Hundreds of small white disks the size of a quarter washed up on Bailie Beach in Mattituck over the weekend, and authorities believe they may have been accidentally released from a New Hampshire sewage treatment plant.
The Suffolk County Health Department is investigating the matter, Bill Faulk, a legislative aide to County Legislator Ed Romaine, said Tuesday.
The disks are plastic biofilm chips designed to allow bacteria colonies to grow on them. Bacteria help break down waste material.
Local officials speculate that they may have come from a sewage treatment plant in Hooksett, N.H., which accidentally released millions of the disks into the Merrimack River after a heavy rain on March 6. Those disks have been showing up on New Hampshire and Massachusetts beaches ever since, but media reports in Massachusetts said the thin, waffle-design disks found there were about two inches in diameter.
The thicker, honeycombed disks found in Mattituck are about the size of a quarter.
Massachusetts health authorities told WCVB TV Boston that the level of bacteria on the disks found there did not pose a public health threat, but advised beachgoers to avoid contact with them.
Southold Town Supervisor Scott Russell advised North Fork beachgoers to be careful as well.
“When a product that is unknown and is clearly not of natural origins washes ashore, then caution needs to be the first line of defense,” he said. “I am hoping the Suffolk County Department of Health can shed some light on this and evaluate the risks so they can be mitigated.”