USA: EPA Finalizes Gowanus Canal Cleanup Plan
The U.S. Environmental Protection Agency has finalized a plan to clean up the Gowanus Canal Superfund site in Brooklyn, New York, one of the nation’s most seriously contaminated bodies of water.
The final plan, announced on the banks of the canal by EPA Regional Administrator Judith A. Enck with Congressmember Nydia Velázquez, state and local officials and community representatives, will require the removal of contaminated sediment and the capping of dredged areas. The plan also includes controls to reduce sewage overflows and other land-based sources of contamination from compromising the cleanup. With community input, EPA has decided on the option in the proposed plan that will require the disposal of the least contaminated sediment at a facility out of the area rather than building a disposal facility in the water near Red Hook.
The cost of the cleanup plan is currently estimated to be $506 million.
“More than 150 years of industrial waste, storm water runoff and sewer overflows turned the Gowanus Canal into one of the most extensively contaminated water bodies in the nation, threatening people’s health and the quality of their daily lives,” said Judith A. Enck, EPA Regional Administrator. “The cleanup plan announced today by EPA will reverse the legacy of water pollution in the Gowanus. The plan is a comprehensive, scientifically-sound roadmap to turn this urban waterway into a community asset once more.”
More than a dozen contaminants, including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and heavy metals, including mercury, lead and copper, were found at high levels in the sediment in the Gowanus Canal. PAHs and heavy 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 and their manufacture was banned in 1979.
PCBs and PAHs are suspected of being cancer-causing and PCBs can have neurological effects as well. To this day, people can still be found fishing in the Gowanus despite advisories about eating fish from the canal.
The EPA has divided the Gowanus Canal cleanup into three segments that correspond to the upper, middle and lower portions of the canal. The first segment, which runs from the top of the canal to the 3rd Street Bridge, and the second segment, which runs from 3rd Street to just south of the Hamilton Avenue bridge, contain the most heavily-contaminated sediment. In the third segment, which runs from the Hamilton Avenue Bridge to the mouth of the canal, the sediment is less contaminated than in the other segments.
For the first and second segments of the canal, the EPA plan requires dredging of approximately 307,000 cubic yards of highly contaminated sediment. In addition, in areas of the deep sediment that are contaminated with liquid coal tar, which bubbles up toward the surface, the sediment will be stabilized by mixing it with cement or similar binding materials. The stabilized areas will then be covered with multiple layers of clean material, including an “active” layer made of a specific type of absorbent material that will remove PAH contamination that could well up from below, an “isolation” layer of sand and gravel that will ensure that the contaminants are not exposed, and an “armor” layer of heavier gravel and stone to prevent erosion of the underlying layers from boat traffic and currents. Finally, clean sand will be placed on top of the “armor” layer to restore the canal bottom as a habitat.
For the third segment of the canal, the EPA requires the dredging of approximately 280,000 cubic yards of contaminated sediment and capping of the area with active, isolation and armor layers and a layer of sand to help restore habitat. The plan also requires removing contaminated material placed in the 1st Street turning basin of the canal decades ago and restoring approximately 475 feet of the former basin. In addition, the EPA is requiring the excavation and restoration of the portion of the 5th Street turning basin beginning underneath the 3rd Street Bridge and extending approximately 25 feet to the east of the bridge.
The final plan includes various methods for managing the contaminated sediment after dredging, depending on the levels of contamination. The methods include transporting the dredged sediment that is highly impacted by liquid coal tar away from the area to a facility where it will be thermally treated for the removal of the organic contaminants and then put to beneficial reuse such as a landfill cover, if possible. For the less contaminated sediment, treatment includes stabilization of the sediment at a facility out of the area, followed by beneficial reuse.
Following is a statement by Phillip Musegaas, Hudson River Program Director at Riverkeeper:
“Today’s announcement is a critically important milestone for the future of the Gowanus Canal and surrounding communities. We commend EPA for developing a cleanup plan that addresses both historical and ongoing pollution, recognizing that the full range of environmental insults levied against this unique waterway must be brought to an end. Riverkeeper urges the City of New York and the New York State DEC to embrace this plan, and join with the Gowanus community as we work to reclaim the Canal.
As a member of the Community Advisory Group (CAG) for the Gowanus Canal, we are also pleased with the EPA’s active engagement with the community thus far, and we encourage the agency to continue in this vein once the cleanup begins. This historic cleanup can only succeed if the passionate supporters of the Gowanus are fully involved from the day of listing to the day the last load of toxic sediment is removed from the Canal.
Riverkeeper has a long history of advocating for a cleanup of the Gowanus Canal and has actively been involved with the Superfund site since the canal was nominated for inclusion on the National Priorities List in 2009. We look forward to continuing our work with the CAG and EPA as the cleanup is designed and implemented.”
Press Release, October 1, 2013