Jeremy Olson of the Pioneer Press answered several questions related to contamination in Minnesota water supplies:
Q. How often are Minnesota water supplies contaminated?
A. A state health department spokesman estimated there are only one or two boil orders per year due to E. coli. Hibbing was the only city larger than 5,000 people that reported excessive bacterial contamination between 2000 and 2004. A test of the regional water system serving St. Paul found coliform bacteria in one location in February 2004. Required follow-up testing showed no presence of E. coli.
Q. How are the water supplies contaminated?
A. E. coli comes from human and animal wastes. Rainfalls and snowmelts can carry the bacteria into rivers, lakes, groundwater and other drinking water sources. Large municipal water systems routinely chlorinate drinking water to eliminate bacteria, but sometimes the level of chlorination is inadequate.
Q. What are the health risks?
A. Ingestion of E. coli bacteria can cause severe digestive problems, including diarrhea and vomiting. The elderly and small children are at greatest risk. Dehydration is a common result of infection.
Q. What precautions should be taken?
A. Bottled or boiled water should be consumed and used in cooking until contaminants are removed from the water supply. Contaminated water shouldn’t be used to make coffee, freeze ice cubes, rinse out toothpaste or feed pets. Showers and baths are OK, though not for children who swallow bath water. Washing machines can be used. Dishwashers shouldn’t be used, unless they heat water to a degree that kills bacteria.