Drinking water safety during overland flooding

Press release

 Due to the current heavy rainfall event, surface waters in Southern Alberta have become contaminated.  This includes the contamination of rivers, streams, ponds, irrigation systems, and storm-water collection systems.  Depending on the source of your drinking water supply, this could impact the safety of your drinking water, because it might have been contaminated with storm-water runoff.



Concern is focused in the rural areas where residential water is sometimes untreated. Personal water sources such as cisterns and wells may be contaminated. It is important for people to take measures to prevent the contamination of these drinking water supplies.

“We are particularly concerned about people in our zone who are connected to raw water co-ops or have their own private source of surface water such as dugouts,” says Dr. Vivien Suttorp, Medical Officer of Health in the South Zone.

“Raw water pipelines come from different reservoirs and deliver water to people’s homes. We really want to encourage those people to properly filter and disinfect that water before consuming it.”

This is especially true after heavy rains disturb silt and parasites below the water’s surface or increase runoff into bodies of water. Surface water untreated from sources such as creeks, streams, rivers, dugouts, irrigation canals and pipelines is not safe and should be properly treated or vigorously boiled (one to three minutes) before being consumed.

No boil-water orders have been issued in the zone and there are no concerns at the present time about municipally treated water.

“There is always some level of disease-causing bacteria present in surface water but the likelihood of contamination increases when we get a lot of rain,” Suttorp says. “Symptoms of water-borne illness can include diarrhea, nausea and upset stomach.”

Swimming or playing in surface water is very unsafe and can lead to injuries as well as a range of illnesses.