New Menauhant Bridge

Widening of Bournes Pond Inlet

September 2019 – The largest source of controllable nitrogen in Bournes Pond is from wastewater from on-site septic systems. To assist in this nitrogen removal, without sewering the Davisville area, the Town of Falmouth has opted to pursue inlet widening for Bournes Pond.

According to a September 2019 report to the Town of Falmouth Board of Selectman, the project is now in its final design and permitting phase. To date, all pre-construction permits have been obtained. It is anticipated that construction will begin as early as Fall 2020 with completion currently anticipated by December of 2022.

The Notice of Project Change (NPC) for the inlet widening project was filed in 2016. Several ecological assessment studies were conducted between 2015 and 2018 by Stantec, AECOM, and Applied Coastal to evaluate flood impacts, eelgrass beds, and shellfish locations in relation to the widened inlet. The project is now in its final design and permitting phase, and to date, all pre-construction permits have been obtained.

In addition to the inlet widening, the Town is currently evaluating suitable potential acreage for significant shellfish aquaculture activities in Bournes Pond which could remove about one-third of the total nitrogen needed to meet the TMDL goal. Additional nitrogen reductions are anticipated from shellfish bio-deposit denitrification.

To meet the remaining nitrogen removal requirements to achieve the TMDL, the Town's plan expects the fertilizer bylaw and stormwater management practices will receive the State-approved nitrogen reduction credit of 25% reduction of the total attenuated load from these sources. It is estimated that the nitrogen reduction from the inlet widening, State-approved credits, and shellfish aquaculture will be close to meeting the TMDL. Since Falmouth has adopted an adaptive management approach, if these efforts do not fully meet the nitrogen removal requirements, the Town can consider sewer extensions along Route 28, the use of I/A systems, exploring sites for a PRB in the upper watershed, and exploring nitrogen reduction options entering from Bournes Brook to achieve TMDL compliance in the Bournes Pond watershed.