The Connecticut River Basin (CRB) is one of the largest basins draining into the Long Island Sound between the metropolitan New York City region and the southern coast of New England. A previously-completed study of conditions in the Sound has identified low dissolved oxygen (DO), or 'hypoxia', as its most pressing problem, and related research and computer modeling efforts have linked the low DO occurrences to excess loading of nitrogen to the system. In response to this situation, the Connecticut Department of Environmental Protection (CTDEP) and the New York State Department of Environmental Conservation (NYSDEC) completed a total maximum daily load (TMDL) analysis for DO in the Sound. The Long Island Sound (LIS) TMDL, approved by the U.S. Environmental Protection Agency in April 2001, identifies actions necessary to attain water quality standards (WQS) for DO in the Sound by 2014.