Municipal wastewater has not been extensively examined as a pathway by which pesticides contaminate surface water, particularly relative to the well-recognized pathways of agricultural and urban runoff. A state-of-the-science review of the occurrence and fate of current-use pesticides in wastewater, both before and after treatment, indicates this pathway is significant and should not be overlooked. A comprehensive conceptual model is presented to establish all relevant pesticide-use patterns with the potential for both direct and indirect down-the-drain transport. Review of available studies from the United States indicates 42 pesticides in current use. While pesticides and pesticide degradates have been identified in wastewater, many more have never been examined in this matrix. Conventional wastewater treatment technologies are generally ineffective at removing pesticides from wastewater, with high removal efficiency only observed in the case of highly hydrophobic compounds, such as pyrethroids. Aquatic life reference values can be exceeded in undiluted effluents. For example, seven compounds, including three pyrethroids, carbaryl, fipronil and its sulfone degradate, and imidacloprid, were detected in treated wastewater effluent at levels exceeding U.S. Environmental Protection Agency (US EPA) aquatic life benchmarks for chronic exposure to invertebrates. Pesticides passing through wastewater treatment plants (WWTPs) merit prioritization for additional study to identify sources and appropriate pollution-prevention strategies. Two case studies, diazinon and chlorpyrifos in household pesticide products, and fipronil and imidacloprid in pet flea control products, highlight the importance of identifying neglected sources of environmental contamination via the wastewater pathway. Additional monitoring and modeling studies are needed to inform source control and prevention of undesirable alternative solutions.
Occurrence and Sources of Pesticides to Urban Wastewater and the Environment
Preferred Citation
Sutton, R; Xie, Y; Moran, KD; Teerlink, J. 2019. Occurrence and Sources of Pesticides to Urban Wastewater and the Environment. In Pesticides in Surface Water: Monitoring, Modeling, Risk Assessment, and Management. American Chemical Society: Washington, DC. pp. 63-88.
Secondary Title
Pesticides in Surface Water: Monitoring, Modeling, Risk Assessment, and Management
Place Published
Washington, DC
Publisher
American Chemical Society
Abstract
Number of Pages
63-88
DOI
10.1021/bk-2019-1308.ch005
Programs and Focus Areas
Clean Water Program
Emerging Contaminants
Bay Regional Monitoring Program
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