The New Jersey Toxics Reduction Workplan for NY-NJ Harbor:

Distribution of Cd, Pb, Hg, and Methyl Hg in Ambient Waters

Joel A. Pecchioli (1), Timothy Wilson (2), Jennifer Bonin (2), and K. Nadia Dimou (3)

(1) Division of Science, Research and Technology, NJ Department of Environmental Protection, P.O. Box 409, Trenton, NJ 08625; 609-633-2200; joel.pecchioli@dep.state.nj.us

(2) U.S. Geological Survey, 810 Bear Tavern Road, Suite 206, West Trenton, NJ 08628; 609-771-3900

(3) Center for Environmental Systems, Stevens Institute of Technology, Castle Point on Hudson, Hoboken, NJ

Researchers involved with the New Jersey Toxics Reduction Workplan for NY-NJ Harbor collected ambient water samples at twenty locations in the estuary from June 2000 to June 2003. A total of 97 grab samples were analyzed for Cd and Pb (USEPA Method 1638), Hg (modified USEPA Method 1631B), and methyl-Hg (modified USEPA Method 1630). A rigorous Quality Assurance Program used field, equipment, and laboratory method blanks to correct for background contamination of the samples. The dissolved and total mean concentrations of these metals varied by approximately an order of magnitude among the sampled locations. Mean total Cd at the sampling sites ranged between 22.1 and 203 ng/L, and mean dissolved Cd values were between 14.1 and 125 ng/L. Mean total Cd (< 40 ng/L) and dissolved Cd (< 22 ng/L) concentrations were low at the heads-of-tide of the Hackensack and Raritan Rivers and in the upper Raritan River. Mean total Pb ranged between 1,420 and 10,900 ng/L, and mean dissolved Pb concentrations were between 177 and 1,740 ng/L.  Mean total Pb concentrations were lower (typically < 2,000 ng/L) at the heads-of-tide of the Passaic, Hackensack, and Raritan Rivers, in the tidal Raritan River, and in Newark Bay and the Kills. Mean particulate-Pb concentrations were < 400 g/g sed, except at the head-of-tide on the Elizabeth River (930 g/g sed). Mean total Hg at the sampling locations ranged between 5.92 and 191 ng/L, and mean dissolved Hg values were between 0.31 and 7.13 ng/L.  Dissolved methyl-Hg ranged between 0.0035 and 0.127 ng/L, and a limited number of total methyl-Hg samples had a range of 0.0375 to 7.12 ng/L. The NJ State Water Quality Criteria – Aquatic Chronic for total Hg was exceeded by the mean concentration at 14 of the 20 sampling locations; no other New Jersey WQC was exceeded. The highest concentrations of total Hg were consistently observed in the upper tidal reaches of the Hackensack River (mean = 191 ng/L; all other stations mean = 31 ng/L). This was the result of a combination of elevated particulate-Hg (mean = 5,590 ng/g sed; all other stations mean = 2,170 ng/g sed) and suspended sediment (mean = 45.3 mg/L; all other stations mean = 20.2 mg/L) levels. Additional studies have been implemented to develop a better understanding of the distribution and transport of Hg in the Hackensack River.

Funding for this project was provided by the Port Authority of New York-New Jersey via the New Jersey Department of Transportation Office of Maritime Resources.