 

key aquatic organisms should be evaluated where justified on pesticide 

use basis. Then the "nonstandard" but reasonably expected local 

environmental conditions that substantially alter persistence and 

toxicity occurring downstream from application areas should be 

identified and researched. An exhaustive literature review could 

supply much of this information. 

215

This overall approach provides a means of selecting those pesticides 

that should be the primary candidates for subsequent laboratory and field 

research and monitoring programs. Furthermore, this approach should 

specifically delineate or further identify needed research. 

4. We need standardization OK development of methodology to experimentally 

and routinely determine: a) standard persistence, toxicology and 

adsorptivity; b) the altered toxicity upon adsorption or in 

association with other pesticides (synergistic effects); and c) 

the altered persistence upon adsorption, changed 02 pH, status, 

temperature, etc. Perhaps the study of the selected pesticides 

in multiphase microcosms may be useful for isolating potential 

problems. Obviously, the pesticides studied should not be chosen 

at random, but should be of at least intermediate persistence, toxicity 

and used in considerable amount according to survey. 

5. Certain environmental exceptions exist that should be researched even 

if not defensible by pesticide use. These include: a) dredge spoil 

as a renewed source of adsorbed pesticides, particulary the organochlorine 

insecticides; and b) altered K and persistence of selected 

pesticides partitioned into or exposed t,d highly polluted sediments 

(lipophilic wastes, industrial wastes, municipal sewerage, etc.). 

216

DISCUSSION 

/A,. L. HetZing: The way you are going at the pesticide issue is usage. Is 

it possible or thinkable to go at it the other way? We are interested in 

those pesticides or those types that are bio-accumulating in the environment. 

Could one go and take certain test organisms or test fish or something else 

at a lake and measure them for the range of these things, and if they are 

not accumulating, not worry about them? 

Dr. H. Pionkc: I wasn't really suggesting that we start on a full-blown 

programme, collecting all these numbers. I am saying that in certain cases 

there are probably missing data that could be supplied. I think that some of 

the EPA people would like to speak to this, but I think there is already a 

movement afoot to try and get some of this basic information. As I mentioned 

earlier, this is in the context again of the IJC. We are talking about the 

Great Lakes watershed. There are many compounds in use across the country. 

They are not used in any amount on the Great Lakes watershed. I think if 

you turn it around and get the cart before the horse and start talking about 

what compounds could create a potential problem without asking whether or not 

they are being applied, is the wrong way to go. 

217

Forms and Sediment Associations of Nutrients (C.N. 6 P.) 


Trace Metals 

Ulrich F6rstner 

The availability of trace metals for metabolic processes is 

closely related to their chemical species both in solution and in particulate 

matter. For this reason a thorough investigation into the 

behaviour of trace metals in the dissolved state was undertaken. In comparison, 

very little is known about the chemical association of metals in 

suspended materials and sediments, although the knowledge of characteristic 

bonding types may be the key to the detection of specific pollution sources 

in the aquatic environment. 

TRANSPORT OF TRACE MALS IN RIVERS 

The source of trace metals in rivers significantly determines 

their distribution ratio between the aqueous and solid phases. For example, 

the bulk of the detrital trace element particulates never leaves the 

solid phase from initial weathering to ultimate deposition. Similarly, 

metal dust particles (e.g. from smelters) and effluents containing heavy 

metals associated with inorganic and organic matter, undergo little or no 

change after being discharged into a river. This is attributable to the 

average residence times (of the order of days or weeks), too short €or the 

establishment of stable, dynamic equilibria between water and suspended 

material. ' 

There are characteristic differences in the metal distribution 

between the aqueous and solid phases. Examples are given in Table 1, 

indicating the fractions of metals in particulate form as percentages of the 

total metal discharges from U.S. rivers', rivers in West Germany3 and from 

the Rhine River in the Netherlands' respectively. 

The order of sequence of the mobility for a few selected metals 

is as follows. Alkali and alkali-earth metals are predominantly present in 

a dissolved form; for trace metals like boron, zinc and cadmium, the ratio 

of dissolved species to particulate species is between 2:l and 1:l; copper, 

mercury, chromium and lead exhibit ratios of the solid phases to the aqueous 

phases of between 2:l and 4:l; whereas iron, aluminum (and manganese under 

normal Eh conditions) are almost totally transported as solid particles. 

The preferential bonding of heavy metals in effluents to the solid phase is 

of particular significance for tracing sources of pollution. During 

reduced rates of river flow, suspended material settles to the river bed, 

becoming partially incorporated into the bottom sediment. By virtue of their 

composition, sediments conserve heavy metal contamination and "express the 

state of a water body"'. Vertical sediment profiles (cores) often uniquely 

preserve the historical sequence of pollution intensities6; lateral distributions 

(quality profiles) serve to determine and evaluate local sources 

of pollution . 

219

Metal 

(example) 

Sodium 

Calcium 

Strontium 

Boron 

Cadmium 

Zinc 

Copper 

Mercury 

Chromium 

Lead 

Aluminum 

Iron 

*Federal Republic of Germany 

TABLE 1 

Percentage particulate-associated metals 

of total metal discharge (solid + aqueous) 

U.S. Rivers' F.R.G.* Rivers3 Rhine (Neth.)' 

- 

0.5 

2.5 

21 % 

30 % 

- 

- 

30 

40 % 45 

63 % 55 

- 

59 

76 % 72 

84 % 79 

98 % 98 

98 % 98 

220 

% 

% 

- 

- 

% 45 % 

% 37 % 

% 64 % 

% 56 % 

% 70 % 

% 73 % 

% - 

% -

Two effects, however, must be considered when sediment analyses 

are used for the identification of sources of pollution. Firstly, under 

conditions of high water discharge, erosion of the river bed takes place, 

and generally leads to a lower degree of local contamination. LSzl6’, for 

example, obtained data from the Sajo River, Hungary, which indicated that 

three months after a flood, the mercury concentration in bottom sediments 

had been reduced to approximately one-quarter of the values found immediately 

before the flood. Secondly, it is often overlooked that it is imperative 

to do base metal analyses from river sediments on a standardized procedure 

with regard to particle size’, since there is a marked decrease in the 

content of metals as sediment particle size increases. An example is given 

in Figure 1, indicating the concentrations of cadmium in different grain size 

fractions of sediments from the highly polluted Rhine and Main Rivers in 

the Federal Republic of Germany”. Maximum concentrations of Cd occur in 

the fractions of 0.2 pm - 0.6 pm; from there the metal contents decrease 

both toward finer and coarser grain diameters (relatively high levels of Cd 

in the sand fractions are probably due to the input of coarse waste particles). 

Several methods have been introduced in order to include most of 

the substances active in metal enrichment, i.e., hydrated oxides, sulphides, 

amorphous and organic materials, but to exclude coarser-grained sediment 

fractions which are largely chemically inert: (i) reduction of grain size 

effects, e.g. the pelitic fraction of < 2 pm diameter”, by extrapolation 

from the grain size distribution” or by correction for the specific surface 

area”; (ii) selective chemical treatment for the extraction of acidsoluble 

fractions by including 0.1 M hydrochloric acid’l*, 0.1 M nitric 

acid15 and aqua regia/ignition lossIb procedures; (iii) using mineral 

separation techniques as exemplified by the quartz correction method”; 

(iv) taking conservative elements, e.g. aluminum, silicon, potassium, and 

sodium as a reference base for cultural metal inputs’’”’. The question as 

to which trace metals are characteristic of nonpoint or diffuse sources, 

which is of particular interest to the present Workshop, cannot be answered 

to any degree of satisfaction. In areas of heavy environmental pollution 

such as highly industrialized areas, one generally finds high levels of 

lead, zinc, mercury and cadmium in the river deposits whereas at the same 

time other metals such as iron, manganese, nickel, and cobalt have only 

increased insignificantly in comparison. High levels of chromium, cadmium 

and copper can usually be attributed to industrial waste”, particularly 

from the tanning and electroplating industries; enrichment of lead and zinc 

can usually be connected with diffuse sources such as atmospheric emissions 

in the case of lead, and urban sewage effluents for zinc”. Apart from 

this, the temporally changing influence in the various catchment areas as 

well as seasonal effects must be taken into consideration as was done by 

Schleichert” in his study on the metal transport of suspended matter in 

the Rhine. 

CHEMICAL FORMS OF TRACE BTALS IN FLWIATILE SEI)IE:MS 

The ratio of heavy metal distribution between the aqueous and solid 

phases is subject to change due to a general shift of equilibria toward 

the solid phase. Thus, the total amount of heavy metals in solution generally 

diminishes along the course of a river during normal flow conditions. 

This is of importance for the elimination of dissolved wastes, e.g. from 

metal processing (electroplating, galvanizing), the removal of trace metals 

from the aqueous phase being effected by mechanisms as such sorption, 

precipitation, co-precipitation and complexing. 

221

In spite of their different origins, environmentally related 

types of metal bonding are comparable to the natural forms. The most 

common associations of heavy metals in particulate substances are compiled 

in Table 2: 

(1) Heavy metals are transported and deposited as major, minor 

OK trace constituents in the natural rock detritus, mostly 

in inert positions. 

(2) Slight alkalinity prevailing in normal surface waters results 

in the formation and precipitation of hydroxides, carbonates, 

sulphides and phosphates of heavy metals. 

(3) Sorption and cation exchange particularly takes place on 

fine-grained substances with large surface areas. A generalized 

sequence of the capacity of the solids to sorb heavy was metals 

established by Guy 6 ChakrabartiZ4 in the order 

MnOz > humic acid > hydrous iron oxides > clay. 

Experiments with different sorbents and seawater indicated an 

extensive extraction of zinc, copper and lead by hydrous iron-and manganeseoxides, 

clay minerals and peat substances; nickel, cobalt and chromium are 

closely associated with Mn-oxidesZ5. In experiments on competing exchange 

of metal cations performed with equal concentrations of humic substancesz6, 

copper was preferentially sorbed (53%). followed by zinc (21%), nickel 

(14%). cobalt (8%) and manganese (4%). 

(4) Dissolved organic polymer is increasingly being regarded as a 

carrier material in the transfer of metals from the mineral 

phase into the organic material. The younger, less condensed 

humic acids (fulvic acids) play an especially important role 

in the bonding of heavy metals in aquatic systems because of 

their large number of functional groups”. In a summary of 

organic matter-metal interactions in recent sediments, Nissen - 

baum L Swaine” mention concentrations of up to 0.4% copper and 

0.45% zinc in humic substances from marine reducing environment^^^. 

A high degree of positive correlation between the content of 

organic substances, and metal concentrations may, however, not 

always be interpreted as being the result of direct bonding of 

heavy metals to organic substances. In highly polluted areas, 

for instance, contamination by characteristic heavy metals simply 

coincides with the accumulation of organic substances, both derived 

from urban, industrial or agricultural sewage effluents. 

Extraction of metals from fulvic and humic acids in sediments 

from Lake Malawi indicated that only zinc, copper and vanadium 

were accumulated in organic material, whereas iron, manganese, 

chromium, cobalt and nickel are more or less diluted by the organic 

acids”. 

(5) Co-precipitation of heavy metals with hydroxides and carbonates 

appears to be an important mechanism controlling the metal 

concentrations in the aquatic environment”’ 32. Experiments on 

calcium carbonate precipitation in the presence of heavy metal 

ions33 indicated that heavy metal carbonates having a low solubility 

(e.g. cadmium and lead) will be completely eliminated 

222

TABLE 2 

CARRIER SUBSTANCES AND MECHANISMS OF HEAVY METAL BONDING 

Minerals of natural rock debris 

(e. g. heavy minerals) 

Heavy metal 

- hydroxides 

- carbonates 

- sulphides 

Clay minerals 

(Sorption) 

PH 

~ Bitumen, Lipids PH 

Humic substances 

, Residual organics 

Hydroxides and oxides 

of Fe/Mn 

Calcium carbonate 

PH 

PH 

223 

metal bonding predominently 

in inert positions 

Precipitation as a result of 

exceeding the solubility product 

in the area of the water course 

Physico-sorption 

(electrostatic attraction) 

Chemical sorption 

(exchange of H+ in SiOH, AlOH and 

A1 (0H)z) 



(exchange of H+ in COOH-, OH-groups) 

complexes 



(exchange of H+ in fixed positions) 

Co-precipitation as a result of 

exceeding the solubility product 


Pseudomorphosis 

(dependent on supply and time) 

Co-precipltation 

(Incorporation by exceeding the 

solubility product)

from the solution as a result of co-precipitation with calcium 

carbonate (Table 3). Examples from the hcavily polluted Elsenz 

River (a tributary to the Neckar River) and the Elbe River in 

West Germany have demonstrated the actual importance of coprecipitation 

phenomena with hydroxides of iron and calcium carbonate 

in the natural environment 34 ' . The presence of large amounts 

of iron hydroxide in the Elsenz River was caused by the mixing 

of normal Elsenz water with alkaline waste water from a local 

galvanizing industry. The measured concentration of heavy 

metals found in iron hydroxide concretions are far higher than 

the concentrations found in the clay-sized fraction of the 

surrounding Elsenz sediments. Compared to this surrounding 

clay-sized sediment fraction, heavy metal enrichment by factors 

of up to 30 times for Cd, 17 for Zn and 1.4 for Cu were measured 

in the iron hydroxide concretions". Groth's3' investigations 

on the co-precipitation of trace metals with hydrous Fe/Mn 

oxides (also taking the competition of organic complexing agents 

into account), indicated an almost complete co-precipitation of 

copper occurring under all conditions, whereas zinc and cobalt 

are precipitated to a much lesser extent in the presence of strong 

EDTA complexing agents than of natural organic chelating substances 

(Table 4 ). 

In contrast to iron hydroxide, calcium carbonate was found to have 

concentrated heavy metals far less than those found in the 

surrounding clay size ELbe sediment fraction". Calcium carbonate 

coatings had been formed locally in the Elbe River as the result 

of mixing effects upon the contact of normal Elbe River water 

with alkaline waste waters from a local Dow Chemicals Plant. 

Compared to the geochemical background values of heavy metals 

in carbonate rocks37, enrichment factors of approximately 10 

times for Cd, 6 for Cu, 4.5 for Zn and 4 for Co were measured 

in calcium carbonate coatings. 

SELECTIVE EXTRACTION PROCEDURES 

Many attempts have been undertaken for a selective extraction of 

the different forms of metal association in both natural and polluted 

sediments: Hirst & Nicholls3* differentiated the metal contents in the 

detrital and non-detrital fractions of carbonate rocks by acid treatment. 

Goldberg & Arrhenid6 used EDTA to establish the partition of elements 

between detrital igneous minerals and authigenic phases in pelagic sediments. 

Arrhenius & Korkish4' tried to separate the iron fraction of the 

ferro-manganese nodules with 1 M hydrochloric and dilute acetic acid. 

Chester & Hughes" distinguished the lithogenous and non-lithogenous components 

in recent aquatic sediment by acid-reducing 1 M hydroxylamine 

hydrochloride + 25% acetic acid; this method reached particularly wide 

application in marine ge~chemistry~'-~'. A combination of different 

extraction procedures was first used Ni~senbaum~~ 

by 

for sediments from the 

Okhotsk Sea (Table 5a), then by G i b b ~ for ~ ~ analyses of trace metals 

associated with different carrier substances in suspended materials of the 

Amazon and Yukon Rivers (Table 5b). Engler and co-workers4' developed a 

separation technique, particularly for dredged materials, precluding 

atmospheric oxidation at sensitive steps (Table 5c); sediments from Mobile 

224

TABLE 3 

CO-PRECIPITATION OF TRACE METALS WITH CALCIUM CARBONATE 

-LOG L = NEGATIVE EXPONENTS OF THE SOLUBILITY PRODUCTS OF METAL CARBONATES 

Original Metal contents in the precipitate 

concentration in % of the original concentration 

(Pdl) Cd Pb Co Zn Cu Ni 

25 100 100 100 100 96 96 

250 100 100 100 100 - 43 

2000 100 100 96 96 75 - 

-log L 13.2 12.8 12.0 10.2 9.85 6.85 

TABLE 4 

CO-PRECIPITATION OF TRACE METALS WITH Fe/Mn-HYDROXIDES 

Solution Percent of metal additive in the precipitate 

Fe cu Zn Mn co 

distilled water 98% 95% 14% 47% 80% 

lake water 

no admixture (a) 99% 98% 86% 67% 25% 

EDTA (b) 99% 88% 18X 25% 25% 

Peat extract (c) 99% 97% 88% 75% 25% 

225

TABLE 5 

SELECTIVE EXTRACTION PROCEDURES FOR METAL ASSOCIATIONS IN SEDIMENTS 

(PRE- AND INTER-TREATMENT STEPS - WASHING, CENTRIFUGATION, FILTRATION 

ETC. - ARE NOT INCLUDED IN THE TABLE; - DEFINITATION A 

OF THE CHEMICAL 

PHASE ACCORDING TO THE AUTHORS) 

- a. NISSENBAIIM, 1972 

Treatment of sediment Ref. Chemical phasea 

1) 30% Hz02 

2) 2 N acetic acid (pH - 3) 

3) 6 N HC1 

4) Fuse with Na~C03 

- b. GIBBS. 1973 

Perox. fraction 

Acetic ac.-fraction 

HC1-fraction 

Residue fraction 

Treatment of sediment Ref. Chemical phasea - 

1) 1 N MgClz-solution. pH=7 Cation exchange + adsorption 

2) Reduction with sodium dithionite/ 

complexing with sodium citrate 

Metallic coatings 

3) Sodium hypochlorite, pH=8,5; see (2) Solid organic material 

4) lithium metaborate lOOO"C, HN03 Detrital crystalline material 

- c. ENGLER, BRANNON, ROSE & BRIGHAM, 1974 (modified by GUPTA & CHEN, 1975) 

Treatment of sediment Ref. Chemical phasea - 

1) 1N ammonium acetate, sediment-pH 

2) 1M acetic acid (G & CH) 

3) 0.1M hydroxylamine hydrochloride 

solution in 0.01M nitric acid 

4) 30% hydrogen peroxide at 95OC, 

extract with 1N NHbOAc, pH=2,5 or 

extract with 0.01M HN03 (G 6 CH) 

5) Sodium dithionite/citrate or 

0.04M NH20H.HC1 in 25% acetic 

acid at 100°C for 3 hrs (G 6 CH) 

6) Digestion with HN03, HF, HClOs 

- d. PATCHINEEJAM, 1975 

Exchangeable ions 

Carbonate, some Fe/Mn-oxides 

Easily reducible phase 

(manganese oxide + amorphous 

iron oxide) 

Organic phase 

(organics + sulphide) 

Moderately reducible phase 

(iron oxide) 

Lithogenous fraction 

Treatment of sediment Ref. Chemical piesea 

1) 0.2 N BaClz-tri.ethanolamine Adsorption + cation exchange 

2) 0.1 N NaOH Humates + Fulvates 

3) COZ-treatment Carbonate co-precipitates 

4) 1 M NHzOH.HC1/25% acetic acid Hydrous Fe/Mn-oxides co-prec. 

