Pesticides in Streams of the United States--Initial Results from the National Water-Quality Assessment Program

U.S. GEOLOGICAL SURVEY
Water-Resources Investigations Report 98-4222
Sacramento, California, 1999

SUMMARY AND CONCLUSIONS

Pesticides were commonly detected in streams draining small agricultural and urban basins (agricultural and urban indicator sites) and in large streams and rivers draining major basins with mixed land uses (integrator sites). Of the 46 targeted pesticides and pesticide degradation products, all were detected in at least 1 of the approximately 2,200 samples analyzed. On average, about 20 of the target compounds were detected at each site regardless of land-use setting and basin size, and an average of 6 to 7 of the target compounds were detected in each individual sample.

The pesticides that were detected most frequently were among the pesticides with highest national agricultural use, including the herbicides atrazine, metolachlor, alachlor, and cyanazine. Several other pesticides with high national use, however, such as the herbicides trifluralin, pendimethalin, and butylate, and the insecticides methyl parathion, phorate, and terbufos, were detected in less than 5 percent of samples. In general, the relation between the frequency of detection of pesticides in streams and the amount used in the basin was significant, but variability in pesticide use accounted for only about 25 percent of the observed variability in detection frequencies of the target compounds as a group. Herbicides generally were detected more frequently than insecticides, particularly in streams draining agricultural basins. Some compounds, including several insecticides, were detected more frequently in streams draining urban areas than in streams draining primarily agricultural areas. Concentrations in streams generally were less than 1 µg/L for all compounds, although concentrations greater than 1 µg/L were frequently measured for several herbicides during seasonal peaks. Herbicide concentrations were higher than insecticide concentrations at most agricultural and integrator sites. In areas where a large variety of crops are grown, especially vegetables and orchard and vineyard crops, insecticide concentrations often were higher than herbicide concentrations. Concentrations of several insecticides consistently were higher at urban sites than at most of the agricultural indicator sites and the integrator sites.

Seasonal patterns in pesticide occurrence were observed at most agricultural and integrator sites. At many of these sites, elevated concentrations of several compounds, particularly herbicides, occurred during the early part of the growing season. At other sites, the seasonal patterns were determined by local pesticide application and irrigation practices. Seasonal patterns were less evident in most of the urban streams where low levels of several compounds persisted for much of the year.

Annual stream loads of pesticide parent compounds (not including degradation products) generally accounted for less than 2 percent of the amounts applied agriculturally in the drainage basins. For several herbicides, including atrazine, cyanazine, and metolachlor, the amount transported in the streams consistently represented about 1 percent of the amount applied in most of the agricultural and integrator basins. For other herbicides and all insecticides, the amount transported in the streams represented a much smaller (10 to 100 times lower) portion of the amount applied in the basins. Transport of pesticides in urban streams could not be compared to the amount applied in the urban basins because of the lack of information on nonagricultural pesticide use. The annual total insecticide yields for many of the urban basins, however, were as high or higher than the annual total insecticide yields for most of the agricultural or integrator basins.

Concentrations of several compounds frequently were higher than water-quality standards and criteria established for these compounds in drinking water. When expressed as a long-term mean concentration, however, the concentrations measured at these 58 sites rarely exceeded USEPA-established standards and criteria for drinking water. It should be noted that human-health criteria have not been established for 20 of the target compounds.

Criteria values established for the protection of aquatic life, which generally are lower than the human-health criteria values, were frequently exceeded. One or more aquatic-life criteria values were exceeded at 39 of the 58 sampling sites. For some compounds, particularly herbicides, this occurred primarily during relatively short seasonal pulses of elevated concentrations that followed periods of pesticide application. For some insecticides, concentrations were higher than the aquatic-life criteria values for longer periods, particularly at some of the urban sites and at agricultural sites in California and Oregon. At a number of sites, concentrations of several compounds were higher than their aquatic-life criteria values in the same samples or during the same period. The established criteria do not account for the presence of mixtures of pesticides or pesticide degradation products. In addition, aquatic-life criteria have not been established for 28 of the target compounds. These and other limitations hinder the assessment of the environmental significance of the pesticide concentrations measured in this study.

REFERENCES CITED

Anderson, J.R., Hardy, E.E., Roach, J.T., and Witmer, R.E., 1976, A land use and land cover classification system for use with remote sensor data: U.S. Geological Survey Professional Paper 964, 28 p.

