Surface Water
Monitoring for Pesticides in the Water
The California Department of Pesticide Regulation (DPR) evaluates and samples both groundwater and surface water for pesticides to determine if there is contamination, identify sensitive areas, and develop mitigation measures if pesticides are moving into the water.
Surface water monitoring looks at both agricultural and nonagricultural sources of pesticide residues.
Surface Water Protection
Before the use of a pesticide in California, our scientists will model pesticide risk to surface water by evaluating pesticide use and toxicity data, application methods, and risk to drinking water or aquatic organisms to protect both human health and the environment.
As an ongoing part of our work, DPR scientists sample surface water throughout California to monitor for pesticide residues, identify the sources of any contamination, determine the mechanisms of off-site movement of pesticides to surface water, and develop site-specific mitigation strategies.
We sample surface water in both agricultural and nonagricultural settings to address contamination. We implement mitigation measures that will protect water quality in coordination with the State Water Resources Control Board (SWRCB) and the Regional Water Quality Control Boards (RWQCB). Both the SWRCB and DPR have responsibilities to protect water quality from the potential adverse effects of pesticides. In 2019, the SWRCB and DPR signed an updated Management Agency Agreement (MAA) and adopted an associated Implementation Plan replacing the original agreement from 1997. The MAA and Implementation Plan coordinate interactions, facilitate communication at both staff and executive levels, promote problem-solving, and ultimately assure the protection of water quality.
Surface Water Modeling
We have developed a model to prioritize pesticides for surface water monitoring in agricultural and urban areas of California. Our Surface Water Monitoring Prioritization (SWMP) model incorporates pesticide use and toxicity data, as well as chemical properties, monitoring results, and application information.
To prevent problematic chemicals or pesticide products from being registered, we also use the Pesticide Registration Evaluation Model (PREM) to evaluate aquatic impacts of pesticide products seeking registration in California. PREM assesses risks of product use to aquatic and benthic organisms which allows DPR to protect the environment and human health.
Contact us for additional user manual information and technical reports.
Surface Water Reports: Surface Water Database (SURF)
We maintain a surface water database called SURF, which contains data from a wide variety of environmental monitoring studies designed to monitor for the presence or absence of pesticides in California surface waters.
We are currently in progress with updating our database functionality and formatting. During this time, results from SURF will continue to be available for download as comma-delimited files for import into spreadsheet and database programs.
Two files are available: one with all available surface water data and one with all available sediment data. The files will automatically open with the proper formatting in newer versions of spreadsheet programs. Note that the surface water data file contains over 943,000 records and will not import properly into older versions of spreadsheet programs which are limited to a maximum of 65,000 records.
Submitting Data to DPR’s SURF Database
We encourage submissions of surface water monitoring data from any organization that conducts studies that monitor the presence of pesticides in California’s surface water. You can submit to the contact listed below. All data submissions should fulfill the following requirements:
- Name of sampling agency or organization
- Date that each sample was collected
- Date of each sample analysis
- County where samples were taken
- Detailed sampling location information (including latitude and longitude, with datum specified (NAD83, WGS84, etc.)
- Name or description of the water body sampled
- Name of the active ingredient analyzed
- Concentration detected (with unit of measurement)
- Limit of quantitation (with unit of measurement)
- Description of analytical QA/QC plan, or statement that no formal plan exists
Sign Up for Email Updates
Keep in the loop by subscribing to one or more of our email distribution lists.
Still have a Question or Need More Information?
Please contact us with questions or visit the Contact Us page on our website to connect with other programs at DPR.
Email: Surfacewater@cdpr.ca.gov
Department of Pesticide Regulation
1001 I Street, P.O. Box 4015
Sacramento, CA 95812-4015