GZA Kicks Off Geotechnical Campaign for Deepwater Wind

GZA GeoEnvironmental has begun offshore geotechnical engineering program for Deepwater Wind in Rhode Island Sound.

Working from a 200-foot class lift boat mobilized earlier this month from Quonset Point, Rhode Island, a 28-person GZA-led crew is now taking and evaluating soil samples from the sea floor in 100 to 120 feet of water about 15 miles southeast of Block Island.

GZA will analyze the composition of the sand, gravel, silt, and clay extracted by the drilling operation to advise Deepwater Wind on how various wind turbine foundation options will perform in various areas.

The soil samples will come from multiple locations in the offshore wind energy site Deepwater Wind has leased from the federal government to develop its South Fork Wind and Revolution Wind projects delivering power to Rhode Island, Connecticut, and New York, and additional future wind installations.

“We’re embarking on this major scientific endeavor so we can better understand the seafloor where we’ll build these next wind farms,” said Deepwater Wind CEO Jeffrey Grybowski. “When we’re done, we’ll know more about this part of the ocean than ever before. Local laborers, mariners and scientists will help us get the job done.”

GZA Associate Principal Diane Y. Baxter, P.E., PhD., from the firm’s Providence office, is overseeing a two-shift, 24-hour-a-day geotechnical drilling and analysis effort that involves taking 3-inch-diameter cores of the soils below the sea floor, extending as far as 200 feet below the sea floor. “The geology of this part of the sea floor is proving to be highly complex and variable, which is something we saw when we worked on the Block Island Wind Farm,” Baxter said.

The offshore sampling is one of the early phases of what will be a 5-month-long review by Deepwater Wind off its offshore leased property. Once permits are in hand, local construction work on the 90-megawatt (MW) South Fork Wind Farm will begin in 2021, with the wind farm in operation in 2022.

Construction on the 400 MW of power from Revolution Wind would start as early as 2020 to serve Rhode Island, and in 2021 on the 200 MW of power from Revolution Wind to serve Connecticut. Revolution Wind is planned to begin operations in 2023.