By Marissa Kaika, Special to The New London Day

Stonington — The Eastern Connecticut Conservation District will be installing a variety of stormwater management components at a condominium complex in Quanaduck Cove to help prevent contaminated water from flowing into Stonington Harbor and Long Island Sound.

The project, in partnership with the Quanaduck Cove Court Condominium Association, is funded by a roughly $59,000 grant from the Long Island Sound Futures Fund and is targeted at improving the water quality of Long Island Sound and its surrounding waterways. The ECCD matched the grant with approximately $44,000, resulting in a total of about $103,000 for the conservation effort.

According to the ECCD, nitrogen pollution from stormwater runoff poses a very large threat to the Sound’s water quality and marine life. When rain falls on paved surfaces, it can’t be absorbed or filtered by the ground, so it flows into nearby water bodies instead.

To help address nitrogen pollution in Quanaduck Cove and consequently Long Island Sound, the ECCD plans to install 20 downspout planters and three rain gardens to help intercept and filter polluted stormwater, according to ECCD conservation technician Heather Palardy. Downspout planters purify stormwater by using a large box of flowers or vegetation as a water filter. Stormwater from the roof is diverted from a gutter downspout, or vertical pipe, into a planter where the water is filtered through the soil before draining into the cove.

Similarly, rain gardens help absorb and filter stormwater that falls on paved surfaces like driveways or parking lots. Additionally, the ECCD will be removing invasive species and enhancing the site’s riparian buffer — a vegetated area near a waterway — to keep away geese and to feed nutrients into the cove.

“With the Long Island Futures Fund grant, we’re trying to address nitrogen pollution discharges into Long Island Sound,” ECCD Executive Director Dan Mullins said. “If you have too much nitrogen in Long Island Sound … you can have algae blooms that cause hypoxia, low levels of oxygen, or anoxia, where there’s no oxygen in the water, and that causes fish kills (die-offs) and other issues.”

Additionally, stormwater pollution can greatly impact a variety of recreational activities in coastal areas, including swimming or fishing. When bacteria and pathogens from stormwater flow into bodies of saltwater, the excess bacteria can lead to beach closures and poor water quality, Mullins said.

Once completed, the Quanaduck Cove project is expected to prevent approximately 43,560 gallons of polluted stormwater from entering Stonington Harbor and Long Island Sound each year, according to the Long Island Sound Futures Fund.

While the project’s main goal is to help reduce stormwater runoff pollution into the Sound, the Quanaduck Cove site also will serve as a demonstration site for developers, managers and residents of other multi-unit residential complexes. As a part of the conservation effort, the ECCD will create a manual detailing how multi-unit residential complexes can implement different stormwater management practices into their facilities.

“Getting condominium associations involved with installing green infrastructure to address stormwater pollution is really important,” Mullins said. “It’s kind of a niche that hasn’t really been filled yet by anybody, so we’re excited that we’re going to be developing a brochure or a guide for condominium associations to use so they can implement stormwater infrastructure at their facilities as well.”

The project is ongoing, but due to a delay in receiving the grant, the ECCD anticipates that it’ll take longer than expected to remove the invasive species in the area now that they’re in bloom. The deadline for the project’s completion is March 2024.