BACKGROUND

Abstract

Historically, agricultural activities have been the focus of investigations into pesticide impacts on water bodies. In recent years, however, pesticide use in urban areas is increasingly being examined as a potential source of aquatic pollutants. Although applications of pesticides in urban areas are typically on a small scale, the wide variety of chemicals used and the frequency of applications can result in a substantial amount of pesticides used. Urban-use pesticides can move off application sites and enter storm drains which route surface runoffs into urban creeks. These pesticides can also end up in urban sewage which then travels to wastewater treatment plants. Although conventional wastewater treatment techniques employed by Publicly Owned Treatment Works (POTWs) may remove certain pesticides with high efficiency, others may not be sufficiently removed. Thus, these pesticides can be present in the treated effluent and eventually be released into a receiving water body. Under the California Porter Cologne Act, the Regional Water Quality Control Boards (RWQCBs) regulate the quality of treated effluent by issuing wastewater discharge permits to POTWs. These permits prohibit toxic substances in the treated effluent at concentrations that may cause harm to aquatic species