A massive steel wall is coming to the Gowanus Canal
This is what the infamous black mayonnaise at the bottom of the canal looks like.
One of the main groups responsible for the Gowanus Canal’s pollution will begin building an 880-foot wall along the waterway this fall as part of the federal Superfund site’s overall cleanup.
The massive fence, paid for by National Grid, will serve as an environmental barrier to prevent liquid tar from the former Fulton Manufactured Gas Plant from entering and re-contaminating the canal. It will also provide structural support for future remediation efforts.
The wall will be made out of steel sheet piling and be placed on the eastern side of the canal in front of the existing bulkhead (the border between the shore and the water). It will stretch from the head of the canal around Butler Street to the Union Street Bridge and is slated to be completed by August 2020.
On Monday, an excavator was relocating the infamous black mayonnaise from the sides of the canal to the middle of the waterway, so that a larger barge could eventually come in to install the barrier. An employee on site told the Brooklyn Eagle that the workers, hired by National Grid, are not contractually allowed to remove the muck.
After the “pre-clearing operations” are complete, the actual wall will be installed, according to a National Grid spokesperson.
The Fulton Manufactured Gas Plant operated from 1879 through the early 1930s. It was eventually sold to Brooklyn Union Gas, a predecessor of National Grid. The utilities company, along with the city’s Department of Environmental Protection, is tasked with paying for the majority of the cleanup, with more than 25 smaller private parties also contributing.
In order to get all of the necessary equipment into the waterway, a barge pushing an excavator traversed the canal, causing both the Carroll Street and Union Street bridges to go up. Work related to the barrier wall got off to a shaky start, however, after that barge partially sunk during a rainstorm on Oct. 27.
“A tugboat subcontracted by National Grid’s environmental contractor, working on activities related to the Fulton former manufactured gas plant site, took on water during the heavy rain,” the spokesperson told the Eagle.
“The boat was moored and not in use when this occurred. There was no observed environmental impact. The tugboat was removed from the canal the following day and replaced that same day with another boat.”
EPA project manager Christos Tsiamis said the bilge pump — which normally removes liquid — failed, causing rainwater to weigh the boat down. An EPA representative confirmed that there were no delays or other impacts due to the incident.
Cleaning of the canal involves maintaining combined sewer overflow — a mixture of storm runoff and human waste — with two massive $1.2 billion retention tanks, dredging contaminated deposit that has accumulated due to industrial and sewer discharge, and capping the bottom of the waterway.
Tsiamis said at a recent community meeting that the dredging at the head of the canal is expected to begin in August or September of next year, but National Grid wants to delay the start date until May 2021.
“We had objections to the schedule they were presenting,” Tsiamis said.
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