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The Block Island Wind Farm (BIWF) is the first offshore windfarm to be constructed in the United States. Located approximately 3 miles southeast of Block Island, Rhode Island, this new wind farm will be able to provide enough power for approximately 17,000 Rhode Island homes, meeting the majority of Block Island’s electricity needs. It will also provide an alternative energy source to the diesel-fired generators currently used to power Block Island. Deepwater Wind Holdings, LLC selected Tetra Tech to support the siting, permitting, and environmental evaluation required for the 30-megawatt (MW) offshore wind farm and the associated Sea2Shore: Renewable Link (formerly referred to as the Block Island Transmission System [BITS]).

The BIWF consists of five 6-MW turbines that will be able to generate more than 125,000 MW-hours annually. In addition, the transmission system will allow excess power from the wind farm to be exported to the Rhode Island mainland. This 25-mile bidirectional submarine cable will connect in Narragansett, Rhode Island. The project also involves a new substation on Block Island, a new switchyard in Narragansett, and interconnection with an existing substation in South Kingstown, Rhode Island.

Tetra Tech’s role included federal, state, and local permit acquisition and environmental analyses required for the construction and operation of the BIWF and the Sea2Shore. Work also included the environmental assessment under the National Environmental Policy Act and assessments as required for other federal, state, and local approvals for the project. Tetra Tech also completed extensive characterization and impact assessments of project activities on public health and safety; land and marine uses; and benthic, biological, water, cultural, visual, and socioeconomic resources.

In consultation with multiple jurisdictional agencies, Tetra Tech developed and executed intensive field efforts and studies. We completed air quality analyses related to emissions of criteria pollutants and greenhouse gasses as required under the Clean Air Act. Our avian and bat experts collected detailed information on the movement of birds and bats through the near-shore waters of Block Island.

We developed and implemented a successful National Oceanic and Atmospheric Administration–approved marine mammal and sea turtle identification, monitoring, and avoidance training program to support all project offshore marine survey activities. Tetra Tech completed in-air sound propagation modeling and underwater sound propagation modeling to determine impacts to the surrounding acoustic environment.

Deepwater Wind completed installation of the five BIWF turbine foundations in 2015. During this period, Tetra Tech provided on-site underwater noise monitoring of the construction activities. The remainder of the project’s construction and commissioning activities are on target to be completed in 2016.


The BIWF was highlighted in Engineering News-Record. Access the article here.