CSO Tank Updates
RH-034 Tank
- Drilling of micropiles below tank is ongoing and will continue through end of summer.
- Purpose is to support the weight of the tank when full during CSO events and prevent upward force on the tank when it is empty.
- Tank structure waterproofing and concrete forming / pouring expected to begin in early July and will continue through summer 2026.
- Construction of new outfall structure at end of DeGraw Street is ongoing.
OH-007 Tank
- New concrete sidewalks poured.
- Construction of the new salt shed roof and walls and compost facility roof expected to complete in late July / early August.
- Perimeter wall construction is ongoing, 98 of 138 panels completed (70+%), and will continue through September.
- Permeation grouting of the completed panels down to the bedrock layer is under way.
DEP response to question regarding odors generated as a result of installing micropiles:
The drilling of micropiles generates little to no spoils. Any spoils that are generated are contained within the footprint of the CSO Tank excavation area. There is a very low potential for odors to be generated during the drilling operation but the project team continues to implement the odor control strategies that were successful in controlling odors during the mass excavation phase, including:
- Remedial Odor Eliminator Concentrate: Applied directly at the source to neutralize odors.
- Interior Misting Systems: Equipped with odor-neutralizing agents to mitigate airborne smells.
In addition, the ongoing monitoring efforts include:
- Community and onsite odor walks: Regular inspections to assess and respond to odor conditions.
- Community Air Monitoring Program (CAMP): Continuous sampling for PM10 and BTEX compounds.
- Twice weekly SUMMA canister air sampling at 15 locations.
Five-Year Review
- The first Five-Year Review has been signed and is published on the site profile page: https://www.epa.gov/superfund/gowanus-canal
RTA2
- Bulkheads – Bulkhead installation along RTA2 is currently in progress.
- Remedial Design – The Trust submitted a 100% design for RTA2 earlier this month and it is under review.
RTA1
- Sheens at head of canal – EPA is aware of the fact that there have been sheens detected at the end of Douglass Street near the outfall of the flushing tunnel. We are working closely with the Trust to determine the source of the sheens and find a plan to mitigate the issue (seal the area).
Carroll Street Bridge
- The Carroll Street Bridge construction started in April and is currently underway.
- Expect the reopening of the bridge in early 2026.
RTA2 Groundwater Modeling
- As promised at the June 24th CAG meeting, I have attached the portion of the draft RTA2 design document here that contains the groundwater model that is specific to RTA 2. To be clear, this is not an area-wide groundwater model. It was designed to look at the impacts (i.e. mounding, for example) of the EPA’s selected remedy for the Gowanus Canal (dredging, ISS and capping) on groundwater flow in the area.
Thomas Greene Park Remediation Timeline
- The response to the CAG’s Land Use Committee request for the remediation plan and timeline for Thomas Greene Park has been drafted. Once finalized it will be sent to the Land Use Committee.
July 22nd Monthly Meeting CAG Agenda
It is my understanding that the ISGS pilot study at Thomas Greene Park is unlikely to start in September. As a result, a discussion of this agenda item can be deferred to another monthly CAG meeting. The current items that may be included in the July CAG meeting agenda are:
- RTA2
- Capping
- Groundwater modeling – this discussion will focus on the portion of the design document (here) specific to RTA2
- 1st Street Turning Basin restoration design
- New members
- Charter revisions
Please note, I will work with the Facilitation Committee to determine which items should/will be included as part of the agenda for the July monthly meeting.