The Long Island Sound Study (LISS) was initiated in 1985 by a partnership between the federal government and the states of Connecticut and New York. In 1987, the Long Island Sound was designated an "Estuary of National Significance" under the National Estuary Program (NEP). The NEP is conducted under the auspices of Section 320 of the Clean Water Act to protect nationally significant estuaries from pollution, development, and overuse.

The Long Island Sound Comprehensive Conservation and Management Plan was approved in September 1994. Researchers, regulators, user groups and other concerned organizations and individuals, collectively known as the LISS Management Conference, have been working together to protect and improve the health of the Sound by implementing the CCMP. The New York State Clean Water/Clean Air Bond Act has provided over $200,000,000 for CCMP implementation and the restoration of Long Island Sound.

 What is Suffolk County's role in the LISS?

The Long Island Sound Study has mandated a 58.5% reduction in anthropogenic (from human activities) nitrogen inputs. This reduction applies to each “management zone,” including Suffolk County (“LISS Zone 11"). As part of the nitrogen reduction process, a Total Maximum Daily Load (TMDL) for nitrogen has been adopted by New York State to meet the 58.5% load reduction requirement. Plans must be developed to attain the TMDL, and it must be implemented over 15 years. Unlike many other LISS management zones, Suffolk County is unlikely to meet the nitrogen reduction requirements based on sewage treatment plant upgrades alone. Therefore, New York State recognized the need to conduct a watershed planning process that considers land use management and non-point source pollution.

The Office of Ecology received a $300,000 grant from NYSDEC to manage the LISS Suffolk County North Shore Embayments Watershed Management Program. A water quality monitoring program was established in the spring of 1999 to support this effort. Areas sampled included the Huntington/Northport Bay complex, Nissequogue River, Stony Brook Harbor, Port Jefferson Harbor, Mt. Sinai Harbor, and Mattituck Creek. These areas continue to be sampled on an approximate monthly basis by SCDHS staff. Consultants hired to conduct the embayments study (Nelson, Pope and Voorhis, and EEA) produced a final report in 2007 that presented a range of recommendations for reducing nitrogen inputs to the sound. To obtain a copy of the report, please contact the Office of Ecology at (631) 852-5760.