By David Briggs
On January 24, the EPA Gowanus Canal Public Information meeting was held in the auditorium at PS 58 in Carroll Gardens. Walter Mugdan, the EPA Region 2's Director of the Emergency and Remedial Response Division announced that the agency was on schedule with the remedial investigation and feasibility study of the Gowanus Canal Superfund site and that the proposed plan, which will identify the Agency’s preferred cleanup option, will be unveiled later this year. Once the proposed plan is published, there will be a public comment period followed by a selection of the remedy by the end of 2012.
A draft version of the feasibility study is available for public input and can be found at here .
The EPA’s press release is here.
The presentation slides from the January 24 public meeting can be found at here.
After Mr. Mugdan’s introduction, a brief presentation was made by the consultant, Patricia White of CH2M Hill, who presented a conceptual site model that described the extent of the contamination. Ms. White mentioned that the depth of the Non-Aqueous Phase Liquid (NAPL) contamination extends below the practical depth of removal and the bulkheads lining both sides of the canal are in poor condition. Since the EPA’s responsibility extends only to remediation of the canal sediment, there are concerns about the potential of recontamination once EPA completes its work.
The meeting proceeded with a detailed explanation of the six steps of remediation, summarized as follows:
Step 1: Develop remedial action objectives, such as: Reduce risks to organisms, wildlife, and humans; keep NAPLs from contaminating groundwater.
Step 2: Establish numerical goals for clean up.
Step 3: Define target areas. In the case of the Gowanus Canal, the target areas are: a) the Upper Level, between Butler Street and 3rd Street;
the Middle Level, between 3rd Street and the Gowanus Expressway; and c) the Lower Level, between the Gowanus Expressway and New York Harbor.
Step 4: Identify and screen remedial technologies. These technologies include dredging, containment, in situ treatment, monitored natural treatment, dredged sediment treatment for beneficial use or disposal. Each of these is evaluated for effectiveness, implementability, and cost.
Step 5: Develop and screen alternatives for the type of clean up. These include various combinations of dredging, capping, and treatment (both onsite and offsite) that, depending on the level of contamination, will be considered. One other alternative is “No Action,” which Mr. Mugdan stated is required by law to be considered, but that the EPA has already decided will not be an acceptable solution. Interestingly, one of the primary costs to remediation is transporting the contaminated material offsite. In last year’s Gowanus by Design competition, “Gowanus Lowline: Connections,” the first and second prizewinners proposed in situ remediation while the neighborhood was being developed.
Step 6: Conduct a detailed evaluation of the alternatives using criteria established by the National Contingency Plan, the federal government's blueprint for responding to both oil spills and hazardous substance releases.
Mr. Mugdan noted that the most sustainable solutions involved either: a) onsite stabilization with beneficial use, b) onsite stabilization with an onsite CDF (containment disposal facility), or c) offsite stabilization with an onsite CDF. With that in mind, the two preferred treatments at this point appear to be either dredge all soft sediment at the bottom of the canal and install a three-layer cap (estimated cost range: $351-439 million), or dredge all soft sediment at the bottom of the canal, solidify the exposed surface and install a two-layer cap (estimated cost range: $369-456 million).
The next steps in the process include treatability studies and pilot testing in several locations along the canal, coordination of the clean up efforts by New York City’s DEP, New York State’s DEC, National Grid, and other potentially responsible parties, and the proposal, selection, and implementation of an appropriate remediation plan.
Following the presentation, several questions were asked about the combined sewer overflows (CSOs), clean up of the former sites of the three manufactured gas plants, and the city’s willingness to assist with the clean up. Both Mr. Mudgan and Christos Tsiamis, the EPA Project Manager for the Gowanus Canal Superfund project, pointed out that the EPA’s jurisdiction is limited to cleaning up the canal sediment. In other words, ongoing contamination of the water due to the CSOs and surface runoff is still an open issue and consensus has not been reached between the EPA, DEC, and DEP on how this will be addressed. However, if the EPA does not feel that the DEC is sufficiently addressing the water quality issue, they can step in and insist on a more direct approach. The DEC is responsible for maintaining ambient water quality standards and guidance values for surface waters and groundwaters throughout the New York State. Despite this, many bodies of water in New York, including the Gowanus Canal, fail to meet the state’s own standards and the requirements of the federal Clean Water Act. A nice summary of the Clean Water Act’s history and purpose can be found here: http://www.epa.gov/lawsregs/laws/cwahistory.html.
Council member Brad Lander, who represents the 39th Council District, responded to a question by expressing a desire to work with the EPA to explore solutions for a more comprehensive clean up of the surrounding properties. In a short conversation after the presentation, Mr. Lander noted that one of the more interesting ideas was proposed by the EPA -- to use the flushing tunnel between Buttermilk Channel and the pump station at Butler Street for short term storm water retention during heavy weather events. Ideas like this are exciting, but they will only be ideas until the state and city actively invest in this and other ambitious public works (e.g., combined sewer infrastructure upgrades, transit oriented development, restoration of the bulkheads) that build upon the small projects, such as bioswales and sponge parks, that are currently being funded. The community must insist that its local and state elected officials pressure our agencies for a comprehensive clean up of the neighborhood. Bold solutions are required at all government levels and right now the EPA is leading the charge. It is time for our state and city to share the responsibility.