Dissolved Pesticides in the Alamo River and the
Salton Sea, California, 1996-97

By Kathryn L. Crepeau, Kathryn M. Kuivila, and Brian Bergamaschi



Open-File Report 02-232

Sacramento, California 2002

Prepared in cooperation with the California State Water Resources Control Board
Text of Report (544 KB PDF)

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Water samples were collected from the Alamo River and the Salton Sea, California, in autumn 1996 and late winter/early spring 1997 and analyzed for dissolved pesticides. The two seasons chosen for sampling were during pesticide application periods in the Imperial Valley. Pesticide concentrations were measured in filtered water samples using solid-phase extraction and analyzed by gas chromatography/mass spectrometry. Generally, the highest concentrations were measured in the Alamo River. The concentrations of carbaryl, chlorpyrifos, cycloate, dacthal, diazinon, and eptam were highest in samples collected in autumn 1996. In contrast, the concentrations of atrazine, carbofuran, and malathion were highest in samples collected in late winter/early spring 1997. The highest concentrations measured of atrazine, carbofuran, dacthal, eptam, and malathion all exceeded 1,000 nanograms per liter.




Sample Collection, Processing, and Analysis

Sampling Results

Quality Assurance

References Cited

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Water Resources of California

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