Gowanus Canal Superfund Site
The U.S. Environmental Protection Agency has completed its investigation of the Gowanus Canal Superfund site in Brooklyn, N.Y. The investigation confirmed the widespread presence of numerous contaminants in the canal and identified the sources of contamination. The investigation also identified characteristics of the canal that will influence future plans for a cleanup. A companion human and ecological risk assessment found that exposure to the contaminants in the canal poses potential threats to people’s health and the environment. The Gowanus Canal was originally built to allow access for industrial needs by bulkheading and dredging a tidal creek and wetland that had previously been fished for oysters. After its completion in the 1860s, the canal quickly became one of the nation’s busiest industrial waterways, home to heavy industry including gas works, coal yards, cement makers, soap makers, tanneries, paint and ink factories, machine shops, chemical plants, and oil refineries. It was also the repository of untreated industrial wastes, raw sewage, and surface water runoff for decades, causing it to become one of New York’s most polluted waterways. Although much of the industrial activity along the canal has stopped, high contaminant levels remain in the sediments.
The Gowanus Canal is a 100-foot wide,1.8-mile long canal located in the New York City borough of Brooklyn, Kings County, New York. Connected to Gowanus Bay in Upper New York Bay, the canal borders several residential neighborhoods including Gowanus, Park Slope, Cobble Hill, Carroll Gardens, and Red Hook. The adjacent waterfront is primarily commercial and industrial, currently consisting of concrete plants, warehouses, and parking lots.
Numerous sampling events have shown the sediments in the Gowanus Canal to be contaminated with a variety of pollutants, including polycyclic aromatic hydrocarbons (PAHs), volatile organic contaminants (VOCs), polychlorinated biphenyls (PCBs), pesticides, and metals. PAH concentrations were found to be as high as 45,000 milligrams per kilogram (4.5%) and the contamination was found to traverse the entire length of the canal. Many of the detected
contaminants are known carcinogens. The contaminated sediments pose an immediate risk to the fishery located just downstream of the canal in Gowanus Bay. This fishery is a well documented case, and fish caught there are used as food.
The human health risk assessment of the Gowanus Canal found that people are at risk from exposure to PCBs if they consume fish and crabs caught in the canal. People coming in regular contact with water and sediment from the canal could be at risk from exposure to PAHs. Several contaminants were found in the air directly around the canal, but not at levels that present an unacceptable risk.
EPA’s ecological risk assessment revealed that organisms living in the sediment of the Gowanus Canal could be at risk because of contamination in the sediment, primarily PAHs, but also because of PCBs and metals. Ducks may be threatened by exposure to PAHs in the canal’s sediment and heron could be at risk from eating contaminated fish.
The results of the investigation, referred to as a remedial investigation, are in a draft report which is available for public review online and at the EPA’s document repository in Brooklyn. Based on the results of the investigation and the human and ecological risk assessment, EPA will commence work on a study that will outline all of the options for addressing contamination in the Gowanus Canal. This study, called a feasibility study, will take place over the coming months. It is anticipated that a draft feasibility report containing an assessment of all options will be completed by the end of this year.
The remedial investigation identified several site-wide issues to be addressed before cleanup activities can proceed. The stability of the bulkheads abutting the canal could be threatened by dredging activities that could be used to remove contaminants. In addition, debris of various sizes is pervasive in the canal, including sunken vessels near the 4th and 6th Street basins.
For further information: http://yosemite.epa.gov/opa/admpress.nsf/0/E99317DA92C631CE8525782B0057E138