Numerous surveys have demonstrated elevated levels of metals in sediments and organisms in different parts of the lower HR and particularly the Newark Bay complex. Metal contamination is associated with municipal wastewater treatment plants, urban runoff, combined sewer overflows, automobile emissions, metals-basedindustries, effluents from chemical manufacturing plants, and atmospheric deposition (Williams et al., 1978; Meyerson et al., 1981). A comprehensive survey of water quality in the lower HR estuary demonstrated few exceedances of water quality criteria for metals, with the exception of Hg (Great Lakes Environmental Center, 1996). However, sediments often accumulate the metals that enter the aquatic environment. Metals can bind to sediment particles to varying degrees, are released into interstitial water, and exert harmful effects on biota.
Surveys done in the 1990s at locales around Newark Bay demonstrated that surficial sediments from the lower Passaic River and the Arthur Kill had the highest levels of contamination in the area; concentrations of As, Cd, Cu, Hg, Ni, Pb and Zn exceeded several benchmark sediment quality values (Bonnevie et al., 1994). Many of the sediment samples from the lower Passaic River had metals (Cu, Pb, Hg, Ni, Zn) at concentrations that greatly exceeded the Long and Morgan (1991) Effects Range- Low (ER-L) and Effects Range - Medium (ER-M) values. In general, metal concentrations at these sites were lower at the surface, reflecting decline of new inputs after environmental regulations took effect and high sedimentation rates. The highest amounts of metals were deposited in the 1950s and 1960s, followed by a subsequent decline (Wenning, Bonnevie, and Huntley, 1994).
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