The Aquatic Pesticide Monitoring Program

Reprinted from NorCal SETAC News, Volume 13, No. 2, Fall 2002

On January 1st of 2002, an entirely new research and monitoring effort began at SFEI. This project is investigating the behavior of aquatic pesticides in the environment throughout the state and is known as the Aquatic Pesticide Monitoring Program (APMP). This project will be looking exclusively at pesticides applied directly to bodies of water and not at pesticides that were initially used on land.

The APMP arose from the fallout of a 2001 legal decision in the U.S. Ninth Circuit court (Headwaters, Inc. v. Talent Irrigation District) which was interpreted as requiring that aquatic pesticide users obtain a National Pollution Discharge Elimination System (NPDES) permit prior to discharging pesticides to U.S. waters. Previously, pesticide use was governed only under federal pesticide law (FIFRA). In order to keep aquatic pesticide users legal under the recent court decision, last July the State Water Resource Control Board (SWRCB) issued an emergency permit. However, the advocacy group Waterkeepers felt that this permit did not require adequate monitoring and challenged the permit in court. As a settlement with Waterkeepers, the SWRCB agreed to fund two years of research and monitoring to provide the state with enough information to develop a good general NPDES permit when the current emergency permit expires.
Because of SFEI’s experience in conducting and managing large-scale monitoring plans, the SWRCB selected SFEI to run the APMP. This work will complement the water quality monitoring that individual permit applicants must already conduct. This year the APMP’s efforts will be directed in two distinct areas: methods development and the pilot testing of monitoring techniques and methods.

Methods
In conversation with various technical experts, it was concluded that current methods of aquatic pesticide analysis may not be adequate to measure concentrations at environmentally significant levels. Existing methods will be tested to determine if they provide acceptable data. New analytical methods will be developed where current methods are deemed insufficient. In addition, sampling methods will also be verified and developed. Daniel Oros of SFEI is working with Kathy Kuivila (USGS) and Dave Crane (DFG Water Pollution Lab) on the chemical analytical methods of the monitoring plan. Toxicity tests will also be developed that are appropriate for each type of pesticide and for use in California waters. Brian Anderson (UCD Marine Pollution Studies Lab) is heading up this effort, along with Frank Riley (DFG-Aquatic Toxicity Lab), Victor deVlaming (UCD-Aquatic Toxicty Lab), Scott Ogle (Pacific Ecorisk), and Dan Schlenk (UCD).

This methods development work will provide a tested set of tools and methods with which to monitor the behavior of aquatic pesticides in the environment. Once the methods have been proven, efforts will be made to transfer this knowledge to private commercial labs that are doing the sample analysis for the individual discharge permit applicants. The standardized methods will allow greater confidence in the data generated by discharger monitoring plans.

Pilot Testing
The second area of focus for this summer’s APMP effort is to conduct research that will augment and deepen the monitoring plans of several current discharge permit applicants from southern, central, and northern California. It was decided that APMP’s initial monitoring efforts would be more efficiently achieved by piggybacking on existing monitoring plans rather than trying to develop totally new sites. This work will give the APMP good basic data on selected areas of the state and will help it develop a more comprehensive monitoring plan for the next phase of this project, which begins next year. Between July and November of this year, the sampling sites will include two reservoirs of the Marin Municipal Water District (for copper sulfate), sites within the Merced Irrigation District (for acrolein and fluridone), and a storm water drainage canal in Orange County (for glyphosate). At these sites, temporal and spatial sampling of water and sediment will occur in conjunction with pesticide application. Water, tissue, and sediment chemical analysis will also be conducted, as well as acute and chronic toxicity testing.

Future Efforts
Next year, a large-scale monitoring program will be developed. The studies conducted this summer will be continued, with the addition of studies that identify fate and transport of applied materials, assess impacts to beneficial uses, and survey communities to identify pesticide impacts on nontarget plants or animals. Additional sites separate from applicant monitoring plans will also be selected. The data that SFEI produces over the next two years, will then be used by the SWRCB to decide how to monitor the continued use of aquatic pesticides and help ensure the safety of California’s water.