Controlling Legionella with UV water disinfection

Those with lowered immune systems are at higher risk of contracting the disease, which can be transmitted through hot and warm water systems such as those found in aged care facilities and hospitals. The sources of Legionella bacteria in outbreaks of Legionnaires’ disease have typically been traced to either large air-conditioning plants or hot water distribution systems that have been incorrectly commissioned or poorly maintained.

UV-Guard Managing Director Richard Vallance explained that low levels of Legionella are commonly found in drinking water supplies — and these multiply quickly within warm water infrastructure if there are no disinfection strategies in place.

“Thermostatic mixing valves, commonly used in health care and hospitality industries to provide water to a preset temperature, do not provide microbial control and can, in fact, promote the growth of Legionella and other microorganisms,” Vallance said.

Each Australian state has different regulations relating to how the Legionella risk must be controlled. The good news is that UV water disinfection can be an effective safeguard against Legionella, with Vallance noting, “An established and cost-effective method of Legionella control is to install a UV disinfection system on either or both the warm water outlet or return line of the water heater.”

UV-Guard’s S-Series system is suitable for controlling Legionella as it is a robust and dependable UV water disinfection system able to provide recommended UV dose rates at flows of up to 737 L/min, from commercial business installations to hospitals, mining camps and more. Vallance said, “The S-Series, as with all UV-Guard products, is food-grade compliant and accredited by the WaterMark certification scheme, a requirement documented within The Plumbing and Drainage Code Australia.

“This is in comparison to some non-certified products on the market that are being imported from overseas. Customers need to be aware that they are not WaterMarked or regulated and are not in compliance with the Plumbing Code of Australia.”

Plumber Andy Murray, from Andy Murray Gas Services in Queensland, came to UV-Guard looking for a solution to an outbreak of Legionella at one of his plumbing clients’ aged care facilities.

“The facility is housed in a very old building, and I had previously been advised by another company that the only way to fix the Legionella problem was to replumb the whole building, which is almost an impossible task,” Murray said.

“I had seen a UV-Guard system installed at another aged care facility I worked with so I called UV-Guard to help us find a solution. We’ve decided to go down the UV route with this new building and UV-Guard have been a great company to work with.”

UV-Guard’s water treatment engineers can custom-design a UV water treatment system to specific needs. When it comes to warm water systems, the company can provide lamps, quartz and other spares; complete UV disinfection systems; and water quality sampling, testing and management.

The company has additionally released the following tips to help reduce the risk of a Legionella outbreak:

• Ensure all fittings and thermal mixing valves are maintained to the manufacturer’s specifications.
• Establish a regular water quality monitoring program.
• Disinfect potential Legionella hot spots, including shower heads and taps.
• Undertake shock disinfection of the complete warm water system.