Legionella are ubiquitous in the enviroment and water treatment professionals frequently report that even the well maintained systems can get colonised by the bacteria from time to time. Yet when high profile public buildings get contaminated there is the potential for political fall-out as well as the legal and health implications from Legionella bacteria in a water system. Earlier this year it came to light that a building at the Scottish Parliament had been contaminated - the media concern was not that there had been a specific health risk, nor whether the UK’s Approved Code of Practice (ACoP) had been followed - rather the suggestion that there may have been some sort of cover-up. Now it seems that on the other side of the world the situation is being replicated, as the Australian North Teritory Parliament has had a similar problem - with similar accusations about unnecessary secrecy.

Positive Legionella tests results are not uncommon. Indeed this is one of the main reasons for testing water systems for Legionella - to ensure the effectiveness of existing control measures. If the results were always negative there would be little value in testing. How you respond to positive results has the potential not only to mitigate legal and health risks but also to ensure that political and commercial issues are properly managed also. A well managed water system will not only document the control and monitoring measures necessary to reduce the risk, but also clearly identifies the actions required when contamination is discovered. That should include guidance on information that may be appropriate to share with building users, employees etc. With freedom of information acts and policies on open government stretching across the western world it is almost innevitable that eventually this information will reach the public domain eventually, and political opposition or the media will use it to their advantage. Even commercial organisations need to give thought to openness in this situation - the brand or reputational damage is almost certainly higher if it is eventually believed that there has been some sort of cover up.

Within the UK it may be argued that an employer must advise employees whenever Legionella is discovered in a water system that they come into contact with - since there is a requirement to consult employees on the risk assesment and control measures - and the ACoP expects duty holders to review and revise risk assesment and control measures whenever Legionella is discovered in significant numbers.

Pressures to reduce water consumption for economic and ecological reasons are encouraging both new building designers and existing facilities managers to install grey water systems for applications which don’t need potable quality - such as flushing of toilets. In most systems rain water is collected from the roof, although more extreme approaches exist. It is important to recognize that rain water collection systems are not treated and so will almost certainly contain bacteria and must not be allowed to mix with domestic hot and cold water systems. Assuming that the water systems are properly segregated and potable quality is not required this can be a very effective mechanism for reducing water consumption in the cold water system - however there is a downside: since toilet flushing is typically one of the major water uses in buildings such as offices, the reduction in water consumption can lead to water sitting stagnant in tanks and pipework for much longer - with the resulting opportunity for bacteria growth. We recently heard on one of our customers who was removing their grey water system after low water throughput was thought to have contributed to Legionella proliferation.

It is unusual for “payouts” in Legionnaires’ disease compensation cases to reach the press, even more so when the settlement is out of court. However, a Sheffield firm has settled a claim from a former sub-contractor after he contracted Legionnaires’ disease whilst working on their cooling tower in 2005. He has now seemingly made a full recovery. The payout was for around £20,000 + legal costs, which given the size of a potential claim had it gone to court doesn’t seem that high.

Mineral water bottlers in Israel have resumed production after a month of down time, but it is estimated they have lost almost 25% of their market share as a result. Meanwhile three different brands of bottled water have failed microbial tests in Vietnam. Production seems to have continued despite instructions from health officials to stop when pseudomonas and coliform bacteria were discovered.

Reports from NASA that the International Space Station (ISS) has problems with microbial contamination in its water supply show that even with world leading technology and multibillion dollar budgets preventing bacteria colonising a water system is extremely difficult. The microbe in question, Wautersia, is a common water and soil based bacteria back down on earth, and probably presents no risk to the astronauts - however the ability of an organism to enter the water supply and grow unhindered does raise questions about the control measures that NASA has in place to safeguard supplies. If Wautersia can colonise the water it is quite likely that other similar bacteria (e.g. Ralstonia, Bulkholderia, Pseudomonas) could also proliferate given the opportunity. However it is interesting that the ISS seems to repeatedly have problems with Wautersia (going back to at least 2007) so either it is particularly robust or there is some deficiency in the cleaning and control measures.

Environmental blogs Tree Hugger and Green Daily have picked up on the risks associated with Legionnaires’ disease and hot water systems.

There is a conflict between energy saving (whether for ecological or ecconomical reasons), scald risk and the potential for Legionella bacteria to proliferate. It is well known that Legionella can survive at quite high temperatures and guidelines and regulations generally advise storing water at 60 deg C (140 F), and delivering it to the taps at at least 50 deg C (120 F). Unfortunately where the very young or old are involved those temperatures may present a significant risk of scalding, heating and storing water at those temperatures also has an energy, and therefore environmental impact. It appears that a number of organisations may have been promoting the environmental arguments without highlighting the potential risk to health if Legionella is allowed to proliferate.

One might assume that if the municipal water supply is clean you will be safe to turn down the temperature, afterall they add chlorine to kill off bacteria don’t they?
Actually our experience is that even with well maintained municipal water supplies they are far from sterile. They shouldn’t contain harmful levels of bacteria - but there will be some background flora present which are just waiting to multiply up in a warm environment. Its also misleading to expect chlorine to work in your hot water system - most hot water system will have no chlorine reserve left (heat speeds up the reactions which consume hypochlorite and drive off Cl2 gas). In any case Legionella are more resistant to chlorine than other common drinking water pathogens. It would also be wrong to assume that the inside of hot water tanks (or cold water tanks that feed them) is clean and free from sediment which acts as a ‘hiding place’ for the bacteria as well providing nutrients - especially if there is no regular maintainence program in place to prevent problems developing.

So if you want to save the planet - make surre you have considered the risks to those who are exposed to your water from showers, taps (faucets), etc - and put in effective control and monitorring strategies first.