SUMMARY

California. Water samples showed no detects of fenoxycarb, hydramethylnon, pyriproxyfen, chlorpyrifos, dimethoate, and methidathion. Bifenthrin was detected at three sites ranging from 0.05 to 1.24 parts per billion (ppb). Diazinon was detected in seven samples ranging from 0.067 to 0.969 ppb. Toxicity was tested at San Diego Creek at Campus Drive, an integrated site. This site was significantly toxic (55 % mortality) to Ceriodaphnia dubia in the water collected. At a nursery site, a filter strip planted with Canna has been added to the drainage to mitigate offsite movement of insecticides and nitrates. Bifenthrin and diazinon were detected in all samples with a general trend of declining concentrations as the water passed through the filter strip. SCOPE OF THIS MEMORANDUM This memorandum reports results of water sampling conducted by the Department of Pesticide Regulation (DPR), under interagency agreement with the California Department of Food and Agriculture (CDFA), for the Red Imported Fire Ant (RIFA) control project. Data included here are from the January 17 and 18, 2001 monitoring, and encompass results from both chemical analyses and aquatic biotoxicity testing. This memorandum summarizes results for bifenthrin, fenoxycarb, hydramethylnon, pyriproxyfen, and five organophosphorus insecticides