As COVID-19 vaccination rates continue to inch upward across the U.S., office buildings and other businesses that remained closed are now springing back to life. However, because nobody has been around — to flush toilets, wash their hands, and drink from the water fountains — the water inside these facilities that remained stagnant long enough to harm those who return, if not properly addressed.
Legionnaires’ disease, a lung infection caused by Legionella bacteria, is one of the biggest threats. Legionella, which are commonly found in water, can proliferate in stagnation, which is at increased odds of occurring as fewer people visit and occupy buildings. Given the circumstances resulting from the coronavirus outbreak are expected to exacerbate that risk, combating Legionella’s spread must be prioritized by building managers as they navigate reopening.
Experts say large buildings may pose the greatest danger of Legionnaires’ disease because their extensive plumbing creates a great deal of surface area for biofilms to form. For example, if cooling towers are not well maintained, they create a contaminated aerosol that can spread through the air-conditioning.
When water is stagnant, hot water temperatures can decrease to the Legionella growth range (77–113°F, 25–42°C), according to the CDC. Stagnant water can also lead to low or undetectable levels of disinfectant, such as chlorine. Ensure that your water system is safe to use after a prolonged shutdown to minimize the risk of Legionnaires’ disease and other diseases associated with water.
For facility managers, the CDC recommends 8 steps to minimize Legionella risk before reopening:
- Develop a comprehensive water management program (WMP) for your water system and all devices that use water.
- Ensure your water heater is properly maintained and the temperature is correctly set.
- Flush your water system.
- Clean all decorative water features, such as fountains.
- Ensure hot tubs/spas are safe for use.
- Ensure cooling towers are clean and well-maintained.
- Ensure safety equipment, including fire sprinkler systems, eye wash stations, and safety showers, are clean and well-maintained.
- Maintain your water system.
Each of these steps contains more detailed guidance and resources to help through the process.