The Topsham Fair Mall Stream Watershed Boundary Topsham Fair Mall Stream Watershed Plan

The Topsham Planning and Development Committee plans to take steps to improve water quality in the town’s Fair Mall stream watershed.

The 1.4-mile stream flows through an area of high-density commercial development and a section of Interstate 295, with small residential development areas at the upper and lower edges of the watershed.

While streams typically begin to show impairment when their watersheds exceed 8-10% impervious cover, meaning the ground struggles to absorb and filter water, this watershed is 30% impervious.

According to the Topsham Fair Mall Watershed Plan, the stream does not currently meet Maine water quality standards and must undergo restoration under the U.S. Clean Water Act.

“The plan identifies multiple issues of impairment that include chloride levels, temperature, untreated impervious surface, and morphological changes,” said Topsham’s Planning and Development Director Rod Melanson. “The ongoing issue that we are attempting to address in the watershed is to reduce the amount of chloride that enters the stream.”

The select board on Thursday authorized the planning department to sign a grant agreement with the Maine Department of Environmental Protection to fund the project, which comes with an estimated $156,000 price tag.

As part of the project, a biofiltration system will be installed, deicing procedures for roads in the area will be changed to reduce chloride runoff, and landowners will be eligible for funding for storm water system upgrades.

Melanson said there is a two-year timeframe to implement this grant.