The U.S. Environmental Protection Agency (EPA) on Friday 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.”
Please read this attached PDF for more information.