Five Huron County beaches are under a no-swim advisory heading into the August long weekend.
Weekly water sampling by Huron Perth Public Health found that Amberley, Pavilion Road, Hay Township, and Goderich Main and Rotary Cove beaches have unsafe levels of bacteria.
Swimming not recommended signs have been posted at the impacted beaches, warning that the water could cause diarrhea or infections.
The waters will be resampled on Friday with results shared on Saturday.
Last Thursday, all 13 beaches were found to be unsafe, before resampling cleared all but Goderich Main Beach.