Municipal Separate Storm Sewer System (MS4)

In the spring of 2009 the Town of East Hampton was notified by New York State Department of Environmental Conservation (NYSDEC) that the Town would be covered under what is called an MS4 (Municipal Separate Storm Sewer System) permit issued by the Environmental Protection Agency (EPA) and administered by NYSDEC. The reason for the Town to be included in this permit is due to the fact that a few of our waterbodies, Accabonac Harbor, Lake Montauk and Northwest Creek, have surpassed their TMDL (total maximum daily load) levels of pathogens.

Over a 3-year period, following notification of coverage, the Town is required to implement a stormwater management program (SWMP) to satisfy the appropriate water quality requirements of the Environmental Conservation Law and Clean Water Act.

Development within the Town increases the amount of impervious surfaces, which leads to an increase in runoff and runoff borne pollutants. These pollutants are deposited from the atmosphere, leaked from vehicles or are windblown from adjacent areas. During storm events these pollutants quickly wash off and are rapidly delivered to downstream waters or stormdrains. The Pollutants of Concern (POC) entering our waterbodies are pathogens; these are found in pet and other animal waste along with failing septic systems and other waste storage facilities. Other pollutants that are not addressed in this permit, but which are detrimental to the environment are suspended solids, trace heavy metals, hydrocarbons (oil and grease), nutrients (phosphorous and nitrogen), pesticides and chlorides (road salt).