Nutrients

The U.S. Geological Survey, New England Water Science Center, in collaboration with the U.S. Environmental Protection Agency (EPA), is modeling seasonal nutrient loads to Long Island Sound (LIS). Nutrients that originate from within the 41,867-square-mile section of the LIS watershed that is north of the Sound include both point (specific) and nonpoint (widespread) sources. Dynamic modeling of the...

During the past 20 years, nitrogen loads to Long Island Sound (LIS) have been substantially reduced in large watersheds affected by municipal wastewater loads.

Coastal estuaries in southern New England and New York show the effects of excess nutrients and coastal eutrophication. These include excessive growth of macroalgae, excessive blooms of phytoplankton, oxygen depletion, hypoxia and deteriorated substrates. State and Federal regulators have responded to these nutrient-caused impairments by requiring more stringent permit limits for National...

The USGS, in cooperation with the Connecticut Department of Energy and Environmental Protection will be collecting water-quality and hydrologic data at four embayments from April 2021 to March 2025: Mystic, Norwalk, Saugatuck, Sasco-Southport complex, and Farm.

The Pawcatuck River and the Pawcatuck River Estuary and Little Narragansett Bay form part of the boundary between the States of Connecticut and Rhode Island. Both states have identified water quality impairments within these waters related to nutrients (insufficient oxygen) and bacteria. Studies of the eutrophication potential of Long Island Sound embayments have identified that the Pawcatuck...

In 2018 USGS began work on the development of regional-scale groundwater flow and nitrogen transport models of areas along the Connecticut coast. The model will be used as a quantitative tool to evaluate groundwater flow and nitrogen loading to Long Island Sound.

The 2,983 miles of streams in Connecticut support a range of uses, including drinking water, recreation, and fish and shellfish habitat. The State is required by the Clean Water Act to assess the health of these waters every two years.

River-borne nutrients, especially nitrogen, contribute to water-quality degradation in Long Island Sound. The Connecticut River is the largest tributary to the Sound, and quantification of nutrient loads from the three upper States in the watershed, as well as the State of Connecticut, is essential for prioritizing efforts to improve the Sound’s water quality.