5) Digestion with HF/HClO,, HN03 Detrital silicates 

226

Bay (Alabama), Ashtabula, Ohio (Lake Erie) and Bridgeport, Connecticut (Long 

Island Sound) were investigated4'. Further modification of the Engler scheme 

was performed by Gupta & C~~II'~ and applied on sediments from Los Angeles 

Harbor. Patchineelam differentiated the metal contents associated with cation 

exchan e positions, humic acids, carbonate minerals and hydrous Fe/Mn 

oxides". The first three examples' 5' ' compiled in Figure 2, represent 

relatively unpolluted systems (Dead Sea: 14 ppm Cu, 13 ppm Pb, 36 ppm Zn), 

while both the latter area^'^'^^ are strongly contaminanted by heavy metals 

(Los Angeles Harbor: 568 ppm Cu, 342 ppm Pb, 632 ppm Zn). In the example 

of the Lower Rhine sediment3', two groups of metals can be distinguished 

from a comparison of metal data of recent Rhine deposits with analyses of 

ancient Rhine sediments obtained from drilling cores in the Cologne area". 

High percentages of detrital fractions are found for those elements which 

are less affected by man's activities, e.g. iron (3.0% in fossil Rhine 

deposits - 3.4% in recent pelitic sediments of the Rhine), nickel (85 ppm - 

165 ppm), and cobalt (14 ppm -35 pprn); on the other hand, lattice-held 

fractions are very low for metals such as (30 lead ppm - 333 pprn), zinc 

(115 ppm - 1558 ppm) and cadmium (0.3 ppm - 28.4 ppm). In the Rhine sediments, 

lead, copper and chromium are particularly associated with the 

hydroxide phases. These findings can be explained by the specific sorption 

of lead to iron-hydroxide5', by the effective co-precipitation of copper 

together with hydrous Fe/Mn oxides36, and by the absence of carbonate 

phases of chromium in natural aquatic systems. The preferential carbonate 

bonding of zinc and cadmium, on the other hand, be attributed can to the 

relatively high stability of zinc-carbonate and cadmium-carbonate under the 

pH-Eh conditions of common island as well as to the characteristic 

co-precipitation of these components with calcium-carbonate. Copper and 

cadmium contents are found to be closely associated to organic substances. 

The metal fractions in cation exchange positions represent less ten than 

percent of the total metal content associated to sediment. Similar results 

were obtained by Gupta & Chen" particularly with respect to the low metal 

concentrations in exchangeable form and to the sequence of metals associated 

with detrital (silicate) minerals. The only exception is copper (98% in 

detrital phase) of which 0nJ.S; 10 to 14% is bonded to silicates in Nissenbaum's 

study on the Sea of Okhotsk . 

THE RLEASE OF TRACE F~ALS FROM RIVER SEDIMENTS 

Heavy metals which are "immobili~ed"~~ in the bottom sediments of 

rivers and dams constitute a potential hazard to water quality since they 

may be released as a result of chemical changes in the aquatic milieu: 

(1) Increased salinity of the water body leads to competition 

between dissolved cations and adsorbed heavy metal ions and 

results in partial replacement of the latter. Such effects 

should particularly be expected in the estuarine environment. 

Apart from the highly complicated situation there5', however, 

it was demonstrated, that the decrease in heavy metal concentrations 

at the river/sea interface is caused by mixing processes 

of polluted river particulates with relatively "clean" marine 

sediments5' rather than by solubilization and/or desorption. 

(2) A lowering of pH leads to the dissolution of carbonate and 

hydroxide minerals and also - as a result of hydrogen ion 

competition - to an increased desorption of metal cations. 

227

N 

N 

m 

FIGURE 1: Cadmium concentrations in different grain size fractions of 

sediments from the rivers Maine (*) and Rhine".

SEA OF OKHOTSK 

(NISSENBAlJM.1972) 

"Pwox ~ Froctlon" 

"Acotlc acid " 

YUKON RIVER 

( OIBES, 1973 1 

Mn 

Fe Ni Co Cr Cu Pb Zn Cd 

FIGURE 2: 

Extraction of different forms of metal associations in sediments 

(examples). 

229

Long-term changes of the pH-conditions have been observed from 

highly industrialized areas by atmospheric SO2 emissions 59 ' 6o mainly in waters poor in bicarbonate ions. Acid mine drainage 

effects a 1,000 - 10,000- fold increase of iron, manganese, 

nickel, cobalt, copper and zinc61'62. 

A change in the redox conditions is usually caused by the increased 

input of nutrients. Oxygen deficiency in the sediments leads to 

an initial dissolution of hydrated manganese oxide, followed 

by that of the analogous iron compound63. Since these metals 

are readily soluble in their divalent states, any co-precipitates 

with metallic coatings become partially remobilized. There are 

indications, that, for example, copper, zinc and cadmium are 

released from anoxic sediments into surface water64. These 

processes, however, seem to be controlled rather more by bacterial 

activity and subsequent complex formation than by ion migration65; 

since the calculated stability for the sulphide compounds is 

strongly exceeded by the concentrations of Cu, Cd, Zn, Pb and 

other metals in the pore 

The growing use of synthetic complexing agents (e.g. nitrilotriacetic 

acid) in detergents to replace polyphosphates6' increases 

the solubilization of heavy metals from aquatic sediment69'70. 

A considerable number of heavy metal chelates are not destroyed 

during water pr~cessing~~, for example by bank filtration7', 

and may lead to a potential danger for the drinking-water supply. 

Microbial activities enhance the release of metals in three 

main ways: (i) by formation of inorganic compounds capable 

of complexing metal ions; (ii) by influencing the physical 

properties and the pH-Eh-conditions of the environment; 

(iii) by means of oxidative and reductive processes catalyzed 

by enzymes, microorganisms can convert inorganic metal compounds 

to organic molecules; organo-mercurial transformations show that 

such mechanisms may strongly increase metal toxicity' 3'74. 

The latter two mechanisms may be further aided by physical 

effects such as erosion, dredging and bioturbation, which 

also affect the release of pore solutions rich in metals. 

The senior author (U.F.) wishes to express his thanks to the 

organizers of the Workshop for their kind invitation to participate; 

additional support by the Centre Europben d'Etudes des Polyphosphates is 

gratefully appreciated. We are indebted to Dr. G. T. W. Wittmann (Pretoria) 

for providing data and valuable suggestions. 


1. Wittmann, G. T. W. & Forstner, U. Water S.A., (1976) 2, 67-72. 

2. Kopp, J. F. & Kroner, R. C.. (1968). Trace Metals in Waters of the 

United States. U.S. Dept. Interior, FWPCA, Cinncinnati. 

230

3. Heinrichs, H., (1975). Diss. Gottingen, 97 pp. 

4. 

5. 

6. 

7. 

8. 

9. 

10. 

11. 

12. 

13. 

14. 

15. 

16. 

17. 

18. 

19. 

20. 

21. 

22. 

23. 

24. 

25. 

DeGroot, A. J., &., (1973) Sware Metalen in Fluviatiele en 

Mariene Ecosystemen. Symp. May 24-25. 

Zullig, H., (1956). Schweiz. Zeitschr. Hydrologie, 18. 7-143 

Forstner, U., (1976) Naturwissenschaften, 63, 465-470 

Forstner, U. & Muller, G., (1974). Schwermetalle in Flussen und Seen 

als Ausdruck der Umweltverschmutzung. Spring-Verlag Berlin 

Laszlo, F., (1975) Abstr. Int. Conf. Heavy Metals Environm., Toronto, 

C-130. 

Wittmann, G. T. W. 6 FoKstneK, U.S. (1976) Afr. Jour. Sci. I?_, 

242-264 

Working Group Metals, Water Research Program of the German 

Research Society (Deutsche Forschungsgemeinschaft), unpubl. 

data. 

Banat, K., et&., (1972) Naturwissenschaften. 2, 525-528 

DeGroot. A. J., e. (1971) Geol. en Mijnb., 50 393-398 

Oliver. B. G., (1973) Environmn. Sci. Technol., 2, 135-137 

Piper, D. 2.. (1971) Geochmin. Cosmochin. Acta, 25, 531-550. 

Jones, A. S. G., (1973) Mar. Geol., g, Ml-M9. 

Literathy, P. 6 Laszlo, F., (1975). Int. Symp. Geochim. Natural 

Water, Burlington. 

Thomas, R. L.. (1972) Can. J. Earth Sci., 2. 636-651 E., 

(1973) lo. 194-204. 

Bruland, K. W., d., (1976). Environmn. Sci. Technol. 5, 425-432. 

Kemp, A. L. W., etg., (1976) Fish. Res. Board Can., 22, 440-462. 

Forstner, U. & Muller, G. Geoforum, (1973a). g 53-61 Rupert0 

Carola, (1973b), 51, 67-71 Fortschr. Miner., (1976) 12, 271-288. 

Schleichert. U. & Hellmann, H. (1973) Lit. Rept. Bundesanstalt 

fur Gewasserkunde Koblenz, 32 pp. 

Schleichert, U. (1975) Deutsche Gewasserkundl. Mitt., 19, 150-157. 

Forstner, U. 6 Patchineelam, S. R., (1976) Chemikerzeitung, 100, 

49-57. 

Guy, R. D. 6 Chakrabarti, C. L. (1975) Abst. Inst. Conf. Heavy 

Metals Environnm., Toronto, D-29. 

Krauskopf, K. (1954) Geochmin. Cosmoschim. Acta, 2, 1-34.

26. 

27. 

28. 

29. 

30. 

31. 

32. 

33. 

34. 

35. 

36. 

37. 

38. 

39. 

40. 

41. 

42. 

43. 

44. 

45. 

46. 

47. 

48. 

Rashid, M. A., (1974) Chem. Geol., 13, 115-123 

Rashid, M. A., (1971) Soil Sci., 111, 298-306 

Nissenbaum, A. & Swaine, D. J. (1976) Geochim. Cosmochim. Acta 

809-816 

Presley, B. J. et g., (1972) Geochim. Cosmochim. Acta, 2, 1073-1090 

Forstner, U. (1976) Proc. SIL/UNESCO-Symposium on Interactions Between 

Sediments and Freshwater, Amsterdam, 6-13 Sept., (in press) 

Lee, G. F., (1975) In: Heavy Metals in the Aquatic Environment (P.A. 

Krenkel, ed.), 137-147 

Patchineelam, S . R., (1975) Unpublished Diss. Heidelberg, 137 p. 

Popova, T. P., (1961) Geochemistry 12. 1256-1260 

Patchineelam, S. R. Paper Submitted for Publication 

Patchineelam, S. R. Paper Submitted for Publication 

Groth, P., (1971) Arch. Hydrobiol. 68, 305-374 

Wedepohl, K. H. (1970) Verh. Geol. Bundesanstalt Wien, 6, 692-705 

Hirst, D. M. 6 Nicholls, G. D. J. (1958) Sediment Petrol., E. 461-468 

Goldberg, E. D. & Arrhenius, G.O.S. (1958) Geochim. Cosmoschim. Acta, 

- 13, 153-212 

Arrhenius, G.O.S. & Korkish, J., (1958) Am. Assoc. Adv. Sci., 

Chester, R. & Hughes, M. J., (1967) Chem. Geol., 2, 249-262 

Chester, R. & Hughes, X. J., (1969) Deep-sea Res., 16, 639-654 

Chester, R. & Hessiha-Hanna, R. G., (1970) Geochim. Cosmochim. Acta, 

- 34. 1121-1128 

Sayles, F. L. etg., (1975) Bull. Geol. SOC. her. 36, 1423-1431 

Nissenbaum, A. (1972) Israel J. Earth Sci., 11, 143-154 w., 

(1976) 3, 111-116 

Gibbs, R. J. (1973) Science 180, 71-73 

Engler, R. M. a. (1974) 168th ACS Natl. Meeting, Atlantic City, 

N.J. 

Brannon, J. M. et 4.. (1976) U.S. Waterways Experim. Station Misc. 

Paper D-76-18. 

232

49. Cupta, S . K. & Chen, K. Y. (1975) Environm. Lett., 10, 129-158 

50. Jackson, M. L. (1958) Soil Chemical Analysis, Prentice-Hall Inc., 

Englewood Cliffs, N. J., 498 pp 

51. Holmgren, 6 . S. (1967) Soil Sci. SOC. Amer. Proc., 3, 210-211 

52. Chao, L. L. 1974) Soil Sci. SOC. Amer. Proc., z, 764-768 

53. Volkov, I. I & Fomina, L. S. (1974) APPG Mem., 2, 456-476 

54. .Jenne, E. A. 

55. Hem, .J. D. ( 1 972) Water Resour. Res. S, 661-679 

56. 

57. 

58. 

59. 

60. 

61. 

62. 

63. 

64. 

65. 

66. 

67. 

68. 

69. 

70. 

71. 

72. 

73. 

74. 

(1968) Am. Chem. SOC. Adv. Ser. G, 337-387 

Koppe, P. (1973) Gas-Wasserfach, 114, 170-175 

Ouinker, .J. C. 6 Nolting, R. F. (1976) Neth. J. Sea. Res. LO, 71- 

102 

Muller, C. & Forstner, U., (1975) Environm. Geol., 1, 33-39 

Oden, S. & Ah., T. Sartryck Ur Ymer, 103-122 (Arsbok 1970) 

Whitby, L. X. &. (1976) Can. Mineralogist, 14, 47-57 

Forstner, U. & Wittmann, G. T. W. (1976) Geoforum 1. 41-49 

Hiller, K. D. (1973) in: Cycling and Control of Metals, EPA Cincinnatti, 

91-94 

Tessenow, U. & Baynes, Y. (1975) Naturwissenschaften, 62, 342-343 

Reinhard, D. & Forstner, U. 

301-320 

(1975) N. Jb. Geol. Palaont. Mh., 

Cline, J. T. & Upchurch, G. B. (1975) Proc. 16th Conf. Great Lakes 

Res., 349-356 

Brooks, R. R. &. (1968) Geochim. Cosmochim. Acta, 2, 397-414 

Elderfield, H. & Hepworth, A. (1975) Mar. Poll. Bull., 6. 85-87 

Epstein, S. S. (1972) Int. J. Environm. Stud., 2, 291-200 

Banat, K. 9 &. (1974) Chem. Geol. 14, 199-207 

Chau, Y. K. & Shiomi, M. T. (1972) Water, Air, Soil Poll., 1_, 149-155 

Schottler, U. (1975) Ztschr. Dtsch. Geol. Ges. 126, 373-384 

Lagerwerff, J. V. (1967) Am. Assoc. Adv. Aci. Publ. 95, 343-364 

Fagerstrom, T. & Jernelov, A. (1972) Water Res., 6, 1193-1202 

Wood, J. M. (1974) Science, 183, 1049-1052 

233

I NTRODUCT I ON 

Geochemistry of Sediment/Water Interactions of Nutrients, 

Pesticides and Metals, Including Observations on Availability. 

Nutrients 

D. R. Bouldin 

During the period September 1972 through September 1975, phosphorus 

fractions and flow were monitored in a 300 km2 (126 mi2) watershed in central 

New York. In addition several studies were made of composition and flow in 

selected subwatersheds for portions of this experimental period. 

The water samples were collected manually. Sampling frequency was 

concentrated during periods of high discharge rate. The total phosphorus in 

the water was separated into three fractions according to the following 

scheme. Within 2 to 3 hours after removal from the stream, the sample was 

centrifuged at high speed to remove particulate matter. The untreated supernatant 

was analysed immediately for inorganic phosphorus and this fraction 

was labelled molybdate reactive phosphorus (MRF'). Another portion of the 

supernatant was oxidized with persulfate and the results of this analysis 

were labelled TSP. Finally, samples of the particulate matter were analysed 

for total phosphorus. Hence we derive 3 fractions: a) a molybdate reactive 

fraction which is probably mainly dissolved inorganic phosphorus, b) a 

fraction which includes the molybdate reactive plus organic phosphorus and 

c) the particulate fraction which is primarily the phosphorus associated with 

the suspended solids. 

The total quantity of these various fractions carried out of the 

watershed during a specified time interval (loading) was calculated as follows. 

The concentration of MRP increased as discharge rate increased and the concentration 

of MRP was higher on the ascending limb of the hydrograph relative to 

the descending limb; hence, regressions of MRP on discharge rate and rate of 

change of discharge rate were calculated and these regressions were used for 

interpolation purposes. The loading of MRP was then calculated as the sum of 

the product of discharge per 2 hours, times concentration calculated from the 

regression. In general the difference in concentration between MRP and TSP 

was relatively constant and seemed to vary in a random fashion about the mean 

of 12 microgrammes P/1. The phosphorus content of the particulate matter 

varied randomly about a mean 0.11% of P. 

There are 3 aspects of the data which will be discussed in detail. 

These are: 1) The removal from solution of soluble phosphorus inputs from 

point sources during movement downstream, presumably by reaction with the 

streambed. 2) A procedure for allocating the loading of soluble phosphorus 

to a) biogeochemical ("natural" or "background") sources, b) diffuse sources 

associated with human activity and c) point sources associated with human 

activity. 3) A rationale for the working hypothesis that the soluble phosphorus 

will have a major impact on the biology of lakes while the phosphorus 

associated with the particulate matter will have only a minor impact. 

