Nantucket demands answers in wake of broken Vineyard Wind turbine blade

Nantucket leaders are demanding 100% transparency from both Vineyard Wind and GE Vernova about the recent breaking of a wind blade on a turbine in waters southwest of the island, vowing to hold the companies accountable, and even calling for renegotiation of the town's Good Neighbor Agreement with the offshore wind developer.

For the second week, the July 13 blade failure was the top subject during the Nantucket Select Board's weekly meeting on Wednesday night, taking up nearly two hours of discussion.

Board Chair Brooke Mohr emphasized that the board members are "deeply concerned" about the safety, environmental and economic effects of the "catastrophe," and want to know exactly what chemicals and materials are in the debris that has washed up on local shores and remains in the water column around the island.

The board plans to meet with company representatives next week "to establish a process for reimbursing the community for costs and damages sustained as a result of the accident and recovery efforts."

Representatives of Vineyard Wind and GE Vernova, which manufactures the blades and is the blade installation contractor, were on hand Wednesday to give updates and answer questions.

Preliminary environmental report reviewed

GE Vernova chief sustainability officer Roger Martella reviewed the preliminary findings of an environmental analysis being conducted by Arcadis , a Dutch design and engineering firm hired by GE Vernova.

The primary risk, he said, is "people coming into physical contact with the materials: the fiberglass, the foam — which is the kind of foam you see in chairs and things like this — and the balsa wood."

He said anyone finding debris should avoid handling it and instead report it on the town website call the hotline.

Martella said the main toxicological finding is that the debris is "inert" and is the same type of material that goes into things like recreational boats and textiles.

But Select Board member Malcolm MacNab, a physician, said he challenges the assertion there are no toxic materials. "I mean, this is not asbestos, but it is harmful to human beings and potentially harmful to animals," he said.

Mohr asked if there is any "immediate risk to people ingesting shellfish or fish that they catch" from local waters. Martella said the continuing assessment will look at risks to aquatic species and wildlife, but that it would be part of "next steps, longer term."

In response, Mohr pointedly remarked, "I would say that our community doesn't consider that a future risk. They consider that an immediate risk."

Water quality testing ordered

Arcadis plans to do water quality testing, but the town has ordered its own assessment from Nantucket Natural Resources Department to make a comparison, he said.

"It’s not as simple as going out with a specimen jar," Mohr said.

MacNab agreed, saying the testing "has to be done in a clear, verified, acceptable manner."

Are there PFAS in the debris?

Questions have also been raised about whether the debris contains per- and polyfluoroalkyl substances, or PFAS , which are man-made chemicals that have been linked to harmful health effects in humans and animals. PFAS are used in products such as nonstick cookware, water-repellent clothing, stain- and wrinkle-resistant fabrics and carpets, some cosmetics, some firefighting foams and products that resist grease, water and oil.

"I want to say at the outset the materials that we've seen on the shore and in the water — the foam, the fiberglass, the wood — those do not contain PFAS. The coatings of the blade do not contain PFAS. The blade itself, the main part of the blade does not have PFAS," Martella said.

He said there are, however, elements called aerodynamic add-ons that are about 6 inches by 7 inches, which are applied near the top exterior of the blades and which "have a small concentration" of polytetrafluoroethylene, or PTFE, a synthetic polymer compound that is a type of PFAS. As a household brand it's known as Teflon.

According to the Arcadis report, the PTFE content of the blade's 240 add-ons amounts to 0.00005% of its total weight. Martella said none of these add-ons have appeared among the debris recovered from the water or from beaches. According to Arcadis, at least 67 of the add-ons are visible on the root segment of the blade that remains in place on the turbine, and others "may be present on parts of the blade that are not currently visible."

Last blade remnant yet to be removed

GE Vernova said it wants to remove the last blade remnant "at the earliest opportunity" but it's a delicate undertaking. To help, the company has hired Resolve Marine , the firm that cleaned up after the March 26 collapse of the Francis Scott Key Bridge in Baltimore.

GE Vernova is also committed to determining the exact cause for the blade's failure.

"We have to study this very closely to make sure we do everything we can to learn from this to prevent the likelihood of it happening again," Martella said.

What's the probable cause of the blade breaking?

The preliminary cause shows a combination of manufacturing and inspection problems but it does not indicate any fundamental design flaws, Martella said.

"We did identify what we call a 'manufacturing deviation,'" he said. "Some of the adhesives that are supposed to work for the blade did not do their job."

Quality control also fell short. Detailed ultrasound photos are routinely taken of all blades that come off the assembly line at the factory in Gaspe, Canada, he said. Engineers will now scrutinize all images of the offshore wind blades, including the ones already installed on the Vineyard Wind turbines, all that have been delivered to New Bedford and all that are yet to be shipped.

At present 24 of 62 planned turbines are in place, with a total of 72 blades installed. At least 10 of the turbines were commissioned and operational, the remainder, including the turbine with the broken blade, were still undergoing testing.

Heather McCarron writes about climate change, environment, energy, science and the natural world, in addition to news and features in Barnstable and Brewster. Reach her at hmccarron@capecodonline.com, or follow her on X @HMcCarron_CCT

This article originally appeared on Cape Cod Times: Nantucket demands answers in wake of broken Vineyard Wind turbine blade