Ix. Dredging Impacts to Water Quality

Keystones of the MEP include modeling support upon request of municipalities and the analysis of non-traditional approaches to nitrogen mitigation. In the case of the Popponesset Bay System, channel dredging was evaluated to determine potential effects on nutrient related water quality. Dredging of inlets and channels is conducted for a variety of reasons throughout southeastern Massachusetts and even within a single system. For example, within New Bedford Inner Harbor dredging has recently been conducted in one region for removal of PCB contaminated sediments and in another region for navigation associated with port activities. In the case of the Popponesset Bay System, maintenance dredging of the inlet has been conducted over the past several years for navigation and for the general health of the system and additionally for beach nourishment (Popponesset Spit). The Mashpee Waterways Commission has developed various dredging plans for dredging within the Bay System, some of which are currently underway, some for which permits are being sought and some for future design (Figure IX-1). The various dredging projects are conducted by both municipal and private entities.