Christos Tsiamis, Remedial Project Manager for the Gowanus Canal
Natalie Loney, EPA Region 2 Community Outreach Coordinator
Brian Carr, EPA Region 2 Legal Council
Jeff Edelstein, facilitator for Gowanus Canal Community Advisory Group
Many of the members of the
Gowanus Canal Community Advisory Group (CAG) had attended at least one of the public meetings held in late January by the Environmental Protection Agency Region 2 on the
Proposed Remediation Plan for the polluted waterway.
On Monday night at PS 58, the CAG had an opportunity to ask Christos Tsiamis, EPA's Remedial Project Manager, more detailed questions and to delve into more detail.
The discussion focussed on three particular points:
*the 5th Street Basin
*The contamination and remediation at Thomas Greene Park and Douglas Street Pool, that were built on an old Gas Manufacturing Plant and the proposed Combined Sewer Overflow retention basin for the site.
*the proposal of using a particular Red Hook site for staging work related to dewatering dredged material. In addition, if the community agrees, the EPA is proposing the construction of a Confined Disposal Facility (CDF) to treat and store the least contaminated dredge collected from the lower part of the Gowanus Canal.
Here are some of the clarifications provided by Christos Tsiamis on those three points.
The 5th Street Basin.As part of the Proposed Plan, the First Street Basin will be dredged and reclaimed as part of the canal. Members of the CAG wanted to know why the 5th Street Basin, which was filled between 1953 and 1964, was not going to be dredged as part of the clean-up.
Tsiamis explained the ground water and soil contamination at the two basins is distinctly different. The First Street Basin has much, much higher levels of contamination and causes a much greater risk. It was also found at depth that would cause a risk of re-contaminating the bottom of the canal after the clean-up. "We have not seen the same at the 5th Street Basin," Tsiamis added. "There is contamination at the 5th Street Basin. The basin is one of six upland sites we have referred to the
NYS Department of Environmental Conservation for further investigation."
Douglass Greene Park and Pool And Proposed Retention BasinDouglas Greene Park and the pool at Douglass Street were constructed over a former
Brooklyn Union Gas Manufacturing Plant (MGP), which operated on the site from 1879 to 1929. Today, the land underneath the park is still heavily contaminated with coal tar. Some of this free liquid tar is moving towards the canal.
National, Grid, which bought Brooklyn Union Gas/National Grid in 2006, is now responsible for the remediation. The work will be done under
NYS Department of Environmental Conservation supervision.
Some members of the CAG expressed concern about the swimming pool, which most certainly will have to be removed.
"This park is part of the Superfund site. You have a pool that's sitting on coal tar," Tsiamis stated. "The pool was placed on the most polluted part of the canal."
Considering the nature and the extend of the work that will need to be done to remove the coal tar, the pool cannot stay. "I don't think that children should be around when the work is being performed," he added.
As part of the Plan, EPA has suggested building a retention tank underneath the area of the swimming pool to mitigate the Combined Sewer Overflow issue that needs to be addressed as part of the clean-up.
The retention tank would allow the storage of excess water and sewage that now flows into the canal during rain events to be stored for one or two days until it can be pumped to the sewer treatment plant for treatment.
Tsiamis has proposed this particular location for a retention tank for a few reasons:
*The largest outflow, which is responsible for much of the raw sewage into the canal, is at the head of the canal at Douglass Street, near the park.
*The park is one of the only open pieces of land in this densely populated area.
*The land is already owned by New York City.
*The CSO issue needs to be address to avoid recontamination of the canal after the Superfund clean-up.
Tsiamis explained that the retention basin would be "controlled construction" to remedy an "uncontrolled situation."
1928 photo of the former MGP site at Douglass Street, where Thomas Greene Park is now
Original Sandborne map of the MGP . Green line indicates online of the entire plant
Detail of what is now Thomas Greene Park
Douglas Greene pool
Dewatering Staging Site and proposed Confined Disposal Facilty in Red Hook
Once the actual work of cleaning the Gowanus Canal starts, the sludge at the bottom of the canal will have to be dredged.
In order to de-water the dredge, a staging area is needed. The EPA has scouted for a suitable location and has identified a site by Columbia Street in Red Hook, which belongs to
John Quadrozzi of GBX.Since it is ideally situated at the bottom of the canal, the dredge can be transported there by barge, limiting truck traffic through the neighborhood.
In total, an estimated 600,000 cubic yards will needs to be dredged and dewatered. Most of the very toxic material from the top and the middle of the canal will then be shipped off site for treatment.
The EPA has proposed to stabilize the least toxic material (about 200,000 cubic yards) from the bottom part of the canal at the facility in Red Hook by mixing it with cement, which will turn it into regular concrete that is neutral and not harmful.
One option, which the EPA is exploring is to build a Confined Disposal Facility on underwater land with filling right owned by GBX. The stabilized sediment material would be placed in this CSF.
(Imagine a huge concrete tub, in which the treated material would be placed and capped.)
All work would be done by an expert qualified contractor hired by the EPA. The agency would also put restrictions on the land gained from building a CDF and would regularly inspect it.
On February 13, the EPA will be in the Red Hook community to discuss in more detail the specifics of the Proposed Plan and the proposed CDF. That meeting is scheduled to begin at 6:30 PM at P.S. 15, located at 71 Sullivan Street in Red Hook, Brooklyn. The public is welcome.
Christos Tsiamis was clear that the facility will only be considered if the community wishes. If residents object, there are other options.
Potential location for Confined Disposal Facility in Red Hook
Similar press will be used to dewatered dredge
Liquid from de-watering process will be treated.
