T1 PM Contaminant Cycling Assessment and Prevention in the NY/NJ Harbor (Part 2)
Tuesday, 15 November 2005: 1:50 PM - 5:30 PM in Ballroom 1

(ACC-1117-831105) Historical contaminants in the sediments of the Lower Passaic River.

Accardi-Dey, A.¹, Garvey, E.², Desai, M.¹, Zeiner, C.¹, Gbondo-Tugbawa, S.², ¹ Malcolm Pirnie, Inc., White Plains, New York, USA² Malcolm Pirnie, Inc., Fair Lawn, New Jersey, USA

ABSTRACT- Beginning with its role in the American Industrial Revolution, the Passaic River has been subject to industrial discharges laden with contaminants. Among the more well known discharges are the dioxin discharges associated with the Diamond Alkali site in Newark, NJ. As part of the site investigation being conducted under CERCLA and WRDA, a preliminary geochemical analysis on the Lower Passaic River was performed using sediment core data collected from 1990 to 2000 from the lower six miles of the river. Surface concentrations of dioxins, DDT, and PAHs were examined to assess the extent of tidal mixing versus the existence of local sources. The analysis showed that surface concentrations of organic contaminants are relatively uniform over much of the lower six miles, suggesting that tidal mixing is sufficient to mix and homogenize these contaminants over this distance. The surface sediment data (0-15 cm) also exhibit a sharp concentration gradient over the last mile of the river with surface concentrations declining a factor of 3 or more, which we attribute to effects of tidal exchange and sediment transport between the Passaic River and Newark Bay. Sediment contaminant profiles from dated sediment cores vary across the Lower Passaic River, consistent with depositional environment changes. The profiles reveal nondepositional locations, absent of environmental contamination, as well as locations with over 5 m of contamination. Sediment profiles show historical concentrations of dioxins and DDT as much as 200 ppb and 200 ppm, respectively, with maximum concentrations occurring in the 1940s and 1950s. Of particular note is the continued presence of DDT and dioxin in recently deposited material despite the cessation of the major discharges. The analyses conducted to date are consistent with previous investigations that suggest that the Lower Passaic River is a source of contamination to Newark Bay.

Key words: Passaic River, sediment geochemistry, dioxins, DDT