This summer's highest E. coli levels to date have prompted a beach closure in New Baltimore.
Samples collected Thursday at returned Friday with results of 2,265.57 coli cells per 100 milliliters of water. That led to the beach closing Friday. The closure remained in effect over the weekend and Monday. More samples were collected Monday morning with results expected late Tuesday morning, said Steve Lichota, Macomb County associate environmental director of health.
Once those results are in, health officials will decide whether to reopen the beach for swimming, Lichota said.
E. coli figures the day before heightened levels were found are low in comparison at 129.50. The lowest level shown this year for the New Baltimore beach was at 1.00, according to the Macomb County Health Department chart.
Daily samples must be below 300 cells per 100 milliliters of water in order for it to be deemed safe for swimming, according to the Michigan Department of Environmental Quality.
"It's hard to say what caused it," Lichota said. "It's hard to pinpoint."
Heavy rainfall leading to water runoff into the lake or bird droppings could be among the factors that caused the high E. coli levels.