One Lake Huron beach tested weekly for water quality has been deemed unsafe for swimming.
Lambton Public Health says warning signs have been posted at Highland Glen due to recent high levels of E. coli bacteria.
Other area beaches tested are okay. They include Grand Bend, Ipperwash, the Pinery, Bright's Grove and Canatara.
We're reminded that water at area beaches may be temporarily polluted for up to 48 hours after heavy rainfall.