Because of concerns expressed during the consultations, Interior has required the developer to change the design and configuration of the wind turbine farm to diminish the visual effects of the project and to conduct additional seabed surveys to ensure that any submerged archaeological resources are protected prior to bottom disturbing activities. Under the revisions, the number of turbines has been reduced from 170 to 130, eliminating turbines to reduce the visual impacts from the Kennedy Compound National Historic Landmark; reconfiguring the array to move it farther away from Nantucket Island; and reducing its breadth to mitigate visibility from the Nantucket Historic District.
Salazar said, "After almost a decade of exhaustive study and analyses, I believe that this undertaking can be developed responsibly and with consideration to the historic and cultural resources in the project area. Impacts to the historic properties can and will be minimized and mitigated and we will ensure that cultural resources will not be harmed or destroyed during the construction, maintenance, and decommissioning of the project."
He pointed out that Nantucket Sound and its environs are a working landscape with many historical and modern uses and changing technologies. He said a number of tall structures, including broadcast towers, cellular base station towers, local public safety communications towers and towers for industrial and business uses are located around the area. Three submarine transmission cable systems already traverse the seabed to connect mainland energy sources to Martha's Vineyard and Nantucket Island. Visual and physical impacts associated with Nantucket Sound and its associated shorelines abound; it is not an untouched landscape.
Salazar disagreed with the Advisory Council's conclusion that visual impacts from the proposed wind farm, which will be situated between and at substantial distance from Cape Cod, Nantucket Island and Martha's Vineyard, provide a rationale for rejecting the siting of the project. The viewshed effects are not direct or destructive to onshore traditional cultural properties. In no case does the turbine array dominate the viewshed. The project site is about 5.2 miles from the mainland shoreline, 13.8 miles from Nantucket Island and 9 miles from Martha's Vineyard.
The Secretary also disagreed that it is not possible to mitigate the impacts associated with installation of piers for wind turbines in the seabed, noting that piers for bridges, transmission lines and other purposes are routinely built in relatively shallow waters consistent with those found in Horseshoe Shoals. A number of marine archaeological studies have indicated that there is low probability that the project area contains submerged archaeological resources. Most of the area has been extensively reworked and disturbed by marine activities and geological processes. The Advisory Council's regulations provide that the Interior Department must take into account the Council's comments on particular projects. The Department, as the decision-making authority, is required to consider the Council's comments but is not legally bound to follow its recommendations or conclusions.
The Cape Wind Associates, LLC facility would occupy a 25-square-mile section of Nantucket Sound and generate a maximum electric output of 468 megawatts with an average anticipated output of 182 megawatts. At average expected production, Cape Wind could produce enough energy to power more than 200,000 homes in Massachusetts. Horseshoe Shoals lies outside shipping channels, ferry routes and flight paths but is adjacent to power-consuming coastal communities. One-fifth of the offshore wind energy potential of the East Coast is located off the New England coast and Nantucket Sound receives strong, steady Atlantic winds year round. The project includes a 66.5-mile buried submarine transmission cable system, an electric service platform and two 115-kilovolt lines connecting to the mainland power grid.
Access a release from DOI with links to a Fact Sheet, Project Site Map, the Secretary's Response to the Advisory Council on Historic Preservation, and additional information on the project (click here). Access the MMS website for the project for complete background information and extensive documents (click here).