Long Island Sound is a cherished national natural resource, surrounded by some of the most densely populated land in the country. It has long provided sustenance, economic opportunities and comfort to the spirit for those who inhabit or visit its shores and waters. Like many of our Nation's water bodies, it drains a substantial and diverse watershed, and suffers a broad range of environmental insults. The problem of most concern is the severe shortage of oxygen in the deep waters of the western part of the Sound during summer months. This hypoxia is attributable to excess nitrogen that fuels the growth of algae in which, when decomposing, draw oxygen from the water, denying it to other aquatic life. While a considerable amount of nitrogen derives from surface runoff and atmospheric deposition, the main contributors are the many sewage treatment plants that pour thousands of pounds of nitrogen into the Sound and its tributaries each day. To address this problem, the two states primarily encompassing the Sound, New York and Connecticut, have taken measures to upgrade their sewage plants with nitrogen removal technologies. Connecticut has gone further, devising a program under which sewage plants may create, sell and purchase credits in order to meet their nitrogen effluent limitations.
Ann Powers, The Connecticut Nitrogen Exchange Program, 14 Penn St. Envtl. L. Rev. 195 (2006), http://digitalcommons.pace.edu/lawfaculty/205/.