For numerous years, the California Department of Pesticide Regulation and the University of California at Davis (UCD) have evaluated the efficacy of a constructed water quality treatment pond (CWQTP) in Folsom, California, to reduce pesticides from urban runoff. Since 2015, runoff flow measurement has allowed for collection of flow-weighted samples and subsequent calculation of mass loading into and out of the CWQTP. During 2015 – 2016, flow-weighted samples were collected during three rainstorm events, each event lasting slightly longer than 24 hours. Using autosamplers, 85% - 100% of storm runoff was sampled, collecting between 20 – 47 L of runoff into a single container. Collected water was divided into 1-L water samples and analyzed for pyrethroids, imidacloprid, fipronil, 2,4-D, dicamba, MCPA, and triclopyr. The UCD Aquatic Health Program also conducted 96-hr <i>Hyalella azteca</i> water column laboratory toxicity tests. The CWQTP reduced the mass of fipronil, bifenthrin, and 2,4-D. For other routinely detected pesticides (imidacloprid, dicamba, MCPA, and triclopyr), pesticide loading into and out of the CWQTP was inconsistent, sometimes increasing and in other events decreasing. The CWQTP had little effect on toxicity to <i>H. azteca</i>, likely due to incomplete pesticide removal, the presence of other, unmonitored, toxins or synergistic effects.

Flow-weighted sampling to measure efficacy of a constructed water quality treatment pond in Folsom, CA

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.