Posted By Tony abc jprhdnMurphy legionella threat is extremely low but the consequences are siesmic, hence why people get all uptight and certain conditions must be met. the water authority is your best bet. if they are happy, and you have met the requirements in terms of minimising risk you are fine. we always seek wras approval prior to installation, and we always follow the guidelines. alternateively call Dr Tom, he is always ready to help

Posted By clairel Legionnaires disease can develop in vulnerable people after inhaling droplets of water that contain sufficient quantities of the legionella bacteria. I emphasise 'inhale' because you can drink contaminated water and be ok. Legionnaires disease is a lung disease. It is quite rare in this country and elderly people, smokers and those with a few other medical conditions are most suseptible. Because an inhalable spray is required most establishments have a very low risk from their hot and cold water supply (showers pose the greatest risk). Hotels, hospitals and nursing homes are the main risk from hot and cold water supplies. Legionella bacteria favours temperatures of 20-45 degC. Unlikely to proliferate below 20 and won't survive above 60. Control is through temperature control and through minimising food source in the water (clean tanks and pipes) Advice is: Water should be heated and stored above 60. Water should be distributed at least 50. For both above points look at insulation of tanks and pipes to prevent falling below those temps. Tanks covered. Dead legs removed. Clean and descale showers quarterly. Run through little used showers weekly. Water samplling is not control but monitoring of effectiveness of control. TMV's are then concerned with preventing scalding by hot water of vulnerable people (usually the elderly). TMV's should be fitted close to every outlet not near the boilers - because then the water would be circulating at a lower temp than 50. Usually is full body immersion that is the issue for scalding and the recommended temps are 44 for a bath and 41 for a shower. However, there is also a guide temp of 41 for handbasins too. Very very brief heads up. Hope it helps.

Posted By Jo O Actually this is a shower case: http://news.bbc.co.uk/1/...and/somerset/5256926.stm :-)

Posted By Jo O ok the prosecution details lol http://www.hse.gov.uk/pr...ils.asp?SF=CN&SV=4044286

Posted By Adrian Watson Possibly; there is evidence that aerosols (in the 10 µm range) from cooling towers, misting systems and spa baths. There is evidence that hot and cold water systems may cause exposure to legionella sp. However, it must be borne in mind that the risk of death from legionellosis in domestic premises is estimated to be 1 in 4.6 million persons. Regards Adrian

Posted By MT Adrian, I beg to differ. There were two fatalities due to Legionnaires' disease in Scotland last year, both attributable to Legionella bacteria living in dirty shower heads. http://www.eveningtelegr.../18/story11230323t0.shtm http://www.thecourier.co.../newsstory11103043t0.asp Yes, they are only news reports, but they were sent to me by a fellow Officer who was involved in the cases. To this end, several LAs in Scotland are now taking a much closer interest in compliance with L8, and in particular regular descaling and disinfection of showerheads. I also attended a Legionella training day run by the HSE in December, and they cited showerheads as being a breeding ground for the bacteria.

Posted By A Campbell Regarding shower heads.... If you risk assess you may likely find that showers that are infrequently used would likely be at greater risk of allowing dormant water... similar to a potential 'dead leg'. Offices may have this depending on how often the shower is used by staff? In such cases as in my own premises I advocate descale & soak of the shower head in commercial biocide solution and a 5 minute flush of the shower in order to ensure the flow is actually coming from the tank.

Posted By TT With regard to the original post, I would suggest that there is 'some' cause for concern but lets not go mad. Aerosol generation from taps is possible but pretty low. The main controls for legionella proliferation in domestic water services (after design) are temperature and flushing. From your description, the temperature of the hot water may be falling slap bang in the middle of ideal growth temperatures for legionella. Do you therefore think that you could reasonably be doing more to control the risk? The guidance out there would say that boilers/stored hot water should actually be capable of getting to 60 degrees C with over 50 degrees at the furthest outlet. TMV's complicate that nicely as accurate measurement becomes trickier - if you can easily access pipework then you can use surface temperature probes on the pipe to give you a representative figure. 50 degrees prevents growth and 60 degrees should give you a kill. If you're worried about running at 60 degrees then you can develop procedures to simply boost temperature to that level and flush periodically 'out of hours' in order to achieve similar. If its a small run of pipework then this may be more than adequate. Before we go temperature mad though, you should consider the level of use these runs of pipework get. If the water is sitting at 36 degrees for weeks between use then you have a major problem compared to sitting there for 10 minutes. Also, the smaller and less complicated the run of water regs compliant pipework between boiler and outlet, the less chance for biofilm to form. A whole myriad of things to consider and risk assess and, frankly, without more detail I wouldn't really be able to offer you a firm opinion. Having said that, my feeling on the matter (as someone who deals with legionella a fair bit) is that a 70l boiler at 36 degrees C and never any higher is an issue regardless of the level of flushing and usage.

