Groundwater in the Great Lakes Basin

tive; however, concerns about chronic wasting disease
(CWD) prions in ungulate carcasses may confound this
disposal method (Kolb, 2006; Chambliss, 2007).
Traditional cemeteries have long been recognized as
threat to groundwater quality since they are most often
located in groundwater recharge zones on hilltops
in easily excavated soils and are ‘hotspots’ for many
contaminants including embalming fluids containing
arsenic, formaldehyde and gluteraldehyde (Stowe,
Schmidt and Green, 2001; Konefes and McGee, 2001).
The recent trend to ‘natural burials’ has the potential
to further compromise groundwater quality (Righton,
2008; White, 2007).
NUTRIENTS
Excess nutrients, including ammonia, nitrogen, phosphorus
and carbon from manure, can enter waterways
bringing about impaired water quality, eutrophication
and reduced oxygen levels resulting in fish fatalities
(CDC, 2008; U.S. EPA, 2004; ECO, 2000). In 1996 it
was estimated that five of the ten areas in Canada that
produced the most manure per hectare (between 4,000
to 6,000 kg of manure per hectare annually) were in
southwestern Ontario (McRobert, 2004). There are
an estimated 20 million farm animals in Southwestern
Ontario which produce an estimated 15 million tonnes
of manure a year (Richmond, 2007). As of 2000, Ontario
alone had more than 3.4 million hogs which produced
as much raw sewage as the province’s entire human
population (ECO, 2000). Of these hogs approximately
1.8 million are located within Southwestern Ontario
(Richmond, 2007). CAFOs can produce as much
manure as a medium-size city (U.S. EPA, 2004). In
1998, seven families in Hope Township had their
water wells contaminated by manure from a hog farm
(ECO, 2000). In 1999 a pig farm in Chatham, Ontario,
discharged 1.5 million liters of manure, some of which
entered a nearby drain and Lake Erie (ECO, 2000).
High animal density destroys vegetation and results
in greater production of manure than can be utilized
by crops. The U.S. Department of Agriculture (USDA)
indicates that between 1982 and 1997 there was a 20%
increase in the amount of excess nutrients produced
through increased manure, and a corresponding
decrease of 1.4 acres per 1000 pounds of live animals
(U.S. EPA, 2003a). Total manure nitrogen and phosporus
produced in the United States each year is
approximately 12.9 and 3.8 billion pounds respectively
(U.S. EPA, 2004). The ECO noted that large-scale farms
produce vast quantities of manure yet they often do
not have corresponding large areas of farm land (ECO,
2000). Bare ground and insufficient crop land allows
run-off, rich in nutrients from manure, to enter and
Figure 2.
contaminate groundwater. Over-application of manure
to farm land results in a buildup of excess nutrients.
Build-up of mineral salts including sodium, calcium,
magnesium, potassium, chloride, sulfate, bicarbonate
and nitrate is also a concern since they can contribute
to surface water salinization and leaching salts can
affect groundwater quality (U.S. EPA, 2004). In a risk
assessment report by the U.S. EPA (2004) it was stated
that, “Underlying all the environmental problems associated
with CAFOs is the fact that too much manure
accumulates in a restricted area. Traditional means of
using manure are not adequate to contend with the
large volumes present at CAFOs.”
Since rapid drainage is desired when applying liquefied
manure to fields, tile-drained areas are frequently
utilized. Drain tiles are placed approximately 2 to 4 feet
below the surface, with the expectations that contaminants
will be filtered out before reaching the drain
(Haack and Duris, 2008). However, in areas where the
soil is clay-based, there can be an abundance of worm
holes, desiccation cracks and other openings such as
animal burrows which can form conduits for contaminants
to reach the tiles. This results in little to no filtration
before liquid manure reaches the drain (Egan, 2007).
ANTIBIOTICS
Road killed deer carcasses dumped in a
roadside pit awaiting burial
Photo provided by: Elisabeth Kolb, NYS DOT
Antibiotics, natural and synthetic hormones and trace
elements including arsenic, copper, selenium and zinc
are now being implemented in farms to enhance livestock
growth and to act as biocides (U.S. EPA, 2004).
Overcrowded living conditions, such as in CAFOs,
result in the use of large quantities of antibiotics
in order to prevent the spread of disease. Since the
1950s the recommended level of antibiotics in animal
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