A recent outbreak of legionella in Queensland underscores the importance of building owners and managers adopting proactive measures to prevent the disease, a Sydney-based facilities manager says.

In an interview with Sourceable, Colin Ramsden, a facilities manager who has worked in the building industry since the 1970s, said concerns surrounding the disease extend beyond healthcare facilities and include commercial, multi-residential, domestic and other forms of buildings.

Ramsden has first-hand experience with the disease after he came close to losing a family member afflicted by legionella-like symptoms in 2002 – an experience which prompted him to conduct extensive research in order to understand the problem and subsequent treatment options.

Legionella is a group of bacteria which can cause legionnaires disease (a type of pneumonia) as well as a less serious flu-like condition known as Pontiac fever. Both are usually contracted by breathing in a mist or vapour containing the relevant germs, which tend to grow in high numbers in warm stagnant water - typically between 20 and 50 degrees Celsius.

Outbreaks are often associated with contaminated cooling towers which are part of air-conditioning systems in large buildings as well as hot water tanks, large plumbing systems, hot tubs and decorative fountains.

Colin Ramsden

Colin Ramsden

Ramsden says the disease is a concern in any environment in which water is stored at temperatures conducive to bacterial growth.

“That’s why we chlorinate backyard pools and public pools that heat up in the sun,” he says.

“The same for the built environment. Where you’ve got water that is being stored and it may be stagnant and subject to being warmed, that is the ideal environment for bacteria to grow and legionella is one of them.”

He says the key to prevention lies in regular testing and maintenance of cooling towers, evaporative condensers and associated equipment. He says that while local councils require this, problems can occur when changes in personnel precipitate a loss of knowledge with regard to the existence of equipment or equipment maintenance regimes.

While stressing his understanding of the recent outbreak at Wesley Hospital is limited to media reports and that he is not commenting specifically on this or any other individual cases, Ramsden says there are alternative solutions to avoid building occupants being scalded when showering without resorting to lowering the temperature to levels at which bacteria can proliferate. In a statement on June 7, Wesley confirmed it maintained water temperatures at 43.5 degrees to prevent scalding.

Ramsden says one approach would be to have a high temperature water heating unit heat the water to around seventy or eighty degrees, a pumping system that transfers water around through insulated pipes to maintain the temperature and metering valves to control temperature at the outlet by mixing the hot water with cooler water – a system which would avoid any scenario in which the water needed to be stored at less than sixty degrees.

Asked about the level of awareness among building owners and facility managers regarding the disease, Ramsden says there is a likelihood some misconceptions exist as a result of a general misunderstanding regarding how legionella is contracted. He says while professional associations are generally proactive in promoting awareness within their membership, not every facility manager is a member of an association, and problems can arise among personnel who are inexperienced or not on receiving end of knowledge provided.

“That’s either the very young or inexperienced straight out of uni or college, especially if they are not working with somebody on site who can pass that knowledge on,” Ramsden says. “Or somebody who has come into the industry from a different field and they are just completely unaware of the situation.”

He would like to see a mandatory training register, preferably organised by the industry under a type of voluntary code, which would ensure those involved with management of building update their knowledge on a periodic basis.

Recent events have put legionella back in the public spotlight. They have also served to remind building and facility mangers about the importance of measures to prevent this and other diseases.

  • I fully support the above article and the words and concerns of Colin Ramsden. Control of legionella is conducted in many building water systems through out Australia using the heat sterilization method as described above. The disadvantages are high power bills to heat the water to 70 to 80°C, high labour contracts to carry this out on a regular basis and the danger of scolding people who use the hot water. However as soon as the water is cooled or mixed to a lower temperature legionella spores can recolonise taps and shower heads exposed to the atmosphere and start the process all over again. The answer is not heat treatment but continuous dosing of a chemical that can kill the legionella virus and spores and remove the biofilm inside the pipework of both the hot and cold water systems that the legionella live in. Such a chemical is Chlorine Dioxide which when continuously dosed at very low rates into the incoming water flow will disinfect the hot water system to 40°C, the cold water system and keep a residual disinfectant level to prevent reinfestation through external taps and showers. Chlorine Dioxide is a reactive chemical, best generated on site using weak solutions of Sodium Chlirite and Hydrochloric acid, it is then dose immediately into the water flow. I represent a manufacturer of such equipment and would be happy to offer information on this to any building owners who are concerned with Legionella in their buildings and would like to investigate this option further.

    • Hi Peter, Are you saying that chemical additive alternatives to high temperature water heating systems are possible, or are proven?
      I wouldn’t want to shower at 40C, and can tell you that the continuing cost of a circulating HW supply is still far cheaper than the alternative cost of restarts and system lags in delivery.