Coal tar recovery well on the site
It's not every day that one gets to tour the gated former Citizens Gas Works MGP site in Carroll Gardens. So when representatives of National Grid offered to take members of the Epa's Gowanus Canal Superfund Community Advisory Committee (CAG) for a walk around the vast track of land, located between Smith Street and the Gowanus Canal, I immediately signed up. The tour allowed Andrew Prophete, project manager for National Grid, and his colleagues to go over the proposed remedial design for the heavily polluted land and for CAG members to get a better understanding of the clean-up effort. As many in the neighborhood know, the fenced-in site became home to the Citizens Gas Light Company's 12th Ward Gas Work plant in the 1820's. The plant turned coal and petroleum products into flammable gas for the surrounding neighborhood. Citizen later sold to Brooklyn Union Gas, which became Keyspan, which is now National Grid.The plant was decommissioned in the early 1960's. What was left behind was contamination, mostly in the form of coal tar, a brownish, oily substance that over time seeps deep into the ground.The results of the Remediation Investigation for the Citizens Gas Works MGP site showed significant amounts of coal tar in depths up to 150 feet. The responsibility for the clean-up falls on National Grid under the supervision of NYS Department of Environmental Conservation. To date, 50% of National Grid's remedial design has been approved by DEC. Since the coal tar plume on the site is so large, National Grid has already installed coal tar recovery wells in advance of the actual clean-up. From the beginning of 2011 till now, 8,000 gallons have been recovered. Regularly, the coal tar is removed and temporarily stored in yellow drums, before it is carted to a licensed disposal facility where it is recycled into asphalt and roofing tar or burned into inert material. These recovery wells will stay on the site for years if not decades. The deepest pockets of coal tar will most probably remain on the site forever.
The coal tar and contaminated ground water has also been oozing into the Gowanus Canal from this site for decades. Because of the pollution, the Environmental Protection Agency has named National Grid one of the Primary Responsible Parties (PRPs) when the Gowanus became a Superfund site. By far the most complex part of this MGPs site clean-up plan involves a 50 foot sheet pile construction wall along the canal side, which will serve as a barrier to prevent the lateral movement of the contaminants into the waterway. Made of marine grade steel, sections of this barrier wall will be vibrated into the ground and the joints will be heavily reinforced with special epoxies. The rebuilding and relocation of a section of the Bond Street sewer line that traverses the site, storm water and ground water management, the removal of the old holding tanks and grading of the terrain further complicate an already complex remedial design.
Of course, only time will tell if the remediation for the former Citizens Gas Works MGP site will ultimately be successful in addressing all these complexities. I, for one, shudder when I hear that the city of New York has slated Parcel I and II (see map above) for residential development. Sure, Gowanus Green, as the 774-unit community and retail project it ironically called, will include a large number of affordable for-sale and rental units, but can anyone ever be 100% sure that future residents will be safe? So far, our local electeds are still behind the housing plan. Of course, one wonders how confident they would feel if their loved ones moved to Gowanus Green. Just saying....
I would like to thank National Grid for the opportunity to tour the site. Thank you also for the information on the map below, showing the result of soil boring on Former MGP site and surrounding area.
