Wadsworth Falls State Park on the Middletown-Middlefield town line was closed Tuesday after recent water testing indicated possible contamination.
While the tests did not pinpoint the cause, geese droppings and heavy rainfalls can cause problems. For now, people must stay out of the water.
"It's a great place to come and hang out with families and friends, but safety is first," Nino Shka, of Middletown, said.
Research by the NBC Connecticut Troubleshooters found Wadsworth Falls is in the middle of the pack when it comes to how frequently it is closed compared to other state parks.
The state has scheduled further tests for Wadsworth Falls to determine when it can reopen.
The Troubleshooters have assembled a list of websites and phone numbers to find out the status of dozens of Connecticut beaches. Click here to see the list.