New York agrees to modified CSO consent decree incorporating green infrastructure

According to the New York Times, between 2006 and 2009 more than 9,400 of the US’s 25,000 sewage systems have violated the law by dumping untreated or partly treated human waste, chemicals and other hazardous materials into rivers and lakes and elsewhere, according to data from state environmental agencies and the EPA.   In New York the sewer system overflows just about every other time it rains.  According to the New York Riverkeeper, more than 27 billion gallons of raw sewage and polluted stormwater discharge from 460 combined sewer overflows (CSOs) into New York Harbor each year.

The New York State Department of Environmental Conservation (DEC) and New York City Department of Environmental Protection (DEP) have announced a $3.8 billion agreement over 18 years to reduce combined sewer overflows.  $2.4 billion has been allocated for green Infrastructure projects.  These include blue roofs and green roofs, which use mechanical devices or vegetation to slow down drainage from roofs, porous pavement for parking lots, tree pits and streetside swales for roadways, wetlands and swales for parks, and rain barrels in some residential areas.  $1.4 billion has been allocated for gray infrastructure such as holding tanks for CSO overflows in wet weather and treatment plant expansions.

The agreement resolves all outstanding compliance issues associated with the Consent Order mandating the City to reduce CSOs.  The state has agreed to defer decisions on more gray infrastructure projects in certain parts of New York until completion of the green infrastructure demonstration projects.  The modified Consent Order puts into place the elements of a green infrastructure adaptive management approach.  Over the next 18 years, the City will control the first inch of rain from 10 percent of the City's impervious surface with green infrastructure.  The Consent Order requires five-year incremental milestones to meet that goal, and annual reporting on progress. The City will invest $187 million in public funds toward the achievement of the first five-year target.  The remainder of the funding will be a combination of public and private.