CONCORD, Mass. – The Chelmsford Department of Public Works (DPW) is seeking a permit from the U.S. Army Corps of Engineers, New England District to conduct work in waters of the U.S. in conjunction with placing fill material to build the Merrimack River Bank Stabilization project in Chelmsford, Mass
The proposed project is to perform work and place fill material below the ordinary high water line (OHWL), of waters of the U.S. in order to build the Merrimack River Bank Stabilization Project. Some 1.36 acres of fill below the OHWL would be placed along 3,950 linear feet of river bank to stabilize the river bank along a stretch of the Merrimack River.
An adjacent residential condominium complex occupies approximately 82 acres along 4,520 linear feet of shoreline. Approximately 1,605 residents live in 535 residential units. Wastewater disposal for the condominium complex is collected in an existing gravity sewerline located parallel and adjacent to the Merrimack River. Sewage flows by gravity easterly to a pump station, from which sewage is pumped to, and treated at, the Lowell Wastewater Treatment Facility. The purpose of this bank stabilization project is to prevent further erosion which could wash out, expose, and rupture the existing gravity sewer which serves the 535-unit condominium complex.
The river bank in this location is eroded with vertical, nearly vertical, and undercut banks. The proposed project is a hybrid design that incorporates a combination of structural and non-structural methods to provide the required level of protection, and it incorporates living materials to stabilize the bank and provide habitat.
Three stabilization techniques are proposed: Bank Support (timber toe protection and vegetation management), Bank Repair (installing stone sill and soil to stabilize the slope), and Bank Restoration (restoring the entire slope cross-section by installing a stone sill and reconstructing the bank with coir fiber rolls and replanting the slope). In all three treatment zones, an invasive species management plan would be developed and implemented to promote the growth of native species.
Additionally, trees on the slope and along the top of slope that are in imminent danger of toppling would be removed to maintain the integrity of the reconstructed, repaired, and supported bank reaches. The project would be performed under a grant from the Federal Emergency Management Agency (FEMA).
Stabilizing the riverbank would involve work along the toe of slope within the Merrimack River. The following measures are proposed in order to avoid and minimize impacts to the water quality and riverine habitats during construction: a turbidity barrier would be installed in the river around active work areas to contain turbid water and prevent its transport outside of the work zone; a proposed “marine mattress” and stone sill would be installed and would provide a raised work platform on which construction equipment can work.
This would minimize equipment working on river sediments and in the water column. After the installation of the marine mattress and stone sill, all other work would occur above the water elevation.
This proposed project would impact 1.36 acres of Essential Fish Habitat (EFH) for Atlantic Salmon. This habitat consists of riverbank habitat. Loss of this habitat may adversely affect Atlantic Salmon. However, the Corps has made a preliminary determination that the site-specific adverse effect will not be substantial. Further consultation with the National Marine Fisheries Service regarding EFH conservation recommendations is being conducted and will be concluded prior to the final permit decision.
The public notice, with more specifics on the work proposed by Chelmsford DPW, can be viewed on the Corps website at www.nae.usace.army.mil/Missions/Regulatory/PublicNotices.aspx. The application for the federal permit was filed with the Corps in compliance with Section 10 of the Rivers and Harbors Act, which provides for federal regulation of any work in, or affecting navigable waters of the U.S.; and Section 404 of the Clean Water Act, which regulates the discharge or fill of material in U.S. waters, including wetlands.
Public comments on this work proposed by the Chelmsford DPW (file # NAE-2016-1969) should be forwarded no later than May 25, 2017 to the U.S. Army Corps of Engineers, New England District, Regulatory Division (ATTN: Kevin Kotelly), 696 Virginia Road, Concord, MA 01742-2751. Additional information is available from Permit Project Manager Kevin Kotelly at 978-318-8703 or toll free 800-343-4789 or 800-362-4367 (if calling from within Massachusetts) or by email to: email@example.com.