As our economy begins to open back up, the U.S. Centers for Disease Control and Prevention (CDC) and California State Water Resources Control Board (State Water Board) have issued guidance for reopening facilities closed for an extended period during the COVID-19 pandemic. Taking precautionary steps will ensure the safety of building water systems and devices.

Businesses that are reopening after an extended shutdown should consider flushing plumbing fixtures of stagnant water before resuming normal operations.

Stagnant or standing water has the potential to cause conditions that increase the risk for growth and spread of Legionella and other biofilm-associated bacteria. Flushing involves opening taps and letting hot and cold water run through all points of use (such as faucets and showerheads) for a sufficient amount of time. The goal is to replace stagnant water in interior pipes and/or outlets with fresh water.

The CDC recommends that facility owners and managers create a comprehensive water management program and offers specific guidance for hotels and public hot tubs/spas, as well as recommendations for flushing water systems and maintaining water heaters, decorative water fountains, cooling towers and safety equipment such as fire sprinkler systems.

Here are a few flushing tips following CDC and industry guidelines 

  • Flush the entire water system to replace all water. Flush hot and cold water through all points of use (e.g. sink faucets and hose bibs) for a sufficient amount of time, including all water-using appliances like ice machines and dishwashers. Flush until the hot water reaches its maximum temperature.
  • Depending on the facility’s size, flushing may need to occur in segments (e.g. per floor or individual rooms).
  • Remove all aerator screens before flushing.
  • During flushing, operate all valves in the fully open position to flush through any particulate matter.
  • Adjust valves back to normal operating positions to ensure system re-balance.
  • Return hot water systems to normal operating temperatures.
Sewer floor drains

Roseville also recommends that if the building has floor drains, you should pour water into the drain to fully restore the trap, which is necessary to keep sewer gases from entering the building. Functioning drain traps also protect occupants from health risks and need to remain “wet.”

We're here for you

Your water utility is working around the clock to ensure you receive high water quality at your meter, but you are responsible for your water system in your facility. The public water system has remained pressurized and operational since the Placer County Health Order to shelter in place. We continue to conduct routine water quality sampling and analysis throughout the water distribution system on a weekly basis.

More information

For other resources and additional information, please visit If you have questions, please contact our Water Utility customer service staff at (916) 774-5750 and [email protected].