Baker, D.B., 1985, Regional water quality impacts of intensive row-crop agriculture: A Lake Erie basin case study: Journal of Soil and Water Conservation, v. 40, no. 1, p. 125-132.

Barbash, J.E., and Resek, E.A., 1996, Pesticides in ground water: Distribution, trends, and governing factors: Chelsea, Mich., Ann Arbor Press, Pesticides in the Hydrologic System series, v. 2, 588 p.

Canadian Council of Resource and Environment Ministers, 1991, Canadian water quality guidelines: Ottawa, Ontario, Environment Canada, Inland Waters Directorate, Water Quality Branch, variously paged.

Capel, P.D., 1991, Wet atmospheric deposition of herbicides in Minnesota, in Mallard, G.E. and Aronson, D.A., eds., U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings of the technical meeting, Monterey, California, March 11-15, 1991: U.S. Geological Survey Water-Resources Investigations Report 91-4034, p. 334-337.

Capel, P.D., Spexet, A.H., and Larson, S.J., 1999, The occurrence and behavior of the herbicide prometon in the hydrologic system: Environmental Science and Technology, in press.

Colborn, Theo, and Clement, C.R., eds., 1992, Chemically-induced alterations in sexual and functional development: The wildlife/human connection: Princeton, N.J., Princeton Scientific Publishing Co., Advances in Modern Environmental Toxicology series, v. 21, 403 p.

del Rosario, Aurora, Remoy, John, Soliman, Violeta, Dhaliwal, Joginder, Dhoot, Jagdev, Perera, Kusum, 1994, Monitoring for selected degradation products following a spill of VAPAM into the Sacramento River: Journal of Environmental Quality, v. 23, no. 2, p. 279-286.

Draper, W.M., and Wakeham, D.E., 1993, Rate constants for metam-sodium cleavage and photodecomposition in water: Journal of Agricultural and Food Chemistry, v. 41, no. 7, p. 1129-1133.

E&S Environmental Chemistry, Inc., and Tetra Tech, Inc., 1995, Willamette River Basin Water Quality Study, Phase II--Non-point Source Pollution in the Pudding River Sub-Basin of the Willamette River: Corvallis, Oregon, and Redmond, Washington, prepared for Oregon Department of Environmental Quality, Portland, variously paged.

Gentile, I.A., Ferraris, L., and Crespi, S., 1989, The degradation of methyl bromide in some natural fresh waters. The influence of temperature, pH, and light: Pesticide Science, v. 25, p. 261-272.

Gentile, I.A., Ferraris, L., Sanguinetti, M., Tiprigan, M., and Fisichella,G., 1992, Methyl bromide in natural fresh waters: hydrolysis and volatilization: Pesticide Science, v. 34, no. 3, p. 297-301.

Gianessi, L.P., and Anderson, J.E., 1996, Pesticide use in U.S. crop production: National data report: Washington, D.C., National Center for Food and Agricultural Policy, unpaged.

Gilliom, R.J., Alley, W.M., and Gurtz, M.E., 1995, Design of the National Water-Quality Assessment Program: Occurrence and distribution of water-quality conditions: U.S. Geological Survey Circular 1112, 33 p.

Gilliom, R.J., and Thelin, G.P., 1997, Classification and mapping of agricultural land for national water-quality assessment: U.S. Geological Survey Circular 1131, 70 p.

Goodbred, S.L., Gilliom, R.J., Gross, T.S., Denslow, N.P., Bryant, W.L., and Schoeb, T.R., 1997, Reconnaissance of 17ß -estradiol, 11-ketotestosterone, vitellogenin, and gonad histopathology in common carp of United States streams: Potential for contaminant-induced endocrine disruption: U.S. Geological Survey Open-File Report 96-627, 47 p.

Goolsby, D.A., and Battaglin, W.A., 1993, Occurrence, distribution, and transport of agricultural chemicals in surface waters of the midwestern United States, in Goolsby, D.A., Boyer, L.L., and Mallard, G.E., compilers, Selected papers on agricultural chemicals in water resources of the Midcontinental United States: U.S. Geological Survey Open-File Report 93-418, p. 1-25.

Goolsby, D.A., Battaglin, W.A., Fallon, J.D., Aga, D.S., Kolpin, D.W., and Thurman, E.M., 1993, Persistence of herbicides in selected reservoirs in the midwestern United States: Some preliminary results, in Goolsby, D.A., Boyer, L.L., and Mallard, G.E., compilers, Selected papers on agricultural chemicals in water resources of the Midcontinental United States: U.S. Geological Survey Open-File Report 93-418, p. 51-63.

