California Environmental Protection Agency

Department of Pesticide Regulation

Environmental Monitoring and Pest Management

1020 N Street, Room 161

Sacramento, California 95814-5624

October 31, 1996

Protocol for a Pilot Study to Characterize the Relationship Between Temporal Distributions of Pesticide Concentrations and Aquatic Toxicity at Two Sacramento-San Joaquin Delta Sites



I. Introduction

The Sacramento-San Joaquin Delta is a significant economic and ecological resource. The Delta drains a quarter of the total area of California and provides two thirds of the water consumed in the state (Connor, 1994). In addition, the Delta provides habitat and migration routes for one half of the anadromous fish in California (Connor, 1994). The Sacramento River and San Joaquin River are the major inputs into the Delta. Pesticides applied in the agricultural areas of both the California Central Valley and the Delta itself may be transported into the Delta waterways. Use of dormant sprays (diazinon, chlorpyrifos, methidathion, etc.) during the winter months in the Central Valley coincides with the majority of the seasonal rainfall in California. Evidence from field samples indicates that rain run-off transports these pesticides into waterways (Ross, pers. comm.).

Several studies have detected dormant sprays and other pesticides in ambient water samples from various Central Valley and Delta sites (Foe and Sheipline, 1993, Kuivila and Foe, 1995, Foe, 1995, Ross, 1992, Ross 1993). Dormant spray pesticides have been implicated as the cause of toxic responses to ambient water samples by the toxicity test organism, Ceriodaphnia dubia (cite Foe and Sheipline, 1993; Kuivila and Foe, 1995; Foe, 1995, Finlayson et. al., 1993). In addition, pesticides applied to alfalfa for weevil control in the spring, including diazinon, chlorpyrifos and carbofuran, have been detected in Central Valley and Delta waterways. These pesticides have also been implicated as the cause of toxicity to C. dubia in ambient water samples (Foe and Sheipline, 1993).

Toxicity testing has been frequently used to test ambient water samples from Sacramento and San Joaquin River watershed sites. Ambient water samples from Delta sites have less commonly been tested for toxicity. Foe and Sheipline (1993) and Kuivila and Foe (1995) included some Delta sampling. In 1993, the Bay Protection Toxic Clean-up Program (BPTCP) initiated toxicity monitoring to determine the extent, severity, and sources of toxicity at sites in the Sacramento-San Joaquin Delta (Deanovic et. al., in prep). The final report from the 1993-94 monitoring year has not yet been released. Also in 1993, the San Francisco Estuary Regional Monitoring Program (RMP) for Trace Substances began monitoring Bay and Delta sites (SFEI, 1994). The RMP is a large scale monitoring program for a wide range of trace substances, including polynuclear aromatic hydrocarbons (PAH's), metals, polychlorinated biphenyls (PCB's), organochlorine pesticides and diazinon. However, it includes very limited application of toxicity tests. In 1994, Mysidopsis bahia was used to test samples from 13 Estuary sites on only one date in February and one date in September. Results from these toxicity tests were inconclusive. For example, toxicity was shown at the Napa River and Red Rock sites in February but no contaminants were detected in the samples, in spite of picogram detection limits. Toxicity was not shown at any other site.

Kuivila and Foe (1995) recommend more extensive chemical and toxicity testing in the Delta. The California Department of Fish and Game (CDFG) in their hazard assessment documents for diazinon, chlorpyrifos and methyl parathion also recommends monitoring of the Sacramento-San Joaquin Estuary to more completely assess the hazards to aquatic life due to exposure to these pesticides (Menconi and Cox, 1994; Menconi and Paul, 1994; Menconi and Harrington, 1992). The Department of Pesticide Regulation (DPR) regulates the sale and use of pesticide products. To legally require a change or restriction in use of a pesticide product, DPR must have documentation that the registered pesticide is responsible for causing an adverse effect to the environment.

This pilot study is an exploratory monitoring program initiated as a first step by DPR to collect data intended to assess the hazard that pesticides may present to Delta aquatic life. The specific objective of this pilot study is to examine the temporal distribution of toxicity and pesticide concentrations in the Delta over a one year period. Two sites in areas of important fisheries habitats will be monitored. Both toxicity and chemical analysis will be conducted on all samples. Frequency of toxic conditions and co-occurrence of toxicity and pesticides will be of particular interest. It is assumed that follow-up studies will be required. Results from this pilot study will show the direction that these follow-up studies should take.

II. Objective

The objective of this pilot study is to characterize and relate the temporal distribution of toxicity and pesticide concentrations at two sites important to fisheries in the Sacramento-San Joaquin Delta.

