Surface Water Monitoring Program
for Pesticides in Salmonid-Bearing Streams

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2006 Sampling Period
Fact Sheet
Final Report

Summary 2003 - 2005 Sampling Periods
Fact Sheet
Summary Report

2004 Sampling Period
Fact Sheet
Final Report

2003 Sampling Period
Fact Sheet
Final Report

Quality Assurance Project Plan

BACKGROUND

WSDA and the Washington State Department of Ecology (Ecology) are conducting a multi-year monitoring study to evaluate pesticide concentrations in surface waters. The study was designed to address pesticide presence in Endangered Species Act (ESA)-listed, salmonid-bearing streams during typical pesticide use periods. Monitoring is conducted weekly in selected salmonid-bearing streams from March through October.

The data collected will allow WSDA, EPA, and the National Atmospheric and Oceanic Administration (NOAA) - Fisheries to refine exposure assessments for pesticides registered for use in Washington state. Understanding the fate and transport of pesticides used in Washington state allows regulators to make appropriate decisions to protect ESA-listed species while minimizing the economic impacts to agriculture.

Ecology's Environmental Assessment Program (EAP) conducts the sampling program and laboratory analyses. A wide range of pesticides including organochlorines, organophosphates, carbamates, as well as historical use pesticides and breakdown products, are included in this study. The samples are analyzed at or through Ecology's Manchester Laboratory.

EAP also enters the data into Ecology's Environmental Information Management database. [external link]

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Summary: 2006-2008 Sampling Periods

Surface Water Monitoring Program for Pesticides in Salmonid-Bearing Streams 2006-2008 Triennial Report

The summarized results for 2006-2008 are reported in Surface Water Monitoring Program for Pesticides in Salmonid-Bearing Streams 2006-2008 Triennial Report. [PDF]

Monitoring is being conducted in five basins:

• Thornton Creek in the Cedar-Sammamish basin representing urban land use.
• Lower Skagit-Samish basin representing western Washington agricutultural practices.
• Lower Yakima basin representing irrigated agriculture.
• Wenatchee and Entiat basins representing tree fruit agriculture.

During the 2006-2008 monitoring period, the majority of detected pesticides met water quality standards or assessment criteria.

Over the three years, 74 pesticides were detected. Of these, six insecticides did not meet a water quality standard or assessment criterion: permethrin, chlorpyrifos, diazinon, azinphos-methyl, malathion, and endosulfan. The other pesticide that did not meet a water quality standard was total DDT, which has not been registered for use in the United States since 1972.

For all monitoring sites, co-occurrence of insecticides with a similar mode of action (acetylcholinesterase inhibitors) rarely occurred.

The only significant trend found in pesticide levels was a decrease in the number of herbicide detections in Thornton Creek during 2006-2008 as compared to 2003-2005.

None of the sites sampled in 2006-2008 met water quality standards for temperature. In addition, Thornton Creek and the Skagit-Samish agricultural drainages did not meet water quality standards for dissolved oxygen.

High water temperatures and low dissolved oxygen levels are of concern for the fisheries resource in Indian Slough, Browns Slough, and Big Ditch in the Skagit-Samish basin. Temperature levels for the lower Yakima sites during some periods are of concern for steelhead fisheries.

Pesticide concentrations found in this 2006-2008 study likely do not directly affect salmonids. Pesticide concentrations at some sites may affect aquatic invertebrate populations which serve as a prey base for salmonids.

2007 Sampling Period

FACT SHEET - July 2008

WSDA has developed a fact sheet [PDF] summarizing the sampling activities and results and includes a brief description of the future direction of the Surface Water Monitoring Program. The fact sheet may be downloaded and reproduced.

