Niantic River Tree Filters

The Eastern Connecticut Conservation District (ECCD) has received funding from  CT DEEP through the Clean Water Act §319 NPS program to install storm water tree filters in downtown Niantic and on Mago Point in Waterford, in partnership with the Towns of East Lyme and Waterford.

Tree filters improve water quality by filtering stormwater runoff from impervious surfaces (like rooftops, roadways, parking lots, driveways and sidewalks) through a specially formulated soil mixture that removes common pollutants. These pollutants include sand (from winter road sanding), the plant nutrients nitrogen and phosphorus (commonly found in commercial fertilizers), pathogens, and heavy metals and chemicals from automotives. After stormwater has filtered through the special soil mix, it either soaks into the ground surrounding the tree filter, or during a big rainstorm, is directed into a nearby stormdrain via an underdrain that connects the tree filter to the storm drain.

Schematic of a tree filter system depicting open frame concept and underdrain connection to nearby stormdrains.

Schematic of a tree filter system depicting open frame concept and under-drain connection to the nearby storm drain system.

Four tree filters have been installed along Pennsylvania Avenue in partnership with the Town of East Lyme, as part of a STEAP-funded Downtown Niantic Improvement project. These tree filters will intercept and treat polluted stormwater from a heavily traveled section of Pennsylvania Avenue and soak it into deep sandy soils found under downtown Niantic. Previously this stormwater flowed directly into the Niantic River without any water quality treatment. With the installation of these four tree filters, approximately 162,000 gallons per year of contaminated stormwater have been removed from the Niantic River, helping to make it cleaner and safer for recreation and wildlife.

Tree filters along Pennsylvania Avenue in Niantic.

Tree filters along Pennsylvania Avenue in Niantic.

In September 2016 four tree filters were installed at the State of Connecticut overflow boat launch parking lot at Mago Point in Waterford. These tree filters were installed as part of a parking lot improvement in partnership with CT DEEP’s Boating Division and the Town of Waterford. The tree filters and other LID practices to be incorporated into the parking lot design will treat approximately 950,000 gallons of stormwater runoff each year, helping to protect and improve water quality in the Niantic River so that it is safe for boating, swimming and shellfishing.

A tree filter installed at the CT DEEP Mago Point (Waterford) overflow parking lot.

A tree filter installed at the CT DEEP Mago Point (Waterford) overflow parking lot.

A tree filter installed along Mago Point Way at the CT DEEP overflow parking lot on Mago Point.

A tree filter installed along Mago Point Way at the CT DEEP overflow parking lot on Mago Point.

 

Check out this power point for additional information on this project.

 

For more about tree filters, you can visit these sites:

            * LID Urban Design Tools

            * Tree Box Demonstration Project 

            * Stormwater Tree Pits