The water quality at the upper beach at Hopkinton State Park has been deemed safe for swimming after water quality testing Thursday revealed a decrease in bacteria levels for the first time in more than a month.

On Wednesday, the state’s Department of Conservation and Recreation announced that there were high levels of enterococci bacteria, posing a harm risk if a person is submerged in or ingests the water. This level fell by more than half from 40.2 MPN in a most probable number in water quality testing on Tuesday to 20 MPN in Thursday’s testing. The five-test Geometric Mean Standard for enterococci of 35 for marine water and 33 for freshwater.

The water at the main beach still remains unsafe for swimming.

Beaches statewide have been experiencing high levels of bacteria in recent weeks during the time of year when they are in the greatest demand for recreation. One cause is the amount of goose droppings in the water.

Lake Maspeenock remains safe for swimming.