The prolonged shutdown of businesses and buildings during the COVID-19 pandemic has resulted in significant reductions in normal water use for many commercial buildings, hotels, and public facilities. These reductions have increased the opportunity for Legionella growth in building water systems and created a significant risk for transmission of this waterborne bacteria to returning occupants. It's important that building owners and managers understand the risks leading to increased Legionella growth and consider them as part of an overall reopening strategy.
A key step to managing the risk of Legionella-associated illness in your building is the development of a water management plan (WMP). A WMP is a building-specific risk assessment and detailed operating procedure, intended to systematically control, monitor, and prevent Legionella growth in your building’s water systems. Developing a WMP should be the combined effort of a multidisciplined program team that includes the building owner, employees and key stakeholders, and technical professionals such as engineers, Certified Industrial Hygienists, and water treatment specialists.
According to ASHRAE standard 188, the components of WMP should include:
Key strategies to prevent the amplification of Legionella in domestic water systems include:
If water systems have undergone prolonged interruption or decreased use, remedial treatment may be necessary to return these systems to a safe condition within control limits. Treatment options range from short-term chemical shock with high-levels of disinfectant, to thermal shock with high-temperature water, or flushing of hot and cold domestic systems. The selection of treatment options is complex and should be conducted in consultation with qualified experts to prevent harm to building occupants or damage to water system components.
In summary, water management planning is an effective strategy to reduce the risk of Legionella associated illness in commercial buildings, hotels, and public facilities. Although this strategy has been recommended by public health authorities for years, particularly in buildings occupied by high-risk populations, commercial buildings, hotels, and other public facilities may not have anticipated a need for these voluntary guidelines.
Due to the increased risk for Legionella growth during prolonged shutdowns, ongoing decreases in water usage due to remote work and occupancy restrictions, and the continued potential for further shut-downs during the COVID-19 pandemic, now may be the time to plan ahead. To learn more about how to protect your water from Legionella or to create a water management plan contact us today.
References
ASHRAE. 2018. “Legionellosis: Risk Management for Building Water Systems (ANSI/ASHRAE Standard 188).” Atlanta, GA: ASHRAE. Print. https://www.ashrae.org/technical-resources/bookstore/ansi-ashrae-standard-188-2018-legionellosis-risk-management-for-building-water-systems
ASHRAE. 2020. “Managing the Risk of Legionellosis Associated with Building Water Systems (ASHRAE Guideline 12-2020).” Atlanta, GA: ASHRAE. Print. https://www.techstreet.com/ashrae/standards/guideline-12-2020-managing-the-risk-of-legionellosis-associated-with-building-water-systems?product_id=2111422
CDC. 2020. “Guidance for Reopening Buildings After Prolonged Shutdown or Reduced Operation”. Atlanta, GA: U.S. Center for Disease Control. Retrieved from: https://www.cdc.gov/ coronavirus/2019-ncov/php/building-water-system.html
CDC. 2016. “Legionnaires’ Disease: Use water management programs in buildings to help prevent outbreaks”. Atlanta, GA: U.S. Center for Disease Control. Retrieved from: https://www.cdc.gov/ coronavirus/2019-ncov/php/building-water-system.html
CDC. 2018. “Legionella: History, Burden, and Trends”. Atlanta, GA: U.S. Center for Disease Control. Retrieved from: https://www.cdc.gov/legionella/about/history.html