Exploring Innovative and Cost-Effective Solutions to Contaminated Sediments to Achieve Ecological Restoration of the Lower Neponset River

Abstract

This past decade has seen financial and volunteer investment in a cleaner, more accessible Neponset River. With these tangible improvements has also come a campaign to re-orient the public, and their perception of the river, from its previous reputation as an "open sewer" to a new role as a habitat for anadromous fish, venue for recreation on its waters, celebrations on its banks, and an inspiration for revitalizing the village of Lower Mills. From an ecological perspective, the Neponset is unique among urban rivers as its estuary remains largely intact and only two dams prevent anadromous fish from reaching fifteen miles of free-flowing habitat. However, the U.S. Geological Survey has documented elevated levels of polychlorinated biphenyls (PCBs) in the soft sediment impounded behind the two dams and the water column in the lower five miles of the Neponset River. Decision-making about river restoration and sediment remediation must proceed concurrently when traditionally they would proceed on separate regulatory pathways. In addition, alternatives for fish passage and ecological restoration must not constrain remediation options and, conversely, remediation options must not limit the feasibility of alternatives for fish passage and ecological restoration. This workshop explores a range of potential remedial options, from traditional to innovative in the context of an ecological restoration effort that includes dam removal among the suite of alternatives.