Sanitary and industrial wastes at the Pinellas Plant of the U.S. Department of Energy, prior to December 1982, were combined, treated, and disposed of by ponding and spray irrigation on a 10-acre tract within the plant site. Prior to 1972, the treated wastes were released to surface drainage features. An electromagnetic survey for ground conductivity was made to identify changes in the ground conductivity that may be due to the spray irrigation disposal operations. Water samples from four test wells drilled into the surficial aquifer and the two disposal ponds and bottom material from the ponds were analyzed for priority and nonpriority pollutants, total organic carbon, volatile organic carbon, herbicides, insecticides, trace metals, nutrients, and major constituents. Overall, concentrations of constituents in the water samples were (1) less than the detection limits, (2) within U.S. Environmental Protection Agency quality criteria for water, or (3) within the range of results for a designated background water-quality site. Concentrations of 12 priority pollutants were found to be considerably above detection limits. Concentrations of these compounds, mostly coal-tar derivatives, ranged from 220 to 5,500 micrograms per kilogram; the detection limit for these compounds is 10 micrograms per kilogram. Included in these compounds were anthracene, pyrenes, and chrysene.