Vineyard Wind, LLC (Vineyard Wind) is proposing to construct a commercial wind energy project (the Project) within Bureau of Ocean Energy Management (BOEM) Lease Area OCS-A 0501, which is located off the coast of Massachusetts. Vineyard Wind intends to install wind turbine generators (WTGs) and electrical service platforms (ESPs) in the northeast portion of the Lease Area, referred to as the Wind Development Area (WDA). The Construction and Operations Plan (COP) provides a detailed description of the Project, including a tentative schedule outlined in Section 1.5.3 of Volume I of the COP (July 2018). The Project COP was submitted for review to BOEM on December 19, 2017. Pursuant to this review, BOEM provided technical comments to Vineyard Wind, and requested additional detail on specific acoustic and non-acoustic impacts to marine fauna during Project construction. For additional information on species presence and environmental baseline for marine mammals and sea turtles, please see Sections 6.7 and 6.8 of Volume III of the COP.
This supplemental document was prepared to address BOEM’s request for further information on acoustic and non-acoustic impact producing factors (IPFs) of the Project. These IPFs include noise from pile driving, habitat modification, and vessel traffic during construction. The marine species evaluated include marine mammals and other marine fauna, such as sea turtles, that may occur in or near the WDA and surrounding area. The assessment uses the most recent science available in the peer-reviewed literature relative to sound propagation, animal movement modeling, and potential impacts to and responses by marine species that may be present in the vicinity of the Project.
JASCO Applied Sciences (JASCO) conducted acoustic modeling of underwater sound generated during piling installation (Appendix A). The sound energy from pile driving is transmitted into the water from both the pile wall and through marine sediments. Acoustic models predict the levels of this sound energy, and ranges to acoustic thresholds in water that may result in injury to marine fauna, or that have the potential to elicit behavioral response.
The basic modeling approach is to characterize the sound source, and then determine how the sounds propagate in specific construction areas in multiple seasons and how they are potentially received by marine species. The modeling results inform an analysis of the potential effects of pile driving on marine species that may be present near the WDA during construction. In this study, a conservative modeling approach was adopted to account for both adjustments to Project plans and environmental variability. Two scenarios were modeled in the study: Maximum Design and Most Likely. Each of these scenarios were modeled to assess the installation of one- and two-piles per day. These scenarios include the two potential WTG and ESP foundation types in the Project Envelope: monopiles (larger diameter steel piles) and jackets (steel structures that include either three or four smaller diameter piles connected with welded steel tubular cross bracing). The Maximum Design scenario considers the installation of up to 90 monopiles and 12, four-pile jackets. The Most Likely scenario considers the installation of up to 100 monopiles and two, four-pile jackets. Both scenarios were modeled over a construction period that excluded the months of January to April when endangered North Atlantic Right Whales (NARW) (Eubalaena glacialis) are likely to be present in relatively high numbers. This reflects Vineyard Wind’s self-imposed prohibition on pile driving in these months for the protection of this species.