COMBINED SEWER OVERFLOWS (CSOS) AS SOURCES OF SEDIMENT CONTAMINATION IN THE LOWER PASSAIC RIVER, NEW-JERSEY .2. POLYCHLORINATED DIBENZO-P-DIOXINS, POLYCHLORINATED DIBENZOFURANS, AND POLYCHLORINATED-BIPHENYLS

Polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are contaminants ubiquitous to the sedime nts of industrialized waterways. Non-point sources, such as atmospheri c deposition, urban runoff, and combined sewer overflows, are recogniz ed by the U.S. Environmental Protection Agency as important uncontroll ed sources of these compounds. The purpose of this study was to invest igate the, impact of combined sewer overflows (CSOs) on sediments of t he Passaic River in New Jersey. In this investigation. we (1) characte rize PCB and PCDD/F contamination in sediments impacted by these CSOs, (1) evaluate the spatial distribution of these contaminants, and (3) evaluate the possible sources of PCBs and PCDD/Fs within the respectiv e CSO districts. Ten surficial sediment samples were collected adjacen t to each of four CSO outfalls along the lower Passaic River and analy zed for coplanar PCBs and PCDD/Fs. Principal components analysis (PCA) was utilized to assess differences in the distributional patterns of PCB and PCDD/F congeners at each of the four CSO sampling areas. The r esults indicate that sediments proximate to the CSO outfalls are conta minated with elevated concentrations of these compounds. The spatial d istribution and fingerprint patterns of PCBs and PCDD/Fs strongly sugg est that the CSOs are a source of contamination in sediments near thes e outfalls. Evaluation of the industries operating within the CSO dist ricts provides a link between tile facilities that discharge wastes to the combined sewer system and PCBs and PCDD/Fs found in the sediments . Until adequate controls are implemented, CSOs will continue to be si gnificant on-going sources of PCB and PCDD/F contamination affecting t he water and sediment quality of the Passaic River. (C) 1997 Elsevier Science Ltd.