The U.S. Environmental Protection Agency (EPA) Region 1 has published its Final Rule to designate an Ocean Dredged Material Disposal Site Isles of Shoals North (IOSN), as described below, for the Southern Maine, New Hampshire, and Northern Massachusetts Coastal Region, pursuant to the Marine Protection, Research and Sanctuaries Act, as amended (MPRSA). The Final Rule was published in the Federal Register, Today, September 25, 2020 at 85 FR 60383. EPA has also released a Final Environmental Assessment and Evaluation Study for Designation of an Ocean Dredged Material Disposal Site for the Southern Maine, New Hampshire, and Northern Massachusetts Coastal Region, September 2020 (Final EA) which includes our response to comments and Site Management and Monitoring Plan (SMMP).
The IOSN is located in the Gulf of Maine, approximately 10.8 nmi east of Portsmouth, New Hampshire, 9.55 nmi southeast of Kittery, Maine, and 6.04 nmi northeast of Eastern Island, the closest of the Isles of Shoals. The site is delineated as an 8,530 ft diameter circle on the seafloor with its center located at 70° 26.995′ W and 43° 1.142′ N. Water depths at the IOSN range from 295 ft on the western edge of the site to 328 ft on the eastern edge as the seafloor gradually slopes from west to east. The surficial sediments at the site are predominately soft, fine-grained silts and clays. The seafloor within the site is generally a smooth, soft-textured surface with topographic highs present outside the western, northern, and southeastern, boundaries of the site.