Dissolved pesticides were measured in weekly water samples from 85 wadeable streams in Central Coastal California over a variable six-week period during March-May, 2017, as part of the California Stream Quality Assessment (CSQA) study conducted by the U.S. Geological Survey's (USGS) Regional Stream-Quality Assessment (RSQA) Project. The 85 streams consisted of 40 urban sites (5-100percent urban land in the lower basin), 9 agricultural sites, 24 mixed land-use sites, and 12 undeveloped sites. Water samples were filtered (0.7 micrometers) and analyzed for 253 pesticide compounds by direct-injection liquid chromatography with tandem mass-spectrometry (LC-MS/MS). Two similar LC-MS/MS methods were used: a broad-spectrum (223 compounds) method in use since 2012 and a newly developed method for 30 new-generation fungicides and diamide and neonicotinoid insecticides. This Data Release provides sampling-site locations, analyte information, concentration data for pesticide compounds in environmental weekly water samples, quality-control data for the new method (to supplement previously published quality control data for the standard method), aquatic-life benchmark and Pesticide Toxicity Index toxicity concentration values that were used to assess potential toxicity, estimates of agricultural and nonagricultural pesticide-use data, and streamflow data for gaged sites, in support of the journal article, "New-generation pesticides are prevalent in California" Central Coast streams," by Sandstrom, M.W., Nowell, L.H., Mahler, B.J., and Van Metre, P.C.
|Title||Pesticides in Weekly Water Samples from the NAWQA California Regional Stream Quality Assessment (2017)|
|Authors||Jennifer L Morace, Lisa H Nowell, Barbara J Mahler, Peter C Van Metre|
|Product Type||Data Release|
|Record Source||USGS Digital Object Identifier Catalog|
|USGS Organization||Oregon Water Science Center|