Goolsby, D.A., Thurman, E.M., Pomes, M.L., Meyer, M., and Battaglin, W.A., 1997, Herbicides and their metabolites in rainfall: Origin, transport, and deposition patterns across the midwestern and northeastern United States, 1990-1991: Environmental Science and Technology, v. 31, no. 5, p. 1325-1333.

Goss, D.W., and Wauchope, R.D., 1990, The SCS/ARS/CES pesticide properties database: II Using it with soils data in a screening procedure, in Weigman, D.L., ed., Pesticides in the next decade. The challenges ahead: Blacksburg, Va., Virginia Water Resources Research Center, p. 471-493.

Hirsch, R.M., Alley, W.M., and Wilber, W.G., 1988, Concepts for a national water-quality assessment program: U.S. Geological Survey Circular 1021, 42 p.

Hitt, K. J., 1994, Refining 1970's land-use data with 1990 population data to indicate new residential development: U.S. Geological Survey Water-Resources Investigations Report 94-4250, 15 p.

International Joint Commission, 1977, New and revised Great Lakes water quality objectives, International Joint Commission Canada and United States, 155 p.

Kalkhoff, S.J., Kolpin, D.W., Thurman, E.M., Ferrer, I., and Barcelo, D., 1998, Degradation of chloroacetanilide herbicides: the prevalence of sulfonic and oxanilic acid metabolites in Iowa ground and surface waters: Environmental Science and Technology, v. 32, no. 11, p. 1738-1740.

Kent, R.A., Pauli, B.D., Trotter, D.M., and Gareau, J., 1991, Canadian water quality guidelines for metolachlor: Environment Canada, Inland Waters Directorate, Water Quality Branch, Scientific Series No. 184, 34 p.

Kimbrough, R.A., and Litke, D.W., 1996, Pesticides in streams draining agricultural and urban areas in Colorado: Environmental Science and Technology, v. 30, no. 3, p. 908-916.

Kolpin, D.W., Barbash, J.E., and Gilliom, R.J., 1998, Occurrence of pesticides in shallow groundwater of the United States: Initial results from the National Water-Quality Assessment Program: Environmental Science and Technology, v. 32, no. 5, p. 558-566.

Larson, S.J., Capel, P.D., Goolsby, D.A., Zaugg, S.D., and Sandstrom, M.W., 1995, Relations between pesticide use and riverine flux in the Mississippi River Basin: Chemosphere, v. 31, no. 5, p. 3305-3321.

Larson, S.J., Capel, P.D., and Majewski, M.S., 1997, Pesticides in surface waters: Distribution, trends, and governing factors: Chelsea, Mich., Ann Arbor Press, Pesticides in the Hydrologic System series, v. 3, 373 p. Leahy, P.P., Rosenshein, J.S., and Knopman, D.S., 1990, Implementation plan for the National Water-Quality Assessment Program: U.S. Geological Survey Open-File Report 90-174, 10 p.

Leonard, R.A., 1990, Movement of pesticide into surface waters, in Cheng, H.H., ed., Pesticides in the soil environment: Processes, impacts, and modeling: Madison, Wis., Soil Science Society of America, p. 303-349.

Majewski, M.S., and Capel, P.D., 1995, Pesticides in the atmosphere: Distribution, trends, and governing factors: Chelsea, Mich., Ann Arbor Press, Pesticides in the Hydrologic System series, v. 1, 214 p.

Meister, R.T., ed, 1996, Farm Chemicals Handbook `96: Willoughby, Ohio, Meister Publishing Company, variously paged.

Miltner, R.J., Baker, D.B., Speth, T.F., and Fronk, C.A., 1989, Treatment of seasonal pesticides in surface waters: Journal of the American Water Works Association, v. 81, no. 1, p. 43-52.

Mitchell, W.B., Guptill, S.C., Anderson, K.E., Fegeas, R.G., and Hallam, C.A., 1977, GIRAS: A geographic information retrieval and analysis system for handling land use and land cover data: U.S. Geological Survey Professional Paper 1059, 16 p.

Nowell, L.H., and Resek, E.A., 1994, National standards and guidelines for pesticides in water, sediment, and aquatic organisms: Application to water-quality assessments: Reviews for Environmental Contamination and Toxicology, v. 140, p. 1-164.