235

Two independent subwatersheds which together comprised about 3/4 of 

the total area of the whole watershed were selected for detailed study of 

behaviour of soluble phosphorus. One of these subwatersheds (location 16) 

contained a secondary sewage treatment plant serving 1200 people who effluent 

was emptied into the stream. This served as a major point source of soluble 

phosphorus. The other subwatershed (location 15) was similar in other aspects 

but did not contain such well a defined point source. One set of data which 

illustrates that the total soluble phosphorus (TSP) was not conserved in 

the stream is presented in Table 1. Particularly noteworthy are the losses 

during low flow periods, which were primarily the summer months. Presumably 

this loss is associated with reaction between phosphorus in the water and 

material in the streambed. During the periods of higher flow, there appeared 

to be some redissolution of this phosphorus, but recovery was not complete. 

Two small subwatersheds which were almost devoid of human activity 

were selected for study of total soluble phosphorus loading in the absence of 

human activity, and in addition the water from 4 wells sunk in an active 

agricultural area located on well-drained outwash was monitored. All of the 

samples from these sites contained about same the amount of MRP and TSP 

regardless of source. The averages were 62 0.3 microgrammes MRP/1 (123 samples) 

and 15% 0.9 microgrames TSP/1 (107 samples). Thus the loading of these phosphorus 

fractions in the absence of human activity was set equal to these concentrations 

times total discharge, which averages about 0.5 meter/ year in the 

area we studied. 

The remainder of the MRP and TSP was allocated to the sum of the 

diffuse and point sources. The landscape is a mosaic of point and diffuse 

sources. There are numerous single family dwellings (%3000), a sizeable 

fraction of which are served by septic tank-disposal fields which are not 

functioning properly and many simply overflow into drainageways. Milk house 

wastes are often emptied into drainageways. There are about 125 dairies in 

the watershed most of which have barnlots and the manure from these is spread 

on the associated cropland. Since the strategy for control of this multitude 

of sources is very different and since control of all is probably impractical, 

some means of estimating the relative importance would provide useful insights. 

The rationale for the separation of these sources is as follows. 

The diffuse sources have a major impact on water composition only when water 

runs over the soil surface and into drainage ways. Thus there is a soil 

factor and a precipitation intensity-distribution factor. Some soils are so 

permeable to water that only on very rare occasions will water run over the 

surface and into flowing drainageways. These are usually the most intensively 

farmed soils, and also receive the most manure. On the other hand, overland 

flow of water is common on less permeable soils and this is particularly true 

for barnlots where the compaction from the animal traffic reduces permeability. 

In contrast, milk house wastes and sewage inputs are mostly the same each day 

regardless of precipitation intensity. 

The foregoing discussion suggests that the major impact of diffuse 

source loading will be on the high discharge associated with precipitation 

events which produce large amounts of surface runoff. A complicating factor 

(during high discharge) is the dissolution of phosphorus from bed sediment 

which has reacted with point sources during the preceding low discharge 

intervals. 

236

TABLE 1 

Comparison of loading of total soluble phosphorus during selected 

periods for 2 major subwatersheds (locations 15 and 16) and the 

total watershed (location 1). The areas of subwatersheds 15 and 16 

are 147 and 104 km2 respectively and the area of watershed 1 is 

330 km’. Note that during low discharge intervals, the MRP loading 

from 15 and 16 was considerably higher than that at location 1, 

even though location 1 included 15, 16 and an additional 78 km2 

of area. Location 16 includes the secondary sewage treatment plant. 

r 

Discharge at 

location 1 

Period 

(m3 x 

15 

May 1974 

through 

October 1974 

November 1974 

through 

May 1975 

May 1974 

through 

August 1975 

40 

153 

210 

237 

340 

822 

1253

We proceeded to analyse high discharge events as follows utilizing 

the hydrograph analysis of Chow. This separates flow into 3 components: 

a) that associated with a base flow reservoir 

b) that associated with an interflow reservoir and 

c) that associated with surface runoff. 

Then a plot of the concentration MRF' of against surface runoff as a 

fraction of total flow was made and the results were extrapolated to 100% 

surface runoff. which served to estimate the concentration of MRP in the 

surface runoff. 

The results for the whole watershed for three winters are illustrated 

in Figure 1. The results indicate the concentration of MRP in the surface 

runoff is in the range of 34 to 60 microgrammes MRP/1, which is considerably 

higher than the 6 microgrammes MRP/l estimated for biogeochemical sources. 

The loading of diffuse sources was then calculated as the product of the 

estimated concentration at 100% surface runoff multiplied by the estimated 

amount of surface runoff (5 12 to 15% of total discharge). Finally, the 

point source inputs were estimated by difference. 

To summarize the calculations, the biogeochemical inputs were 

estimated as the product of total flow times average concentration MRP (or of 

TPS) in wells and stream flow from watersheds devoid of human activity. The 

inputs associated with human activity were estimated as the difference between 

total loading and biogeochemical loading. The diffuse source loading (associated 

with human activity) was calculated as the product of estimated concentration 

in surface runoff times estimated amount of surface runoff (% 12- 

15% of total flow in the watershed studied). Finally the point source inputs 

were estimated as the remainder. 

Samples of the results of this analysis are presented in Table 2. 

Clearly one can raise many questions about the validity of this procedure. 

We defend it to the extent that it represents a reasonable first approximation 

and simultaneously suggest a more precise and less arbitrary procedure 

should be developed. 

The third aspect of our analysis is associated with the implications 

of results of loading of phosphorus to the biota of lakes. The phosphorus 

Carried in streams is distributed among several chemical forms and physical 

states. Consideration of the nature and behaviour of these several components 

suggests that their effect on the biology of lakes differs. A major fraction 

of the total phosphorus carried out of a watershed by a stream is associated 

with the particulate matter suspended in water, the much of which is delivered 

during a relatively short period of time when the discharge rate is very high 

and hence the velocity of flow is sufficient to transport particles of varying 

sizes and densities. A smaller fraction of the total phosphorus is dissolved 

in the water. For example, during storm periods Fall Creek water often 

contained 500 to 1000 microgrammes of phosphorus per litre associated with 

particulate matter and 20 to 40 microgrammes per litre of dissolved phosphorus. 

Upon reaching the lake these fractions behave very differently; the larger 

particles soon settle to the bottom because water movement in the lake is no 

longer sufficient to keep them in suspension. At least in the lakes in 

central New York, a few days after large a storm which delivers large amounts 

of suspended solids, the water in the lake (even near stream outlets) becomes 

relatively clear and only the fine particles remain in suspension plus, of 

238

TABLE 2. 

ALLOCATION OF MOLYBDATE REACTIVE PHOSPHORUS (MRP) 

IN WATER AT LOCATIONS 15, 16 AND 1 FOR THE PERIOD 

MAY 1974 THROUGH AUGUST 1975. 

BGC 11 

Human Activity 

Point Diffuse Total 

Location kg x 

kg x 

kg x kg 

15 

16 

1 

"Biogeochemical 

45 

1260 41 

n 

a 

x 00 

394 22 

1100 61 

885 20 

590 47 1250 95 8 565 

310 17 

I I I 

025 050 0.75 1.0 

SURFACE RUNOFF + TOTAL DISCHARGE 

Figure 1. The regressions of MRP concentration on fraction of 

the total flow as surface runoff at location 1 for 

three winters. 

239 

30 

1800 

3060 930

course, the dissolved constituents. Lake samples seldom contain more than a 

total of 10 to 50 microgrammes of phosphorus per litre in all forms. Thus 

the phosphorus remaining in the lake water is very different in nature and 

amount from that delivered by the stream during storm periods. 

According to the reasoning which follows, the amount of particulate 

phosphorus delivered by the stream has only a minor effect on the biology of 

lakes, while the dissolved phosphorus has a major effect. 

First, the bottom of the lake is covered with sediment delivered by 

past events from the lake basin. If the phosphorus in the sediment delivered 

by past events was essentially in the same forms as that delivered by current 

events, accumulation of more of the same seems unlikely to change the effect 

of the bottom sediments on lake biology; that is, adding a few millimetres 

of sediment to several metres of sediment seems unlikely to have an important 

effect on lake biology. 

Second, questions can be raised about the chemical activity of the 

particulate phosphorus; for example, if samples of suspended solids were 

leached with phosphorus-free water, how rapidly would the solid phase phosphorus 

dissolve and what would be the concentration of phosphorus in the leaching 

water? The results of such studies show that there is a small amount (usually 

considerably less than 10%) of the total phosphorus which dissolves fairly 

rapidly and that the concentration of leachate decreases as leaching continues. 

Such phosphorus is referred to as labile or sorbed phosphorus. Once this 

labile phosphorus is removed, the remainder dissolves very slowly and concentrations 

in solution are only few a microgrammes per litre. Furthermore, 

this is consistent with the fact that most of the phosphorus associated with 

the suspended solids has persisted through long geological periods; its 

resistance to dissolution must be considerable or it would have been leached 

out of the unconsolidated mantle and carried to the sea long ago. The results 

of studies with Fall Creek sediments demonstrate that the particulate matter 

contains about 1.1 milligrammes of total phosphorus per gram and about 0.04 

milligrammes (4%) of this is in a labile or sorbed form. 

Further evidence that soluble, not adsorbed, phosphorus is the 

critical factor determining phytoplankton concentrations is provided by 

comparative studies of the way lakes respond to phosphorus loadings. Detailed 

investigations on a group of New York lakes revealed that average summer 

standing crops of phytoplankton were better correlated with loadings calculated 

as soluble phosphorus than with those determined in the form of total 

phosphorus. Models resulting from this work have subsequently been extended 

to a global basis for temperate latitude lakes. These and other arguments 

lead us to formulate the following hypotheses about the effects of these fractions 

for temperate systems with soils and bedrock similar to those of the New 

York lakes: 1) probably 100% of the molybdate reactive phosphorus (MRP) and 

most of the total soluble phosphorus (TSP) is available to organisms in 

lakes. 2) probably the labile or sorbed fraction of particulate phosphorus 

is of limited importance to the biology of lakes. 3) probably the remainder 

of the particulate phosphorus is of no consequence to the biology of lakes. 

A most important aspect of the preceding paragraphs is to at least 

emphasize the question of biological effects of the different phosphorus 

fractions. There seems to be no reasonable defense for the hypothesis that 

all fractions are of equal biological importance. Thus measurements of 

loading based on the single parameter of total P delivered by streams seem to 

240

e of limited value in terms of estimating impact on lake biology. However, 

total P in the photic zone of the lake is an important parameter, but it 

should be noted that total P delivered by the stream and total P in lake 

water are entirely different; in fact, MRP the and TSP fractions measured 

in stream flow are probably comparable in many respects to total P in lake 

samples. 

Major portions of the work reported here were performed in cooperation 

with an interdisciplinary team funded in part by the Rockefeller 

Foundation, FT70103. A more comprehensive summary of the project is to be 

found in the following book: 

Porter, Keith, ed. Nitrogen and Phosphorus: Food Production, 

Waste and the Environment. Ann Arbor Sci. Publications, 

Inc. Ann Arbor, 1975. 

241

DISCUSSION 

Dr. T. Logan: You mentioned the method that you used for estimating the 

labile phosphorus by using the equilibrium phosphorus concentration and 

extrapolating to the amount that is desorbed. We have been doing more or 

less the same type of procedure to find what fraction of the particulate 

phosphorus might be bio-available. The only thing that bothers me about 

that method is that it is time-dependent. It is the amount that you are 

going to desorb in a given time which you pretty well define by your experimental 

conditions. But if you consider the situation that might be 

occurring in the lake, it is possible that you can regenerate additional 

labile phosphorus if you let the sediment rest or put it through a rest 

period. We have done some of this and in fact you can regenerate a considerable 

amount of labile phosphorus. I want to know how we try and resolve 

these types of problems. 

Dr. D. Bouzdin: The argument I would use is that we are interested in the 

incremental effect on the phosphorus associated with the sediments we that 

are adding. We assume that the sediments already there contain the phosphorus 

that they inherited from the geological materials and that adding a fresh 

batch really is not going to have too much influence on the lake. The thing 

is, the new sediment coming in has this labile fraction that in may fact 

have a much larger impact on the lake than the old sediment. That is our 

rationale, and to be sure I would not say that what we did was the best. 

It is a crude estimate and you can go into a lot of refinement with that, 

and I think you probably should. The only point I am trying to make Is that it is not a very large fraction of the total sediment phosphorus that 

we are dealing with. It is a relatively small fraction in our particular 

case and I do not think this is something that you extrapolate everywhere. 

Dr. T. Logan: The other point is, do you think that this labile phosphorus 

is a sediment parameter? Do you see it changing with land use OK fertilization 

practices, manure practices, this type thing, of or is it more or 

less determined by the soil characteristics? 

Dr. D. BouZdin: I think it should very much depend on the kinds of treatment. 

I would think the suspended solids derived from a non-agricultural landscape 

are quite different in nature from those derived from a barnlot. The amount 

243

of labile phosphorus on the barnlot sediments is quite high. Let me say 

one other thing, I am just convinced from everything I see and all the 

analysis of the data I can carry out, that well over 50% of the total suspended 

solids in the Fall Creek Watershed are simply derived from stream bank 

erosion, and this is not the kind of erosion that is the reworking old sediments. 

In one case in the stream sub-watershed that gives me the highest 

loading of suspended solids, the stream is clearly eating its way through an 

old terminal moraine. It has not got there yet. It is still chewing away on 

that and you can see that in very many places in the watershed. We have got 

a little bit of suspended solids from the barnlots mixed up with a lot of 

stuff that has never seen phosophorus or manure or anything else. It is 

ground up glacial debris that has been sitting there 10,000 for years. 

244

INTRODUCTION 

Geochemistry of Sediment/Water Interactions of Nutrients, 


Pesticides 

J. B. Weber 

Pesticides used in agricultural production eventually reach the 

soil where they are acted upon by various processes. The chemicals may 

be decomposed by chemical, biological, or photochemical degradation. 

They are also acted upon by transfer processes such as adsorption, exudation, 

retention and accumulation by organisms, adsorption by soil 

colloids, and other surfaces, and movement in the vapour, liquid and 

solid state through the atmosphere, soil, and water (1. 2, 3). In this 

paper, we are concerned primarily with pesticides and particulate matter 

that end up as sediment in water. 

SEDIKNT 

Soil sediment is defined as the solid material, both mineral 

and organic, that is in suspension, is being transported, or has been 

moved from its site of origin by air, water, gravity, or ice and has come 

to rest on the earth's surface either above or below sea level (4). It 

is by far the United States' single largest water pollutant, exceeding the 

sewage load by some 500 to 700 times (5). About half of all sediment 

originates on agricultural land (6) and some of it contains adsorbed 

pesticides (7). 

The properties of sediment influence its effect on the environment. 

Physical properties, including size, density, and shape of the particles 

affect the sediment movement. Coarse sediment is relatively inert, but fine 

sediments composed of silt, clay, and organic materials are chemically 

active and may absorb or desorb chemicals from solution. The bulk of the 

sediment problem, however, is caused by the colloidal fractions of sediment. 

The colloidal material may be a mixture of clay minerals, of the expanding 

or nonexpanding type, and of organic materials ranging from relatively 

hydrophilic and undecomposed to highly lipophilic and highly decomposed. 

Little is known about the chemistry of sediment in field situations, but 

information is available on the interaction of pesticides with various 

soil colloids and specific adsorbents (3,8). It is also known that 

radioactive materials from fallout selectively erode with soil sediment 

and may result in higher concentrations of radioactivity in reservoir 

deposits (7) and there is a good possibility that an analogous situation 

is occurring with pesticides. A recent survey along tributaries of the 

lower Mississippi River revealed isolated bottom sediment deposits containing 

as much as 0.5 ppm DDT (9).

Complete elimination of soil erosion is impossible, so guidelines 

are being developed to define acceptable levels of erosion and sedimentation 

(10). Models for predicting runoff (11) and pesticide movement through 

soils (12) are being developed. An excellent bibliography on the effects of 

agricultural practices or environmental quality is also available (13). 

PESTICIDE I~RACTION~ 

Herbicides, insecticides, and fungicides vary greatly in their 

physical and chemical properties and in their behaviour in the environment 

(1, 3, 14, 15, 16). Of the many properties that regulate pesticide behaviour, 

at least four are of primary importance. They include: (a) ability to ionize; 

(b) presence of complexing elements (P, As); (c) water solubility; and 

(d) ability to vapourize (3). A classification of pesticides based on the overall 

characteristics of these four properties of selected pesticides is shown 

in Table 1. Chemical names for the compounds are given in Table 2. 

PESTICIDE FROPERTIES 

The ability of a pesticide to ionize determines whether or not the chemical 

will have an ionic charge in aqueous solution. Cationic pesticides, such as 

the herbicides cyperquat, difenzoquet, diquat, and paraquat, are readily 

adsorbed by negatively charged surfaces of colloidal soil sediment (3). 

They are completely removed from aqueous solution by colloidal sediment and 

move with the sediment (3). Anionic pesticides, such as the acidic herbicides 

dalapon, dicamba. picloram, and 2,4-D are adsorbed in only small 

amounts by colloidal soil sediment and are readily desorbed in aqueous 

systems (3). They are, therefore, found primarly in the solution phase in 

waters. Basic pesticides, such as the 6-triazine herbicides ametryn, 

atrazine, prometon, and prometryn are adsorbed by acidic colloidal surfaces 

in relatively large amounts and by neutral or basic colloidal surfaces in 

much smaller amounts. Since their adsorption is dependent on the acidity of 

the system, the amount that is retained or released by soil sediment depends 

on the pH of the system (3, 17). They are, therefore, in equilibrium with 

the sediment and the solution phase. Nonionic pesticides are adsorbed by 

colloidal surfaces primarily through physical adsorption forces the and 

amount that is retained by soil sediment is dependent to a large extent upon 

the water solubility of the pesticide and the hydrophilic/lipophilic characteristics 

of the sediment (3). Relatively water soluble, nonionic pesticides, 

such as aldicarb, CDAA, dimethoate, molinate, carbetamide, fenuron, 

methomyl, and propoxur, are adsorbed soil by colloids in very small amounts 

and are readily desorbed in dynamic, aqueous systems. Pesticides of very 

low water solubility such as aldrin, BHC, lindane, trifluralin, DDT, dieldrin, 

endrin, and oryzalin, are adsorbed by highly lipophilic organic colloidal 

sediments but not by hydrophilic clay colloids. They are in equilibrium 

with the surrounding aqueous phase, but because of their low solubilities 

desorb only slightly. Nonionic pesticides of moderate water solubilities 

are intermediate between the low and high water soluble compounds in their 

reaction with colloidal sediments. Pesticides which possess complexing 

elements such as phosphate, (demeton, disulfoton, glyphosate, parathion, and 

phorate) or arsenic (DSMA, MAMA and MSMA) readily complex with clay colloids 

and move with these sediments. 

