Attendees
Joan Salome-Rodriguez (Facilitator), Katia Kelly, Louis Kleinman, Susan Yung, Erica Eliason.
Guests: Terri Thomson, Aaron Kaufman, Corinne Brenner
The Committee discussed the following questions and decided which answers from Victoria Sacks (EPA Remedial Project Manager) needed follow-up (I will be drafting a follow-up for Victoria, Erica will put it on a Google Doc for editing by the committee):
1) What will go in the gap between the old and new bulkheads on the Whole Foods site?
A minimum one-foot layer of AquaBlok will be placed in the gap, followed by gravel to existing grade. For structural stability, the new bulkhead support system requires tieback anchors to be drilled through the face of the wall.
Per Aaron Kaufman: AquaBlok goes down at the bottom of where the old bulkhead meets the new bulkhead. The gravel goes up to the level of the parking lot. The tieback attaches to the new bulkhead and through the old one and deep into the soil (up to 50 feet deep) and the soil holds it in place. This type of tieback is an industry-accepted standard and has been used elsewhere (in answer to Louis’s question).
2) Was the Whole Foods site footprint remediated when it was built?
The Whole Foods property is in NYSDEC’s Brownfield Cleanup Program and was remediated in approximately 2013. EPA was satisfied with the remedy at that time. Please refer to the NYSDEC Brownfield Cleanup Program website for further details.
Although the answer to this question was yes, see the answer to # 3 below – not so reassuring.
3) Can the new bulkhead be perforated?
Perforations have been made solely to extend existing outfalls. Otherwise, these bulkheads are typically required to be sealed without perforations as a backup cleanup measure in case there was undetected residual subsurface contamination present.
4) What is the plan on the “mural” side (south side of the channel)?
Assuming that this is the bulkhead support in front of Dykes Lumber, this bulkhead replacement was completed as part of the Turning Basin 4 pilot study with minimal need to offset into the Canal.
5) How much water (Canal surface area) are we losing?
Encroachment into the Canal along the newly installed bulkhead support system along the Whole Foods properties varies from one foot to 10 feet. This encroachment was unavoidable due to the condition of the existing sheet pile bulkhead that was installed at a significant incline. EPA is still considering potential approaches with respect to this encroachment.
This answer is, so far, not responsive. In terms of how much water we are losing in the turning basin, that question remains outstanding. We cannot know if we are getting this volume back at other places on the Canal if we don’t know what the volume lost is.
6) How will what we lose here be returned to us at Turning Basins 1 & 11 (near Lowe’s in Remedial Target Area 3)?
In coordination with EPA, the Trust is currently designing a wetland in the former First Street Turning Basin to provide ecological value and recreational benefits to the community and to offset water area lost by bulkhead encroachment throughout the project area. Additional encroachment mitigation will occur beneath the Third Avenue bridge and slightly into the Fifth Street Turning Basin, pursuant to plans which are still being developed. At Turning Basin 11, encroachment from the bulkhead construction is anticipated due to structural limitations from the former Pathmark building.
Sadly, it sounds from this answer as though we will not get anything back at Turning Basin 11. So we want to know what is anticipated to be lost at this turning basin as well. As far as the 1st Street and 5th Street turning basins go, we have no idea yet what the designs will look like – they are in the planning stages.
7) Will the CAG be involved in the designs for Turning Basins 1 & 11?
EPA anticipates sharing the designs for these areas with the CAG to obtain feedback.
8) Are there preliminary designs already?
Turning Basin 1 is currently at the conceptual design phase. We anticipate that the design will advance in 2025. There have been no changes made to the Turning Basin 11 design from the RTA2 Remedial Design.
I will follow up with an email to Natalie to add to the January meeting agenda a walk-through of the Remedial Design Plan for RTA 2. We’d like to know what encroachment is happening in RTA 2 and what we are getting back: actual numbers, actual volume.
9) As for the fill between the bulkheads, what will it be?
As in the Whole Foods property, a minimum one-foot layer of AquaBlok will be placed in the gap between old bulkheads and new bulkheads, followed by gravel to existing grade.
10) Can we expect mounding of the water from the underground streams?
Based on groundwater modelling efforts documented in the RTA2 100% Design Appendix B18 calculation package, the forecasted mounding near Whole Foods ranges from less than 0.5 foot to 1.5 feet. Groundwater mounding in the vicinity of Turning Basin 1 will be evaluated as part of the TB1 design effort.
A number of questions arise from the question and answer above. Is the mounding a rise in groundwater level of 0.5 feet to 1.5 feet? If so, where does that put the groundwater level at and around the Whole Foods area and the other side of that turning basin. Under what circumstances is mounding happening? Is the mounding due to underground streams? Anecdotally, at least two CAG members are hearing from Park Slope residents as far up the slope as 8th Avenue that they are experiencing basement flooding that they never experienced before; the water is coming through their basement walls. Has a new hydrology/groundwater study been done that takes the underground streams extending up into Park Slope into account?
11) Is there a plan to use rip rap (layers of stones, dirt, pebbles, in essence) for fill? Presumably there would need to be weep holes or cutback of the new bulkhead for that to even work.
Bulkhead support system designs in RTA2 all require a one-foot layer of AquaBlok followed by gravel backfill. The bulkhead supports have been designed to not require weepholes. The only perforations in the bulkheads are for extending select outfalls. EPA is reviewing options for minimizing the extent of and visual impacts from the encroachment.
We next turned to the issue of following up with DEC regarding reclassification of the waters of the Gowanus Canal. Erica is drafting and will send a follow up to Mr. Fegal at DEC to check the status since we don’t know what changes at EPA may affect the cleanup and/or the reclassification oversight by EPA of DEC.
Louis will reach out to a former SWIM Coalition member to see if that person still has contacts with SWIM. We will check to see what they may or may not be doing with regard to reclassification of New York waters, including the Gowanus. Louis believes that they sought reclassification of the Gowanus as well.