For complete results from the surface water monitoring study, refer to the report, Surface Water Monitoring Program for Pesticides in Salmonid-Bearing Streams, 2007 Data Summary. [PDF]

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FINAL REPORT - SURFACE WATER MONITORING PROGRAM FOR PESTICIDES IN SALMONID-BEARING STREAMS, 2007 DATA SUMMARY

The results from the 2007 study are reported in Surface Water Monitoring Program for Pesticides in Salmonid-Bearing Streams, 2007 Data Summary. [PDF]

Five watersheds were monitored for the 2007 study because they support several salmonid populations, produce a variety of agricultural commodities, and have a high percentage of cultivated land area. The monitoring locations were 1) Thornton Creek — WRIA 8, 2) Lower Skagit-Samish — WRIA 3, 3) Lower Yakima — WRIA 37, 4) Wenatchee — WRIA 45, and 5) Entiat — WRIA 46.

Year 2007 is the first in a three-year study cycle to investigate pesticides in the Wenatchee and Entiat watersheds, second in a three-year cycle in the Skagit-Samish watershed and the fifth in a six-year cycle in the Cedar-Sammamish and Lower Yakima watersheds.

The study analyzed 152 registered and historical-use pesticides, including organochlorine, organophosphorous, and carbamate pesticides. Conventional water quality parameters – total suspended solids, pH, conductivity, temperature, and flow – were also measured to better understand factors influencing pesticide toxicity, fate and transport, and general water quality.

During 2007, 64 currently registered pesticides, historical-use pesticides and degradates were detected. The majority of pesticide detections where close to analytical detection limits. Herbicides were the most commonly detected class of pesticides. However, regional differences in pest pressures are illustrated by the different percentages of pesticide classes detected in each basin.

In the urban basin, dichlobenil (Casoron^®) was the most frequently detected pesticide. Tebuthiuron, atrazine and DDE (a degradate of DDT) were the most commonly detected compounds in the agricultural basins – Skagit, Lower Yakima and Wenatchee/Entiat respectively.

Azinphos-methyl, chlorpyrifos, diazinon, DDT, DDE and endosulfan exceeded either a state water quality standard or recommended water quality criteria at least once in 2007.

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2006 Sampling Period

FACT SHEET - July 2007

WSDA has developed a fact sheet [PDF] summarizing the sampling activities and results and includes a brief description of the future direction of the Surface Water Monitoring Program. The fact sheet may be downloaded and reproduced.

For complete results from the surface water monitoring study, refer to the report, Surface Water Monitoring Program for Pesticides in Salmonid-Bearing Streams, 2006 Monitoring Data Summary. [PDF]

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FINAL REPORT - SURFACE WATER MONITORING PROGRAM FOR PESTICIDES IN SALMONID-BEARING STREAMS, 2006 MONITORING DATA SUMMARY

The results from the 2006 study are reported in Surface Water Monitoring Program for Pesticides in Salmonid-Bearing Streams, 2006 Monitoring Data Summary. [PDF]

In 2006, pesticide concentrations were measured in three watersheds representing urban and agricultural land-use patterns. The monitoring locations and watersheds that were chosen had a likely combination of off-site pesticide transport and use by salmonids.

Thornton Creek in the Cedar-Sammamish watershed was selected as the urban watershed. The Lower Skagit-Samish Watershed and the Lower Yakima watershed were selected to represent western and eastern agricultural land-use practices, respectively.

Laboratory analyses were conducted for 165 pesticide, herbicide, and degradate compounds. These compounds were selected based on the use of the pesticide, toxicity to non-target organisms, transport potential, and cost of analysis. Conventional water quality parameters - total suspended solids, pH, conductivity, temperature, and flow - were measured to better understand factors influencing pesticide toxicity, fate and transport, and general water quality.

Concentrations of all pesticide detected were generally low and close to analytical detection limits. When pesticides were detected, the most commonly found general pesticide category for both the urban and agricultural basins was herbicides. Dichlobenil (Casoron) was the most frequently detected compound in the urban watershed. Atrazine was the most frequently detected compound in the eastern agricultural basins while 2,4-D was the most frequently detected compound in the western basins.

