New London — Greens Harbor Beach was closed Friday and will remain closed at least through noon Saturday after sewage spilled into the Thames River near the public beach.

Ryan McCammon, senior sanitarian for Ledge Light Health District, said the beach was closed as a precaution. A water sample was collected at the beach Friday and the health district will decide based on results that are expected by noon Saturday whether to reopen it, he said. Greens Harbor is the city’s only free public beach.

Joe Lanzafame, director of public utilities for the city, said the spill occurred Thursday afternoon due to a backup in a clogged sewer line on Crescent Street. About 2,500 gallons of raw sewage entered a storm drain in the parking lot of Calkins Park, but about 2,000 gallons of that was pumped out by trucks from the city and Waterford and brought to the treatment plant before it flowed into the river, he said.

The 500 gallons that were not recovered flowed into the river just north of Greens Harbor Beach, he said.

City crews cleared the clogged sewer line and made other repairs to the system, he said.

“Our crews did a great job with their quick response,” Lanzafame said. “It could have been thousands of gallons that spilled.”

— Judy Benson