III. Personnel

This study will be conducted under the general direction of Randy Segawa, Senior Environmental Research Scientist (supervisor) by Environmental Hazard Assessment Program personnel as follows:

Project Leader: Terri Barry

Field Coordinator: Pam Wofford

Senior Scientist: Lisa Ross

Principal Investigator (Toxicity): California Department of Fish and Game

Chemists: Jorge Hernandez, Hsiao Feng

Agency & Public Contact: Pat Dunn

All questions concerning this study should be directed to Pat Dunn at: (916) 324-4077;

FAX (916) 324-4088

IV. Study Plan

This study will monitor at regular intervals of two weeks, from December 1996 to November 1997, two Sacramento-San Joaquin River Delta sites. The monitoring sites are located in areas of important fish habitat on both the Sacramento and San Joaquin River sides of the Delta (per. comm. B. Finlayson). The first monitoring site is on the Sacramento River at Rio Vista. Samples will be collected from the Highway 160 bridge. The second monitoring site is on the San Joaquin River at Antioch. Samples will be collected from the end of the public pier at the Antioch Shoreline East Bay Regional Park. These sites are located along well mixed sections of the rivers downstream of inputs from both the Central Valley and the majority of the Delta. These monitoring sites will provide an indication of the actual concentrations of pesticides and occurrence of toxicity in areas important to Delta fisheries.

V. Sampling Methods

Single point grab samples will be collected from well mixed sites. The selected monitoring sites are in tidally affected zones. Flow at these sites reverse during the tidal cycle (Kuivila and Foe, 1995). Therefore, water will be collected at each site during the out-going tide to capture flows from the Sacramento and San Joaquin Rivers. All samples will be collected as point samples employing a depth-integrated sampler (D-77) with a 3-liter Teflon® bottle and nozzle. Sufficient water will be collected at each sampling event to provide approximately four liters for chemical analysis, three liter for acute toxicity testing, and any additional water required for quality control (QC) samples. At each site, the surface water sub-samples will be placed temporarily in a stainless steel container until the appropriate volume of water has been collected. The sample will be stored on wet ice and delivered to the processing facility at West Sacramento. Dissolved oxygen, pH, specific conductance, and water temperature will be measured in situ during each sampling event.

Immediately upon arrival at West Sacramento, the composited sample will be split into 1-liter amber glass bottles, using a Geotech® 10-port splitter, then sealed with Teflon® lined caps. Chemical analysis will consist of a carbamate and organophosphate screen. Samples designated for chemical analysis will be preserved by acidification with HCl to a pH between 3 and 3.5. Since diazinon breaks down rapidly in acidic conditions, a separate non-acidified split sample will be used to test for diazinon. After splitting, the toxicity samples will be transported to California Department of Fish and Game (CDFG) Aquatic Toxicity Laboratory (ATL) for analysis. Pesticide residue samples may be stored in a 4C refrigerator until the following business day for delivery to the California Department of Food and Agriculture (CDFA) laboratory. QC samples will be handled in the same manner as primary samples, however, more distant QC laboratories will require shipping samples on blue ice via commercial carrier.

VI. Toxicity Testing and Chemical Analysis Methods

Water samples will be delivered on the day of collection to the CDFG ATL laboratory for acute aquatic toxicity testing. CDFG ATL will follow the most current U.S.EPA procedures for Ceriodaphnia dubia acute toxicity testing (U.S. EPA, 1993) . Under these procedures (U.S. EPA 600/4-90/27F), acute toxicity in ambient samples is to be determined using a 96-hour, static renewal bioassay on undiluted ambient sample water. All toxicity testing must begin within 36 hours of sample collection. CDFG will also analyze the samples for total alkalinity, hardness, and specific conductivity.

Water samples will be analyzed by the CDFA lab for organophosphate and carbamate pesticide residues. Chemical analysis will employ methods previously developed for surface water studies by the CDFA laboratory. The reporting limit will be the lowest concentration that the method can detect reliably in a matrix blank. The pesticides to be analyzed for and their reporting limits for this study are listed in Table 1. Chemical analytical methods will be provided in the final report.

An accounting of the total number of toxicity tests and chemical analyses performed (including quality assurance/quality control samples) during this study are shown below:

Number of Toxicity Tests

1 acute test at 2 sites bi-weekly for one year 52

Quality control

intralaboratory (approximately 10% of acute tests) 6

interlaboratory (approximately 10% of acute tests) 6

Total number of acute toxicity tests 64

Number of Chemical Analyses

3 analyses per acute toxicity test

(1 analysis for each chemical screen required) (3X52) 156

Quality Control (approximately 10% if total analyses) 16

Estimated number of chemical analysis 172

VII. Quality Control

Toxicity

To assess intra-laboratory performance, 10% of the field samples will be split and submitted for duplicate toxicity testing at ATL. The split samples will not be labeled as such and will be submitted as field samples. No samples submitted to ATL will be labeled to identify location of collection. In addition, once a month, one split sample from each site will be sent to the outside QC lab for analysis.

ATL will be requested to provide quality control charts of reference toxicant testing during the course of this study. Reference toxicant testing should be conducted at a minimum of once a month. These data will be used to ensure that the toxicity testing procedures were in a state of statistical control during this study.

