Cooling tower of large building

UV Treatment for Legionella Control

Managing the Risk of Legionella

Legionella bacteria occur naturally in warm, freshwater environments, but they pose a risk when they grow in plumbing systems. Stagnation leads to Legionella accumulating in biofilms, such as on pipe walls. It then spreads when water is distributed throughout the building, and becomes problematic to people when aspirated. 

Points of contamination in a building are numerous and include:

  • Cooling towers
  • Humidifiers
  • Evaporative cooling systems
  • Decorative fountains
  • Showerheads
  • Drinking fountains

In higher risk populations, Legionella can cause a serious type of pneumonia (Legionnaires’ disease) and Pontiac Fever. Legionella is one of the leading water-borne disease agents in the USA, with reported cases increasing more than five-fold from 2000-2017 (CDC). A simple approach to managing Legionella is to adequately treat the water in the buildings' water systems.

    Building with Legionella inset

    How UV Contributes to Legionella Control

    UV light rapidly inactivates microorganisms through a physical process. Exposing Legionella  to certain wavelengths of UV light damages the DNA and renders them unable to reproduce. Most Legionella species are sensitive to UV light, meaning the UV dose requirements for control are generally low. 

    UV Systems for Legionella

    UV can be applied at the point-of-entry (POE) as a complementary treatment barrier for the whole building, or at point-of-use (POU) for high-risk areas within a plumbing or mechanical system. UV is a proven solution for preventing Legionella contamination of building water systems, and can be used in:

    VIQUA PRO20 NSF Class A validated UV system

    VIQUA PRO Series

    The VIQUA PRO Series are robust, point-of-entry systems certified to NSF 55 Class A for flow rates up to 30 GPM. Equipped with a leading flow meter/UV sensor combination providing realtime UV dose, the PRO Series are suited to environments where measurement of ongoing system operation is preferred.

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    VIQUA F4-V NSF Class B validated UV system

    VIQUA Professional

    The VIQUA Professional series spans high-efficiency, compact UV systems certified to NSF Class B designed for small commercial scale flow rates to high commercial flow, multi-lamp UV systems.

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    Aquafine Logic UV system

    Aquafine Logic Series

    The Aquafine Logic series offers robust UV systems well suited to the life sciences market.

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    Aquafine OptiVenn UV system

    Aquafine Optivenn Series

    The OptiVenn Series is a family of robust and flexible UV systems with advanced technology for pharmaceutical, food & beverage, microelectronics and other industrial markets.

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    VIQUA VT4 point-of-use UV system

    VIQUA Tap Series

    For added protection at high-risk areas within a plumbing system, the VIQUA Tap series is designed for low-flow and point-of-use applications.

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