246

N 

c. 

U 

TABLE 1. 

CLASSIFICATION OF SELECTED PESTICIDES BASED ON OVEMLL THE CHARACTERISTICS OF 

IONIZABILITY, WATER SOLUBILITY, PRESENCE OF COMPLEXING ELEMENTS, AND VAPOURIZABILITY 

Ionic Pesticides 

I With 

Complexing High 

Nonionic Pesticides 

Water Moderate Water Low Water 

Elements Solubility Solubility Sol 

Cationic Basic Acidic Non- Non- Non- 

Pesticides Pesticides Pestieides Volatile Volatile Volatile Volatile Volatile Volatile Volatile Volatile 

cyperquat ametryn dalapon demeton DSMA aldicarb carbetamide CDEC butachlor aldrin DDT 

difenzoquat atrazine dicamba disulfoton glyphosate CDAA fenuron EPTC diuron BHC dieldrin 

diquat prometon picloram parathion MAMA dimethoate methomyl pebulate fluometuron lindane endrin 

paraquat prometryn 2,4-D phorate MSMA molinate propoxur vernolate monuron trifluralin oryzalin 

~~

Common 

Name 

cyperquat 

difenzoquat 

diquat 

paraquat 

one t ryn 

atrazine 

prometon 

prometryn 

dalapon 

dicamba 

picloram 

2,4-0 

demeton 

disulfoton 

parathion 

phorate 

DSMA 

glyphosate 

"A 

MSMA 

aldicarb 

Table 2. 

NAMES AND PROPERTIES SELECTED PESTICIDES 

Chemical Name 

Water 

solubility 

(wd 

1-methyl-4-phenylpyridinium ion >lo5 

1.2-dimethyl-3.5-diphenylpyrazium ion >lo5 

6.7-dihydrodipyrido[1,2-a:2',1'-c]pyrazinediium ion>105 

l,l'-dimethyl-4,4'-bipyridinium ion >lo5 

2-(ethylamino)-4-(isopropylamino)-6-(methylthio) 185 

-s-triazine 

2-chloro-4-(ethylamino)-6-(isopropylamino)-s- 33 

triazine 

2,4-bis(isopropylamino)-6-(methoxy)-s-triazine 750 

2.4-bis(isopropylamino)-6-(methylthio)-s-triazine 48 

2,2-dichloropsopionic acid 

3,6-dichloro-o-anisic acid 

4-amino-3,5,6-trichloropicolinic acid 

2,4-dichlorophenoxy acetic acid 

0,O-diethyl-o(and S)-(Z-(ethylthio)ethyl) 

phosphorothioates 

0,O-diethyl-S-(2-ethy1thio)ethyl)phosphoro- 

dithioate 

0,O-diethyl-0-p-nitrophenyl phosphorothioate 

0,O-diethyl-S-(ethy1thio)-methyl phosphoro- 

dithioate 

disodium methanearsonate 

N-phosphonomethylglycine 

monoammonium methanearsonate 

monosodium methanearsonate 

2-methy1-2-(methylthio)-propionaldehyde-O- 

(methylcarbamoy1)oxine 

248 

>lo5 

4500 

430 

900 

250 

66 

24 

50 

>lo5 

>lo5 

loG 

lo6 

6000 

Vapour 

pressurc 

(mm Hg @ 21 

< 10- 

(10-6 

2 x 10-6 

5 x 

3 x 10-6 

a0-6 

1 x 10"~ 

1.8 x 

2.3 x 

1 x 

10" 

Common 

Name 

CDlZA 

dimethoate 

molinate 

carbetamide 

f enuron 

methomyl 

propoxur 

CDEC 

EPTC 

pebulate 

vernolate 

butachlor 

diuron 

fluometuron 

monuron 

aldrin 

BHC 

lindane 

trifluralin 

DDT 

dieldrin 

endrin 

oryzalin 

Chemical Name 

N,N-diallyl-2-chloroacetamide 

0,O-dimethyl-S-(-methylcarbamoylmethyl) 

phosphorodithioate 

S-ethylhexahydro-1H-azepine-1-carbothioate 

D-N-ethyl-2-(phenylcarbamoyloxy)-propioamide 

l,l-dimethyl-3-phenylurea 

Water 

solubility 

(ppm) 

>lo5 

25,000 

800 

3500 

3000 

S-methyl-N-((methylcarbamoy1)oxy)thioacetimidate 10,000 

2-isopropylphenyl-N-methylcarbamate 

2-chloroallyl diethyldithiocarbamate 

S-ethyl dipropylthiocarbamate 

S-propyl butylethylthiocarbamate 

S-propyl dipropylthiocarbamate 

N-butoxymethyl-2-chloro-2',6'-diethylacetanilide 

3-(3,4-dichlorophenyl)-l,l-dirnethyurea 

1,l-dimethyl-3-(a,a,a-trifluoro-m-tolyl)urea 

3-(p-chlorophenyl)-l,l-dimethylurea 

1,2,3,4,10,10-hexachloro-l,4,4a,5,8,8a-hexahydro- 

1,4-endo-exo-5,8-dimethanonaphthalene 

1,2,3,4,5~,6-hexachlorocyclohexane 

gamma isomer of 1,2,3,4,5,6-hexachlorocyclohexane 

2000 

92 

370 

60 

90 

23 

42 

90 

230 

0.2 

a,a,a-trifluor-2,6-dinitro-N,N-dipropyl-p-toluidine 0.05 

dichlorodiphenyltrichlorethane 0.001 

1,2,3,4,10,10-hexachlor-exo-6,7-epoxy-l,4,4a,5,6, 0.25 

7,8,8a-octahydro-l,4-endo-exo-5,8-dimethano- 

naphthalene 

1,2,3,4.10,10-hexachloro-6,7-epoxy-1,4.4a.5.6.7 0.23 

8,8a,-octahydro-l,4-endo,endo-5,8-dirnethanonaphthalene 

3,5-dinitro-N4,N'-dipropylsulfanilamide 2.4 

249 

10 

10 

Vapour 

pressure 

(mm Hg @ 25'C) 

1 x io-' 

5.6 x 

(10- 

2.2 x 10-3 

3.4 x 

3.5 x 

1.0 x 

4.5 x 

5 x 

10- 

5 X 

1.3 x 10" 

1.9 X 

10- 

2.7 X loq6 

2 x 10"

Pesticides with vapour pressures higher than 1 x mm of Hg at 

25' C are considered to be volatile and generally need to be incorporated 

into the soil to be effective (3). Generally the higher the vapour pressure, 

the more volatile is the chemical. Such pesticides, including those listed 

in Table 1 and the esters of the phenoxy acid herbicides, are adsorbed by 

colloidal soil sediments, but they are readily desorbed in dynamic aqueous 

systems; in addition the vapours escape from the aqueous phase into the 

atmosphere. 

PESTICIDE b m ~ ~ 

Studies on the movement of pesticides from agricultural lands 

showed that the chemicals were transported both in the runoff water and 

adsorbed to suspended materials (18, 19, 20, 28). The amounts transported 

in runoff depended on climatic factors such as frequency, intensity, and 

duration of rain; chemical properties of the pesticides; and properties of 

the soils such as soil type, slope, and moisture content and surface condition. 

Barnett % &. (18) found that ester formulations of 2,4-D were 

more susceptible to runoff than the more soluble amine salt forms. The 

ester forms adsorbed to soil particles and moved with the eroding soil, 

whereas the amine forms dissolved and leached into the soil. 

Surface runoff of 2,4-D and picloram was found to be greater from 

sod than from fallow soil surfaces in studies by Trichell (19). The opposite 

was found by Edwards (30) to be the case for atrazine. Runoff of 2,4,5-T was 

about equal under the same conditions (3). Herbicide runoff increased with 

increasing slope and rate of application and concentration decreased when 

runoff passed over untreated sod. 

In studies where trifluralin, DDT, toxaphene, or methylparathion 

was applied to cotton, less than 1%, 3.12%, 1%, and 0.25%, respectively, was 

recovered in the runoff (26, 26). Of the four pesticides recovered, 84%, 

96%, 75%, and 12%, respectively was associated with the sediment. 

The highest concentrations of diuron, summitol, 2,4-D, 2,4,5-T, 

and picloram observed in surface runoff waters were 1.8 ppm, 0.5 ppm, 4.2 

ppm. 1.2 ppm, and 2.7 ppm respectively, in ditchbank weed control studies 

in Utah (29). The greatest herbicide movement occurred during intial storms 

following herbicide application. 

Fluometuron movement in runoff from studies conducted in five 

southern states, and Puerto Rico, ranged from 0.10 to 0.87 ppm in the first 

runoff and decreased to less than 0.2 ppm in later runoff (21). Most of the 

herbicide was found distributed in the 0 to 30 cm zone (22), but in two 

sandy soils it was found in the 15 to 30 cm zone in high enough concentrations 

in injure bioassay plants (23). 

In a study conducted in areas where forest vegetation had been cut 

two years before spraying, less than 0.1% of the 2,4-D, and less than 1% of 

the picloram applied was lost in runoff from the first seven runoff events 

after herbicide application (24). 

250

Sheets st. (25) found, where 2,4-D, 2,4,5-T, picloram, or 

dicamba was applied to small plots in a mountain watershed, maximum con- 

centrations of 2.55 ppm, 0.68 ppm, 4.19 ppm, and 0.16 ppm, respectively, 

occurred in surface runoff during the first OK second event after application. 

BIOACTIVITY OF ADSOREED PESTICIDES 

Biological availability of bound pesticides is dependent upon the 

type of pesticide and colloidal sediment involved (2, 17). Pesticides that 

are weakly adsorbed to the surfaces of colloidal sediment, such as the 

phenoxy acid herbicides, are readily desorbed into the surrounding aqueous 

environment and dissipate primarily through dilution. Pesticides, such as 

diquat and paraquat, that are adsorbed on the internal surfaces of expanding 

types of clay colloids are not released to the aqueous phase and are not 

available to organisms. Pesticides that are very water insoluble are normally 

adsorbed to the surface of lipophilic sediment. They are in equilibrium 

with the surrounding aqueous environment and are released or degraded chemically 

OK biologically, except in those cases where the chemicals have 

become part of the organic collodial matrix. The majority of pesticides are 

intermediate in biological degradability in the bound state. They are in 

equilibrium with the surrounding dynamic media which tends to desorb them 

and make them available for degradation. 

GMCLUS IONS 

The extent to which pesticides applied to agricultural lands may 

pollute runoff water and the eroding sediment depends on the physical, 

chemical, and biological properties of the chemicals, the intensity and 

duration of the rainfall, and edaphic properties such as soil cover, soil 

type, and slope. 


A Primer on Agricultural Pollution. (1971)., J. Soil and Water 

Conservation, g,(2); 44-65. 

Bailey, G. W., R. R. Swank, Jr., and H. P. Nicholson. (1974)., 

Predicting Pesticide Runoff from Agricultural Land: A 

Conceptual Model. J. Environ. Qual., 2,95-102. 

Barnett, A. P., E. H. Hauser, A. W. White, and J. H. Holladay. 

(1967)., Loss of 2,4-D in Washoff from Cultivated Fallow Land. 

Weeds, x, 133-137. 

Barthel, W. F., J. C. Hawthorne, J. H. Ford, G. C. Bolton, 

L. L. McDowell, E. H. Grissinger, and D. A. Parsons. 

(1969)., Pesticide Residue in Sediments of the Lower Mississippi 

River and its Tributaries. Pesticides Monitoring J., 2(1), 

8-66. 

251

Bradley, J. R., Jr., T. J. Sheets, and M. D. Jackson. (1972)., 

DDT and Toxaphene Movement in Surface Water from Cotton Plots. 

J. Environ. Qual., 1. 102-105 

Control of Water Pollution from Cropland. (1975) Vol. 1-A Manual for 

Guideline Development. ARS, USDA, and Office of Research 

and Development, EPA Report No. ARS-H-5-1, Superintendent of 

Documents, Washiongton, D. C. 

Davidson, J. M., G. H. Brusewitz, D. R. Baker, and A. L. Wood. 

(1975)., Use of Soil Parameters for Describing Pesticide Movement 

Through Soils. Environmental Protection Agency Report No. 

660/2-75-009, National Environmental Research Centre, Office 

of Research and Development, EPA, Corvallis, Oregon. 149 pp. 

Edwards, W. M. (1972)., Agricultural Chemical Pollution as Affected 

by Reduced Tillage Systems. Proc. No-Tillage Systems Symposium, 

February 21-22, 1972, Columbus, Ohio., pp. 30-40. 

Environmental Quality: An Annotated Bibliography of Papers, 

Published in the Soil Science Society of America Proceedings, 

(1962-1971)., Soil Science Society of America, Madison, Wisconsin, 

1975. 

Epstein, E. and W. J. Grant., (1968). Chlorinated Insecticides in 

Runoff water as Affected by Crop Rotation. Soil Sci. SOC. 

Amer. Proc., 32, 423-426. 

Evans, J. 0. and D. R. Duseja. (1973)., Herbicide Contamination of 

Surface Runoff Waters. Environmental Protection Agency Report 

R2-73-266. Superintendent of Documents, U.S. Government, 

Washington, D. C., 99 pp. 

Glymph, L. M. and C. W. Carlson. (1966)., Cleaning Up Our Rivers and 

Lakes, Paper No. 66-711. American Society Agricultural 

Engineering, St. Joseph, Michigan. 43 pp. 

Glymph, L. M. and H. C. Storey. (1967)., Sediment--its Consequences 

and Control. Pub. 85. American Association Advancement 

of Science, Washington, D. C., pp. 205-220. 

Peeper, T. F. and J. B. Weber. (1974)., Vertical Fluometuron Movement 

in Runoff Studies of the Southern Region. Proc. So. Weed Sci. 

SOC., 27, 324-332. 

Resource Conservation Glossary., (1970) Soil Conservation Society of 

America, Ankeny, Iowa. 

Savage, K. E. (1975)., S-78 Regional Research Project--Movement and 

Persistence of Fluometuron in the South: I. Persistence and 

Vertical Movement in Soil. Proc. So. Weed Sci. SOC., 8,32 

(abstract) 

Sheets, T. J., J. R. Bradley, Jr., and M. D. Jackson. (1973)., 

Movement of Trifluralin in Surface Water. Proc. So. Weed 

Sci. SOC., 26, 376 (abstract). 

252

Suffling, R., D. W. Smith, and G. Sirons. (1974)., Lateral LOSS of 

Picloram and 2,4-D from a Forest Podzol During Rainstorms. 

Weed Res., 2, 301-304. 

Trichell, D. W., H. L. Morton, and M. G. Merkle. (1968)., Loss of 

Herbicides in Runoff Water. Weed Sci., 16, 447-449. 

Weber, J. B. (1972)., Interaction of Organic Pesticides with Particulate 

Matter in Aquatic and Soil Systems. In R. F. Gould (ed.) Fate 

of Organic Pesticides in the Aquatic Environment, Chapter 4, 

pp. 55-120, American Chemical Society, Washington, D. C. 

Weber, J. B. (1975)., Agricultural Chemicals and Their Importance 

as a Non-point Source of Water Pollution. Proc. S. E. Regional 

Conf. Non-Point Sources of Water Pollution, Virginia Polytechnic 

Institute and State University, May 1-2, 1975, pp. 115-129. 

Weber, J. 8. (1970)., Mechanisms of Adsorption of s-triazines by 

Clay Colloids and Factors Affecting Plant Availability. & 

F. A. Gunther (ed.) The Triazine Herbicides, pp. 93-130, 

Springer-Verlag, N. Y. 

Weber, J. B., Environmental Safety of Pesticides: The Old VS. the 

New. Submitted for publication in Environ. Sci. and Tech., 

June, (1976). 

Weber, J. B. and S. B. Weed. (1974)., Effects of Soil on the Biological 

Activity of Pesticides. Chapter 10, pp. 223-256, W. P. 

Guenzi (ed.) Pesticides in Soil and Water, Soil Science Society 

of America, Inc., Madison, Wisconsin. 

Weber, J. B., S. B. Weed, and T. J. Sheets. (1972)., Pesticides: How 

They Move and React in the Soil. Crops and Soils Magazine, z,(l), 

14- 17. 

Weber, 3. B., T. J. Monaco, and A. D. Worsham. (1973)., What Happens 

to Herbicides in the Environment? Weeds Today, 

4,(1),16-17,22. 

Weed, S . B. and J. B. Weber. (1974)., Pesticide-Organic Matter Inter- 

actions, Chapter 3, pp. 39-66, W. D. Guenzi (ed.) Pesticides in 

Soil and Water, Soil Science Society of America, Inc., Madison, 

Wisconsin. 

White, A. W., A. P. Barnett, B. G. Wright, and J. H. Holladay. (1967).. 

Atrazine Losses from Fallow Land Caused by Runoff and Erosion. 

Environ. Sci. Tech., 1. 740-744. 

Wiese, A. F. (1975). S-78 Regional Research Project--Movement and 

Persistence of Fluometuron in the South: 11. Lateral Movement 

in Runoff Water. Proc. So. Weed Sci. SOC., 28, 322, (abstract). 

253

INTRODUCTION 

Geochemistry of SedimentlWater Interactions of Nutrients, 


Metals 

I. Jonasson 

A knowledge of an element's behaviour at a sediment-water interface 

is of prime concern in the development of an understanding of what may be the 

significant chemical controls on that element's dispersion and perhaps upon 

its fixation into sediments. 

Allied research on the transport of elements in solution as complexed 

species has received wide attention in the geochemical literature. 

