Falmouth committee outlines ‘geo boundaries’ contingency plan for nitrogen reduction, urges public outreach and financing options

Falmouth water-quality advisers on the Water Quality Management Committee presented draft "geo boundaries" that identify parcels the town would require to upgrade onsite wastewater systems as part of a contingency plan to meet state nitrogen-reduction targets.

The plan matters because Massachusetts Department of Environmental Protection watershed plans must show how each watershed will meet its total maximum daily load (TMDL) for nitrogen over a 20-year schedule, with five-year checkpoints and contingency measures if targets are missed. Committee members said the geo boundaries are intended to limit required upgrades to the minimum number of homes needed to meet TMDLs if other credits (for example, fertilizer reduction or aquaculture) are not available.

The committee’s presentation described the scope and scale of the proposal and the questions that remain. Amy Lowell, Wastewater Superintendent for the Town of Falmouth, said the town has identified 14 nitrogen-sensitive watersheds that require watershed plans and that a contingency plan must rely on sewers and advanced on-site alternative (IA) systems, not on shellfish, inlet widening or fertilizer bans. "There has to be a description of all planned actions to achieve the necessary nitrogen load reduction. That can include a number of things, not just sewers or IAs. And then there has to be an implementation schedule with activities that have to occur within 5 year increments," Lowell said.

The committee gave parcel and housing counts to show the potential scale. By the numbers presented, the 14 watersheds…