EPA's Head Engineer For The Gowanus Canal Superfund Clean-Up Confirms Community's Concerns Regarding Environmental Remediation Of Public Place Site

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A revealing, and frankly explosive conversation took place at last night's Gowanus Canal Community Advisory Group (CAG) Zoom meeting in regards to Public Place. Thanks to Christos Tsiamis, the engineer in charge of the Superfund clean-up of the Gowanus Canal, residents finally got a better idea of how polluted the site really is and learned that the proposed cleanup by New York State simply is not thorough enough.

Public Place, the almost 10 acre swath of land, framed by the canal and Smith Street and 5th Street and Huntington Street in Carroll Gardens has been heavily polluted for decades. Once the site of a Manufacturing Gas Site, coal tar plumes have been found at depth of 153 feet.

As part of the proposed Gowanus upzoning,  Mayor de Blasio and our Council member Brad Lander envision 950 units of affordable housing on Parcels I and II, which are city owned.  More housing is planned on the privately owned  Parcel 3.

The site is currently being remediated by National Grid under New York State's Department Of Environmental Conservation under the Brownfield program. The remediation can hardly be called a clean-up. It would be more appropriate to call it a containment, since most of the coal tar will remain forever deep in the native soil.

Just recently, the Carroll Gardens/ Gowanus community learned that  DEC had allowed National Grid to significantly alter and degrade the remediation, sparking concerns that future residents would be exposed to the remaining contamination.

To address this issue, the Land Use Committee of the Gowanus Canal CAG proposed a resolution last night, asking EPA to review and comment on DEC's changes to the remediation of Public Place. (It passed overwhelmingly)

Christos Tsiamis was in attendance at last night's meeting and was kind enough to engage in a conversation on the subject of Public Place. Since he has been studying the contamination of the canal and the uplands since 2009,  he is in a unique position to compare DEC's previous clean-up plan versus the new  downgraded one. It quickly became apparent that he has some grave misgivings about the changes.

Tsiamis, who holds a master's degree in chemical engineering from Columbia University, familiarized himself with reports on Public Place from the beginning, since coal tar from the site is one of the major source of pollution into the Gowanus Canal. The EPA is very protective of their Superfund clean-ups, so that any site, like Public Place, which has the potential of recontaminating the canal,  is rigorously scrutinized.

Christos Tsiamis, project manager for the EPA Superfund Cleanup of the Gowanus Canal

Last night, he recapped NYS DEC's 2007 reports on what was then a voluntary clean-up plan by National Grid.

Back then, the remediation called for 

-the removal of 8 feet of soil on the entire site
-the removal of all  remaining gas holder structures 

-a sealed bulkhead wall at the canal's edge to prevent coal tar from continuing to flow into the canal

-recovery wells to pump the coal tar that will collect behind the wall out of the ground for off site disposal
- the installation of a High Density, heavy plastic liner 2 feet below grade throughout the site as storm water management to prevent rain water absorption, which could dislodge the deeper, remaining pockets of coal tar.
- two water treatment systems to clean the rainwater from the site so it can can be discharged back directly into the Gowanus Canal

-two 'wings' or wall extensions along 5th Street and Huntington Street to prevent coal tar to ooze out of the site onto nearby land.
- 8 feet of clean backfill and regrading of the land.

According to Tsiamis in 2010 the design documents still very much reflected the remediation steps that were in the original documents.  However, by the time the final design was approved and finalized in 2017-2018, the clean-up was being supervised under the Brownfield program and had changed significantly. Gone was the waterproof liner, gone were the two water treatment plants, and gone were the 'wings'. Tsiamis' own Region 2 administration signed off on the design while he was on vacation.  

During subsequent conversations with National Grid and DEC, he was able to at least make sure that the water  treatment systems were added back in.

Tsiamis spoke honestly to the community about his concerns that the current DEC remediation actions will not be sufficient.  In his professional opinion, the coal tar plumes will continue to migrate and collect in front of the barrier wall.  It will likely also find a way to move off site since tar can easily move sideways and choses the path of least resistance.  He envisions the need for more recovery wells to collect more of this toxic viscous material, and suggests that the deeper pockets of tar be stabilized  with a cement like material, very much like what is being employed  as part of the Gowanus Canal remediation.

Since the waterproof liner is no longer part of the plan, Tsiamis is concerned that stormwater infiltration on Public Place will dis-lodge more coal tar. The issue needs to be looked at carefully since Gowanus Green, the planned residential development at Public Place is supposed to move 100% of its stormwater back into the canal.  

More than anything, he warned about the exposure to the fumes discharging from the site.  As long as nothing is built on Public Place, PAHs, the volatile compounds in coal tar, will dissipate into the air.  However, build structures over the site, and dangerous gases like Naphthalene can infiltrate through the foundation, into buildings.

Tsiamis mentioned a meeting he had a few years ago with Michelle de la Uz of the 5th Avenue Committee, one of the five Public Place developers, at which he warned that a planned day care center on the site was right next to the recovery wells and the barrier wall. He thought that  the particular location was perhaps not the best spot to house a center for small children.

At a subsequent meeting, the center had been moved closer to Smith Street on the plans.  

To his dismay,  a school building is once again planned in that first location, were coal tar will be pooling behind the barrier wall.

Tsiamis' honesty on the subject of Public Place last night was a gift to the Carroll Gardens and Gowanus community.  No one at New York State DEC or New York City's Environmental Protection Agency have fought as hard for our safety and heath.

For that, we should be very grateful to him.

Now that we have the knowledge that he shared with us, it is up to us to hold our City and State, as well as our elected officials responsible.  It is up to us to make sure that no one is placed in harms way and that this is the last generation in this neighborhood exposed to dangerous chemicals.

To view a video of the entire meeting, click here.