Indicators:  Sound + Shore

Nitrogen in Long Island Sound

Connecticut’s campaign to reduce nitrogen from sewage treatment plants and large factories has been going well, but progress could be slowing.

The amount of nitrogen dumped into Long Island Sound and its tributaries affects oxygen levels in the water. Overall, Connecticut’s share of the total nitrogen pollution in Long Island Sound is about one-third, and New York’s is two-thirds. In April 2001, the federal Environmental Protection Agency approved the New York and Connecticut joint plan for implementing a Total Maximum Daily Load (TMDL). The TMDL is the maximum amount of pollutants that can be discharged while still allowing water quality standards to be attained. Connecticut’s target for 2014 is 3837 tons (or less) of nitrogen per year. This indicator tracks the nitrogen discharged to the Sound and major rivers by 79 sewage treatment plants, 3 large coastal industrial facilities, and a group of industrial sources in the Naugatuck River watershed. Connecticut's investments in nitrogen-removal technology have been successful. The goal for 2004 was met three years ahead of schedule. The next milestone is a goal of 5505 tons (or less) in 2009. There are large uncontrolled quantities of nitrogen entering Long Island Sound in the rain that runs off lawns and pavement.