USDA Pesticide Data Program Water Monitoring Survey Overview

11 March 2004

Objective

The goal of the Pesticide Data Program (PDP) Water Monitoring Survey is to collect monitoring data on pesticide residues . The data will be used by the Environmental Protection Agency (EPA) in water models to perform human health and environmental

fate risk assessments

.

Background.

Pesticide residue data in drinking water are necessary to suppor t the Food Quality Protection Act ( F QPA) enacted by the U.S. Cong ress in 1996. The PDP water monitoring survey was b egun 2001 when Congress allocated money to AMS for the purpose of providing these data. The PDP water survey is design ed in consultation with EPA, the agency responsible for implementation of FQPA, to provide data for agricultural use pestici d es under evaluation . The sampling frame is designed to provide

coverage in regions of interest for at least two years, to reflect the seasonal and cli matic variability during growing seasons.

PDP work s with EPA and The American Water Works Association (AWWA), an organization of water supply professionals, to identify specific water treatment facilities where monitoring data ar e needed. PDP solicits water treatment facilities for voluntary participation in the program

. Personnel at the water treatment facilit ies collect the samples with a kit provided through a n AMS subcontractor . Sampl es are then mailed to

PDP laboratories for analysis . In return, PDP provides the analytical results to the

facilit ies through

quarterly updates

.

In 2001, PDP began monitoring of several community water systems in New York and

Calif ornia. In FY 2002, the monitoring was expanded to include 5 additional community water systems in 3 more states; Colorado, Kansas, and Texas. Samples were analyzed at State Department of Agricu l t ure l aboratories in California, Colorado, and New York. Sampling at these sites ended in December 2003.

In January 2004, collection began at 16 new sites in Michigan, North Carolina, Ohio, Oregon, Penn sylvania, and Washington State. PDP is collecting paired samples of both raw water at the intake and finished water exiting the plant. The finished water sample s

are taken based on the throughput time of the plant to be as close as possible to the same

p arcel of water taken for the raw sample. These paired samples provide additional information on treatment efficiencies and environmental exposures. The laboratories analyzing these water samples include State Department of Agriculture laboratories in

C ol orado , Montana, and New York.Testing Protoc o ls

PDP laboratories use multi

- residue water methods for water an alyses

. Methods are

validated before the data are a ccepted. Quality assurance and quality control measures are used to verify analytical results . A ll PDP laboratories are working toward s ISO

17025 accreditation. Specific information regarding analytes, limits of detectio n, methods, and quality assurance are available at http://www.ams.usda.gov/science/pdp/Water.htm

.

Data Reporting

Data are sent electronically by testing laboratories to PDP Headquarters in Manassas,

VA. USDA publishe s the data in the PDP Annual Summary, available at http://www.ams.usda.gov/science/pdp/Status.htm

. PD P pr otects proprietary information when publishing data. Interim data are available to program participants ; h owever, PDP reserves the rig ht to be the first to publish these data. Interpreta tion of these data (such as

he a l th consequences of a positive finding) is beyond the scope of PDP activities. As the geologic, hydro logic, geomorphic, land use, climate conditions , and populations are unique to each watershed, the data reflect conditions in the watershed and not national

trends.