CENTERVILLE — With a GQ EMF390 electromagnetic field meter in hand, resident Tom Cambareri paced a section of Covell Beach on Wednesday morning, announcing readings as he went.
The numbers he called out rose, crested and fell like the waves coming to shore nearby — indicators of his passage over the two transmission lines carrying power from the Vineyard Wind 1 wind farm, buried under the beach.
"The signal is a lot weaker on the beach, which is a good thing," he said, because that's where people will spend a lot of time as summer gets underway.
Cambareri has been taking informal measurements of electromagnetic fields created by the cables for a few months, ever since Avangrid began sending power through the cables when the first turbines began churning in the company's lease area south of the Vineyard. At last count, nine of the 62 planned turbines were in operation.
He's been driven by curiosity and concern about safety and public health, and wanting people who spend time at the beach to know the Vineyard Wind transmission cables make landfall there.
Now, as a result of his effort and just in time for Memorial Day, the town has posted two signs at the beach providing information about the wind project and its presence under the beach. They were installed by Barnstable DPW workers on Friday near the comfort station and over the location where the buried cables transition from the beach and parking lot.
"The town has taken my suggestion to heart," said Cambareri, who worked with town administration on the Covell Beach signs project for several weeks.
Initially, the town considered having Avangrid undertake the sign project. Town Council President Felicia Penn said town officials decided to do it instead after disagreeing with the focus of the company's proposals for the signs.
"Vineyard Wind had submitted copy but it was rejected by the town, as it read like an advertisem*nt for Avangrid," Penn said.
More formal EMF monitoring is expected at Covell Beach − eventually.
Barnstable Director of Communications Lynne Poyant said the town is continuing discussions with the company regarding regular communication on safe and compliant operation of their system. The details of the monitoring are still being worked out and coordination with the Massachusetts Department of Public Utilities and Energy Facilities Siting Board is necessary, she said.
The town will eventually add a QR code to the signs, she said, "that will link those interested in accessing additional information to a town-controlled website." The website will have a site plan illustrating the location of buried cables from water’s edge through the parking lot to Craigville Beach Road, any data compiled by Vineyard Wind, the state and the town relative to EMF and information from the state verifying the safety and compliance of the project.
It is as yet unknown how frequently readings would be taken. Cambareri would like to see readings taken daily, perhaps by beach personnel, and posted daily on a chalkboard at the beach, just as water temperature readings are often posted at some beaches.
"I believe every time a new turbine is connected new readings should take place," at the very least, Penn said.
Informal EMF readings below standards
All of Cambareri's readings so far have been far below the current international standard for human exposure limit to magnetic field levels, 2000 milligauss, set by the International Commission on Non-Ionizing Radiation Protection in 2010. They've also fallen well below the EMFs produced by most appliances people are around every day in their homes and offices.
The readings are lowest on the beach itself, he said, where the cables are buried the deepest. They rise closer to the surface under the parking lot en route to the roads that convey the power to the substation at Independence Park.
According to Vineyard Wind,the two export cables from its wind farmare roughly nine feet below Covell Beach at the edge of the parking lot, and approximately 30 feet deep at the water line.
Barnstable resident John Kassakian,Massachusetts Institute of Technologyprofessor emeritus of electrical engineering, said the magnetic field is directly proportional to the current in the lines.
"So, if the nine turbines are operating at maximum load (current), then all 52 turbines operating at maximum load would produce a magnetic field about 6 times higher," he said.
He would expect the field "to be unconcerning, even with all turbines operating at maximum loading," he said.
Baseline EMF readings for Vineyard Wind cables
Vineyard Wind spokesman Craig Gilvarg said a contractor hired by Avangrid on Thursday performed baseline magnetic field readings while the wind farm and all components were de-energized, with town officials present.
"The readings were performed to take baseline data accounting for the earth’s natural magnetic field. Future readings will be performed when the electrical equipment is in operation to assess the levels of magnetic field associated with the cables," he said. "Those readings will be reported to the town and made available to the public."
According to Poyant, on-site testing to verify safety and compliance will also take place next week and "it is the town’s understanding that the Mass. Department of Public Health will be involved relative to verifying the accuracy of the ongoing monitoring."
The town has also retained a third party independent expert to verify readings and data if and when needed, she said.
Heather McCarron can be reached at hmccarron@capecodonline.com, or follow her on X @HMcCarron_CCT.
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