Members of the Gowanus Canal Community Advisory Group were smiling in their Zoom squares when Christos Tsiamis, the Environmental Protection Agency (EPA) engineer leading the Gowanus Canal Superfund cleanup, reappeared on their screens on March 23. Tsiamis had not attended the group’s monthly virtual meetings since December, when he expressed concerns over changes utility company National Grid made last summer to its remedy of Public Place, the contaminated site of a former manufactured gas plant on which the city wants to build 950 affordable apartments, a park, and a public school.
His comments made waves among members of the advisory group and cast doubts over whether the new remediation plan would be sufficiently protective of human health. This angered the New York State Department of Environmental Conservation (DEC), the agency supervising the remedy and that approved National Grid’s changes. In the days after the December meeting, Michael Ryan, DEC’s director of environmental remediation, sent the EPA a letter in which he accused Tsiamis of misinformation, calling his statements “flippant” and demanding he retract them.
Said what I said
Some members of the advisory group had speculated that Tsiamis’s absence at subsequent meetings was a sign that he had been reprimanded for speaking out. But Tsiamis seemed more steadfast than contrite at last month’s meeting. “I have not seen any new data or documents since I last spoke to you, and I have nothing to add to the assessment I provided previously,” he said about his December comments. And while Tsiamis called attention to a joint DEC-EPA letter issued to the advisory group the day before in which both agencies pledged to “work cooperatively” to ensure an optimal remedy, he also asserted the EPA’s authority to comment on Public Place or anything else that might jeopardize its cleanup of the Gowanus Canal. “The Superfund site is not confined between the [canal] bulkheads.” Tsiamis also took a moment to tell group members that he was touched by their expressions of support for the EPA’s work. “I would like to thank you from the bottom of my heart.”
The advisory group’s exchanges with Janet Brown, the DEC representative who had clashed with Tsiamis at the December meeting, were a lot less fuzzy—the patience of some members seemed to fray at the mere sound of her voice. Brown reassured the group that the state’s remediation plan for Public Place would protect its future residents from exposure to the toxic fumes evaporating from coal tar buried beneath the site and stressed that former manufactured gas plant sites can and have been safely remediated for a variety of public uses. “It all comes down to site details, where that contamination is, and preventing exposure. Just because [the contamination is] there, it doesn’t mean it’s going to harm you. It’s only if you come into contact with it.” Group members seemed unswayed, requesting that Brown provide them with more information in the future about comparable remediated brownfields in New York State.
The work of Michael Greenberg, an environmental health and risk assessment expert at Rutgers University’s Edward J. Bloustein School of Planning and Public Policy, suggests that contrasting attitudes towards public officials may be fairly common. People that live around brownfields due for remediation tend to trust government scientists over developers and local elected officials because they may perceive scientists to be more concerned with protecting the public and therefore more likely to give an honest characterization of a site’s environmental risks, Greenberg wrote in a 2003 paper. Quoting Dylan Thomas, Tsiamis assured the advisory group that their faith in him was well-placed. “I will not ‘go gentle into that good night.’ It has always been my life’s goal to shed light on whatever I get involved in, and that I will continue to do.”
Infernal fumes
Prolonged exposure to volatile organic compounds like those found in the toxic vapors emanating from Public Place can damage the liver, kidney, central nervous system, and can cause cancer, according to the EPA. Even so, what Brown told the advisory group is not wrong—site details do matter, and preventing exposure to contaminants is indeed the paramount consideration when crafting a remedy that protects human health. “If there’s no exposure, from a health point of view, other than people’s mental stress, you don’t have a problem,” said Greenberg.
As Tsiamis commented last month, good engineering can accomplish this. He pointed to a former manufactured gas plant on West 18th Street in Manhattan as an example of a similar, successfully remediated site. The remedy there was carried out by ConEd and overseen by the state; it called for digging out and replacing soil down to 14 feet and trapping remaining coal tar by injecting it with cement. In areas of the site that weren’t stabilized with cement, ConEd installed below-grade walls to keep coal tar from spreading to neighboring blocks and a robust, multilayered system of clay, fabric membrane, and concrete to prevent vapors from rising into the building that was later built there.
National Grid’s original remediation plan, drawn up in 2011 by engineering consultant GEI, called for similar measures at Public Place, such as “wing walls” lining the site’s perimeter to stop coal tar from reaching the canal. The plan also contemplated a treatment system to clean water that comes in contact with the site’s pollution before it’s discharged into the canal. These features disappeared from later iterations of the remediation plan that were produced by another environmental consulting firm, Arcadis, in 2017. National Grid made more alterations to the remedy last summer when it changed the depth to which it will excavate and replace contaminated soil to two feet instead of eight.
Deep, please
The answer to whether a brownfield site can be remediated for residential use is yes. Whether the structures safeguarding people from contaminants can stand the wear of time is another matter, said Greenberg. “It’s like your car, if you don’t monitor it, stuff happens, things break.” The difference, he explained, is that when your car breaks down, you find out pretty quickly. Released contaminants, on the other hand, could go undetected for a long time if nobody’s paying attention—something to add to that mental stress Greenberg mentioned. Monitoring a remediated site in perpetuity, as Public Place will have to be, is also really expensive. A lot of money will have to be set aside to guarantee constant vigilance and that there are enough funds to repair any failures.
As far as digging out polluted soil goes, the deeper the better, said Greenberg, though costs can become prohibitive for the party implementing the remedy. That’s why it’s important to have independent oversight: someone that can help determine the depth required for remediating specific areas within a brownfield, he said. “It might be 20 feet in some places, eight feet in other places, and two feet another place. It depends on what’s gonna go there.”
Voice of Gowanus, a local organization that opposes the construction of housing on Public Place and that has sued the city in a bid to stop the proposed rezoning of Gowanus, consulted another expert, Maureen Koetz, during a virtual panel discussion on March 24. Koetz, who directs the sustainability consulting firm Planet A* Strategies and has experience managing Superfunds, said it’s common for remediated brownfields to be converted into open-air public spaces like parks or golf courses, but that putting a residential building or school on a severely contaminated site like Public Place is atypical. “I don’t see it—rarely ever.”
