USA: EPA Investigation of Gowanus Canal Identifies Widespread Contamination, Health and Ecological Problems
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 threats to people’s health and the environment.
“The findings of the investigation of the Gowanus Canal confirmed that contamination of the urban waterway is widespread and may threaten people’s health, particularly if they eat fish or crabs from the canal or have repeated contact with the canal water or sediment,” said EPA Regional Administrator Judith Enck. “The next step is the review of options for cleaning up the Gowanus, so we can move ahead with a full-scale cleanup of the canal that will result in a revitalized urban waterway.”
EPA’s investigation confirmed the widespread presence of more than a dozen contaminants, including polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and various metals, including mercury, lead and copper, at high levels in the sediment in the Gowanus Canal. PAHs and metals were also found in the canal water. PAHs are a group of chemicals that are formed during the incomplete burning of coal, oil, gas, wood, garbage, or other organic substances. PCBs were used as coolants and lubricants in transformers, capacitors, and other electrical equipment. PCBs are suspected carcinogens and can have neurological effects. PAHs are also suspected carcinogens.
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. Links and locations are provided below. 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.
EPA’s investigation also confirmed that a combination of historical and ongoing sources have contaminated the Gowanus Canal. Past industrial activities along the canal contributed a large amount of contaminants that were found in layers of sediment below the surface. A number of industrial facilities are among these sources, including three former manufactured gas plant sites along the Gowanus Canal. Uncontrolled discharges of sewage, storm water and other types of discharges into the Gowanus continue to contaminate the canal.
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. During the investigation, EPA collected and analyzed more than 500 samples of sediment from the Gowanus Canal and more than 80 water samples for the presence of various contaminants. EPA also collected more than 200 fish, including striped bass, eel, white perch and blue crab, to analyze their tissue for contaminants. Air samples were collected at street level and at heights at which people would breathe while boating on the canal.
Eighty-eight ground water and soil monitoring wells were installed along the canal to study the ground water influence on the contamination and to obtain data about the possible sources of contamination from the properties abutting the canal. Sixty-five of these wells were installed by EPA; 14 wells were installed by New York City on city-owned properties and nine wells were installed by National Grid on its properties. The city and National Grid, potentially responsible parties at the site, collected and analyzed the water and soil samples collected at their properties under EPA oversight.
EPA will hold a public meeting to present and discuss the findings of the remedial investigation on February 23 from 6:30 p.m. to 9:00 p.m. at PS 32 at 317 Hoyt Street in Brooklyn, New York.
EPA added the Gowanus Canal to its Superfund National Priorities List of the country’s most hazardous waste sites in March 2010 after meeting with government and elected officials, business representatives, representatives of civic organizations and community members, and reviewing more than 1,300 comments on its proposal to list the site.
Source: epa, February 3, 2011