As Sarnia-Lambton deals with the first heat event of the season, the local health unit has started water sampling at area beaches.
Lambton Public Health regularly tests water quality at Grand Bend, Pinery, Ipperwash, C.J McEwen, Bright's Grove and Canatara Park beaches.
Warning signs may be posted if the water is deemed unsafe for swimming due to high levels of bacteria.
Monitoring will continue until September 2.
Reports are available online at Lambton Public Health.
Residents can also text the word Beach to 226-909-3003, or call the Beach Info Line at 519-383-3816.
The health unit does not conduct water sampling along the St. Clair River.