Azinphos-methyl, chlorpyrifos, and DDE exceeded either a state water quality standard or a recommended water quality criteria at least once during 2006.

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Summary: 2003 - 2005 Sampling Periods

FACT SHEET 2003-2005

WSDA has developed a fact sheet [PDF] summarizing the first three years (2003 - 2005) of the Surface Water Monitoring Program. This summary contains a synopsis of the sampling activities and results, and discussion of the findings. The fact sheet may be downloaded and reproduced.

For detailed information about the first three years of the surface water monitoring study, refer to the report Surface Water Monitoring Program for Pesticides in Salmonid-Bearing Streams, 2003 - 2005. [PDF]

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SUMMARY REPORT - SURFACE WATER MONITORING PROGRAM FOR PESTICIDES IN SALMONID-BEARING STREAMS, 2003 - 2005

The summarized results for the first three years (2003 - 2005) of the study are reported in Surface Water Monitoring Program for Pesticides in Salmonid-Bearing Streams, 2003 - 2005. [PDF]

From 2003 to 2005, approximately 160 currently registered and historical-use pesticides, as well as degradates were included in the study. These compounds were selected based on the use of the pesticide, toxicity to non-target organisms, transport potential, and cost of analysis. Conventional water quality parameters - total suspended solids, pH, conductivity, temperature, and flow - were also measured to better understand factors influencing pesticide toxicity, fate and transport, and general water quality.

During this 3-year period, a total of 453 samples were collected from an urban and agricultural watershed. A total of 51 currently registered pesticides, historical-use pesticides, and/or degradates were detected in the urban and agricultural watersheds. The majority of the pesticide detections were low and close to analytical detection limits.

Ten of the 51 pesticides detected exceeded either water quality criteria or risk quotients for acute or chronic toxicity to fish or for aquatic invertebrates. These 10 pesticides are 4,4-DDE, 4,4-DDT, azinphos-methyl, carbaryl, chlorpyrifos, diazinon, disulfoton, endosulfan sulfate, malathion, and oxyfluorfen.

The azinphos-methyl and malathion detections occured at the same time summer maximum temperatures may restrict summer steelhead (ESA-listed) occupation of monitored stream reaches. If summer steelhead are present, elevated water temperatures outside of their optimal range may make the steelhead more susceptible to pesticide toxicity.

The assessment criteria used for the 3-year report are based on assessing the effects of a specific chemical on an organism and do not take into account the additive or possibly synergistic effects of mixtures or sub-lethal effects.

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2004 Sampling Period

FACT SHEET - September 2005

WSDA has developed a fact sheet [PDF] summarizing the sampling activities and results and includes a brief description of the future direction of the Surface Water Monitoring Program. The fact sheet may be downloaded and reproduced.

For complete results from the surface water monitoring study, refer to the report, Surface Water Monitoring Program for Pesticides in Salmonid-Bearing Streams, April through October 2004. [PDF]

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FINAL REPORT - SURFACE WATER MONITORING PROGRAM FOR PESTICIDES IN SALMONID-BEARING STREAMS APRIL TO OCTOBER, 2004

The results from the second year (2004) of the study are reported in, Surface Water Monitoring Program for Pesticides in Salmonid-Bearing Streams, April through October 2004. [PDF]

Two index watersheds, representing urban and agricultural land-use patterns, were sampled from March through October 2004. Thornton Creek in the Cedar-Sammamish watershed was chosen as the urban drainage. Marion Drain, Spring Creek, and Sulphur Creek Wasteway in the Lower Yakima watershed represented agricultural land-use patterns. Unfiltered water samples were collected weekly at downstream sites and every other week at upstream sites.

Conventional parameters including discharge, temperature, pH, conductivity, and total suspended solid (TSS) were collected to characterize water quality of the streams and to investigate pesticide fate and toxicity.

