Residues of polychlorinated biphenyls, DDT, and DDT metabolites in Pennsylvania streams, community water supplies, and reservoirs, 1974--76.

Pennsylvania streams, community water supplies, and open water reservoirs were analyzed for PCB mixtures, DDT, and DDT metabolites. Streams were sampled in 1974 and again in 1975. Only 4 of 19 stream locations were contaminated. Maximum concentrations in community supplies of Aroclor 1242 (2 locations), Aroclor 1254 (3 locations), and sigmaDDT (2 locations) were 350, 260, and 620 ng/kg, respectively. Of the 110 community water supplies sampled in 1975 and 1976, only 7 contained residues. Maximum concentrations in community supplies of Aroclor 1242 (4 locations) and sigmaDDT (2 locations) were 460 ng/kg and 75 ng/kg, respectively. The seventh contained 0.7 ng/kg of dieldrin. None of the three open water reservoirs contained detectable residues of the compounds of interest. Essentially no correlation was found between PCB and DDT analogs in streams and those in fish from streams which had been samples at similar locations in a related study in 1976.