By Hilary Nardone, Environmental Group Training Manager
Certified ASSE 12080 Legionella Water Safety and Management Specialist
The Legionella Communications Factsheet: A Guide for Health Agency Staff has been recently published by the Association of State and Territorial Health Officials (ASTHO) and the Association of State Drinking Water Administrators (ASDWA). In addition to providing information that health agencies can use when discussing waterborne pathogens with building and facility personnel, the document also provides “information to increase building owner awareness of the potential for pathogens to grow in building water systems…” [1]

Below are three pieces of fundamental concepts to control for Legionella bacteria in potable water systems:
- Because Legionella bacteria can grow in temperatures 77°F – 113°F, best practice is, whenever possible, to store hot water above 140°F and keep circulating hot water above 120°F.
- Loss of a chlorine disinfectant residual can occur due to many reasons including water age and poor water management, and loss of disinfectant is a significant factor in the ability for Legionella bacteria to grow.
- Routine flushing is an integral component of risk minimization as it decreases water age, flushes out sediments and biofilms from outlets and aerators, and helps to maintain effective disinfectant residual levels.
The Legionella Communications Factsheet also stresses the importance of implementing a Water Management Program (WMP). Creating and implementing a WMP that complies with ASHRAE Standard 188 is one of the most effective ways to minimize Legionella bacteria growth and amplification in building water systems. A robust WMP includes a WMP Team, a description of the building water system, a diagram of the building water system, control locations where Legionella bacteria and other waterborne pathogens could grow and spread, control measures and corrective actions for the control locations, a monitoring plan, verification and validation procedures, and an update and documentation plan. [1],[2]
Both building owners and facility managers play important roles in WMP implementation and should be part of the WMP team. In fact, the Legionella Communications Factsheet references a study that surveyed facility managers across the United States. The findings revealed that there is “a high awareness level (87% of respondents) for the potential of Legionella growth in the pluming or cooling towers of buildings. Half of facility managers working in the education and hospitality sectors were aware of ASHRAE 188 guidance for prevention and mitigation of Legionella risk in building water systems.”1 The CDC has found that 80 percent of problems leading to health care-associated outbreaks of Legionnaires’ disease in the United States could be prevented with effective water management, emphasizing the importance of understanding Legionella risk mitigation strategies. [3]
Barclay Water Management, Inc. has created, implemented, and validated hundreds of WMPs in partnership with our customers. Barclay continually utilizes best practice recommendations from organizations including but not limited to ASHRAE, CIBSE, and the CDC to minimize waterborne pathogens in building water systems. Barclay is dedicated to ensuring its WMPs comply with national and local standards and guidelines including ASHRAE Standard 188, CMS, local Health Departments, and the Joint Commission. Be sure to check out our recent blog post about how Barclay’s WMPs comply with the Joint Commission’s new Water Management Program Standard EC.02.05.02.
[1] ASDWA, ASTHO. Legionella Communications Factsheet: A Guide for Health Agency Staff. https://www.asdwa.org/2021/08/27/new-resource-legionella-communications-factsheet/?utm_source=rss&utm_medium=rss&utm_campaign=new-resource-legionella-communications-factsheet. Published August 2021. Accessed November 5, 2021.
[2] ANSI/ASHRAE. Standard 188-2021 Legionellosis: Risk Management for Building Water Systems. ANSI/ASRAE. https://www.techstreet.com/ashrae/standards/ashrae-188-2021?gateway_code=ashrae&product_id=2229689. Updated 2021.
[3] CDC Vital Signs. Legionnaires’ Disease: A problem for health care facilities. U.S Department of Health and Human Services. https://www.cdc.gov/vitalsigns/legionella/index.html. Published June 2017. Accessed November 5, 2021.