Due to the outbreak of the Covid-19 Virus and the Stay-at-home/ Shelter-in-Place orders, many businesses and public facilities have been left vacant with very little water usage for an extended period of time.
Some of these facilities currently have a water use plan in place for situations like these, but most do not. Water professionals have been issuing this guidance in response to these circumstances in order to ensure the safety of the water supply and the health and welfare of our customers as businesses and facilities begin to reopen and the Shelter-in-Place orders are lifted. Facilities should contact a plumber to assist with this guidance. Further information for specific businesses can be found on the CDC website at the link below.
Treated water may contain a residual disinfectant. As water use in a building slows or stops, the water tends to stagnate, causing a loss of this residual disinfectant which can lead to biological growth, as well as taste and odor issues, discolored water, and potential leaching of higher than normal concentrations of service line and premise plumbing materials such as Lead and Copper. Keeping the water moving, flushed and refreshed is crucial in these situations to ensure clean, clear water free of these unhealthy contaminants.
Please NOTE: This Document contains only Recommended Guidance for Water system Flushing. If your facility currently has a Water use plan in place, Please follow your individual plan.
Recommended Guidance for Water System Flushing Before Re-Opening
- Remove or Bypass Point- of- Entry treatment units.
- Take Steps to prevent Backflow or Back Siphoning of contaminants into plumbing.
- Remove all tap aerators/screens where possible prior to flushing.
- Flush the COLD water first.
- Open all outlets on the lowest floor in order to maximize flow and fully refresh the water through the service line.
- Begin to organize flushing throughout every floor and every tap individually, from the lowest floors, up to the highest. Flushing water through only one tap at a time. (about 10–15 minutes from each outlet)
- Drain HOT water tank and flush water first through the open Hot water tank outlet for approximately 30 minutes.
- Close the Hot water tank drain line and flush the Hot water taps individually as before.
- Replace all Point of use filters (on refrigerators, ice machines, whole building treatment systems, etc) before returning to normal usage.
- Water is considered refreshed and ready for use when there is a 0.5 ppm (mg/L) Chlorine residual present at the farthest outlet from the building service. (i.e. Top Floor, cold water tap)
Please also remember to consider draining and refreshing any water in your building’s HVAC system. An HVAC expert should be consulted for this procedure.
For further information and guidance on water use plans and flushing issued by the Centers for Disease Control, please visit their website at: