Many large buildings–schools, childcare facilities, hotels, and others–have shut their doors or reduced occupancy as the nation comes together to slow the spread of COVID-19. The Center for Disease Control and other environmental health experts are raising concerns about how this period of disuse may impact drinking water quality in these facilities. We summarize the key issues, resources, and recommendations on this topic to support building managers as they develop plans to re-open buildings to the public in the coming weeks and months. We also discussed some of these issues in a recent episode of the Buildings Podcast.
Stagnant or standing water in building plumbing systems can negatively influence water quality in the following key ways:
US water systems disinfect drinking water during the treatment process through the addition of chlorine and other practices, but disinfectant residuals can be depleted as water sits in building plumbing. Those residuals prevent the growth of organisms bacteria like Legionella, which can lead to a pneumonia-like illness called Legionnaire’s disease. Longer stagnation periods may also increase the production of harmful disinfection by-products, which form as organic matter in drinking water interacts with disinfectants.
As our school and childcare facility clients know, any facility built before 2014 may have leaded plumbing products and outlets in their buildings. The most common sources of lead in large facilities are likely leaded brass, soldered lines/products, and galvanized steel. Stagnant water can compromise the protective scaling that forms on pipes and cause lead to release or dissolve more readily into drinking water.
Annual backflow preventer tests and standard maintenance of water cooling towers, boilers, and pumps are an essential part of reducing bacterial growth and pathogens in drinking water systems.
If you have staff in the building, flushing now may help to prevent water quality from deteriorating and ultimately reduce the potential for some of the negative outcomes we have discussed. Here is a helpful resource from the Environmental Policy & Research Institute on flushing protocols. Manual flushing is not a cure-all but an advisable preventative measure in this case. Provide flushing teams with Personal Protective Equipment as some organisms can be passed through inhalation and/or dermal exposure.
Now might be a great time to check in and perform any necessary maintenance on equipment that may be malfunctioning to ensure that everything is operating correctly. It’s especially important to check backflow preventers, pumps, cooling towers, boilers, and filtration devices.
If your facility serves elderly populations, you may want to test for Legionella or increase monitoring for temperature and chlorine residuals if you already have a Water Management Plan in place. If your facility treats its own water, discuss the potential need for a higher dose of disinfectant.
Upon reopening, ongoing flushing can continue to re-stabilize protective lining on pipes and may thoroughly wash lead particulates from the plumbing system. The AWWA recommends an industry standard of about 12 weeks on flushing related to lead.
Lead sampling is generally advisable for facilities older than 2014, especially those that serve young children, and sampling after operations resume may help guide your flushing and/or maintenance decisions. Maintain increased monitoring of chlorine residuals and temperature. Call in plumbers or water treatment advisors if you need additional guidance.
It’s essential to establish trust with the communities your facility serves – make sure they know what steps you’ve taken to monitor and provide clean water so that they can have peace of mind as they consume your facility’s water.