2010-10486. Environmental Assessment Prepared for Proposed Cape Wind Energy Project in Nantucket Sound, Offshore Massachusetts

AGENCY:

Minerals Management Service (MMS), Interior.

ACTION:

Notice of Availability of an Environmental Assessment (EA) and Finding of No New Significant Impact (FONNSI)

SUMMARY:

The MMS, in accordance with regulations implementing the National Environmental Policy Act (NEPA), announces the availability of an EA and FONNSI for the Cape Wind Energy Project proposed for Nantucket Sound, offshore Massachusetts. On January 16, 2009, the MMS announced the release of the Final Environmental Impact Statement (FEIS) for the Cape Wind Energy Project. The FEIS assessed the physical, biological, and social/human impacts of the proposed project and 13 alternatives, including a no-action alternative (i.e., the project is not built), and proposed mitigation.

The MMS prepared this EA to determine whether MMS needs to supplement the FEIS for the Cape Wind Energy Project by examining whether there are “substantial changes in the proposed action that are relevant to environmental concerns” or whether “there are significant new circumstances or information relevant to environmental concerns and bearing on the proposed action or its impacts” that either were not fully discussed or did not exist at the time the FEIS was prepared (40 CFR 1502.9). The MMS reviewed information obtained from the scientific/technical literature, government reports and actions, intergovernmental coordination and communications, required consultations, comments made during the FEIS comment period, and comments received during the 30-day comment period after the initial circulation of this EA on March 8, 2010. This included the information discussed in the January 13, 2010, MMS Documentation of Section 106 Finding of Adverse Effect (Revised Finding), contained in the comments received during the 30-day period offered after the Revised Finding was circulated, and the information contained in the April 2, 2010, comment by the Advisory Council on Historic Preservation.

The MMS has determined that there is no new information that would necessitate a re-analysis of the range of the alternatives or the kinds, levels, or locations of the impacts of the Proposed Action on socioeconomic conditions or biologic, physical, or cultural resources. The analyses, potential impacts, and conclusions detailed in the FEIS remain valid. Therefore, the MMS has concluded that a supplemental EIS is not required. The EA and FONNSI are available at http://www.mms.gov/​offshore/​RenewableEnergy/​CapeWind.htm.

FOR FURTHER INFORMATION CONTACT:

James F. Bennett, Chief, Environmental Assessment Branch, Minerals Management Service, 381 Elden Street MS-4042, Herndon, Virginia 20170.

SUPPLEMENTARY INFORMATION:

In November 2001, Cape Wind Associates, LLC, applied for a permit from the U.S. Army Corps of Engineers (USACE) under the Rivers and Harbors Act of 1899 to construct a wind power facility on Horseshoe Shoal in Nantucket Sound, offshore Massachusetts. Following the passage of the Energy Policy Act of 2005 (EPAct) and associated amendments to the Outer Continental Shelf Lands Act (OCSLA), the Department of the Interior was given statutory authority to issue leases, easements, and rights-of-way for renewable energy projects on the Outer Continental Shelf (OCS). Accordingly, Cape Wind Associates, LLC, submitted an application to the MMS in 2005 to construct, operate, and eventually decommission an offshore wind power facility on Horseshoe Shoal in Nantucket Sound.

The project calls for 130, 3.6 megawatt (MW) wind turbine generators, each with a maximum blade height of 440 feet, to be arranged in a grid pattern in 25 square miles of Nantucket Sound, offshore Cape Cod, Martha's Vineyard, and Nantucket Island. With a maximum electric output of 468 MW and an average anticipated output of 182 MW, the facility is projected to generate up to three-quarters of the Cape and Islands' electricity needs. Each of the 130 wind turbine generators would generate electricity independently. Solid dielectric submarine inner-array cables (33 kilovolt) from each wind turbine generator would interconnect within the array and terminate on an electrical service platform, which would serve as the common interconnection point for all of the wind turbines. The proposed submarine transmission cable system (115 kilovolt) from the electric service platform to the landfall location in Yarmouth would be approximately 12.5 miles in length (7.6 miles of which falls within Massachusetts' territory).

Nantucket Sound is a roughly triangular body of water generally bound by Cape Cod, Martha's Vineyard, and Nantucket Island. Open bodies of water include Vineyard Sound to the West and the Atlantic Ocean to the East and the South. Nantucket Sound encompasses between 500 and 600 square miles of ocean, most of which lies above the OCS. The Cape Wind Energy Project would be located completely on the OCS, except for the transmission cables, which would run through Massachusetts' territory to shore. For reference, the northernmost turbines would be approximately 5.2 miles (8.4 km) from Point Gammon on the mainland; the southernmost turbines would be approximately 11 miles (17.7 km) from Nantucket Island (Great Point); and the westernmost turbines would be approximately 5.5 miles (8.9 km) from the island of Martha's Vineyard (Cape Poge).

Dated: April 28, 2010.

Chris C. Oynes,

Associate Director for Offshore Energy and Minerals Management.