HEALTH AND SANITATION 37
UMC Technical Committee working toward addressing Legionella in mechanical systems
By
Zalmie Hussein
Legionnaires ’ disease was first identified in 1976 and is caused by water contaminated with Legionella pneumophilia which , when disseminated in droplets into the atmosphere and inhaled , may infect a person .
The interest and concern in Legionella management and control within building water and air systems has continued to grow as Legionella outbreaks increase . Although plumbing systems are a common source of such outbreaks , mechanical systems such as cooling towers , air distribution systems , spas , fountains , and hot water tanks can also act as breeding grounds for the bacteria that causes Legionnaires ' disease .
During the 2024 edition of the Uniform Mechanical Code ( UMC ) code cycle , the UMC Technical Committee formed a task group to address Legionella in mechanical systems for the UMC . Prior to the formation of this group , the Uniform Plumbing Code ( UPC ) Technical Committee formed a task group for the 2021 edition of the UPC , which resulted in the creation of a new Appendix N ( Impact of Water Temperature on the Potential for Scalding and Legionella Growth ). The
Uniform Codes published by IAPMO consistently endeavor to integrate major health and safety concerns , earning the reputation of being all-inclusive safety codes in an everchanging environment . The UMC is developed via an ANSIapproved development process , which ensures consensus and due process in its development .
Water Management Programme Legionella outbreaks are more likely to occur in buildings with mismanaged water systems and in stagnant water . Therefore , a water management programme is the preferred approach to controlling Legionella in building water and air systems .
Legionella bacteria thrive in cooling towers where standing water is common . A Legionella management plan should include preventive measures for all systems that present a significant risk of Legionella growth and transmission .
David Viola , IAPMO CEO
In the spirit of the sharing of unique experiences that shape the plumbing industries in our respective nations , the following article looks at a task group examining how outbreaks of Legionnaires ’ disease can begin in cooling towers and air distribution systems . Written by IAPMO Mechanical Code Development Administrator , Zalmie Hussein , it is the next in a regular series of similar articles that will run in this magazine .
Markus Distelrath | Pixabay
Legionella bacteria thrive in cooling towers where standing water is common .
“ Legionella outbreaks are more likely to occur in buildings with mismanaged water systems , and in stagnant water .”
January 2022 Volume 27 I Number 11 www . plumbingafrica . co . za