Swimming at Rocky Neck State Park in East Lyme is off limits due to poor water quality, according to the Department of Energy and Environmental Protection.
The state will test the water again on Wednesday, but the results won't be back until Thursday.
It's a different closure than the state park has seen in recent weeks. Rocky Neck has closed to new visitors on several days after the parking lot reached 50% capacity as part of the state's COVID-19 protocols.
It is not clear what test results revealed about the water to require the ban on swimming.