The Department of Health will conduct an extra test of the water at the Narragansett Town Beach today, after unsafe levels of bacteria were found at the adjacent Dunes Club Beach. The results will be in tomorrow.

Because both beaches are “historically clean,” the state tests them only once a month, said Health Department spokeswoman Anne-Marie Beardsworth. But the findings at the Dunes Club Beach, a private beach, have prompted health officials to take an unscheduled test at Narragansett Town Beach. Beardsworth said that storms in the Atlantic may be stirring up bacteria in the water.

The Dunes Club is among four beaches that the Health Department recommended closing yesterday because of bacteria in the water. The others are Atlantic Beach, in Middletown; Conimicut Point Beach, in Warwick; and Echo Lake Campground Beach, in Burrillville. At the four beaches, tests found higher-than-acceptable levels of enterococci, intestinal bacteria whose presence in the water indicates sewage.

Beaches close and reopen frequently throughout the summer, so health officials are urging swimmers to check its beach monitoring Web site ( www.ribeaches.org/index.cfm) or call the beach hot line at (401) 222-2751 before heading to the shore.