Publication Summary

Along Washington′s coast, the Grayland to North Cove area uses two ditch systems to drain surface and ground water from cranberry growing operations and run-off from residential property. Both ditches originate in wetlands around the Grays Harbor/Pacific County line. Currently, both ditches are listed on the states 303(d) list as not meeting water quality standards for multiple toxic pollutants. This Quality Assurance Project Plan will direct a study to evaluate the progress made by growers, to reduce pesticides entering the ditches.

Along Washington′s coast, the Grayland to North Cove area uses two ditch systems to drain surface and ground water from cranberry growing operations and run-off from residential property. Both ditches originate in wetlands around the Grays Harbor/Pacific County line. The Grays Harbor County ditch flows north for about 2.8 miles, discharging into Grays Harbor′s South Bay; while the Pacific County ditch flows south, for about 5 miles, and discharges to the North Cove of Willapa Bay.

A number of studies conducted during the cranberry growing season have identified concentrations of three organophosphorus pesticides (i.e., azinphos-methyl, chlorpyrifos, and diazinon) and carbaryl, a carbamate pesticide, in water that exceeded recommended water quality standards. Currently, both ditches are listed on the states 303(d) list as not meeting water quality standards for multiple toxic pollutants. Efforts by cranberry growers are underway to reduce the discharge of pesticides to the ditches, through implementation of BMPs.

This Quality Assurance Project Plan will direct a study to evaluate the progress made by growers, to reduce pesticides entering the ditches. Organophosphorus pesticides and carbamate samples will be collected at three sites in the Grays Harbor County ditch, six sites in the Pacific County ditch, and one reference site not impacted by cranberry bog drainage. The timing of the study will focus around the most intensive application period of the growing season. Samples will be collected in June and July of 2002 for a comparison to data from 1996 and 1998 studies, and recommended water quality standards.

Link to EIM data for User Study ID RCOO0003