Water-quality data, San Joaquin Valley, California, March 1985 to March 1987

Water quality data were collected at numerous surface water and groundwater sites in the San Joaquin Valley, California, from March 1985 through March 1987. Streamflow and physical measurements were made, and water samples for analysis of major ions, trace elements, suspended sediments, and some pesticides were collected at varying frequencies at 11 continuing-record sites and 31 miscellaneous sites on the San Joaquin River and its tributaries. Physical measurements and water samples for analysis of major ions, trace elements, and some pesticides were collected at 285 groundwater sites in the western and southern San Joaquin Valley. (USGS)