For the second summer in a row, scientific evidence shows improving water quality and ecological conditions for organisms that live in Long Island Sound.
According to the U.S. Environmental Protection Agency (EPA), concentrations of dissolved oxygen are higher than the long-term average in Long Island Sound. Aquatic animals rely on oxygen that is dissolved in water to survive.
When dissolved oxygen levels decline, this can cause some animals to move away, weaken, or even die. Low dissolved oxygen can occur when nutrients such as nitrogen enter a water body in excess, over stimulating plant growth.
Nutrients such as nitrogen can enter a water body through discharges of sewage and from fertilizer runoff.
A two-state effort
In recent years, Connecticut and New York state have worked with the EPA to implement a nitrogen pollution reduction plan to improve the Sound’s dissolved oxygen levels, and to protect aquatic animals and public health.
Much of the improvements in water quality is attributable to wastewater treatment facility upgrades and other measures that are reducing nitrogen pollution to the Long Island Sound.
In 2013, Connecticut and New York wastewater treatment facilities in the Long Island Sound basin discharged 35 million fewer pounds of nitrogen compared to the amount discharged annually in the early 1990s, primarily due to advanced wastewater treatment upgrades that employ technologies to reduce nitrogen.
Flooding and animal life
In addition to causing low levels of dissolved oxygen, there are other harmful effects from high levels of nitrogen and other nutrients. Coastal wetlands that protect coastal communities against flooding can be degraded and harmful algae blooms can flourish, threatening aquatic animals and public health.
“We need to make financial investments in sewage treatment plants, and work to reduce pollution from septic systems and fertilizers, which also degrade water quality in Long Island Sound,” said Judith A. Enck, a regional EPA administrator.