Pitwell (1973) has concluded that the most common complexing ligands present 

in groundwaters are water itself, carbonate, chloride, fluoride and some 

organic acids. Taken to their extreme limits, processes by which metals are 

mobilized, transported, precipitated and remobilized are considered important 

steps in the formation of sedimentary sulphide orebodies. Saxby (1973) has 

suggested that on diagenesis, metal-organic complexes may eventually form 

concentrations of metallic sulphides. 

However, this discussion is concerned primarily with the nature of 

the dynamic interactions, mainly chemical, which affect the cycling of a 

given trace metal ion or its compounds through fluvial systems. 

Firstly it is necessary to deal with organic matter and its involvement 

in such interactions, and then with the influences of certain hydrous 

metal oxides. In nature, these might be regarded as two relatively pure 

systems representing end-members of a full spectrum of interactions in which 

practically any substance present can be regarded as a participant in dispersion 

processes. 

For example, organic matter predominates in the flat-lying terrain 

of the tree covered section of the Canadian Shield and Interior Lowlands. 

Streams are commonly fed by waters from swamps, marshes and muskeg. The 

residence time of waters within organic trash ensures considerable dissolution 

of humic materials. Silts and clays are often covered with finely 

divided organic matter. By contrast, stream sediments from the far north of 

Canada and from the alpine Cordilleran regions are generally clean of organic 

matter; waters derived mainly from snow melt contain very little dissolved 

organics and adsorption of metals directly into clays, rock flour and hydrous 

metal oxides and dissolution of mineral particles are the predominant watersediment 

interactions. 

TAL INTERACTIONS 

(a) Interactions Involving Organic Matter 

Within surficial waters the most significant form of metal-organic 

interaction is generally accepted to involve chelation of trace elements 

255

with the complex, polymeric organic compounds which comprise humic matter 

(Saxby 1969, Bowen, 1966). Experimental studies have shown that, in comparison 

with model organic compounds likely to find their way into natural 

waters, soluble humic matter has the greatest potential to form soluble, 

stable metal complexes in competition with hydrolytic and other precipitating 

reactions. Solid humic matter in a fluvial system exhibits exceptionally 

strong cation exchange properties thus concentrating trace metals from 

solution onto a solid phase of bed a sediment. 

The trace element distribution between sediment and natural water, 

and the chemical factors influencing this are of prime concern. The dominant 

interactions here are suggested to be cation hydrolysis, cation exchange 

reactions and related adsorption-desorption processes, as well as complex 

species formation involving both cations and anions. 

Of the organic species involved, humic acids, fulvic acids and 

humins are the most abundant. A major problem in studies on the nature of 

metal-complex speciation centres in the fact that all of the above compounds 

form part oE an extremely heterogeneous mixed polymer system where the 

differences between the sub-divisions are due to variations in elemental 

composition, acidity, degree of polymerization and range of molecular weights. 

Thus, humins comprise the highest molecular weight groups; highly polymerized 

and largely insoluble in aqueous solution. Humic acids are from the middle 

molecular size range, also very complex and, in part, soluble under certain 

conditions of acidity. Fulvic acids are likely the main transporters of 

metals in solution and comprise hydrophilic polyhydroxy aliphatic and aromatic 

acids. At the low molecular weight end of the range are the so-called yellow 

organic acids commonly observed in swamp waters or in stream waters of certain 

arid zones, particularly where considerable carbonate is present. These 

substances are probably also important in pore waters and interstitial waters 

of bed sediments representing as they do end members of humic matter degradation. 

Micro-organisms are, in part, responsible for the decomposition of 

the higher weight organic acids (Kuznetsov, 1975) producing the smaller more 

soluble fragments. Micro-organisms are also important in mobilizing certain 

metals from sediments by means of very specific biochemical interactions. 

These have been well discussed in the literature and will not be discussed 

further here (Wong et&., 1975 for Pb; Chau et&., 1976 for Se; Wood, 1974, 

1975 for Sn, Hg, As and Se). 

It should also be noted that humic and fulvic acids behave as 

negatively charged species in solution, due to the ionization of their acidic 

carboxyl and hydroxyl groups. Neutralization of this charge, perhaps by 

interacting metal ions, metal oxide colloids, or adsorption onto clay particles 

can lead to flocculation of the colloids and subsequently further 

coprecipitation of metals. Mechanisms by which metallic ions from natural 

waters are absorbed or complexed by such organic matter, have been discussed 

extensively by many authors (e.g. Krauskopf, 1955; Schnitzer and Khan, 1972; 

Curtis, 1966). The attractive interactions of ions with soluble, colloidal 

or particulate organic material range from weak forces leaving the ion easily 

replaceable (physical adsorption) to strong forces indistinguishable from 

chemical bonds and often not replaceable (i.e., chemisorption, or specific 

adsorption). 

The problems involved in studying metal-sediment-water interactions 

either in laboratory models or in the field are many. Several useful reaction 

schemes have been proposed as a basis for laboratory studies. That of Curtis 

(1966) is shown in Figure 1. According to Curtis' idealistic scheme, metal 

ions can show a positive correlation with organic carbon in a sediment when 

256

4* or M(H~o)~+ 

Y 

y 

metal-organic 

compounds or ions 

adsorption of 

metal-organic 

material onto 

clay particles 

(he metal-C correlation) 

no interaction (no element4 correlation) 

CP: clay particles 

ORG: organic matter 

x organic matter and element 

competing for clay particles 

(-ve element - C correlation) 

Figure 1: Generalized metal-organic-solid reaction scheme as proposed by 

Curtis (1966). 

251

metal ions interact in solution with dissolved organic matter that is in 

turn concentrated by adsorption onto particulates such as clay minerals. 

Zero correlations may result when there is no solution phase interaction and 

the dissolved organic matter alone adsorbs onto the particulates. If there 

is competition between metal ions and dissolved organics for adsorption sites, 

then negative carbon-metal correlations are the result. Ong and Bisque 

(1968) and Ong 4. (1970) have refined the Curtis scheme to consider 

colloids as possible transporting agents of metal ions (Figure 2). 

The ability of solid humic matter to physically and chemically 

adsorb metals from aqueous solution has been well documented. For example, 

Rashid (1974) investigated metal adsorption onto sedimentary and peat humic 

acids. A solution containing equal amounts of Co, Cu, Mn, Ni and Zn ions was 

brought into contact with humic acid; Cu was preferentially adsorbed. 

Leaching with various agents showed that Cu was held far more firmly than the 

other metals. From these and similar experiments described in the literature, 

it has proved possible to indicate a probable order of binding strength for a 

* 

number of metal ions onto humic or fulvic acids, e.g., UOn > Hg* > Cu* > 

ft 

Pb* > Zn* > Nift > Co*. Ca* is considered to bind as strongly as Pb . 

Similar experiments by Rashid to adsorb base metals from seawater 

were not nearly so successful probably due to the very low contents of these 

metals in seawater and the dominating presence of alkali and alkaline earth 

cations, which although likely more weakly adsorbed are in much greater 

abundance when in competition for adsorption sites. This an is important 

parameter to be considered in all field studies of freshwater systems as 

well. 

The importance of relative binding strengths should not be overlooked, 

nor should the fact that the order of metal-organic matter stabilities 

will vary somewhat according to the nature and complexity of the organics and 

to conditions such as acidity and redox potential. 

Another major function of organic matter in water-sediment interactions 

concerns the ability of soluble organic acids to chemically leach and 

even dissolve minerals. Thus particulates trapped in organic-rich sediments, 

perhaps as a result of coprecipitation or surface adsorption, will slowly 

undergo a prolonged attack by sorbed fulvic or humic acids which can extract 

a variety of elements including metals. For example Baker (1973) found that 

humic acids rapidly decompose sulphides such as chalcopyrite, chalcocite, 

sphalerite, galena or pyrite and silicates such as clays, micas or chlorite 

and also metal oxides such as pyrolusite or geothite; the last being an 

observation of some relevance to stream systems. The carbonates calcite, 

dolomite and malachite are also vulnerable to dissolution by humic acids. On 

the other hand, Sequi &. (1976) have reported that the alkali solubility 

of soil organic matter, common in stream sediments, is greatly dependent on 

the nature of metal ions present in the stream. 

Therefore interactions among metal ions, minerals, organic 

sediments and water seem to be mutually destructive of all solid species. 

The ultimate result of the breakdown of a mineral or metal-sediment complex 

by organic acids must be to promote the remobilization of that metal ion 

until the adsorption, flocculation, polymerization, precipitation cycle takes 

it out of solution once again.

Organic acids 

(hydrophilic, 

negatively charged 

colloids) 

+ M+ 

Metal-humates Physical 

(precipitates) aspect 

predominates 

M+ 

(neutral colloids) *-. 

Chemical Metal-organic 

aspect 

complexes 

predominates (hydrophilic + M' 

colloids) 

Metal-organic complexes 

(hydrophobic colloids) 

Figure 2: Metal-organic interaction scheme as proposed by Ong etas. (1970). 

259

Organic matter is also capable of acting as a reducing agent. In 

this way ferrous ion can be stabilized in oxygenated solution by complexation 

with certain organic acids (Theis and Singer, 1973) such as tannic or gallic, 

as well as by naturally occurring humic acid compounds (Rashid and Leonard, 

ft 

1973). It is possible that other metal ions such UO;? as , or oxy-anions of 

no, V or As could also be stabilized in solution in a lower oxidation state 

when complexed by humic matter; but there does not yet appear to be general 

agreement on this (Bloomfield and Kelso, 1973). However, the solubilization 

of hydrous Fe and Mn oxides attributed to a reduction process following 

complexation by fulvic acids (Zajicek and Pojasek, 1976); (Koshy g &., 

1967). The fate of metal ions whose dispersion in stream sediments is 

controlled by adsorption and desorption from Fe Mn and oxide surfaces is 

therefore strongly influenced by the operation of such reduction processes 

with humic matter. 

One very specific example of how metal mobilization can be directly 

effected by humic acid reduction concerns the production of Hgo from mercuric 

-4-k +t 

(Hg ) ion (Alberts &. , 1974). By this means, Hg , which is normally 

considered to be very strongly bound to humic matter and not easily displaced 

by other metal ions (Strohal and Huljev, 1970), is freed from its ligand upon 

reduction to elemental Hg which in turn is held by weak absorptive forces 

only. In this way it can easily pass back into solution from reducing sed- 

iment s . 

The influence of sulphide has not been considered to date. A 

number of authors have conducted laboratory tests to investigate competition 

between organic ligands and sulphide ion for dissolved metal ions. Timperley 

and Allan (1974) attempted to determine the forms of binding of Cu, Fe and Zn 

in organic-rich reducing muds. One of the main conclusions drawn was that Cu 

was held mainly by sulphide precipitation, whereas organic complexing was 

more important for Zn and Fe. Their work suggests that there may be some 

value in using the solubility data for simple metal sulphides as a basis for 

predicting metal-sediment interaction behaviour in such sediments. For 

example, Cd might behave like Zn but As and Hg might be largely fixed as 

sulphide or organic-sulphide complexes or adducts. 

In this context, the work of Boulegue and Michard (1974) is relevant. 

They noted that inorganic sulphur is present in sediments as polymeric hydrosulphides 

which are good complexing agents in their own right. They also can 

act as both redox and acidity buffers. Interactions between these and metal 

ions would be expected to be strong. 

One of the major problems in studying water-sediment interactions 

relates to a dearth of information on the nature of metal-ligand speciation. 

However, some powerful analytical tools have come into use recently whereby 

metal ion speciation in natural waters now can be studied. 

Anodic stripping voltametry (e.g. Zirino and Healy, 1972) can be 

used to demonstrate the importance of complexation reactions and perhaps to 

measure the apparent stability constants for strong complexes formed between 

metal ions dissolved in lake (Chau &., 1974) and river waters (Ramamoorthy 

and Kushner, 1975). But as Langford and Gamble (1974) have pointed out, this 

application is limited to relatively "non-labile" complexes with large organic 

ligands (e.g., fulvic acids). They suggest that a study of the kinetics of 

formation of such complex species would be informative in that kinetic 

260

mechanisms of reaction can help to predict solution equilibria. Faster reactions 

involving the formation of kinetically more labile complexes could be studied 

by means of techniques such as stopped-flow spectroscopy. 

By using anodic stripping voltammetry or pulse polarography or 

electrophoresis methods in combination with other experimental techniques, 

considerable data on elemental speciation could be gathered (Raspov &., 

1975). Bilinski gal. (1976) have measured stability constants for some 

hydroxo- and carbonato-complexes of Pb (IT), Cu (II), Cd (II), and Zn (11); 

important species in most surficial waters and certainly in groundwaters. 

Benes and Steinnes (1974) have described in situ dialysis experiments which 

permit determination of truly dissolved and colloidal forms of trace elements 

in natural waters. The more such research which can be done on site, the 

better. 

Field studies on the effects that interactions between trace metals 

and organic matter have on dispersion processes are not commonly encountered. 

Dc (:root (1971) and de Groot 1. (1971) have published extensive data on 

the Rhine River system. The Rhine has been subjected to industrial pollution 

and as a consequence, the reported Hg, Zn, Cr, Pb, Cu and As levels of the 

fluvial sediments were high. But downstream from the freshwater tidal area, 

a pronounced remobilization of these elements into solution was observed. 

It was considered that the change in chemical conditions, e.g., oxygenation 

and increased salinity, prompted intensive decomposition of the sediment 

organic materials which were retaining these metals. From this de Groot 

concluded that the formation of soluble metal-organic complexes was mobilizing 

the pollutant metals from the sediments. It is interesting to observe in de 

GrooL's data that the order of remobilization oE the metals, Hg > Cu > Zn > 

Pb Cr > As > Co > Fe, is roughly the reverse of the solubilities of simple 

sulphides. Therefore it seems likely that the greater complexing affinities 

of e.g., Hg (IT) and Cu (11) towards soluble organic matter are more important 

kinetically than their sulphide solubilities. It has also been suggested that 

dilution by incoming sediments carried by ocean tides is partly responsible 

for the apparent mobilization effects. This may be true, but does not account 

for the observed sequence of elemental mobilization. 

The release of heavy metals from river bottom sediments has been 

studied in the laboratory mainly with the use of radioisotopes. For example, 

Co-60 has been used in the Danube River (Radosavjevric &., 1973); Mn-54, 

211-65, Sc-46, Co-60 and Hg-203 have been used in the Columbia River, (Lenaers, 

1971; Bothner and Carpenter, 1973). 

One of the more interesting studies of metal-sediment interactions 

in stream systems is described by Jackson (1975). He designed model laboratory 

experiments over a pH range to 4 9 to simulate interactions in the system: 

dissolved metal ion-clay -dissolved natural organic acids. The objective was 

to compare results with data from field studies within carefully selected 

stream systems. Interferences due to the presence of dissolved carbonate 

were also observed. The ability of soil-derived humic and fulvic acids to 

desorb metal previously adsorbed on clay and also metal from metal hydroxide 

precipitates, was investigated. Cu (11), Pb (II), Zn (11) and Ni (11) cations 

were chosen for study. 

261

Results indicated that Cu was strongly stabilized in solution, but 

W,IS the most kinetically hindered in desorption reactions. Pb was least 

retained in solution by organic complexing but was effectively removed by 

inducing colloidal coagulation of organic matter. The solubilities of Zn and 

Ni were enhanced by organic complexing but were found to be pH dependent with 

hydrolysis leading to decreased solubilities. Furthermore, Ni solubility was 

also dccreased by carbonate precipitation. 

Jackson, (1975) also embarked upon a field study of selected streams 

in which similar processes were thought to prevail. Predicted behaviour was 

compared with observed hehaviour. He found that the natural dispersion of Pb 

and Fe seemed to be favoured by organic complexing. Cu dispersion was strongly 

governed by sorption to organic-rich sediments. The hehaviour of Ni was 

strongly controlled by interference, reactions - viz., with carbonate and 

llydroxide at alkaline pH. The model reaction scheme was found to be inadequate 

for Zn. .Jackson suggested that these laboratory experiments be continued 

with solid organic phases included in the scheme. 

b) 1-nteractions Involving HydrousLetal Oxides 

Fe and Mn oxides are certainly important species in organic systems 

but their role as direct adsorbers of metal ions is overshadowed by competition 

from the more reactive humic acids and organo-clays or obscured by 

coatings uf u~gduie matter. Moreover, these oxides are unstable in certain 

organic-rich sediments, particularly if at all reducing. However, in fluvial 

systems, such as those found in the Canadian sub-arctic or in alpine regions, 

the role of organic matter in water-sediment interactions is relatively 

unimportant compared with the influences of hydrous Fe and Mn oxides. The 

same situation may also be true of more rugged regions of the Canadian Shield. 

Quite a number of studies have been made on the functions of these 

oxides in fluvial systems (e.g., Perhac, 1972; Crasselly and Hetenyi, 1971). 

ft 

The relevant chemistry of Mn , in aqueous solution has also been described 

(Handa, 1969; Benes, 1967). For example it has been shown that the oxides 

U 

strongly adsorb ions such as Hg , (Lockwood and Chen, 1973; 1974) and Co*, 

H 

Ni* and Zn (McKenzie, 1972). The behaviour of Mn* in water and speciation 

between pH 2-8 has been documented by Angino &. (1971). Most common 

species are Mn(@H):, ElnC!!; XI! prcdomizantly, Mn(H20) g* ion. Micro-organisms 

* 

are capable of oxidizing Mn to Mn (IV) in natural waters (Schweisfurth, 

1972). 

Sylva (1972) has summarized the hydrolysis chemistry of Fe (111) 

along with its polymerization reactions in which colloids and sols are formed. 

The formation of polynuclear species of Fe and Mn oxides is likely a very 

important process in the remobilization of Fe (11) and Mn (11) from reduced 

sediments. Such colloidal species are quite reactive towards trace metal 

ions. 

To illustrate the dominant role Fe and Mn oxides can have in certain 

fluvial systems some studies of arctic drainage by Cameron and co-workers 

(Cameron, 1974; Allan al., 1974; Cameron and Ballantyne, 1975) can be 

summarized. 

262

The drainage in the barren grounds of the Hackett River area of the 

N.W.T. resembles, at first sight, a lake system rather than fluvial-type 

drainage, However chains of lakes are connected by overflow streams in 

spring and early summer during which time most metal dispersion takes places. 

