EPA's Flushing Guidance

The U.S. Environmental Protection Agency (EPA) on Friday, May 8 distributed “Information on Maintaining or Restoring Water Quality in Buildings with Low or No Use” to assist building owners and managers in addressing water stagnation following extended closures due to the COVID-19 response. The material distributed by EPA also draws attention to “Guidance for Reopening Buildings After Prolonged Shutdown or Reduced Operation” prepared and recently updated by the U.S. Centers for Disease Control and Prevention. 

The guidance says stagnant water presents optimal conditions for the growth of pathogens like Legionella. Stagnant water also changes water chemistry, which may increase corrosion and leaching of metals, including lead. “Turning on the water for immediate use after it has been stagnant can pose a risk to public health if not properly managed,” the guidance notes. “Additionally, turning on water after a prolonged period of non-use could disrupt pipe and plumbing scales to such an extent that microbial and chemical contaminants could be released into the water.”

Among the EPA’s recommended steps to maintain water quality while buildings/businesses are closed for building owners/managers are:

  • Review and understand the plumbing configuration and water usage in your building.
  • Inspect the building.
  • Contact your water utility.
  • Flush the buildings plumbing system regularly.

EPA recommends public water systems:

  • Coordinate distribution flushing activities with nearby building owners/managers.
  • Be prepared to provide information on system disinfection activities or proactively post information on the utility’s website.

Before buildings and businesses reopen, EPA recommends the following steps are taken to prepare the building’s water system:

  • Follow the steps described above to replace the water in the building’s plumbing and maintain all building water systems.
  • Consider contacting your local public health department for assistance if you have specific concerns or to determine if any local requirements are necessary prior to reopening.
  • Review the potential impact that the degraded water quality might have on your building occupants considering their use of the building and the building’s water systems.
  • Drain and clean water storage facilities and hot water heaters.
  • Follow appropriate regulations and policies for worker safety and health while performing all activities.

In addition to federal guidance, systems will want to consider state-developed orders and instructions.