Chemical Analysis

Chemical analysis quality control will be conducted in accordance with the Standard Operating Procedure QAQC001.00. Approximately 10% (16 samples) will be submitted randomly for chemical analysis as rinse blanks, matrix blanks, and blind matrix spikes. These samples will be submitted as field samples. In addition, 16 samples collected for chemical analysis will be split and submitted to a second laboratory for interlaboratory comparison.

VIII. Data Analysis

The occurrence of toxicity and pesticide concentrations found at each site will be plotted according to sample date. Statistical analysis will be performed to explore potential relationships between the occurrence of toxic events, concentrations of pesticides and water quality parameters. This statistical analysis will include correlation methods and logistic regression.

IX. Time Table

Site survey and selection, finalization of protocol November 1996

Begin Sampling December 1996

Finish Sampling December 1997

Draft Report June 1998



X. Literature Cited

Connor, V. 1994. Summary of Central Valley ambient monitoring program 1994-95. Central Valley Regional Water Quality Control Board. In: San Francisco Estuary Regional Monitoring Program for Trace Substances 1994 Annual Report. San Francisco Estuary Institute, Richmond, CA.

Finlayson, B.J., J.A. Harrington, R. Fujimura and G. Isaac. 1993. Identification of methyl parathion toxicity in Colusa Basin Drain water. Environmental Toxicology and Chemistry Vol 12:291-303.

Foe, C. 1995. Insecticide concentrations and invertebrate bioassay mortality in agricultural return waters from the San Joaquin Basin. Central Valley Regional Water Quality Control Board. December 1995.

Foe, C. and R. Sheipline. 1993. Pesticides in surface water from applications on orchards and alfalfa during the winter and spring of 1991-92. Central Valley Regional Water Quality Control Board. February 1993.

Kuivila, K.M. and C.G. Foe. 1995. Concentrations, transport and biological effects of dormant spray pesticides in the San Francisco Estuary, California. Environmental Toxicology and Chemistry Vol 14:1141-1150.

Menconi, M. and J.M. Harrington. 1992. Hazard assessment of the insecticide methyl parathion to aquatic organisms in the Sacramento River System. California Department of Fish and Game, Environmental Services Division. Administrative Report 92-1.

Menconi, M. and C. Cox. 1994. Hazard assessment of the insecticide diazinon to aquatic organisms in the Sacramento-San Joaquin River system. California Department of Fish and Game, Environmental Services Division. Administrative Report 94-2.

Menconi, M. and A. Paul. 1994. Hazard assessment of the insecticide chlorpyrifos to aquatic organisms in the Sacramento-San Joaquin River system. California Department of Fish and Game, Environmental Services Division. Administrative Report 94-1.

San Francisco Estuary Institute. 1994. San Francisco Estuary Regional Monitoring Program (RMP) for trace substances. San Francisco Estuary Institute, Richmond, CA.

Ross, L.J. 1992. Preliminary results of the San Joaquin River study: Winter 1991-92. Memorandum to Kean Goh, Environmental Hazard Assessment Program, California EPA, Department of Pesticide Regulation. May 22, 1992.

Ross, L.J. 1993. Preliminary results of the San Joaquin River study: Winter 1992-93. Memorandum to Kean Goh, Environmental Hazard Assessment Program, California EPA, Department of Pesticide Regulation. September 23, 1993.







Table 1. List of active ingredients and their breakdown products to be analyzed by the California Department of Food and Agriculture, Laboratory Services Branch, for the Sacramento-San Joaquin River Delta Monitoring Study.


Organophosphate (OP) Screena

Method: Gas chromatography/ Flame photometric detector

Compound RLb
Azinphos-methyl 0.05
Chlorpyrifos 0.04
DDVP 0.05
Diazinon 0.04
Dimethoate 0.05
Ethoprop 0.05
Ethyl Parathion 0.05
Fonofos 0.05
Malathion 0.05
Methidathion 0.05
Methyl Parathion 0.05
Phosalone 0.05
Phosmet 0.05
Phorate 0.05


N-methyl Carbamate (CB) Screena

Method: High performance liquid chromatography/ Post Column derivatization with fluorescence detector

Compound RL
Aldicarb 0.05
Aldicarb Sulfone 0.05
Aldicarb Sulfoxide 0.05
Carbaryl 0.05
Carbofuran 0.05
3-Hydroxycarbofuran 0.05
Methiocarb 0.05
Methiocarb Sulfone 0.05
Methiocarb Sulfoxide 0.05
Methomyl 0.05
Oxamyl 0.05




Endosulfan

Method: Gas chromatography/ Electron capture detector



Compound RL
Endosulfan I 0.005
Endosulfan II 0.005
Endosulfan Sulfate 0.01






Diazinonc

Method: Gas chromatography/ Nitrogen phosphorus detector

Compound RL

Diazinon 0.04

a) Preserved by acidification. b) Reporting limit in ppb. c) Diazinon will be extracted from the same water sample as endosulfan I, endosulfan II and endosulfan sulfate.