The ongoing remediation plans for the NuHart Superfund site have hit a slight snag. During a virtual community information session hosted by North Brooklyn Neighbors, Assembly Member Emily Gallagher, State Senator Kristen Gonzalez, Council Member Lincoln Restler, and Congresswoman Nydia Velázquez on Thursday night, representatives from the New York State Department of Environmental Conservation, developer Madison Realty Capital, and consulting firm Haley & Aldrich shared updates on the process, including news about phthalates found below the anticipated excavation depth.
While the Brownfield portion of the site at 75 Dupont Street received a certificate of completion in December 2023 and is currently undergoing interior construction and half of the Superfund portion at 65 Dupont Street has been successfully remediated with a foundation built, NYSDEC Regional Remediation Engineer Jane O’Connell reported that elevated concentrations of non-aqueous phase liquids (NAPLs) were found deeper than expected on the western side of the Superfund site (under the tent, for those looking from the street level), causing a modification of remediation plans.
The current sheet pile wall on site only accounts for 19 feet of digging before there’s a risk to its structural integrity, and the found contaminants are roughly 4-5 feet below the current depth. As a solution, NYSDEC, Madison Realty Capital, and Haley & Aldrich are proposing and testing In-Situ Solidification (ISS), a process in which contaminated soil is mixed with cement, creating a solid mass of concrete that no longer allows the NAPLs to be moved by water. Following the ISS process, tents will come down and foundational work for the future building itself will begin.
However, this change — which will also require a Record of Decision amendment — certainly impacts the timeline, which Madison Realty Capital Managing Director of Development Zach Kadden described as being in “the last five yards to getting into the end zone for the cleanup to be completed.”
“We see a light at the end of the tunnel to clean up NuHart, which is a long time coming,” Kadden said.
The ISS (which was already originally considered as a viable option early on in the remediation planning, as confirmed by Haley & Aldrich Principal Consultant James Bellew) is currently in a pilot testing phase to measure the efficiency of the new process, which is being closely monitored by NYSDEC members in the tent and will be used to amend the original Record of Decision and finalize a letter to the state for approval.
“[ISS] is very commonly used at manufactured gas plant sites because it can be used effectively and at depth,” O’Connell explained. “DEC will be providing oversight of this, we’ve used ISS a lot and have a very robust quality control and assurance process — the risk is if the QA and QC come back and it wasn’t done right, they have to go back and do it again. We’re watching carefully and making sure they’re doing this properly.”
Changes to the timeline (which Kadden estimated to be 60-90 days behind schedule with time being of the essence due to loans and deadlines) require getting the information in front of the community and electeds sooner rather than later, with a parallel comment period happening during pilot testing and the ROD amendment process. DEC is targeting March to April as the public input period, with amendment approval anticipated for April or May to allow the project to continue.
“The very worst case scenario here would be that we have a 80% completed cleanup that doesn’t get done, and we would be left with not having a resolved situation for the cleanup of this site,” Councilmember Lincoln Restler said. “We have worked with different ownership groups over extended periods of time to try to get this cleaned up, and the end is in sight. And I really want to make sure that we do everything we can as a community and with DEC and with Madison Realty to get this site cleaned up comprehensively and properly.”
Additionally, Lael Goodman of North Brooklyn Neighbors shared the news that members of NYU’s Division of Environmental Medicine program will begin conducting health surveys and environmental samplings of the people and areas surrounding NuHart.