Swimming is not recommended at some area beaches heading into the unofficial last weekend of summer.
Lambton Public Health has placed warning signs, due to high levels of E. coli bacteria, at Grand Bend North, Highland Glen and Bright's Grove.
Other beaches sampled weekly including Grand Bend South, Canatara Park, Pinery Park, and Ipperwash Main Beach are all clear.
We're reminded that the water at area beaches can be temporarily polluted for up to 48 hours after heavy rain.
While no testing is done on the St. Clair River, caution signs are permanently placed at Seager, Branton Cundick, and Brander parks.