LINWOOD, MI — High bacteria levels closed the first Bay County beach of the year.

The beach at South Linwood Beach Township Park is closed as of Friday, June 2, according to officials from the Bay County Health Department. On Thursday, June 1, results of surface water samples collected from the beach exceeded the State of Michigan’s water quality standard for full body contact recreational activities.

The state’s standard is 300 colonies of E. coli per 100 milliliters of water. Thursday’s results yielded 325.5 colonies — just slightly above the mark.

The source of the bacteria is listed as “unknown,” according to the Department of Environmental Quality.