Businesses and residences that were vacant or minimally occupied during the stay-at-home order could experience degraded water quality. Prolonged water stagnation in a building can cause elevated levels of lead, copper and Legionella at the tap. The city of Durango Utilities Department recommends water systems in these buildings be flushed to ensure safety.
Remove or bypass devices like point-of-entry treatment units (filters or softeners) before flushing.Take steps to prevent backflow or the siphoning of contaminants into plumbing (e.g., close valves separating irrigation systems from plumbing, disconnect hoses attached to faucets, etc.).Organize flushing to maximize the flow of water (e.g. opening all outlets simultaneously to flush the service line and then flushing outlets individually starting near where the water enters the structure).Run enough water through all outlets (e.g., hose bibs, faucets, showerheads, toilets, etc.), removing aerators when possible. Typical flushing durations can range from 10 to 30 minutes for each outlet. A good rule of thumb is to feel the temperature change in the water, it will be cold when clean fresh water from the water main enters the premise.Flush the cold-water lines first, and then the hot-water lines. Note: the hot-water tank can be drained directly; it can require about 45 minutes to fully flush a typical 40-gallon hot water tank.Replace all point-of-use filters, including the filter in refrigerators.Additional precautions may be warranted if there is excessive disruption of pipe scale or if there are concerns about biofilm development. Actions that might be warranted include continued use of bottled water, installation of a point-of-use device, or engaging a contractor to thoroughly clean the plumbing system.
Refer to the American Water Works Association or the Water Research Foundation for additional details. For more information, call the City of Durango Utilities staff at 375-4801.
