The City of South Burlington Stormwater Utility received a grant from the Vermont Agency of Transportation to install two underground Stormwater infiltration practices in vacant lots adjacent to Airport Drive. The project includes the design and construction of two stormwater infiltration basins and drainage infrastructure to allow for the treatment of stormwater runoff form 0.825 acres of impervious surfaces and 0.614 impervious acres, for a total of 1.44 acres of impervious surfaces.
Previously untreated stormwater runoff generated from 1.44 acres of impervious surfaces discharged directly to the impaired Potash Brook near the intersection of Williston Road and Kennedy Drive. This project was identified as part of the Potash Brook Flow Restoration Plan (FRP), prepared by the City of South Burlington, in an effort to reduce flows to the impaired Potash Brook and improve water quality in the Lake Champlain drainage area.
The project reduces the peak flow of the 1-year, 24-hour storm event by 100%, from 2.06 cubic feet per second (cfs) to 0 cfs and infiltrates the water quality volume from 1.44 acres of impervious surfaces, reducing the amount of phosphorous going to Lake Champlain by 2.56 kg/year.
This project received funding from the Transportation Alternatives Grant Program administered by VTrans. The remaining project costs were paid using stormwater utility capital project funding.