About 500 property owners in Ottawa are being asked to run a water tap in their homes around the clock until at least mid April. The City of Ottawa sent an official notice to the homeowners with instructions to turn on a cold water tap with a steady flow in the size of a drinking straw. The notices were sent to homes which have a history of frozen pipes. Homeowners will not be charged for the extra water use. The city says it will use information on previous billings to determine adjustments.