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 support the Food Quality 

Protection Act (FQPA) enacted by the U.S. Congress in 1996. The PDP water 

monitoring survey was begun 2001 when Congress allocated money to AMS for the 

purpose of providing these data. The PDP water survey is designed in consultation with 

EPA, the agency responsible for implementation of FQPA, to provide data for 

agricultural use pesticides under evaluation. The sampling frame is designed to provide 

coverage in regions of interest for at least two years, to reflect the seasonal and climatic 

variability during growing seasons. 

PDP works with EPA and The American Water Works Association (AWWA), an 

organization of water supply professionals, to identify specific water treatment facilities 

where monitoring data are needed. PDP solicits water treatment facilities for voluntary 

participation in the program. Personnel at the water treatment facilities collect the 

samples with a kit provided through an AMS subcontractor. Samples are then mailed to 

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

facilities through quarterly updates.

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

California. 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 Agriculture laboratories 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, Pennsylvania, and Washington State. PDP is collecting paired samples of both 

raw water at the intake and finished water exiting the plant. The finished water samples

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

parcel 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 

Colorado, Montana, and New York. 
Testing Protocols

PDP laboratories use multi-residue water methods for water analyses. Methods are 

validated before the data are accepted. Quality assurance and quality control measures 

are used to verify analytical results. All PDP laboratories are working towards ISO 

17025 accreditation. Specific information regarding analytes, limits of detection, 

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 publishes the data in the PDP Annual Summary, available at 

http://www.ams.usda.gov/science/pdp/Status.htm. PDP protects proprietary information 

when publishing data. Interim data are available to program participants; however, PDP 

reserves the right to be the first to publish these data. Interpretation of these data (such as 

health consequences of a positive finding) is beyond the scope of PDP activities. As the 

geologic, hydrologic, geomorphic, land use, climate conditions, and populations are 

unique to each watershed, the data reflect conditions in the watershed and not national 

trends.