Long Island Sound - Pollution

Pollution

Major environmental problems currently affecting the Sound include hypoxia, toxic substance and pathogen contamination, debris and other man-made pollution, and overdevelopment. Industrial pollution includes mercury influx from the hatting industry in Danbury, Connecticut.

New York City and other municipal sewage systems have long dumped nitrogen, among other pollutants, into the Sound, which contributes to hypoxia. By 1994 a plan to reduce the dumping of nitrogen into the Sound was agreed to by the federal government and the states of New York and Connecticut. The goal was to reduce the amount of nitrogen entering the Sound by 58.5 percent as of 2014. New York City agreed with New York state and Connecticut to reduce nitrogen levels in 1998, but backed off its commitment and was sued by the state. In early 2006 the city agreed to lower nitrogen emissions and was given until 2017 to meet its reduction goals. By 2007, $617 million had been spent in upgrading sewage treatment plants, with 39 out of 104 retrofitted with devices to remove nitrogen.

A 2007 report by the Long Island Sound Study, a project of the U.S. Environmental Protection Agency, said the nitrogen flow is down 20 percent since 1994. But a study released in June 2007 by the Connecticut Council on Environmental Quality stated that in 2006 the area affected by hypoxia was a bit larger than in 1991.

There have been some improvements over the years, according to officials from the Long Island Sound Study. Levels of nitrogen have decreased in the waters off Stamford, Connecticut and in some areas west of Stamford. Yet some nitrogen pollution has been stored in the sediment at the bottom of the Sound, and warmer weather also keeps down levels of dissolved oxygen, according to the Sound Study officials.

"Not a whole lot is going to change until New York City gets on the nitrogen problem," said Tom Andersen, author of This Fine Piece of Water: An Environmental History of Long Island Sound, in a newspaper interview in June 2007. The city Department of Environmental Protection said it is spending millions of dollars to upgrade its four sewage treatment plants, and that the upgrade should significantly cut nitrogen discharges.

The western part of the Sound was in the worst condition, according to the U.S. Environmental Protection Agency's National Estuary Program Coastal Protection Report for June 2007. The report gives a "fair" rating to water quality in the sound and poor marks to fish, bottom-feeders and sediment. High levels of PCBs, were found in fish samples, and high concentrations of DDT were found in sediment. Development resulting from population increases, past industrial pollution and stormwater runoff all contribute to the poor quality of the water, according to the report.

Over the last several decades, excess nitrogen may have adversely affected Diatoms — microscopic, single-celled algae at the base of the food chain, which make shells ('frustules') of opaline silica. When diatoms are less productive, they are replaced by other phytoplankton such as dinoflagellates or blue-green algae, which grow well in waters with high nitrogen levels, but do not need silicon. Such a change in the base of the foodchain could have such consequences as an increase in abundance of jellyfish and decline in shellfish and other fish. Gary Wikfors, a fish biologist with the Milford, Connecticut office of the federal National Oceanic and Atmospheric Administration said he has seen no evidence of fewer plankton in the sound or more blue-green algae. "I study algae blooms," he said in a newspaper report. "I have to go to the Chesapeake Bay to study them. I can't find them in the Sound."

Starting in the 1990s, Connecticut and federal Environmental Protection Agency (EPA) officials created no-dumping areas in which commercial or recreational boat users were prohibited from releasing untreated sewage into the Sound near the coastline. In 2007 state and federal officials announced the ban had extended to the entire Connecticut coast and applied to both treated and untreated sewage. New Hampshire and Maine have similar bans, but not Massachusetts, Maine or New York. From the 1990s to 2007, the number of pumping stations for boat sewage tripled to 90 at marinas up and down the coast. Violators may be charged with a state misdemeanor and face $250 fines, or a federal civil penalty, with fines of up to $2,000.