EPA Requests Comments on New Methodologies to Estimate Pesticide Concentrations in Surface Waters

For Release: January 15, 2020

The U.S. Environmental Protection Agency (EPA) is asking for public comments on new methodologies developed by the agency to estimate exposure to pesticides from surface water sources. These methodologies would increase the accuracy of the agency’s estimates by minimizing underestimation, reducing the magnitude of overestimation, and increasing consistency.

With recent advances in automation and improvements in data quality, EPA is taking another step toward its goal of building new scenarios that better reflect environmental characteristics for use in surface water assessments. These scenarios can be used in EPA’s tool that estimates pesticide concentrations in surface water. Additionally, EPA developed a methodology to use percent cropped area (PCA) to better account for the amount of a crop grown within a watershed that drains to a drinking water intake. The new methodology also uses percent cropped treated (PCT) to better capture the amount of a pesticide used on that crop. These new methods would ensure that the agency’s review of pesticides continues to be protective of human health.

In its review of pesticides, EPA conducts drinking water assessments to determine if pesticide concentrations in drinking water may cause adverse health effects. These assessments include an analysis of the potential for and magnitude of pesticide occurrence in surface and groundwater sources of drinking water. EPA plans to incorporate these new methodologies into future pesticide drinking water assessments to increase consistency in surface water assessments and to refine pesticide exposure estimates.

Comment on these new methods until February 29, 2020, via the following email address: OPPeco@epa.gov.