As we continue to deal with effects of COVID-19 in our everyday lives, facility managers for commercial office buildings, hotels, hospitals, etc. have additional challenges beyond air and surface cleanliness. Water stagnation poses a different, but just as dangerous threat to health and human safety.
Keeping Your Building’s Water Healthy
Stagnant water in a plumbing system can drastically increase the risk of exposure to Legionella and other harmful water borne pathogens. When water is left standing, city supplied disinfectant levels drop, heavy metals like lead and copper increase, and pathogens will build up. According to the Department of Safety and Professional Services, water that is stagnant for 3 weeks or more is considered “old water.”
Below are steps to safely reopen closed or semi-open buildings:
- Conduct a risk assessment on the building (if this hasn’t already been done) to identify potential risk.
- The building water systems need to be flushed vigorously at all outlets (backflows, sinks, showers, drinking fountains, water coolers, hoppers, mop sinks, ice machines, water heaters, water softeners and toilets) for multiple days. Extreme care should be taken when flushing stagnant water systems. Open outlets slowly to avoid splashing and the creation of aerosols. A NIOSH N95 facemask, rubber gloves and safety goggles, if available, are recommended best practices. Note: Keep an eye on drains so they don’t overflow during the flushing process.
- These devices should be inspected for cleanliness. (Aerators, showerheads, drinking fountain spouts, water filters, etc.) These items should be replaced or cleaned.
- All water systems should also be inspected to confirm they are in good working order, including backflows, pumps, air handlers, drains and heaters.
- Remember to pour water down the floor drains to keep sewer gases from entering the building.
- Potable water chlorination and/or bacteria filtration (≤ 0.2 micron) should be considered based on pathogen testing results.
- If Cooling Towers are turned on to these buildings, then ensure they are cleaned & disinfected prior to operation. Ensure that proper treatment is being adding continuously during this time.
- If applicable, consider keeping decorative water features fully drained and off during this time period.
- Consider testing for Legionella after remedial steps above and prior to reopening the building. The culture method takes 10-14 days to receive results.
- Once the building is open and operating then follow your Water Management Program to maintain the water systems in each building as you would in any other building.
Tips & Resources
- As Janet Stout PhD, the world’s leading Legionella epidemiologist says, “TEST TO PROTECT.” The only way to identify if your water systems have been overrun by harmful pathogens is to test the water.
- Consult your CMS and ASHRAE 188 Water Management Plan for best practices for flushing, treating, and testing. Update the plan as conditions change
- Read relevant resources. Click the image below to go to our Knowledge Center and download AWWA’s guide to reopening buildings safely after a complete shut down or reduced use.
If you have any questions or need help assembling a plan for a safe re-opening of your building, please contact us at firstname.lastname@example.org or 414-254-3310.
Director of Water Safety, Watertech of America, Inc.
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