Pollutants in the Water
12:23 pm
Tue July 15, 2014

Nitrogen Pollution in Long Island Sound Continues to Decline

A new report says nitrogen pollution discharged into Long Island Sound continues an overall decline. That's good news for marine life because too much nitrogen can fuel the growth of algae, which dies, settles on the ocean floor, and decays, using up oxygen in the process.

During summer, that can lead to a condition called hypoxia. "Hypoxia is a low-oxygen dead zone in the water," said Kurt Johnson, executive director of Save the Sound, an environmental advocacy group.

Those "dead zones" can make it hard for marine life to survive, particularly in the summer, when water stratifies into temperature layers that hinder the circulation of oxygen-rich water.

In 2001, Connecticut joined up with New York and the federal EPA to set goals for nitrogen discharges by sewage treatment plants. The idea was simple, reduce the amount of nitrogen to increase the amount of oxygen in the water. It appears to be working. State data shows 2013 nitrogen levels down 39 percent from levels in 2004.

There are other factors that can make hypoxia "dead zones" more pronounced -- things like warm weather, and nitrogen runoff from homeowners and roads.

Read more in the Department of Energy and Environmental Protection's 2013 "Hypoxia Season Review."