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Post by tomplum on Apr 13, 2018 19:44:52 GMT
I remember a case near you 30 odd years ago in Horwich caused by air con system spewing out legionaires , can't remember any details,,
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Post by crowsfoot on Apr 13, 2018 21:09:12 GMT
After a legionella incident in the late 90s I was given a talk on legionella by a microbiologist.
What he said was very interesting and before all these reg's came out.
All water naturally contains the legionella bacteria (it always has).
It was first seen when the first microscopes where invented (it was then thought to be harmless for 100s of years).
It is only when a large quantity of cold water becomes stagnant and as a result the legionella bacteria is allowed to breed and attain vast quantities that it can become dangerous (moving water should be of no problem).
You can drink as much as you like of this heavily contaminated water and you will not catch legionella.
You have to get this heavily contaminated water into a very fine mist and inhale it into your lungs to have any chance of catching legionella disease.
Catching it from dead legs, the shower head, water heater anything that's mains fed I would say from the above is very remote.
However, if the reg's say you must do this and then that's what must be done - if you don't you could become someone's scapegoat.
Personally, I would only be wary of showering in old hotels with mixer showers that are always under occupied and that's about it!
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Post by tomplum on Apr 13, 2018 21:24:08 GMT
you only get information like this here experienced plumbers giving their knowledge from real life, not googleing, not telling what joe bloggs wife's has heard in the corner shop, this is the brew cabin, the home of practical tips and how to's welcome all |
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ian
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Post by ian on Apr 13, 2018 21:42:06 GMT
in the I`m just keen to learn good practice and not poison any customers. If this is going to be used commercially, you'd better adhere to the regs. Isolation, drain off cock and double check valve inside the property. An integrated check valve in the tap isn't up to regs in a new install, although it's OK to replace like for like on an existing tap after failure. Rules are for fools, but that won't stop insurers from saying no to a payout if they find out, so for an extra few quid you should do it to regs. As far as dead legs and Legionnaires are concerned it's extremely rare to get an incident bad enough to harm anyone from something like dead legs, but it's possible, there have been cases in hospitals etc. that have caused deaths and made a lot of other people very poorly. It's often from stagnant water in air conditioning systems rather than from the taps, shower heads can be a risk though if not cleaned adequately or anything that sprays the water. You can drink legionella infected water and you'll be fine, it's when it's sprayed and you breathe the infected water vapour into your lungs that it becomes an issue. I remember the Basildon one from years ago, they knew a lot of the plumbing needed re-doing after a survey showed potential risk, they didn't bother, then decided to cut the budget for the water treatment that had been put in place. Shortly after that an old bloke died of Legionnaires. My mum's had dead legs in her house for 40 years from when an extension was done, none of us got Legionnaires. Hi jcplumb. It is not for commercial use, it is just a garden tap at my own home. I don`t do any commercial plumbing just occasional domestic and i always try to do things properly and safely hence all the questions. I did not know an internal drain cock was required but was already planning on internal isolation and double checkvalve. The reason i ask about deadlegs is that according to regs, deadlegs should be removed but it seems in practice nobody seems to bother and some customers just don't want the extra work/cost to remove them. I have also been asked to fit feeds for water dispensing fridges that the customer may (or may not) decide to buy. I was also thinking about situations where properties are left vacant for a long time and so will have standing water in the pipes that could potentially backfeed into the mains. This is relating to the talk about old stoptaps having the jumper and if this would be a good reason to have a checkvalve on the incoming mains or to not use a lever ball valve as a stoptap? |
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ian
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Post by ian on Apr 13, 2018 22:13:13 GMT
After a legionella incident in the late 90s I was given a talk on legionella by a microbiologist. What he said was very interesting and before all these reg's came out. All water naturally contains the legionella bacteria (it always has). It was first seen when the first microscopes where invented (it was then thought to be harmless for 100s of years). It is only when a large quantity of cold water becomes stagnant and as a result the legionella bacteria is allowed to breed and attain vast quantities that it can become dangerous (moving water should be of no problem). You can drink as much as you like of this heavily contaminated water and you will not catch legionella. You have to get this heavily contaminated water into a very fine mist and inhale it into your lungs to have any chance of catching legionella disease. Catching it from dead legs, the shower head, water heater anything that's mains fed I would say from the above is very remote. However, if the reg's say you must do this and then that's what must be done - if you don't you could become someone's scapegoat. Personally, I would only be wary of showering in old hotels with mixer showers that are always under occupied and that's about it! I have never heard of anything other than a/c making people sick with legionnaires but after reading that regs say deadlegs should be removed it has always been in the back of my mind when i see instances of standing water and the last thing i want to do is make someone ill. It did strike me as odd that there does not seem to be any provision in the regs for other instances of standing water such as your example of infrequently used bathrooms, or empty houses as they are effectively a deadleg in the system. After reading yours and jcplumbs post about it not being dangerous to drink legionella it explains why deadlegs are not making people ill. |