Because of the virtual absence of dissolved organic matter in waters and of 

colloidal or dispersed suspensions of humic material, these watersheds can 

be regarded as inorganic systems in which chemical processes follow predictable 

paths described by pH, metal ion hydrolysis and simple complex ion formation. 

For example, the stgble forms of Cu in these waters of near-neutral pH are 

expected to be CuOH , CuCO3' and [Cu(C03)~]-. In fact, in certain lakes 

where Cu is quite abundant in surrounding rocks, the carbonate malachite 

precipitates onto the bed sediments. The water bodies are found to be in 

near equilibrium with these precipitates when Cu, OH- and CO1- are determined 

in the lake waters. Under the same conditions, Zn is likely present in the 

+ 

waters as ZnOH and [Zn(H,O)6]* ions. 

Two watersheds supplied by metal ions from similar buried volanogenic 

Cu-Zn sulphide mineralization can be compared. The first situation, 

at Hackett River, N.W.T. demonstrates the degree of dispersion of Zn and Cu 

when waters near the source of the metal ions retain a pH in excess of 7. 

This was found (Cameron and Ballantyne, 1975) to be due to the presence in 

the catchment of considerable exposures of carbonate-enriched (limy) volcanic 

rocks. Inspection of Figure 3 reveals that dispersion of Zn from the East 

Cleaver zone falls off rapidly over a distance of about 6 miles. Cu is lost 

from solution far more rapidly, reaching its natural background levels (for 

this region) of 1 ppb after about 3 miles dispersion. Dissolved Fe or Mn 

was generally less than 5 ppb, even at source. The second situation, at 

Agricola Lake, N.W.T., is virtually identical to the Hackett River watershed 

except that the underlying volcanic rocks are devoid of carbonate 

minerals. The effects on pH are immediately apparent (Figure 4) at source, 

pH is commonly between 3 and 4 with Fe reaching 800 ppb and Mn reaching 90 

ppb. As well dissolved Zn falls from about 1000 ppb to about 2 ppb over 5 

miles. Figure 4 also displays the change in pH down-drainage. 

The work of Jenne, (1968) has shown that the main controls on Cu 

and Zn dispersion relate to their fixation in hydrous Fe and Mn oxides 

coatings or precipitates. Cameron and co-workers observed that when Fe and 

Mn were initially present at very low levels in the alkaline lake waters of 

the Hackett River area near source, due to the presence of limy rocks restricting 

mobility of those ions, the dispersion of soluble Zn and Cu through chains 

of lakes was more extensive. This is attributed to the absence of an oxide 

scavenger coprecipitating trace metals down-drainage. Thus dispersion can 

be said to be enhanced in spite of the intially high water pH. 

By contrast, in the Agricola Lake watershed where there is 

little limy material to suppress acidity, initially high 

accompanied into solution by initially high dissolved 

hydrolysis of these ions resulted in the coprecipitation 

Zn and Cu were 

Fe and Mn. Rapid 

of Cu and Zn (and 

As, Figure 5) into lake sediments as the pH increased with dilution. 

Therefore dispersion was found to be much more limited than in the Hackett 

River situation in spite of the initially high concentrations of Cu and Zn 

and the very low water pH. Figure 4 also indicates that Zn begins to 

appear in lake sediments when the pH exceeds 4.5, about 2 miles down-drainage, 

i.e., when Fe and Mn oxides are forming as suspensions. Further transport 

of Zn is probably in particulate form. 

263

Figure 3. Distribution of zinc and copper in ppb, and pH in lake waters 

from the Hackett River area, N.W.T. 

(after Cameron & Rallantvne. 1975)

265

1 

N 

0 

N 

- Zn (log pprnl ~n sediments 

0 

I 

R

ORGANIC-INORGANIC INTERACTIONS 

It is clear that the presence of organic matter in these systems 

would have several predictable effects. Complexation of metal ions would 

inhibit hydrolysis of Fe and Mn, redissolve oxide precipitates, and restrict 

the coprecipitation of Cu and Zn. Humic matter is also an efficient acidity 

buffer, therefore it is likely that high acidity as observed in the Agricola 

Lake area would be suppressed at the source and much more localized. What is 

less predictable are the scavenging effects colloidal organic matter would 

have on free metal ions, complexed metal ions and on the interactions 

between all of these species and bottom sediments. 

LITEXATURE CITED 

Alberts, J. J., Schindler, J. E., Miller, R. W. and Nutter, D. E., 

(1974), Elemental Mercury Evolution Mediated by Humic Acid. 

Science, 184, (4139), 879-898. 

Allan, R. J., Cameron, E. M., and Jonasson, I. R., 

(1974), Mercury and Arsenic Levels in Lake Sediments From the 

Canadian Shield. In "Primero Congreso Internacional de 

Mercurio" Barcelona, Tom 11, Publ. (1975), Fab. Nac. Moneda 

y Timbre, Madrid, pp. 93-119. 

Angino, E. E., Hathways, L. R., Worman, T., 

(1971), Identification of Manganese in Water Solutions by 

Electron Spin Resonance, Adv. Chem. Ser., No. 106, 

299-308. 

Baker, W. E., 

(1973), The Role of Humic Acids From Tasmanian Podzolic Soils in 

Mineral Degradation and Metal Mobilization, Geochem. Cosmochim. 

Acta, 21, 269-281. 

Benes, P. and Steinnes, E., 

(1974), In Situ Dialysis for the Determination of the State of 

Trace Elements in Natural Waters, Water Research, 8, 947- 

953. 

Benes, P., 

(1967), On the State of Manganese and Gold Traces in Aqueous 

Solution, J. Inorg. Nucl. Chem., 29, 2889-2898. 

Bilinski, H. Huston, R. and Stumm, W., 

(1976), Determination of the Stability Constants of Some Hydroxo 

and Carbonato Complexes of Pb (II), Cu (II), Cd (11) and Zn (11) 

in Dilute Solutions by Anodic Stripping Voltammetry and 

Differential Pulse Polarography, Analyt. Chim. Acta, $,(I), 

157. 

Bloomfield, C., and Kelso, W. I., 

(1973), The Mobilization and Fixation of Mo, V and U by Decomposing 

Plant Matter, J. Soil. Sci., g, 368-379. 

261

Ik~tI~n~~r, FI. 11. .mi (:,lrpentc-r, K., 

(1')73), Sc,rllt ion-llr~sorption Keartions of Mercury with Suspended 

blntter in tlw Columbia Kiver. Itadioact. Contam. Marine Environ., 

l'roc. Svml~., pp. 73-87. 

l~oulep,tle, J., and Nichard, (:. , 

(19741, Intcxractions Between Sulphur-Polysulphide System and 

Organic Material in Reducing Media, C. R. Acad. Sci., Ser. 

I). 279, (l), 13-15. 

Uowen, 11. .I. M., 

(1966), Trace Elements in Biochemistry, Academic Press, London. 

HoyLt,, I

Groot, A. J. de, Goeij, J. J. M. de and Zegers, C., 

(1971), Contents and Behaviour of Mercury as Compared With Other 

Heavy Metals in Sediments from the Rivers Rhine and Ems., Geol. 

Mijnbouw, 50, 393-398. 

Handa, B. K. , 

(1969), Chemistry of Manganese in Natural Waters, Chem. Geol., 

- 5, 161-165. 

Jackson, K. S., 

(1975), Geochemical Dispersion of Elements Via Organic Complexing, 

Unpubl. Thesis, Carleton Univ., Ottawa, Canada, 344 pp. 

Jenne, E. A., 

(1968), Controls on Mn, Fe, Co, Ni, Cu and Zn Concentrations in 

Soils and Waters: The Significant Role of Hydrous Fe and Mn 

Oxides. In “Trace Inorganics in Water”, Adv. Chem. Ser., No. 73., 

Amer. Chem. Soc., 337-387. 

Koshy, E., Desai, M. V. M. and Ganguly, A. K., 

(1967), Studies on Organo-Metallic Interactions in the Marine 

Environment. I. Interaction of Some Metallic Ions with 

Dissolved Organic Substances in Seawater, Curr. Sci., 2, 

555. 

Krauskopf, K. B., 

(1955), Sedimentary Deposits of Rare Metals, Econ. Geol., 

50th Anniv. Vol., 411-463. 

Kusnetsov, S. I., 

(1975), Role of Micro-Organisms in the Formation of Lake Bottom 

Deposits and Their Diagenesis, Soil Sci., =(I), 81-88. 

Langford, C. H. and Gamble, D. S., 

(1974), Dynamics of Interaction of Cations and Fulvic Acids, Proc. 

Int. Conf. Transport of Persistent Chemicals in Aquatic Ecosystems, 

Publ. 1974 N.R.C. Ottawa, 11, 37-39. 

Lenaers, W. M., 

(1971), Photochemical Degradation of Sediment Organic Matter. 

Effect on Zn-65 release. Report (1971) RLO-2227-T-12-32 64 pp. 

Nucl. Sci. Abstr., %,(20), (1972), No. 48038. 

Lockwood, R. A. and Chen, K. Y., 

(1973), Adsorption of Hg (11) by Hydrous Manganese Oxides, 

Environ. Sci., Technol., 1, (IT), 1028-1034. 

Lockwood, R. A., and Chen, K. Y., 

(1974), Adsorption of Hg (11) by Ferric Hydroxide, Environ. 

Letts., 4, (3), 151-166. 

McKenzie, R. M., 

(1972), Sorption of Some Heavy Metals by the Lower Oxides of 

Manganese, Geoderma, g,(l), 29-35. 

Ong, H. L. and Bisque, R. E., 

(1968), Coagulation of Humic Colloids by Metal Ions, Soil. Sci., 

106, 220-224. 

269

Ong, fl. L., Swanson, V. E., and Bisque, R. E., 

(.L970), Natural Organic Acids as Agents of Chemical Weathering, 

U.S. Geol. Surv., Prof. Paper 700-C, pp. 130-137. 

Perhac, R. M., 

(19721, Distribution of Cd, Co, Cu, Fe, Mn, Ni, Pb and Zn in 

Dissolved and Particulate Solids From Two Streams in Tennessee, 

.I. Hydrol., 15, 177-186. 

Pitwell, I,. R., 

(1973), Some Coordination Effects in Orebody Formation, 

Chrm. Geol., 12, 39-49. 

Radosavl.jevic, R., Tasovac, T., Draskovic, R., Zaric, M. and 

Markovic, V. 

(1973), Complex Behaviour of Cobalt in the Danube River, 

Arch. Hydrobiol., Suppl., 43,(2), 241-248. 

Knmamoc~rthy, S. and Kushner, I). .J., 

(19751, Heavy Metal Binding Sites in River Water, Nature, 

(London), 255, (5516), 399-401. 

kashld, M. A. and Leonard, J. D., 

(19731, Modifications of the Solubility and Precipitation Behaviour 

of Various Metals as a Result of Their Interactions With Sedimentary 

Humic Acid., Chem. Geol., ll, 89-97. 

Rashid, M. A., 

(1974), Adsorption of Metals on Sedimentary and Peat Humic Acids, 

Chem. Geol., 12, 115-123. 

Raspov, B., Valenta, P. and Nurnberg, H. W., 

(1975), The Formation of Cd(I1) - NTA Complex in Seawater, 

Int., Conf., Heavy Metals in the Environment, Toronto (1975), 

Abstr. NO. D-5. 

Saxby, J. D., 

(1969), Metal-Organic Chemistry of the Geochemical Cycle, Rev. 

Pure. Appl. Cilrlu., &, i31-150. 

Saxby, .J. D., 

(1973), Diagenesis of Metal-Organic Complexes in Sediments: 

Formation of Metal Sulphides From Cysteine Complexes, Chem. 

Geol., 12, 241-288. 

Schnitzer, M. and Khan, S. U., 

(1972), Humic Substances in the Environment, Marcel Dekker Inc., 

New York, N.Y. 

Schweisfurth, R., 

(1972), Manganese Oxidizing Micro-Organisms in Drinking Water 

Supply Sytems, Gas - Wasserfach, Wasser - Abwasser, u,(l2), 

562-572. 

Sequi, P., Guidi, C. and Petruzzelli, G., 

(1976), Influence of Metals on Solubility of Soil Organic Matter, 

(koderma, 12, (3), 153-162. 

2 70

Strohal, P. and Huljev, D., 

(1970), Mercury Pollutant Interaction With Humic Acids by Means 

of Radioisotopes, Nucl. Techniques Environ. Pollut., Proc. 

Symp., I'ubl. I.A.E.A. Vienna, (1971), 439-446. 

Sylva, K. N., 

(1972), The Hydrolysis 

22, 115-132. 

of Iron (III), Rev. Pure. and Appl. (:hem., 

~~ 

'Theis, T. L. and Singer, P. C., 

(1973). The Stabilization of Ferrous Lon by Organic Cornpomds 

in Natural Waters. In "Trace Metals and Metal-Organic 1ntcrac:tions 

in Natural WaLers", ed. Singer, P.C., Ann Arbor Publ., Inc., 

Mich., 703-320. 

Timp

EidDVEi 8 

IMPLICATIONS FOR 

THE MEAT MKES

INTRODUCTION 

J. R. Vullentyne 

Here are the three questions posed by the Governments of the United 

States and Canada to the International Joint Commission in the Reference on 

Pollution from Land Use Activities: 

(1) Are the boundary waters of the Great Lakes System being 

polluted by land drainage (including ground and surface 

runoff and sediments) from agriculture, forestry, urban 

and industrial land development, recrcational and park 

land development, utility and transportation systems and 

natural sources? 

(21 If the answer to the foregoing question is in the affirm- 

ative, to what extent, bll what causes, and in what 

Ldcalities is the pollution taking place? 

(3) If the Comission should find that pollution of the 

character just referred to is taking place, what 

remedial measures would, in its judgement, be most 

practicable and what would be the probable cost thereof? 

Dr. D. R. Bouldin commented this morning that if this Workshop, which 

has been arranged to help answer these questions, had been held three ago years 

when PLUARG was just beginning its work, there would have been to nothing talk 

about: the relevant information was not on hand. 1 think he is right. But 

even with the new data, talents and personalities that have been brought to 

bear on the problem within PLUARG and in this Workshop, the issues still remain 

complex and resistant to quantitative interpretation. 

This complexity worries me. I see it as a persistent threat to 

the defendability of proposed remedial measures requested in Question 3 of the 

Reference. If a remedial measure is not defendable it will not be accepted 

by the Commission, by the two Governments, or by the affected people and 

organizations in the two countries. The most important component of any 

strategy for action is therefore a strategy for defence. For this reason, 

the order of attention given by PLUARG is answering the three questions should 

be the reverse of the order in which they were posed. 

From information presented at this Workshop is it apparent that the 

most important factors contributing to the complexity of the problems are: 

(1) the virtual impossibility of tracing the sources and 

ultimate fates of pollutants once they have entered 

into stream transport; 

275

(2) the variety and large number of independent sources 

requiring separate control; 

(3) the variability of climatic factors affecting land runoff, 

their low frequency and unpredictability in time; 

(4) local variations of soil and topographic factors affecting 

runoff ; 

(5) persistent questions concerning the availability to plants, 

or toxicity in the environment of chemicals in different 

phases or forms. 

It will not he easy for PIJJARG, for the Commission or for regulatory 

agencies in Canada and the United States to formulate and defend remedial 

measures perhining to a large number of control points whose effects are 

not easily traceable to boundary waters. Because of this complexity it will 

he impnrtant to stress two aspects of defensive strategy in the technical report 

LO the Commission. 

I, ACCENT TE LONG TERM 

As the time base lengthens the rate of delivery of persistent 

pollutants to boundary waters increases. Al.so, it must he stressed to the 

Commission that pollution of boundary waters arising from Land use activities 

is not going to be solved or even quantitatively understood overnight. The 

need lor changes in human attitudes and hehavioural practices in regard to 

land use activities suggests that it may be optimistic to think in terms of 

Etfrcting solutions in less than a generation's time. I hope that PLIIARG will 

mnkc reference to the need for controliing the rate of growth of human population 

and technology in the Great Lakes i3asin; it is already controlling 

us, as individuals, to an extent we do not realize. I believe that the 

Commission, the two governments and the people and organizations involved 

wi1.l understand the accent on Lhe long term if it is properly presented. Hut 

this accent should not he used as an excuse for inaction or delay. 

War is not an appropriate analogy in the present context; nevertheless, 

a quote from E. Machell-Cox's translation of Sun Tzu's, "The Principles 

of War," written 2300 years ago, is not out of place: 

"Once hostilities have begun, if victory he long deferred, 

weapons will grow blunt and ardour dampened; if the army 

attack a city, it will exhaust its strength; if it he !ong 

in the field, state supplies will be insufficient. Now, 

when weapons are blunted, ardour dampened, strength exhausted 

and treasure gone, the other princes will rise and take 

advantage of your extremity and, though you were a very Sage, 

you should not then remedy the consequences. So it is that 

chough you shall hear of stupid haste in war yet you shall 

IicBvc'r liear tllat long campaigns are clever. There has never 

x'c't heen a country that has benr€ited by a long war." 

276

11. AVOID GENERALITIES 1 . 

AT bCE 

1 THE ~ ~ PLAGUE: Do NOT TRY TO SOLVE EVERYTHING 

Certain land use activities are more likely tc, affect boundary 

waters than others; for example, those in close proximity to boundary waters. 

Because of their small size, large surface area and charge, fine-grained 

particles are likely to be more important that coarse-grained particles in 

transporting pollutants from distant sites to boundary waters. Steep slopes 

are likely to be more susceptible to erosion than flat land with porous 

soils. Let there bt- an heirarchy of priorities in space and time. Over- 

generalization will only antagonize those whose cases do not easily fit into 

the general scheme; and the loss of their support will only weaken the cause. 

In this context it is worth re-emphasizing the importance of a defensive 

strategy to PLUARG with another quote from E. Machell-Cox's translation of 

Sun Tzu's, "The Principles of War." 

