Several months after heavy rains led to the release of 4.3 million small, plastic discs from the Hooksett wastewater treatment facility on the Merrimack River in New Hampshire, the discs have begun washing up on Martha’s Vineyard beaches.
The small, white, mesh discs are approximately two inches in diameter and are used to promote bacterial growth in wastewater plants. They pose no immediate health risk beyond that of other beach trash, according to environmental and health experts.
Matt Poole, Edgartown health agent, said the discs are essentially beach litter. He said the proper response, as with any litter cleanup, is to wear gloves.
Discs have washed up on beaches along the south shore from Chappaquiddick to Gay Head. Chris Kennedy, Trustees of Reservation Martha’s Vineyard superintendent, said beach rangers collected about 175 discs over the last two weeks.
Bret Stearns, director of the Wampanoag Tribe natural resources department, and Mr. Poole have been in contact this week with Geoffrey Brown, vice president of Enpro Services, the environmental cleanup firm that has been assisting the town of Hooksett and other coastal communities in New Hampshire in the cleanup effort.
In a telephone call Wednesday, Mr. Brown said that after weeks in the ocean exposed to the sun and sea the discs pose no health risk. He said New Hampshire and Massachusetts have been routinely collecting and testing the discs.
“Virtually, from the outset, they were finding little or no residual bacteria on the discs, so at this point, it is much more of an aesthetic or debris issue than a health issue,” he said.
He said New Hampshire and Massachusetts health officials recommend people wear gloves when they pick the discs up, but the same recommendation is made for anyone picking up material on the beach as part of a large-scale beach cleanup.
An estimated 4.3 million discs were released from the plant. Mr. Brown estimated 3.6 million have been recovered, in large part due to volunteer efforts in communities along the coast.
Discs have shown up on Cape beaches and Nantucket. The migration along the coast has provided marine researchers with some unexpected data, he said.
According to the New Hampshire Department of Environmental Services, the discs may be collected into plastic bags and disposed in a landfill as solid waste.
According to a published report in the Nashua Telegraph, the discs, called Kreuger Biofilm Chips, provide bacteria a place to dwell. They are used to increase the amount of bacteria in aeration tanks, where sewage is stored for biological breakdown, as part of a treatment process. The Hooksett plant contained some 40 million before the spill.