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ian
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Post by ian on Apr 13, 2018 22:37:21 GMT
you only get information like this here experienced plumbers giving their knowledge from real life, not googleing, not telling what joe bloggs wife's has heard in the corner shop, this is the brew cabin, the home of practical tips and how to's welcome all Thanks to everyone sharing their information and knowledge here. It is great to have reliable info and be able to ask questions as i don`t like to mither the plumbers i meet on site but do want to learn as much as possible. I have even recently got myself an nvq level 3 college book for some light bedtime reading lol. |
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Post by dickpuller on Apr 14, 2018 11:55:54 GMT
My jumper had that little bit of movement in it as well tom so it was wrong for me to say it was a fixed jumper. So it too would have more than likely worked as a check valve if I had only open it a couple of turns (can't really see any point in this though). I personally think that when water supply from the mains was first introduced into peoples homes a stop tap was specially designed to be this way to help protect the mains supply from contamination. 100 years on and it's become known has a traditional stop tap but the original purpose of the check valve design of the stoptap has been lost to the trade over the passage of time. All I've done (due to this thread) is remember a lost lunchtime conversation from many years ago (although someone must have told that plumber who told me). On New Builds mate, Scottish Water will not connect the pavement stopcock(Toby) unless they see a Stopcock & Double Check Valve has been connected in the Plot. Even without the Kitchen fitted. |
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ian
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Post by ian on Apr 14, 2018 14:37:57 GMT
My jumper had that little bit of movement in it as well tom so it was wrong for me to say it was a fixed jumper. So it too would have more than likely worked as a check valve if I had only open it a couple of turns (can't really see any point in this though). I personally think that when water supply from the mains was first introduced into peoples homes a stop tap was specially designed to be this way to help protect the mains supply from contamination. 100 years on and it's become known has a traditional stop tap but the original purpose of the check valve design of the stoptap has been lost to the trade over the passage of time. All I've done (due to this thread) is remember a lost lunchtime conversation from many years ago (although someone must have told that plumber who told me). On New Builds mate, Scottish Water will not connect the pavement stopcock(Toby) unless they see a Stopcock & Double Check Valve has been connected in the Plot. Even without the Kitchen fitted. It makes sense really though i have never seen one fitted in England (admittedly i don't have much dealings with stoptaps and new builds). Anyone know if there is a similar reg for England? |
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ian
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Post by ian on Apr 15, 2018 13:18:23 GMT
Have been looking for an answer to whether a checkvalve is required, in England, on the incoming mains and cant find a definitive answer. I did find this - "Backflow Protection - Q. WHEN DO I NEED TO INSTALL WHOLESITE PROTECTION? The Water Supply (Water Fittings) Regulations and Scottish Water Byelaws only specify two situations where wholesite protection may be required or considered necessary. 1. To prevent backflow between separately occupied premises, an example could be in blocks of flats or other buildings of multipleoccupancy such industrial units or shopping arcade. 2. A water supplier may consider additional protection is needed for the whole or part of buildings where there is an increased risk of backflow occurring." It seems very vague and open to interpretation, for example my house is on a common supply so could potentially backfeed into neighbouring properties. On top of that, all buildings on one street share the same water main in the street so could potentially backfeed into other properties. Where are you supposed to draw the line between necessary or not? Maybe the water providers supply incorporates check valves? Could the external stoptap still have the loose jumper? God knows but you can be sure the next united utilities worker I meet will be getting a quizzing. lol. On a side note I have also read that you may have to seek permission to operate the external stoptap in the street?! Whoever makes this stuff up wants a good fucking. They would probably have me shot if they saw my standpipe. Another interesting thing I have found is the H.S.E. guidance regarding legionnaires disease, its a long read but worth it. There is a lot of responsibility placed onto installers and property owners that largely go unknown/ignored. www.hse.gov.uk/pubns/priced/hsg274part2.pdf |
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