Sunapee Harbor spill cleanup shifts into sustained response phase

Crews tightened the containment zone at Sunapee Harbor on Tuesday, June 23, moving booms closer to shore and significantly shrinking the area affected by an unknown spill near 71 Main Street. The water supply was not threatened and boats in the harbor were not in danger, but some vessels may have been temporarily blocked in while the cleanup continued.

The incident began Sunday, June 21, when the Sunapee Fire Department was dispatched at 5:16 p.m. to Sunapee Harbor over an unknown substance in the water. Lieutenant Timothy White arrived at 5:18 p.m. and confirmed a large sheen covering part of the harbor, triggering an initial response that brought in the New London Fire Department, the New Hampshire Department of Environmental Services, the Midwestern New Hampshire Hazardous Materials Team and the Sunapee Police Department.

By Tuesday, the response had shifted from immediate containment to a more sustained cleanup and monitoring effort. NH DES continued collecting and analyzing samples, with testing planned to determine the source and composition of the material. The source had still not been located or confirmed, even as crews worked to reduce the size of the containment area and search for where the spill began.

Boaters and other members of the public should not move, disturb or try to go around the booms. The barriers were still essential to keeping the product contained.

Some boats may have been temporarily blocked in by the containment area. There was no threat to the municipal water supply and no threat to boats in the harbor.

Sunapee has dealt with a different harbor contamination case before. In 2025, a spill near the Blue Canoe restaurant tested negative for hydrocarbons and was later described as a mixture of sewage and oil and grease rather than petroleum-based contamination. That earlier case showed how harbor incidents in town can turn out to be more complicated than they first appear.