Pesticides and Water Quality - Texas Center for Policy Studies

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which pollutants to monitor for in testing the quality ofsurface water or ground water; (2) decide where to targetmore aggressive pollution reduction efforts; or (3)measure the effectiveness of pollution reduction efforts..B. Water Quality andPesticide Data in TexasOver the past 30 years, the state and federal governmentshave developed fairly detailed data on the presence of“conventional” pollutants in surface water.“Conventional” pollutants include fecal coliformbacteria, organic materials that create biological oxygendemand (BOD) 2 , nutrients such as nitrogen andphosphorus which increase algal growth, and suspendedand dissolved solids. There is a wealth of data on thehealth of our water in relation to these conventionalpollutants. There is also quite a bit of information onhow and where these types of pollutants enter ourwaterways and aquifers, though more information onsome types of sources -- such as storm water run-off,septic tanks, sewage spills and abandoned wells -- isnecessary for a complete picture. 3Much less information is available on “toxic” waterpollutants, however. 4 A program introduced in 1986called the “Toxic Release Inventory” (TRI) 5 requiresmany types of manufacturing plants to report theirreleases of toxic pollutants into the water, air and land.This program has been an important step in getting betterscientific information on toxic water pollution fromindustrial operations and has allowed state and localgovernment agencies to better target monitoring andpollution control efforts for this sector. The TRIprogram, however, does not apply to non-manufacturingsources of toxic water pollution.One potentially important source of non-industrial toxicwater pollution is the use of pesticides—on farms, golf2 Oxygen-demanding pollutants are most frequently associated with sewage.Discharges high in BOD can reduce the in-stream dissolved oxygen (DO)levels. Reduced DO levels can adversely affect aquatic life.3 See Texas Center for Policy Studies, Texas Environmental Almanac,Chapter 2, Water Quality (Austin, 1995). Also available on the internet athttp://www.tec.org.4 Texas Clean Rivers Program/TNRCC, Texas Water Quality: A Summaryof River Basin Assessments (Austin: 1994), p. 38.5 For the most recent Texas TRI trends, seewww.trncc.state.tx.us/exec/media/press/06-98tri.html.2
courses, parks, highway right-of-way and lawns andgardens. Pesticides can reach surface waters throughstorm water and other run-off from these types of sitesand some may leach into the ground water. 6 In someareas, herbicides are being purposefully introduced intolakes and streams to kill hydrilla and other aquaticweeds.Once they reach water, pesticides pose potential risks tohuman health and the environment. They can be carriedthrough drinking water systems to the tap, if the drinkingwater provider does not have special treatmenttechnology in place. They can fall out into the sedimentof waterways and be taken up by fish or other aquaticlife, posing potential problems for humans and animalsthat consume the fish.The present report, which is based on a review of over 50reports on Texas water quality, demonstrates that data onthe presence of pesticides in ambient surface watersystems or ground water is greatly lacking, though thereis more information available on whether pesticides arebeing found in the drinking water provided to the tap.Table 1 provides a brief summary of the results of thisreview.1. Pesticides in Surfaceand Ground WaterIn summarizing the 1994assessments of 15 riverbasins and 8 coastal basins,TNRCC concluded: “Ingeneral, the screeninganalysis of ten and a halfyears of data for toxicsubstances in water revealsthat, in most cases, therewere insufficient data tomake any conclusion ofconcern, possible concern orno concern. This isespecially true of toxicorganic substances, i.e.pesticides.”As discussed in Sections II and III of this report, testingfor the presence of pesticides in ambient surface water,fish and ground water has been extremely limited inTexas, as in most other states. For example, in 1996,only 2 TNRCC fixed surface water quality monitoringstations were tested for pesticides in water (comparedwith 27 stations tested in 1985). The Texas Departmentof Health has no designated funds for testing fish tissuefor pesticides, and can generally only respond to fishkills or other situations where a problem has alreadybeen identified. The Texas Clean Rivers Program BasinAssessments, conducted by river authorities and otherentities, almost uniformly state that very little data areavailable to evaluate water quality with respect topesticides.6 U.S. Geological Survey, Pesticides in Surface Waters: U.S.G.S. Fact SheetFS-039-97 (1997).3
Page 1: I. INTRODUCTION AND SUMMARYA. Effec
Page 5: 1992, 1994 and 1996 Clean Rivers Pr
Page 8 and 9: The TNRCC has also issued “statew
Page 10 and 11: elated monitoring waivers under the
Page 12 and 13: II. PESTICIDES IN SURFACE WATERThis
Page 15 and 16: whether Texas water bodies are expe
Page 17 and 18: screening levels) for fish tissue a
Page 19 and 20: detected pesticides have been banne
Page 21 and 22: section of a segment was considered
Page 23 and 24: which examines the liver and reprod
Page 25 and 26: Water Body Year of Sample Pesticide
Page 27 and 28: Water Body Year of Sample Pesticide
Page 29 and 30: een detected in Texas public drinki
Page 31 and 32: E. Summary of Statewide DataThe fai
Page 33 and 34: The Clean Rivers Program also has a
Page 35 and 36: Brazos/Colorado Coastal BasinDuring
Page 37 and 38: mosquito control program conducted
Page 39 and 40: San Antonio River BasinThe 1994 Ass
Page 41 and 42: • Cibolo Creek Municipal Authorit
Page 43 and 44: Compound No. of Sites Detections No
Page 45 and 46: urban land use areas were the main
Page 47 and 48: These rural landowners are reported
Page 49 and 50: water include the Tulia and Friona
Page 51 and 52: IV. ENHANCING WATER QUALITY PROTECT
Page 53 and 54:
3. A determination of the public wa
Page 55 and 56:
use, the source water assessments c
Page 57 and 58:
V. CONCLUSION:TEXAS NEEDS A PESTICI
Page 59 and 60:
DRINKING WATER MONITORING WAIVERS F
Page 61 and 62:
At the time this report was being p
Page 63 and 64:
Proposed CMR 162 Alternative Monito
Page 65 and 66:
The need for reasonably location-sp
Page 67 and 68:
Table B-3. Pesticide Analysis Costs
Page 69 and 70:
application and treatment rates, al
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