Concentrations of all pesticide detected were generally low and close to analytical detection limits. In the agricultural basin, 2,4-dichlorophenylacetic acid (2,4-D) was the most commonly detected pesticide; however, dichlobenil was most commonly detected in the urban watershed.

Pesticide detections were compared to Washington State promulgated and EPA recommended aquatic life criteria. Detections were also compared to EPA, Office of Pesticide Programs, Environmental Fate and Effects Division acute and chronic toxicological endpoints used for pesticide registration.

Five pesticides - azinphos-methyl, chlorpyrifos, diazinon, malathion, and 4,4'-DDE - were above the numeric component of various standards, but the weekly sampling frequency of this study does not allow for assessment of the temporal component of these standards. A single detection of malathion (3.05 g/L) approached the acute LC50 for rainbow trout (4 g/L) in the Marion Drain.

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2003 Sampling Period

FACT SHEET - November 2004

WSDA has developed a fact sheet [PDF] summarizing the sampling activities and results and includes a brief description of the future direction of the Surface Water Monitoring Program. The fact sheet may be downloaded and reproduced.

For complete results from the surface water monitoring study, refer to the report, Surface Water Monitoring Program for Pesticides in Salmonid-Bearing Streams April to December, 2003. [PDF]

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FINAL REPORT - SURFACE WATER MONITORING PROGRAM FOR PESTICIDES IN SALMONID-BEARING STREAMS APRIL TO DECEMBER, 2003

The results from the Year One of the monitoring effort (April through December 2003) are presented in the report, Surface Water Monitoring Program for Pesticides in Salmonid-Bearing Streams, April to December, 2003. [PDF]

Overall, the sampling results were positive. Both the agricultural and urban sampling resulted in approximately 96 percent non-detections with the remaining 4 percent split between validated numerical results and estimated detected values. Refer to the report for a complete discussion of the sampling results.

Year One of the study assessed the occurrence of pesticides in surface water in two index watersheds that represented agricultural and urban land-use patterns.

Three drainages in the Lower Yakima Watershed Resource Inventory Area 37 (WRIA 37 [external link]) were selected to represent agricultural land use patterns: Spring Creek, Sulphur Creek Wasteway, and Marion Drain. These sub-basins were selected because they have the highest percent area cropped and a diversity of agriculture within the drainage.

Thornton Creek, located in the Cedar-Sammamish Water Resource Inventory Area 8 (WRIA 8 [external link]), was selected as the urban watershed due to prior salmon habitat enhancement efforts and the occurrence of pre-spawning mortality in Coho salmon.

In both the agricultural and urban watersheds, ambient surface waters were sampled for 87 registered pesticides. The surface waters were also sampled for degradates and some historically used compounds such as DDT. In addition to pesticides, sampling for semi-volatile organic compounds (SVOC) was included in the urban basin.

Fieldwork for Year One began the second week of April 2003. Sampling occurred weekly at all sites throughout the spring (April through June 2003). In the agricultural watershed, bi-weekly sampling at the mouths of the three sub-drainages continued through the summer. Semi-volatile organic compounds were measured in Thornton Creek bi-weekly April through June and also during three storm events in the fall of 2003.

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QUALITY ASSURANCE PROJECT PLAN

To assure the data for the project accurately and precisely represented conditions existing at the time of sample collection, WSDA and the Ecology Environmental Assessment Program developed a Quality Assurance Project Plan (QAPP). [PDF] The objective of the QAPP is to provide valid data of known and documented quality for identifying pesticides that do and do not pose a risk to salmonids.

WWSDA and Ecology have amended the QAPP to add the Entiat and Wenatchee watersheds [PDF] (WRIAs 45 & 46 in the Upper Columbia Basin) and the Lower Skagit-Samish watershed [PDF] (WRIA 3) to the monitoring program.

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If you have additional questions regarding the Surface Water Monitoring Program, please contact Jim Cowles at (360) 902-2066 or by e-mail at jcowles@agr.wa.gov.

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