Inactive Plumbing Systems May Require Care to Ensure Safety
Pipe flushing is needed for some buildings to avoid health problems
Water provided by the Otay Water District continues to meet all state and federal drinking water standards — but after the water leaves the District’s distribution system and enters private service connections, the water quality can deteriorate if water becomes stagnant.
Most commercial and industrial buildings have been partially occupied even during the COVID-19 shutdown, and HVAC and water systems continue to be maintained and operated even though many employees are working remotely. However, building owners and managers should take special care with plumbing systems in buildings that have been vacant or have had periods of low water use to protect the public and employees returning to work.
That is because plumbing systems must be actively managed and maintained to prevent bacteria growth. Bacteria can flourish in pipes, fixtures and associated equipment (like fountains, cooling towers and HVAC systems) that are not used for several days. Schools, for example, commonly flush pipes before kids and teachers return from breaks.
Local water agencies, including the Otay Water District, are providing public notice about this plumbing safety; however, it is the responsibility of building owners and managers to address any related issues on their own properties. RESOURCES
Several steps are necessary to prepare inactive plumbing systems for building re-occupancy, and workers performing start-up tasks should wear PPE and receive appropriate training. The steps involve flushing the entire plumbing system with water and testing to ensure “residual chlorine” levels are within the safe range. Testing to ensure effective flushing is recommended; if testing reveals high levels of bacteria in the system, additional steps are needed.
Because this is a national issue, the Centers for Disease Control and Prevention offers several resources for proper management of plumbing systems to reduce the risk of bacteria growth. Washington State Department of Health recently updated its guide for building owners and managers. In addition, California’s Water Boards offer guidance for reactivating service and operations. State-certified California labs can be found by clicking here.
Centers for Disease Control and Prevention – Water Management Programs
San Diego County Water Authority – Plumbing Safety Fact Sheet
State Water Resources Control Board – California ELAP Certified Laboratories
State Water Resources Control Board – COVID-19 Information for Public Water Systems and Affected Communities
Washington State Department of Health – COVID-19 Guidance for Legionella and Building Water System Closures