"Just as it is no great sign of strength to lift an 

autumn hair, of keen sight to see the sun and moon, or of 

sharp hearing to hear thunder, so if the basis of your 

victory is apparent and within the understanding of the common 

herd, it is not of the highest excellence; nor is it of the 

highest excellence if you win a pitched battle and all the world 

cry "Ha!" What the ancients called a clever fighter was a man 

who won, and won easy victories, which brought neither a name 

for wisdom nor credit for courage. His victories came of 

making no mistakes; by making no mistakes he had ensured 

victory, and needed but to defeat an enemy already overcome. 

lhe skillful warrior is one who puts himself in a position such 

that he cannot he defeated, and does not then lose the occasion 

of defeating the enemy. The victorious army first secures its 

victory and then gives battle; the vanquished first engages 

and then seeks to securc victory." 

!7 1

INTRODUCTION 

G. H. Dury 

It would be redundant for me to attempt to summarize, or to review, 

the Workshop contributions on physical processes. Those attending have been 

supplied with abstracts and with papers, have listened to the papers presented 

and to the question-and-answer sessions, have laboured with the various work 

groups, and have contributed to the recommendations which the work groups 

will be making. Readers of the final document will be presented with extended 

abstracts of papers, and with the recommendations that emerge from the Workshop 

as a whole. Rather than attempting to review, or to repeat, what is said 

elsewhere, I propose in these comments to sound certain general themes, to 

suggest a possible means of economizing on environmental monitoring, and to 

draw attention to some possible dangers and difficulties in attempting to 

forecast for the future. 

W~RKSKIP ACTIVITIES AND ATTITUDES 

Like any good conference, this Workshop has led to the informal 

exchange of knowledge and acquaintance. It has also led to, or at least disclosed 

the possibilities of, the interfacing of programs-- programs of research, 

management, and regulation. 

It has also revealed a broad range of viewpoints, particularly 

perhaps among those interested mainly in physical processes. At the one 

extreme comes the urgent need for practical action, in containing, reducing, 

or even eliminating the discharge of sediments, nutrients, and contaminants 

into the Great Lakes. At the other extreme comes the desire for long term 

basic research, especially research into processes of erosion, transportation, 

and discharge or sedimentation. The two corresponding extreme attitudes are 

that of eliminating process studies altogether, in favour of implementing 

immediate control measures, and that of considering control impossible, until 

sources of input are identified and the processes of input are completely 

understood. 

Somewhat related matters are the high variability of observational 

data, and the difficulty of extrapolating to large natural basins the results 

obtained from small basins or from trial plots. Although it may very well 

prove necessary to do whatever is possible with the data already available, 

divergent views on what actually is possible were reflected at the Workshop 

in differing opinions on the potential of computer modelling. On the one 

hand, soil loss equations can be run through a number of existing computer 

programs. On the other hand, some researchers consider that the results 

predicted by computer need careful reappraisal against what happens in the 

real world. In addition, prediction of soil loss, however accurate, may by 

no means foretell what actually will be moved out cf the basin. 

279

BAS I 14 STORAG~ 

'I'ht, rrsidcBnce tinw Cor nutrients and contaminants seems to he 

rr~~,isorl,~lllv wc.1 I ~11~11c~rst11m1, in tc3rms of water cllemistry, soil rllemistry, 

II~(J( llc,nlistrv, .lnd til

A possible means of economy resides in surrogate observations. 

For instance, it can readily be shown that, for the Hurricane Agnes floods in 

New York and Pennsylvania in 1972, the total delivery of water and the total 

delivery of suspended sediment in a given flood wave can be expressed as a 

power function of momentary peak discharge (Dury, press). in This statement 

holds, through a range of recurrence intervals from less than 2 to more than 

100 years (annual series), and through a range of drainage areas from less 

than 1.0 to 16,700 km’. Nearly 97 percent of variation in delivery of suspended 

sediment is statistically explained by variation in momentary peak 

discharge. This latter variable, once a rating curve has been established, 

ran be simply and cheaply recorded by a crest-stage gauge. Once a sediment 

rating curve has been established, momentary peak flows of water can be used 

to give sediment discharge. Methods of this kind are especially attractive, 

since many rivers discharge a very large fraction of total sediment in only a 

few days of high flow. 

Sundry contributions to the Workshop suggest that, for some streams 

at least, discharge of certain nutrients and contaminants can be expressed as 

funrtions of discharge of suspended sediment. Phosphorus, nitrogen, carbon, 

and pesticides were specifically mentioned. Wherever a firm relationship can 

be established between discharge of nutrients/contaminants and discharge of 

suspended sediment, and another between discharge of suspended sediment and 

discharge of water, then the peak flow/flood wave relationship can be used 

to measure total delivery in a particular event of sediment, nutrients, and 

contaminants. 

SPAT I AL VARIATION 

Just as response to sediment input can differ from one part of a 

basin to another (*, between upstream and downstream reaches, so variation 

is to be expected between one basin and another, and between one region and 

another. If surrogate methods of monitoring are to be developed for the 

Great 1.akes rivers, possible regional variation needs to he investigated. If 

such variation dues occur, then sample streams for the individual regions 

could be observed, as against observing all streams throughout the system. 

Basin size is likely to prove an additional, and perhaps an influential, 

variable. Pilot studies in regional and inter-basin variation would seem to 

offer useful possibilities. 

PREDICTION FOR THE FUTURE 

One attendee remarked that a meeting such as this Workshop would 

have been impossible three years ago--the implication being that, in the last 

three years, we have already come a very long way in assembling the data 

necessary for the tasks in hand. The comment is highly gratifying. At the 

same time, a three-year series of Observations is impossibly short for most 

purposes of prediction. 

281

It is axiomatic, that, for magnitude-frequency analysis of streamflow, 

:I 1 -etord nc3eds tu he twice as long as the greatest recurrence interval for 

WII i c.11 confident pt-edirlion tan be undertaken. Thus, a 100-year record is 

nredcvl for the conlidrnt prdiction of the 50-year event. In practice, 

t,vents o f great m.~gnitudc md low frequency may have to be predicted from 

short rc'ror(l scric.s, in which case confidence limits should be stated. 

,As ~IS inc~vit.rl,lt~ tilat m~~gnitudt~-f rclquency analysis will appear increasingly 

. ~ t t 1r.1c.t ivtl. tiowt,ver, nlucll recent and turrent work has tended to reveal 

~ l i ~ ~ ' ~ ~ ~ l t i ~ ~ ~ step ~ ifilnrtii1ns--in t i ~ ~ s - - ~ :i ~ wl1olc ~ m ~ range ~ ~ ~ or r ~ pllenmrna, ~ l 

inclilcling those o f rlirnate, weather, and streamflow. It is, for instonce, 

c~.nti~-elv p~'ssii11c~ an for abrupt shift to occur in the arca/intensity/duratiorl 

1re1.1t ionsilips uf dominant storms, 

to a givcrl fluvial system. 

and consequently in the input of sediment 

1,:ven when very long recor-ds exist, or when the frequency of an 

event ot very great magnitude can reasonably be identified from a short 

rrcord, it may prove impossible to identify thresholds--such, for example, as 

the threshold where severe rhanncl erosion is suddenly initiated, and where 

thc, input of sediment into the flowing water is suddenly increased. A case 

in point is that of the English rivc'r Nene, which in 1947 experienced ii flood 

belonging somewhere between 500 and 1000 years on the annual series (Dury, 

1974). 'l'llis tlood, however, failed to produce significant efCects, either in 

the channcl or on the floodplain. Other rivers are known to respond drastically 

to floods of much lower magnitude (comparatively speaking) and of much 

greater frequency. Despite the obvious difficulties, the identification of 

thresholds of behaviour on the part of stream channels--and, €or that matter, 

of farml.lnd soils--is crucial to the prediction and control of sediment 

input. Once again, pilot studies and regional assessment are in order. 

1. G. H. Dury, in press : Peak Flows, Low Flows, and Aspects 

of (:eomorphic Dominance. Expected to appear in "River 

Channel Clranges"(ed. K. .I. Gregory): Wiley, for the 

British Geomorphological Research Group. 

2. (:. H. Dury, (1974): Magnitude Frequency Analysis and Channel 

Murphomrtry : in "Fluvial Geomorphology", (ed. M. Morisawa), 

State University of New York Publications in Geomorphology, 

9 1-121. 

2x2

EIiFVEB 

4 

CONCLUSIONS AND RECOMMENDATIONS 

FROM THE WORK GROUPS 

RESEARCH NEEUS

RECMNDATIONS OF THE WORK GR~UPS 

The work groups established at the workshop were held in four 

concurrent sessions. Three groups were each assigned a pollutant related 

to the sources and transport of sediment (nutrients, metals and pesticides). 

One group dealt with the physical processes involved in sediment generation 

and transport. It was made clear to eac.h group that they were to consider 

PLUARG's present programme of sediment collection and analysis and make 

any recommendations for changes in sampling and/or analysis. Additionally 

the groups were to consider the potential impact of ongoing research programmes 

and the research needed in the long term to help answer some of the 

questions posed during the plenary sessions. 

By the very nature of the work groups there was considerable overlap 

in the discussions. It would be difficult, for example, to discuss the 

relationship of pesticides to sediment without also discussing the physical 

processes involved in sediment production and movement. Where recommendations 

from work groups have overlapped, they have been edited and combined with 

general recommendations for research needs. 

The recommendations expressed here have been summarized by the 

work group chairmen and are not verbatim accounts of the discussion held. 

PHYSICAL PROCESSES 

This work group focused upon physical processes in fluvial transport 

of nutrients and contaminants although it is recognized that physical, chemical 

and biological processes must all be considered together. The work group 

examined several questions: (1) What do we need to know? - for PLUARG to 

satisfactorily complete its Terms of Reference, - for the Governments to 

manage land use activities to achieve satisfactory Great Lakes water quality, 

(2) What do we know?, and (3) What recommendations should be made to PLUARG 

and to the Research Advisory Board/IJC in terms of recommended actions or 

research needs? 

The Workshop was partitioned into considerations of sources and instream 

transport mechanisms and the discussions of Group 1 are presented here 

within the same categories. Research needs are discussed both within the 

context of immediate needs of PLUARG and with a view of future research which, 

although necessary to answer the PLUARG Terms of Reference, cannot be feasibly 

concluded within the life of PLUARG for reasons of cost, available time, data 

limitations. etc. 

285

Witit reference to the three questions posed in the PLUARG Terms 

(>t Reference, it is :rcrrpted tllet tlie boundary waters of the Great Lakes 

:;ystfni are being polluted lrom land drainage. Further information needs to 

hi, developed to define the extent, CJUS~S and localities in which pollution 

is taking place,, and to define the most practical remedial measures. The 

items listed helow are a statement of PLUARC, objectives within the context 

of (:roup 1 discussions, and necessary to answer the questions posed in the 

I’I.UAR(: ‘Terms of Reference: 

(1) Estimate contemporary fluvial loadings of sediment-related 

nutrients and contaminants into the Great Lakes. 

(2) Assess land use and associated loadings into the Great Lakes 

in the light of alternative management strategies. 

(3) Predict trends of loadings relationships into the future under 

different management strategies. 

(4) Recommend land use practices (remedial measures) in order to 

reduce or eliminate significant contaminant and pollutant 

loadings. 

It should be noted that the Physical Processes group addressed 

~lrr questions of sources of pollutants from land use activities and the 

transport and resultant loadings to the Great Lakes; it did not address the 

questions of impact analysis on the Great Lakes or the processes and fate 

of sediment in lake-river interface areas such as estuaries. 

SOURCES 

The discussion of land use practice and sediment production, 

sediment control and consequent stream loadings of sediment-related quality 

p,lrameters (in upstream areas) centered on the efficacy of detailed site and 

time-specific cause-effect studies as opposed to a more general mode approach 

in which stream loadings either at source of stream terminus are regarded as 

functions of classes of land use practices (either within a deterministic or 

statistical framework). In view of the timeframe for PLUARG, there was a 

consensus that such tmdelb, which adequately permit a “first-cut‘‘ at landuseloadings 

relationships in time and space ought to be tried. It was felt that 

within the timeframe of PLUARG, deterministic process linkages between lake 

loadings and site-specific land use practices upstream could be not made in 

drtail for reasons noted below. Therefore, existing models are the place to 

start since they have produced useful information in parts of the United States 

tor general categories of land use. Such models are likely adequate in the 

short-term for PLUARG purposes, but need to be calibrated with data from the 

(:reat Lakes Basin. Although such models may not have a high level of resolution 

for a11 tributary basins in the Great Lakes when projected downstream to 

lake boundaries, they provide a focus for the experimental and fluvial process 

rescarch required to obtain improved relationships between land use activities 

and lake loadings. 

286

The major deficlency both of existing landuse-loadings models 

and of site specific process-response studies of sediment production by 

specific land use practice, is the inability to link upstream or source 

water quality observations with river mouth loadings. Although the principles 

of sediment transport mechanics are well known, the downstream 

movement and modification of sediment-related water quality variables are 

poorly understood. It is recognized that load modification is noL only 

related to physical processes but also includes biological and chemical 

interactions. In addition to poorly understood biochemical processes, it 

is recognized that contemporary data are inadequate to meet the needs of 

instream process research. These data inadequacies pertain both to poor 

characterization of variables (e.g., particle-size, inorganic/organic 

ratio, speciation of key components, aerosol input, etc.) and to lack of 

definition of spatial and temporal variations associated with parameter 

flux and with in-stream processes (such as sediment storage-remobilization 

mechanisms, time of travel of particle-size classes, short (anthropogenic) 

and long-term (climatic) variations in sediment flux and storage, etc.). 

It is recognized that these inadequacies must be investigated in order that 

extrapolation from loadings in source areas to loadings at river mouths 

reflects stream process both in space and in as time the watershed undergoes 

natural and anthropogenic perturbations. 

DATA 

Routine data on water quality and quantity have been collected for 

at least a decade on both sides of the Lakes, and therefore a special effort 

must be made to assess adequacy of historical data to and fully utilize them 

within limits established by the assessment procedure. In conjunction with 

the PLUARG (intensive and event-oriented) supplementary data collection, 

there is need to examine historical and PLUARG data and collection procedures 

for the purpose of: 

assessing the loads and the accuracy of load estimates for 

sediment, pollutants and contaminants at river mouths (bearing 

in mind the often non-linear discharge dependencies illustrated 

by many variables); 

identifying the watersheds which have a major and deleterious 

effect upon Great Lakes water quality; 

evaluating sampling technique, in terms of depth and flow dependencies 

of problem substances, for identification of temporal 

variation in load and the degree to which these data are site 

dependent; 

updating parameter lists to indicate those recently identified 

as either having a deleterious environmental effect or containing 

information bearing upon in-stream process mechanisms (e.g., 

particle-size, organic/inorganic, metal speciation); 

evaluating sampling network design so that in-stream load modification 

from source to mouth may be inferred and the spatial 

and temporal resolution of loads and source-area contributions 

may be identified. 

287

RECOPMENDATIONS AND RESEARCH NEEDS 

111 view of the lack of familiarity of many of the workshop part 

icipants with the operational organization of PLUARG, recommendations 

a~ld r-rsearcti needs are stated on general scientific grounds. Although 

rrcommendations may not apply equally to U.S. or Canadian activities, 

research nerds reflect inadequacies of state-of-art. Feasibility of recommendations 

and research needs must be determined 

Research Advisory Board. 

by PLUAKG and the 

Using river mouth loads, identify all streams that discharge significant 

loads to the Great Lakes. Of those streams that are important, conduct 

surveys from the mouth (upstream) to identify major problem input sources. 

The collective wisdom is that most serious problems at the mouth will 

relate to problem areas not far upstream. In such cases, management 

scenarios (alternative remedial measures) should be investigated. 

Compnrr stream (aquatic) loading to other sources so you know how 

important (relatively) the stream loading component is. 

Assess adequacy and applicability of existing data. This should 

include an assessment of variables and of the efficacy of present 

Jata collection strategies for their ability to resolve spatial and 

temporal trends in loadings at source and mouth. This recommendation 

does not necessarily imply "more" data collection but rather "better" 

data collection. Necessary changes should be implemented to correct 

data deficiencies. 

Apply existing sediment-loadings models both to assess sediment- 

prodilrtion at source, and in order to derivc upper-bound values for 

stream-mouth loadings by pxtrapolation over large areas. 

Identity and rank present management strategies which focus upon 

major sources. Models should be used to evaluate probable effects 

nf alternative management choices. (The term models, does not 

necess,lrily imply computer programs. It may be simple empirical 

formulae - although computer models are available and would be 

usrful) . 

Initiate preliminary field studies of downstream transport mechanisms 

and load modifications of both a physical and chemical nature in small, 

relativelv simple catchments with transposition to selected Type 

rat clmrnts of greater complexity. 

'88

Research Needs: 

Study of erosion and sediment transfer mechanisms source in areas 

with respect to general principles and their spatial and temporal 

significance. This should include consideration of "partial area 

hydrology" insofar as it relates to probable source areas of sediment. 

Establish causal mechanisms for changes in sediment quality and 

quantity during stream transport in complex stream systems. This 

should include fundamental research into the physical, biological 

and chemical process mechanisms. Such data are required to improve 

present landuse-loadings models to that the effect of upstream 

management alternatives can be assessed in terms of loadings to the 

Great Lakes. 

Develop and apply improved models 

to all tributary basins in which 

significant loadings problems exist to facilitate trade-off analyses 

of alternative remedial measures. Such application should include 

research developments from bl and 112 above.

NUTRIENTS W~RK GROUP 

RESEARCH NEEDS ~CDMVENDATIONS 

Much more effort should be spent on methods to evaluate the 

biological availability of the phosphorus entering the lakes 

from the tributaries. A special group should be set up to 

concentrate on this aspect. 

The kinetics of removal of phosphorus from the water to the 

stream and river sediments should be studied in greater detail. 

The parameters of riverine storage of phosphorus should be 

investigated in detail. 

Based on (2) and (3) a weighting system should be devised for 

the various tributary sources of phosphorus. 

IWEDIATE 

~COFF~ENDATIONS FOR PLuAffi 

(I) Characterize all pilot watersheds for spatial variability and 

attempt to relate this to measured nutrient output based on 

partial area hydrology models. 

(2) The compatibility of various goals should be investigated, i.e. 

is it better to slow erosion to control pesticide transport, or 

to allow it to continue to aid in phosphorus de-activation. 

(3) One must recognize the divers nature of the Great Lakes area. 

Recommendations for control must be made on an almost site 

specific basis. 

