Over the last few weeks more than 12 communities across Ontario’s cottage country have been swamped by intense flooding following heavy rains and rapid snowmelt. This has led Minden to declare a state of emergency as water enters residents’ homes and erodes roadways, while many others remain under flood warning.
Flooding events such as these can pose serious threats to public health, as surface waters become contaminated and seep into groundwater, according to Muskoka Clean Water. Contaminants include chemicals, bacteria, manure, and even sewage, if systems become overwhelmed.
In turn, the more than 2.5 million people in Ontario who get their drinking water from groundwater risk illness if they consume or come in contact with contaminated water.
According to Public Health Ontario (PHO), this largely affects those who rely on private drinking water systems such as wells and surface water intakes, which are common in rural areas and across cottage country. If this sounds like you, Muskoka Clean Water (MCW) recommends getting your water tested at least twice a year, but especially after a flooding event.
If there is a flooding event, assume your well water is not safe to drink. Your well head being submerged, and unusual smells or a residue left in your sink or toilet, are common signs your well has been contaminated, according to MCW.
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To confirm, contact your local public health unit for water quality information and to have your water tested for bacteria by PHO once the flood has ended. For chemical contamination tests, PHO recommends contacting a licensed laboratory from this list. It is also recommended you hire a well inspector to check for physical and electrical damage, and to flush and shock chlorinate the well after the flood has passed.
In the meantime, avoid drinking, preparing food, cleaning, or brushing your teeth with your well water. Instead, use bottled water. The Eastern Ontario Health Unit cautions that boiling water may kill bacteria, but it won’t remove chemical contaminants.
Many cottages, especially older ones, however, rely on surface water intake systems (tubes that draw water directly from the lake to the cottage). Since lakes and rivers are just as vulnerable to contamination as groundwater, cottagers with these systems should also be keeping a close eye on their water supply.
During a flood, debris and sediment can clog filters and reduce the treatment effectiveness of intake systems, according to Public Health Sudbury & Districts (PHS&D). Muddy water or visible debris in your water is a good indication that your supply has been contaminated. But as with well water, you should assume it’s contaminated during a flood and rely on bottled water until you can get your water tested.
After the flood, PHS&D recommends replacing filters and cleaning and disinfecting the UV light and quartz sleeve, which are used to decontaminate your water supply. Then, have your water tested for bacteria and chemicals by PHO and a licensed lab.
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