From November 1973 to July 1977, water samples were collected from wells to identify background water-quality conditions and to determine the effects on ground-water quality by St. Petersburg 's sludge-disposal operation (sod farm). Specific conductance and pH were determined in the field. Samples were collected for laboratory determination of selected nitrogen and phosphorus species, sodium, potassium, calcium, magnesium, chloride, trace metals, chemical and biochemical oxygen demand, and coliforms. (Woodard-USGS)