Blanchette Brook Treatment Areas

Blanchette Brook Treatment Areas


The Colonel Westbrook treatment areas project includes portions of Spring Street, County Road, and commercial properties in the Colonel Westbrook Industrial/Commercial Park, in Westbrook. The project area treats 33 acres, including 17.7 acres of developed land. The area also includes numerous ditches and pipe networks on public and private land that direct stormwater runoff to Blanchette Brook. High temperature, low dissolved oxygen and high flows are the primary water quality problems in Blanchette Brook.

Before construction, a stormwater pond provided flood control but did not treat stormwater. An existing stormwater pond was retrofitted to a gravel wetland, with the goal of removing 99% of the sediments, oils, zinc, and other pollutants before the runoff enters the Brook. 

In addition to the gravel wetland, five underdrained soil filters, one Brentwood StormTank system, and two StormTech chamber systems were also installed on the site. The combination of all of the systems remove pollutants and cools and slows the flow of water into the Brook after storms.

Project Stats

  • Installation Date: 2012
  • Total Acres IC Treated: 16.39
  • Total Installation Cost: $615,796
  • Cost/Acre Treated: $37,571
  • Designed by: Sevee & Maher Engineers, Inc