With further rain in the forecast, and the possibility of flooding, Lambton Public Health is urging those with private wells to test their water supply.
The high water levels could allow harmful bacteria to enter the drinking water, making it unsafe for consumption.
Health Protection Supervisor Lori Lucas said if the water can't be tested, there are some precautions that should be taken in the meantime.
"Use bottled water until you get that test back," said Lucas. "Use it for things like drinking, making infant formula and juices, cooking, making ice, washing fruits and vegetables, and brushing your teeth. Alternatively, you can boil your water rapidly for at least one minute before use to render it safe."
Lucas estimates about 10 per cent of Lambton county uses well water, mostly in rural areas like Brooke-Alvinston, Dawn Euphemia and Lambton Shores.
She said there are some things that can be done if the well water tests positive for bacteria.
"There are treatment systems that can be added to the well if they're not already there. Usually, you can work with a well service provider to look into what the issue is. It could be a problem with the cap on the well that needs to be replaced, or some of the well casing might need to be replaced."
Lucas said the test for bacteria (total coliform and E. coli) and water sample kits are free.
They can be picked up and dropped off at Lambton Public Health, Bluewater Health's CEE lab in Petrolia, and the London Public Health lab.
Water samples must be dropped off within 24 hours of being taken.
Visit Lambton Public Health's website for more information.
