Earlier this month, contractors working for the Environmental Protection Agency began work on a dredging and capping pilot study in the Gowanus Canal’s 4th Street Turning Basin.
The process involves installation of steel sheeting in front of existing bulkheads, followed by dredging of contaminated sediment from the canal, before the installation of a multi-layered protective cap at the bottom of the canal.
The EPA expects to complete this pilot effort in the Spring of 2018.
The results of the study will be used to evaluate and finalize the elements for the dredging and capping of the entire canal.
In October 2016, the first phase of work performed in the turning basin, which consisted of the removal of debris from the bottom of the basin, was completed.
This second phase of work, referred to as the Dredging and Capping Pilot Study, will include dredging contaminated sediment from the turning basin and installing a multi-layer protective cover or cap on the original canal bottom.
Contaminated sediment removed during dredging will be transported via barge for processing at the staging area location (the secured open lot at Smith and Huntington streets which is part of the Citizens MGP State Superfund site).
“There, water drained from the dredged sediment will be removed from the barge and environmentally treated before being discharged to the canal,” EPA said.
Cement-like material will then be added to the dewatered contaminated sediment in order to stabilize it prior to transport via barge to off-site licensed disposal facilities.