Asit Mazumder of the University of Victoria told the Canadian Broadcasting Corp. orders to boil water before drinking it are likely to become more common in British Columbia.
Residents of the Comox Valley watershed on Vancouver Island were warned Thursday that their water supply might be contaminated with E. coli. They were told to bring drinking water to a full boil for a minute and then cool it.
A similar order was issued last month for 12 days in White Rock, a city south of Vancouver. Orders remain in effect until no E. coli is found in tests for three consecutive days.
Mazumder said provincial governments should give municipalities more power to ban possible sources of contamination from watersheds.
E. coli infection can cause stomach problems and in the most severe cases kidney damage. The infection can be fatal.