Warning signs were posted at Grand Bend's north beach and Ipperwash main beach on Tuesday, July 28.
Lambton Public Health said E-coli bacteria levels were estimated to exceed Ministry of Health guidelines.
The south beach at Grand Bend, received an all clear for swimming using predictive models.
Following heavy rainfall and high winds, the water at area beaches may be temporarily polluted with high levels of bacteria for up to 48 hours.
The water quality status is updated daily for the popular beaches in Lambton Shores.
You can receive the latest results by texting the keyword: BEACH to 226-909-3003, you can also call the Beach Info Line at 519-383-3816 or toll-free 1-800-667-1839 ext. 3816, or visit LambtonPublicHealth.ca.
