Over the past several years, DEP engineers and planners have been working to develop new methods to clean water bodies across New York City, conducting research on “tunneling in urban areas,” a spokesperson for the DEP told local media. The agency also plans to construct overflow tunnels for its Newtown Creek and Flushing Bay projects. The construction of a tunnel for the Gowanus Canal could be done for “roughly the same cost as the tanks,” DEP says, which is currently estimated at $1.2 billion.

This October, the DEP presented revised designs for the Gowanus CSO Facility, which includes an eight-million-gallon CSO tank (with a second four-million-gallon CSO tank installed mid-canal), head house, and 1.6 acres of open space. The agency has recently completed the acquisition of a number of plots of land via eminent domain for the facility.