291

PESTICIDES WORK GROUP 

RESEARCH NEEDS RECOWENDATIONS 

It is essential for the regulatory and other agencies in Canada 

and the United States to know precisely the location, names and 

quantities of organic substances being used which may be hazardous 

to the biota of the Great Lakes Basin wherever that biota is of 

economic or peripheral importance. Such knowledge is essential 

to establish research priorities and for current and future 

surveillance. 

A need exists to select and develop standard techniques and 

criteria to evaluate the toxic effects of substances on biota 

of the greatest importance to the Great Lakes Basin ecosystem. 

This will ensure that criteria for all substances in use or 

developed for the future are assessed using the same criteria 

and at levels likely to be found in the environment. 

There is a need to document the case histories of such substances 

as DDT and PCBs to ensure that mechanisms and transfers well as 

as past analyses are thoroughly understood in order to develop 

predictive models for substances of similar nature, but yet to be 

developed or used. There is little likelihood that any substances 

will be as thoroughly studied and documented as the major pesticides 

and derived products used since 1940. The knowledge concerning these 

should be so firmly corroborated in respect to fluvial, point source 

and aerial inputs and transformations that all future studies can 

use the approaches or findings to extrapolate effects before crisis 

develop. 

There is a need for more information on the relative importance 

of the various routes by which organic contaminants enter into the 

Great Lakes Basin ecosystem. This information is needed before 

recommendations relating to land use can be seriously considered. 

The question of open-water disposal of dredged sediments was 

raised but appears to be adequately covered by the report from 

the International Working Group on the Abatement and Control of 

Pollution from Dredging Activities.

[“ETALS W~RK GWUP 

RESEARCH NEEDS ~COMVENDATIONS 

The need,to investigate: 

The biological availability of metals in uplands, streams, 

lakes, and estuaries under various environmental conditions 

i.e., pH, Eh, etc; 

The various release mechanisms available for metals entrained 

with organic and inorganic sediments in uplands, ground-waters, 

streams and lakes; 

The metal concentrations and types associated with various size 

fractions of organic and inorganic sediments and their chemical 

and/or mineralogical composition; 

Whether metals are tied to sediment sizes most difficult to 

control using conventional and existing soil erosion and sediment 

control procedures; 

Whether sediment erosion and control practices used in agriculture, 

urban areas, mining, construction and related land uses are 

adequate to retain these finer-grain sizes. If not, what new 

technology may be applied for their control; 

The probable costs of these control measures and their benefits 

not only with metals but other entrained pollutants, i.e. N, P, 

pesticides, etc.; 

The processes of chemical fractionation of metals. These processes 

may influence metal occurrence, transport and bioavailability. 

Chemical fractionation must be coupled to metal release mechanisms 

to predict resulting concentrations of metals in aqueous systems; 

The organic species (plants, animals, etc.) that tie up metals 

that might, in turn, be converted to the elemental form of the 

metal ; 

The toxicity levels of metals and complexed metals to various 

aquatic plants, animals and segments of food chains; 

(10) The kinetics of metal complexes as these kinetics will shed light 

on metal speciation and metal behaviour within aqueous systems. 

The ionic strengths of metal complexes are influenced by salinity 

and other factors that must be defined. 

295

RECOWENDATIONS FOR PLUARG 

(1) 'The reproducibility of results of chemical analyses for 

meLals using various sampling times, sampling procedures, 

and analytical techniques must be assured through the con- 

tinuance of the PLIJARC interlaboratory comparison programme. 

(2) PLLJAKG must determine the atmospheric loadings of metals. 

Tlw sources and source regions must be found and an estimate 

made of possible control measures and costs to reduce this 

loading. 

296

EilFVEl 

Fl 

WORKSHOP ORGINIZERS 

AND ATTENDEES

WORKSHOP AITENDEES 

Dr. John R. Adam 

Water Quality Management Program 

Toledo Metropolitan Area Council of 

(:overnments 

Suite 725 

420 Madison Avenue 

Toledo, Ohio 43604 

Ilr. Herbert E. A1lc.n 

Assistant: Professor 

Illinois Institute of Technology 

Chicago, Illinois 60616 

Dr. (:arl )s Alonso 

[KIM Sedimentation Laboratory 

1'. 0. Box 1157 

Oxford, Miss. 38655 

Dr. Eugene .J. Aubert 

Director 

Great Lakes Environmental Research 

Laboratory 

2'300 Waslltenaw Avenue 

Ann Arbor-, Michigan 48104 

l'rofrsso~ David B. Baker 

River Sttldies Laboratory 

Heidelberg College 

Tiffin, Ohio 44883 

Dr. Keith Bedford 

Water Resources Centre 

The Ohio State University 

1791 Neil Avenue 

Columbus, Ohio 43210 

Professo~ David R. Bouldin 

Cornell I!niversity 

Department of Agronomy 

Bradfielo and Emerson Halls 

Ithaca, New York 14850 

299 

Mr. J. E. Brubaker 

Agricultural Engineering Extensions 

Branch 

Ontario Ministry of Agriculture 

and Food 

Guelph, Ontario 

Ms. Margery Bynoe 

Department of Geography 


Kingston, Ontario 

Mr. Thomas 1%. Cahill 

Resource Management AssociaLes 

P. 0. Box 740 

West Chester, PA 19380 

Mr. Wayne Chapman 

Soil Conservation Service 

c/o EPA 

Non Point Sources Branch 

WH 554 

401 M Street, S.W. 

Washington, D. C. 20460 

Dr. Y. K. Chau 


P. 0. Box 5050 

Burlington, Ontario I.7R 4126 

Dr. C:. Cllesters 

Director 

Water Resources Center 


1975 Willow Drive 

Madison, Wisconsin 53706 

Dr. Richard Coote 

Engineering Research Services 


Ottawa, Ontario KlA OC6

Mr. .I. Culht~rtsm 

U.S. 1)ep.lrtrncnt of the Lnterior 

L(~ologiva1 Survev 

Kt~ston, l'irginia 2209Z 

Ur. Trevor Ilic kinson 

Engineering Department 


Ouelpll, Ontario N1(: LW1 

I'r

Mr. Ken Kemp 

Indiana Stream Pollution Control Board 

Planning Section 

310 W. Michigan Avenue 

Indianapolis, Indiana 

Dr. .J. Knox 

Institute for Environmental Studies 

University of Wisconsin-Madison 

1042 Warf Building 

610 Walnut Building 


Dr. .I. (;. Konrad 

Superviscr of Special Studies 

Wisconsir Department of Natural 

Resources 


Dr. A. K. Lebeuvre 



Burlington, Ontario L7K 4A6 

Professor '7'. I.ogan 

'The Ohio State Univfrsity 

1885 Neil Avenue 

Columbus. Ohio 43210 

Ms. Elsie MacDonnld 

Soil Kescaarch lnstitute 


Ottawa, Ontario K1A 0C6 

Mrs. Edit.1) MacIntosh 

Mayor 

City of Kitchener 

City Hall 

Kitchenei, Ontario 

Dr. A. D. McElroy 

Ireatmen! and Control Processes Section 

Midwest l{esrarch Institute 

425 Volktlr Voulevard 

Kansas City, Missouri 

Mr. William F. Mildner 

U.S. Soil Conservation Service 

Hyattsville, Maryland 20782 

301 

Professor M. H. Miller 

Department of Land Resource Science 

Ontario Agricultural College 

University of Cuelph 

Cuelph, Ontario N16 2W1 

Dr. 11. V. Morley 


Room 1113 

K. W. Neatby Building 

Carling Avenue 

Ottawa, Ontario KlA 0C6 

Dr. M. D. Mullin 

US Environmental Protection Agency 

Grosse Ile Laboratory 

9311 Groh Koad 

Grosse Ile, Michigan 48138 

Dr. Carl Nordin 

U.S. (:e(,logical Survey 

Mailstop 413 

Box 25046 

Denver Federal Centre 

Lakewood, Colorado 80225 

Mr. .I. E. O'Neill 

Water Kesources Branch 

Ministry of the Environnwnt 

135 St. Cllir Avenue West 

Turonto, Ontario M4V 1P5 

Dr. E. D. Ongley 

kpartment of Geography 

()wen's University 


Mr. R. C. Ostry 

Water Quality Management Branch 

Ontario Ministry of the Environment 

135 St. Clair Avenue West 

Toronto, Ontario M4V 1P5 

Dr. Richard K. P,irizek 

Ilepartment of Geosciences 

Pennsylvania State University 

University Park, Penn. 16802

Ms. Jean Percival 




Dr. Harry B. Pionke 

Research Leader 


111 Research Building A 

University Park, Penn. 16802 

Mr. J. Ralston 

Water Resources Planning Unit 




Mr. J. D. Roseborough 

Director 

Fish and Wildlife Research Branch 

Ontario Ministry of Natural Resources 

P. 0. Box 50 

Maple, Ontario LOJ 1EO 

Professor G. K. Rutherford 



Kingston, Ontario K7L 3N6 

Professor Joseph Shapiro 

Geology & Ecology Department 

University of Minnesota 

Minneapolis, Minnesota 55455 


International Joint Comisslon 



Windsor, Ontario N9A 6T3 

Dr. D. B. Simons 

Engineering Research Centre 

Colorado State University 

Fort Collins, Culorado 80523 

Dr. P. G. Sly, Chief 

Lakes Research Division 



Burlington, Ontario L7R 4A6 

302 

Dr. William Sonzogni 

Great Lakes Basin Commission 

3475 Plymouth Road 

P. 0. Box 999 

Ann Arbor, Michigan 48106 

Dr. R. L. Thomas 

Director 

Great Lakes Biolimnology Laboratory 




Mr. Robert E. Thronson 

Environmental Protection Agency 

Waterside Mall 

Room 2417-D 


Dr. J. K. Vallentyne 

Ocean and Aquatic Affairs 

Fisheries 6 Marine Services 


580 Booth Street 

Ottawa, Ontario K1A OH3 

Dr. F. H. Verhoff 

Route 7 

Box 307 

Morgantown, W. Va. 26505 

Mr. Eric Veska 

Department of Geological Sciences 

Brock University 

St. Catharines, Ontario L2S 3A1 

Dr. Greg Wall 


Guelph, Ontario N1G 2W1 

Dr. D. E. Walling 


Armor Building 

Rennes Drive 

Exeter, England EX4 4RJ 

Dr. A. E. P. Watson 

International Joint Commission 



Windsor, Ontario N9A 6T3

Mr. G. M. Wood 

Solid Waste Unit 


135 St. Clair Avenue Vest 

'Toronto. Ontario M4V 1P5 

Dr. Stephen Yaksich 

Corps of Engineers 

Department of the Army 

1776 Niagara Street 

HufIalo, New York 14207

PWARG ~MBERSHI P 

Norman A. Berg (Chairman) 

Associate Administrator 



P. 0. Box 2890 


Konald ldaybrant 

Water Quality Appraisal Section 

Water ()uality Division 

Michigan Department of Natural Resources 

1’. 0. Box 30028 

Lansing, Michigan 48909 

I.. Robert Carter 

Coordin.ltor of Environmental Programs 

Office of the Assistant Commissioner 

for Environmental Health 

1330 West Michigan Street 

Indianapolis, Indiana 46206 

Leo J. Ifetling 

Environ~nental Quality 

Kesearcll and Development Unit 

New York State Department of 

Envir(mmenta1 Conservation 

50 Wolf Road 

Room 510 

Albany, New York 12201 

Richard R. Parizek 

Professt~r of Geology 

Department of Geosciences 

The Pennsylvania State University 

University Park, Pennsylvania 16802 

305 

Merle W. Tellekson 

Technical Support Branch 

Surveillance & Analysis Division 

Environmental Protection Agency 

Region V 

230 South Dearborn Street 

Chicago, Illinois 60604 

John G. Konrad 

Supervisor of Special Studies 

Wisconsin Department of Natural 

Resources 


Floyd E. Heft 

Division of Soil & Water Districts 

Ohio Department of Natural Resources 

Fountain Square 

Columbus. Ohio 43224 

John Pegors 

Minnesota Pollution Control Agency 

1015 Torrey Building 

Duluth, Minnesota 55802 

Gerald B. Welsh (Secretary) 

Resource Development Division 



P. 0. Box 2890 

Washington, D. C. 20013

Murrav (;. .Johnson (Chairman) 

Director General 

Ontario Region 

Fisheries and brine Service 

Ilepartment of Fisheries h Environment 

3050 Harvester Road 

tiurlington, Ontario L7N 351 

K. I>. l't~omas 

Director 

(:rc.at Lakes Uiol imnology Laboratory 

Canada Ccntrc for Inland Waters 

1'. 0. Box 5050 

RurlingLon, Ontario L7R 44.6 

Ii. V. Morley 

Kesfnr?t? ('or~r,+inntor 

(Lnvi rvnment and Krsources) 

Agriculture (:anada 

K.W. Neathy Building 

Room 1111 

Carling Avcmue 

Ottawa, Ontario KIA 0C6 

K. Stiikaze 

Chief 

Environmental Control Division 

Environmental Protection Service 

Department of Fisheries & Environment 


2nd Floor 


K. Code 


Room 6602, Whitney Block 

Queen's Park 

Toronto. Ontario 

306 

Donald N. .Teffs 

Assistant Llirector 

Water Resources Branch 




(:. Martin Wood 

llead, Solid Waste Unit 




.I. E. Urubaker 

Agricultural Engineering Extensions 

Branch 

Ontario Ministry of Agriculture & 

Food 

(helph, Ontario N1G 2W1 

.John Ralston 

Head 

Water Resources Planning Unit 

Ontario Ministry of the Environmen 



John D. Wiebe (Secretary) 

Environmental Assessments Coordina 

Ontario Region 

Environmental Management Service 

Department of Fisheries & Environrr 

3050 Harvester Road 

Burlington, Ontario L7N 351 

Secretariat Responsibilities: 


Biologist 



100 Ouellette Avenue, 8th Floor 

Windsor, Ontario N9A 6T3

W~RKSI-KIP ORGANIZERS 

Dr. Leo J. Hetling 

Director, Environmental Quality 

Research and Development Unit 

New York State Department of 

Environmental Conservation 

50 Wolf Road 

Albany, New York 

Mr. John N. Holeman 

Sedimentation Geologist 

United States Department of 

Agriculture 


Washington, D. C. 20250 

Dr. Dale D. Huff 

Iksearch Hydrologist 

Environmental Sciences Division 

Buildlng 3017 

Oak Ridge Nationdl Laboratory 

Oak Ridge, Tennessee 37830 

Dr. Edwin D. Ongley 

Associate Professor 




307 


Aquatic Biologist 




Windsor, Ontario N9A 6T3 

Dr. Richard L. Thomas 

Director 

Lakes Research Division 




Dr. Jack R. Vallentyne 

Senior Scientific Advisor to the 

Assistant Deputy Minister 

Ocean and Aquatic Affairs 

Fisheries and Marine Service 



Ottawa, Ontario K1A OH3

Dr. D. I. Mount (Chairman) 

Director 

Environmental Kescarch Laboratory 

6201 Congdon Avenue 

L)uluth, Minnesota ‘15804 

Professor Joseph Shnpiro 

Geology Department 

University of Minnesota 

220 I’illsbury Hali. 

Minneapolis, Minnesota 55455 

Dr. Eugene J. Aubert 

Uirector 

Great Lakes Environmental Research 

Laboratory 

National Oceanographic and Atmospheric 

Administration 

2300 Washtenaw Avenue 

Ann Arbor, Michigan 48104 

Professor Leonard 1%. Dworslcy 

Civil and Environmental Engineering 

Cornell University 

302 HolLlster Hall 

Itltaca, New York 14853 

RESEARCH ADVISORY ~ A R D ~ E R S H I P 

(AS OF OCTOBER 1976) 

308 

Mr. Alvin R. Balden 

19 Alina Lane 

fiot Springs Village, Arkansas 71901 

Mrs. Evelyn Stebbins 

Citizens for Clean Air and Water Inc. 

705 Elmwood 

Rocky River, Ohio 44116 

Dr. Herbert E. Allen 

Assistant Professor 

Department of Environmental 

Engineering 

Illinois Institute of Technology 

Chicago, Lllinois 60616 

Professor Archie J. McDonnell 

Department of Civil Engineering 

Water Resources Research Center 

The Pennsylvania State University 

University Park, Pennsylvania 16802 

Ex Officio 

” 

.~ 

Mr. Carlos M. Fetterolf, Jr. 

Executive Secretary 

Great Lakes Fishery Commission 

1451 Green Road 

Ann Arbor, Michigan 48107

Canadian 

Dr. A. R. LeFeuvre (Chairman) 

Director 




Rurlington, Ontario L7R 4A6 

Mr. Arnold J. Drapeau 

Professor 

Ecole Polytechnique 

Campus de L'Universite de Montreal 

C.P. 6079 - Succursde "A" 

Montreal, Quebec H3C 3A7 

Mr. H. R. Holland 

462 Charlesworth Lane 

Sarnia, Ontario N7Y 2R2 

Mr. Paul D. Foley 

Coordinator 

Development and Research Group 



'Toronto, Ontario M4V 1P5 

Dr. J. C. N. Westwood 

Professor & Head of Microbiology and 

Immunology 

Faculty of Medicine 

University of Ottawa 

Ottawa, Ontario K1N 6N5 

309 

Mr. J. Douglas Roseborough 

Director 

Fish and Wildlife Research Branch 


P. 0. Box 50 

Maple, Ontario 1.O.J 1EO 

Mrs. Mary Munro 

3020 First Street 

Burlington, Ontario L7N 1C3 

Dr. .J. R. Vallentyne 

Senior Scientific Advisor 

Ocean & Aquatic Affairs 

Fisheries & Marine Service 



Ottawa, Ontario K1A OH3 

Ex Officio " 

Mr. Floyd C. Elder 

A/Head, Basin Investigation and 

Modelling Section 




Burlington, 0ntar:io L7R 4A6 

" Secretariat-Responsibilities: 

Dr. Dennis E. Konasewich 

Scientist 



1.00 Ouellette Avenue, 8th Floor 

Windsor, Ontario NYA 6TJ

E t 50- a F 5 - International Joint Commission

Create successful ePaper yourself

Delete template?

Save as template?