The New London Day 12/9/2025

Stonington — The Department of Public Works began work in front of Stonington High School last month on a project to improve water quality.

As part of a broader plan to clean stormwater before it enters the groundwater, the Department of Public Works is installing a rain garden at the corner of Route 1 and Spellman Drive to clean runoff from most of the high school parking lot and a portion of the roof.

The engineered rain garden, called a bioretention cell, is essentially a large, landscaped hole designed to capture rainwater and hold it temporarily while vegetation like native grasses and flowering plants naturally filters out contaminants like oil, salt, harmful chemicals and heavy metals.

Town Engineer Chris Greenlaw explained Tuesday that the first 1.3 inches of rain that falls will flush the majority of contaminants from the parking lot and roof, and the system is designed to capture that “first flush” of stormwater runoff.

Jeff Pescosolido, Public Works director, said Tuesday that the work should last another week, weather permitting, and is being funded through the department’s operating budget.

Civil Engineer Steve Trinkaus, a recent hire to the Public Works Department Engineering division, said planting will have to wait until spring, when a wildflower mix will go into the bottom of the garden.

“Then there’s cluster plantings of other native plants on the side slopes of the basin that will bloom at different times of year for birds and bees,” Trinkaus explained.

The project is just one part of broader work the town is undertaking as part of federal Municipal Separate Storm Sewer System compliance and to implement low-impact development practices in town.

Low-impact development seeks to reduce flooding, replenish groundwater and limit the pollutants that enter waterways in a sustainable and aesthetically pleasing manner that mimics natural processes.

The work will also support other town efforts to improve the quality of water in the Wequetequock watershed and Wequetequock Cove including a $545,000 project funded by a Connecticut Department of Energy and Environmental Protection grant to install rain gardens and other natural stormwater filtration tools in and around Spellman Drive and nearby neighborhoods.

Wequetequock Cove consistently receives poor water quality scores and received an overall grade of D- in the 2024 Save the Sound Water Quality Report Card.

A 2021 plan to mitigate the pollution in the Anguilla Brook/Inner Wequetequock Cove watershed prepared by the Eastern Connecticut Conservation District identified a number of sources of contamination but primarily pointed to water runoff that included animal waste and fertilizer among other substances as well as failing septic systems and cesspools.

https://theday.com/news/821091/stonington-addresses-water-quality-with-spellman-drive-project