CONCORD, Mass. – Neptune LNG, LLC 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 the decommissioning of the Neptune Deepwater Liquid Natural Gas (LNG) Port off the coast of Marblehead, Mass.
This work is proposed in the Atlantic Ocean three miles off the coast of Marblehead. The work proposed by Neptune LNG, LLC involves the decommissioning of the Neptune Deepwater LNG Port. The proposed decommissioning work plan will include the complete removal of the hot tap assembly that attaches the Neptune LNG line to the Algonquin LNG Hubline, three transition manifolds, two submerged turret loading buoys, and 16 mooring lines consisting of wire rope and chain. The applicant’s preferred work plan proposes to abandon in place 13.1 miles of 24-inch pipeline which is buried 1.5 feet below the mudline, and 16 suction piles that will be capped with trawl guards. This proposed action will result in the addition of 11,500 square feet of new structures sitting 6.4 feet above the mudline in waters of the U.S.
The applicant has provided three other alternatives for the removal or abandonment of the suction piles:
Alternative 1 involves full removal of all 16 suction piles utilizing a reverse installation method which would result in 6,086 square feet (0.13 acres) of temporary impacts to waters of the U.S. The applicant does not prefer alternative 1 as they state pile removal may fail resulting in a larger portion of pile(s) partially exposed above the mudline and full pile removal poses a larger danger to divers working on the decommissioning.
Alternative 2 involves cutting the suction piles 15 feet below the mudline. A 56-foot radius would be excavated around the pile, the pile cut, the 15-foot cut section removed from the area, and the excavated sediment placed back over the cut pile. Alternative 2 would result in 4.97 acres of temporary impacts to waters of the U.S. The applicant does not prefer alternative 2 as they state it results in larger impacts to waters of the U.S. compared to the preferred alternative of abandoning piles in place and covering the piles with trawl guards.
Alternative 3 involves cutting the suction piles 3 feet below the mudline. A 17-foot radius would be excavated around the pile, the pile cut, the 3-foot cut section of pile removed, and the excavated sediment placed back over the cut pile. Alternative 3 would result in 0.74 acres of temporary impacts to waters of the U.S. The applicant does not prefer alternative 3 as they state it results in larger impacts to waters of the U.S. compared to the preferred alternative of abandoning piles in place and covering the piles with trawl guards.
This proposed project may have an adverse effect on 0.13 (full pile removal) to 4.97 (piles cut 15 feet below mudline) acres of Essential Fish Habitat (EFH), depending on the final decommissioning plan chosen, for various species and life stages. This habitat consists of fine sandy substrate in a subtidal area with depths ranging from 122 feet (at hot tap) to 260 feet (at buoy locations) of water. Loss of this habitat may adversely affect these species. The Corps has made a preliminary determination that the site-specific impacts may be substantial. Accordingly, the Corps will submit an expanded EFH assessment to the National Marine Fisheries Service, who in turn will provide conservation recommendations to the Corps. The Corps will coordinate with the applicant regarding implementation of these recommendations. The EFH consultation will be concluded prior to the final permit decision.
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. The public notice, with more specifics on the work proposed by Neptune LNG, LLC, can be viewed on the Corps website at www.nae.usace.army.mil/Missions/Regulatory/PublicNotices.aspx.
Public comments on this work proposed by Neptune LNG, LLC (file # NAE-2005-658) should be forwarded no later than March 29, 2017 to the U.S. Army Corps of Engineers, New England District, Regulatory Division (ATTN: Christine Jacek), 696 Virginia Road, Concord, MA 01742-2751. Additional information is available from Permit Project Manager Christine Jacek at 978-318-8026 or toll free 800-343-4789 or 800-362-4367 (if calling from within Massachusetts) or by email to: firstname.lastname@example.org.