The Interplay of Dredging and Discharges: a Conceptual Model of Contamination in the Lower Passaic River
Type:
Presented during:
WODCON XVIII - 2007 Orlando, Florida, USA
Authors:
Garvey
Abstract: The Passaic River has served as a center for industry since the American Revolution. It has also served as a means for conveyance for the disposal of industrial and municipal wastes for nearly the same period. The river was extensively channelized for navigation during the first half of the 20th century. However, maintenance dredging was not routinely performed for much of the channel as navigational needs declined in the latter half of the 20th century. The extensive dredging of the river followed by a failure to maintain the channel has created a unique setting for the trapping of sediments in the Lower Passaic. The coincidence of the navigational and industrial events has resulted in a uniquely large inventory of highly contaminated sediments whose fate is currently the subject of much discussion. In support of the jointly sponsored remedial investigation (US EPA, US ACE-NY and NJ DOT) for the Lower Passaic River Restoration Project, Malcolm Pirnie, Inc. conducted an extensive geochemical evaluation of the historical data relating to contamination in the Lower Passaic River. In this evaluation, we examined the vertical and horizontal extent of contamination in the Lower Passaic River as well as evidence to identify contamination source areas. In addition to the use of historical geochemical data, we also evaluated historical bathymetric data and incorporated the results of a 15.5-mile side-scan sonar survey conducted in 2005. Recent investigations of the river have provided additional information on the history of contamination, showing the decline over time for various contaminants, including 2,3,7,8-TCDD, PCBs, mercury, PAHs, and lead. Additionally, recent core data also documents the potential depth of some contaminants, providing perspective on the history of their releases. In this paper, the various data sources are integrated to construct a conceptual site model for the Lower Passaic. The complete geochemical report and other information can be found at http://ourpassaic.org.
Keywords: Dioxin, channelization, estuary, urban rivers, river restoration