Legionella bacteria, which cause Legionnaires’ disease, thrive in stagnant water systems. Buildings that have experienced prolonged shutdowns or facilities operating at a reduced occupancy are at increased risk.
Why This Matters
Since the onset of the COVID-19 pandemic, many buildings are now operating below capacity or have been shut down periodically. These conditions allow water to stagnate, increasing the risk of Legionella growth along with other pathogens. Without proper precautions, legionella outbreaks can occur, especially in large buildings with complex plumbing systems such as hospitals, hotels, and office buildings.
General water management guidelines
- Flush all water systems: Run water through all outlets (sinks, showers, fountains) to remove stagnant water.
- Check water temperatures: Ensure hot water is above 140°F and cold water below 68°F to inhibit Legionella growth.
- Inspect mechanical systems: Verify operation of pumps, backflow preventers, and water heaters.
- Test for Legionella: Especially in buildings with cooling towers, decorative fountains, or large plumbing systems.
- Maintain documentation: Record flushing schedules, temperature readings, and any corrective actions.
- See CDC Legionella Reopening Guidance for more comprehensive information.
Operating with Reduced Staffing
- Weekly flushing: Rotate rooms and outlets to ensure water movement.
- Monitor disinfectant levels: Check chlorine or other residuals to ensure water safety.
- Coordinate with water treatment providers: Adjust treatment plans for low occupancy periods.
- Drain unused equipment: Ice machines, storage tanks, and infrequently used fixtures should be cleaned or shut down.
Healthcare specific guidelines
- Follow ASHRAE Standard 188 also known as Legionellosis Risk Management for Building Water Systems: Implement a water management program tailored to healthcare settings.
- Protect vulnerable populations: Take extra precautions during maintenance to reduce generating aerosols to protect patients and staff that are at higher risk.
- Routine testing: Conduct regular Legionella testing, especially before reopening or increasing occupancy. Regular could mean monthly, quarterly, or semi-annually, or some other interval that your facility builds into its water management plan.
- Disinfection protocols: Maintain supplemental disinfection systems and follow manufacturer guidelines.
Recommissioning After Shutdown
- In addition to the general guidelines: Coordinate with infection control teams, align water safety plans with broader health protocols.
- Flush and disinfect: Include all outlets, medical equipment connections, and water storage systems.
- Document all actions: Maintain detailed logs for inspections, flushing, and water quality testing.
Resources and toolkits
Macomb County Legionella toolkit for:
- Businesses
- Healthcare
List of Environmental companies with Legionella experience.
Contact the Environmental Health Services Division
Mount Clemens: 586-469-5236 | Email: environmental.health@macombgov.org