Panshin, S.Y., Dubrovsky, N.M., Gronberg, J.M., and Domagalski, J.L., in press, Occurrence and Distribution of Dissolved Pesticides in the San Joaquin River Basin, California: U.S. Geological Survey Water-Resources Investigations Report 98-4032.

Patrick, J.E., 1990, Pesticides in Ontario municipal drinking water from surface sources, 1987: Ontario Ministry of the Environment, Water Resources Branch, Drinking Water Section, 35 p.

Rathbun, R.E., 1998, Transport, behavior, and fate of volatile organic compounds in streams: U.S. Geological Survey Professional Paper 1589, 151 p.

Richard, R.P., and Baker, D.B., 1993, Pesticide concentration patterns in agricultural drainage networks in the Lake Erie Basin: Environmental Toxicology and Chemistry, v. 12, no. 1, p. 13-26.

Schottler, S.P., Eisenreich, S.J., and Capel, P.D., 1994, Atrazine, alachlor, and cyanazine in a large agricultural river system: Environmental Science and Technology, v. 28, no. 6, p. 1079-1089.

Shelton, L.R., 1994, Field guide for collecting and processing stream-water samples for the National Water-Quality Assessment Program: U.S. Geological Survey Open-File Report 94-455, 42 p.

Stephan, C.R., Mount, D.I., Hansen, D.J., Gentile, J.H., Chapman, G.A., and Brungs, W.A., 1985, Guidelines for deriving numerical national water quality criteria for the protection of aquatic organisms and their uses: U.S. Environmental Protection Agency, PB 85-227049.

Thurman, E.M., Goolsby, D.A., Meyer, M.T., and Kolpin, D.W., 1991, Herbicides in surface waters of the midwestern United States: The effect of spring flush: Environmental Science and Technology, v. 25, no. 10, p. 1794-1796.

U.S. Department of Commerce, 1995, 1992 Census of Agriculture: Washington, D.C. [CD-ROM, dBase format].

U.S. Environmental Protection Agency, 1991, Water-quality criteria summary: U.S. Environmental Protection Agency, Office of Water, Office of Science and Technology, Health and Ecological Effects Division, wall poster.

--- 1994, Guidelines establishing test procedures for the analysis of pollutants (App. B, Part 136, Definition and procedures for the determination of the ): U.S. Code of Federal Regulations, Title 40, revised July 1, 1994, p. 635-637.

U.S. Geological Survey, 1990, Land use and land cover digital data from 1:250,000- and 1:100,000-scale maps: U.S. Geological Survey Data User Guide, no. 4, 25 p. (Accessed January 1998 on the World Wide Web at URL ftp://www-nmd.usgs.gov/pub/ti/LULC/lulcguide)

--- 1998, NAWQA analytical methods, MDLs, and performance characteristics for pesticides in water, Table 2: U.S. Geological Survey data, accessed July 1, 1998, on the World Wide Web, at URL http://ca.water.usgs.gov/pnsp/anstrat/#t2

U.S. Geological Survey, 1999, Data on pesticides in surface and ground water of the United States: Results of the National Water Quality Assessment Program (NAWQA): U.S. Geological Survey data available on the World Wide Web, accessed January 28, 1999, at URL http://wa.water.usgs.gov/ccpt/pns_data/data.html

Whitmore, R.W., Kelly, J.E., and Reading, P.L., 1992, Executive summary, results, and recommendations, v. 1 of National home and garden pesticide use survey: Research Triangle Park, North Carolina, Research Triangle Institute, RTI/5100/17-01F68-WD-0032, 140 p.

Wnuk, M., Kelley, R., Breuer G., and Johnson, L., 1987, Pesticides in water supplies using surface water sources: Des Moines, Iowa, Iowa Department of Natural Resources, 33 p.

Wotzka, P.J., Lee, J., Capel, P.D., Ma, L., 1994, Pesticide concentrations and fluxes in an urban watershed, in Peterson, G.L., ed., Proceedings of the American Water Resources Association National Symposium on Water Quality: American Water Resources Association technical publication series, no. TSP 94-4, p. 135-145.

Zaugg, S.D., Sandstrom, M.W., Smith, S.G., and Fehlberg, K.M., 1995, Methods of analysis by the U.S. Geological Survey National Water-Quality Laboratory: Determination of pesticides in water by C-18 solid-phase extraction and capillary-column gas chromatography/mass spectrometry with selectedion monitoring: U.S. Geological Survey Open-File Report 95-181, 49 p.