The plan, announced on Tuesday by Mayor Michael R. Bloomberg, calls for building an infrastructure to capture and retain storm water before it reaches the sewer system and overloads it. The city would foster investments in projects like green roofs with plantings, porous pavement for parking lots, rain barrels, wetlands and depressions for collecting water in parks, for example.The key is managing runoff from rains and reducing the overflows.
Such strategies would complement more traditional methods to control sewage overflows like underground storage tanks and tunnel systems.
The plan is intended to block the overflow of untreated sewage and storm water into bodies of water like New York Harbor, Jamaica Bay and Newtown Creek when it rains. This week, Newtown Creek, which straddles Brooklyn and Queens, was designated a federal Superfund cleanup site by the Environmental Protection Agency because of severe pollution that includes discharges from sewer pipes that would otherwise overwhelm the city’s 14 wastewater treatment plants.
And another sewage-choked body, Gowanus Canal in Brooklyn, was designated a Superfund site in March.
The problem of overflow from sewers is common around the country, and the city’s proposed solutions parallel approaches that are being tried in other cities.
City officials said that the natural features like plantings would help reduce sewer overflows by 40 percent by 2030 and reduce the city’s sewer management costs by $2.4 billion over 20 years, helping to keep water bills down for ratepayers. Up to 30 billion gallons of overflows from the city’s sewer system, which carries both sanitary sewage and storm water from the streets, end up in the waterways each year.
“Our green infrastructure plan is bringing a new approach to an old problem by using natural means to capture the storm water that too frequently overloads the system,” Mr. Bloomberg said in a statement. “The plan will help clean our waterways, green the city and reduce the costs for residents and business owners, who pay the bills for maintaining the city’s water and sewer systems.”
Raw sewage that finds its way into area waters can lead to beach closures, incidences of gastrointestinal disease and foul stenches that can persist.
The following video shows quite clearly what happens following a serious rainfall. It was taken along the Gowanus canal (which was just declared a Superfund site) following the massive storm on September 16, 2010 that rumbled through the New York City metro area and spawned two tornadoes and a macroburst, but it is typical during any significant rainfall.
That massing tidal bore of sewage is what happens - and that ends up in area waterways every time there's a major rain event.
While the city has gotten better at reducing sewage emissions, the problem during rain events persists.