Posted By Phil Rose Adrian I am not a legionella expert by any means but surely you concede that your original post of "There is no evidence of a risk that showers cause legionellosis!" wasn't a particularly helpful comment? In your most recent post you say "... it may not be the shower..." so I assume you are now saying that it MIGHT well be the shower. The number of deaths resulting from exposure to legionella may be higher than previously thought. I understand that in the past hospitals have not routinely tested those hospitalised with pneumonia to see if they are actually suffering from legionellosis. Regardless of this, my advice to Naomi and anybody else is that they can't go too far wrong by following the ACoP and guidance etc in L8 and which identifies shower heads as a risk and has a section that deals with the frequency of inspection of shower heads etc.

Posted By Phil Rose A 'no risk' water system, ummmmmmmmmmm. Could I suggest to Naomi that the risk is likely to be LOW rather than 'no'? The fact is that we don't actually know what the turn over is as Naomi hasn't told us, has she?

Posted By TonyB All, What a lot of angry debate. I can't see the problem. People are arguing about the level of risk, when in real terms it doesn't matter. L8 sets out very simple and low cost controls for water systems. Therefore, whatever the risk may be the conrols are still 'reasonably practicable' and should be used. The controls were clearly described by Claire and others above. Oh, and remember the HSE/EHO can and do prosecute for not having the required controls in place without a case of legionella or even legionella being found in the system! Why take the risk (whatever size it is!) TonyB ps - my understand is that most non-work related cases of legionella are caused by people taking a shower on their return from holidays. The showerhead contains water allowed to cool naturally and left undisturbed for a couple of weeks!

Posted By D H Agree with Tony - what an angry debate. There is no doubting Adrians knowledge in this subject - and as has been quite rightly stated - if you do not know the facts, you are guessing. May I suggest Naomi - that the heaters are "work equipment" - therefore coming under the PUWER Regs and as such must be inspected by a competent person. Get someone in to check the boilers and make sure the temperature gauges are working correctly and get the certificates to say they are safe. Dave

Posted By TT Also a moderate example of thread hijacking as the original poster didn't mention showers at all..... Adrian, I don't wish to get into a heated debate with you on the matter either. If you say there is evidence regarding water droplet size from showers being inappropriate then so be it. I'd genuinely be interested in the reference for that information. For everyone else: From my point of view, the leading UK scientists on legionella at the HPA have always and still do count showers as a potential source and the L8 ACOP lists control measures for showers quite explicitly. Whilst the ACOP is not statute, it CAN be taken into a court of law to demonstrate non-compliance with readily available guidance...consequently I'd always be tempted to follow the simple control measures it lays down and would recommend anyone else to do the same unless they can demonstrate a darn good reason why they're not.

Posted By TT For your punishment you shall be forced to take part in the next health & safety TV documentary going. :)

Posted By Phil Rose I don't think it was an angry debate at all. Claire guidance was absolutely fine and in line with L8. I personally don't understand the point of the comment "There is no evidence of a risk that showers cause legionellosis!" - I still don't see what useful purpose it served or was intended to serve! On the face of it Adrian does seem knowledgeable, so I was surprised at his 'no risk' conclusion, especially in the face of pretty limited information. Sod I'm going to burn L8 it's obviously a work of fiction!!!!!

Posted By Ninapalmer Hi Naomi, I'm legally not allowed to call myself an expert, but am certainly able to assist - do you have a schematic diagram of the property in question or better still a water risk assessment? If so, please feel free to send over to nina@city-water.com and I can give it the once over and make some recommendations for you in accordance with ACOP L8 I look forward to hearing from you Nina