Officials have identified the cause of a mysterious sheen that appeared Monday on a pond that feeds into a river that runs through New Hampshire and Massachusetts.
Firefighters responding to the area of the Powwow Pond and the Powwow River around 10 a.m. found a large sheen on the water in the pond, according to the East Kingston Fire Department.
A drone unit from the Merrimac Police Department in Massachusetts was called in to determine the size of the sheen, while firefighters from multiple communities set up booms to contain the material.
The New Hampshire Department of Environmental Services later determined through water testing that the sheen appeared to be caused by broken-down organic material and minerals…