I'm not aware of any window cleaners catching Legionares in the summer months so why would I worry about it?
I'm sure if the risk was high enough, or even a risk at all, we would have heard about it by now from companies like Gardiner or Ionics, etc, as they would have tried to sell us something to stop or reduce the risk.
As a side note, I've been drinking RO water for over 5 years. Try making tea with RO water, no scum from the tea bag and no staining of the cup.
Tap water now tastes like ughhhhh.
Mark - it's not the storing of water that causes Legionares. It's the temperature, which I can't remember but it's about 50C, that causes it to rapidly become active and multiply.
This is a quote from a PDF document I have on my computer on Legionella.
"Legionella bacteria are common and can be found naturally in environmental water sources such as rivers, lakes and reservoirs, usually in low numbers. Legionella bacteria can survive under a wide variety of environmental conditions and have been found in water at temperatures between 6°C and 60°C. Water temperatures in the range 20°C to 45°C seem to favour growth. The organisms do not appear to multiply below 20°C and will not survive above 60°C. They may, however remain dormant in cool water and multiply only when water temperatures reach a suitable level. Temperatures may also influence virulence; legionella bacteria held at 37°C have greater virulence than the same legionella bacteria kept at a temperature below 25°C."
With us having such a warm summer, the tank water in the van has reached temperatures higher than 20°C and that's with a duvet over it. Infact the temperature of the cold tap water was 20°C when I took a reading about a month ago. There were times that the inside cab temperature reached 44°C at roof level with the van standing in the sun and the windows slightly open. (My van is dark blue in colour.) We live in the North East which isn't the hotest part of the country.
On the face of that, Legionella is a risk for us. Chlorine kills the bacteria, so our tap water is safe, but we remove the chlorine before purifying.
However, in practise, with so many of us now using WFP, we don't seem to have experienced or caused any outbreak of the desease that we know about as rosskesava has noted. WFP is used in much hotter countries, ie Cyprus. Would we have heard about it had there been a legionella issue in these countries? I'm sure the ladder mamufacturers would be sighting cases if they did exist.
Vin flushes his tanks a couple of times in the summer with a bleach mix which kills most bacteria. I ask if we should be adding a bit of chlorine (as in the chloine used in swimming pools) to our water tanks every night as a treatment as this would be the only way ensure our tanks would be bacteria free. Chlorine disipates in the day with sunlight, but would it in a van with unglazed rear doors and a full metal bulkhead?
But chlorine gas, which is generated with the destruction of organic materials in swimming pools causes respiratory problems. So chlorine isn't the complete answer.
I didn't know the one pass of that UV light does not prevent Legionnaires. UV light is used in a lot of Scottish rural homes where household water is taken from local mountain streams. The system they use is a 'one pass' and then onto the water tap - but that's a closed circuit. Our tanks are open circuit and open to the environment, so this could be the reason why it needs to be continually circulated as in a hot tub or swimming pool.
I think the issue we have about drinking our tank water is that ours goes through the resin wash before it is stored in our IBC tank. At one time we bought FDA approved resin from RoMan as the purified water was fit for human consumption. The stuff we use now is commercial grade and hence not FDA approved.
Tea and coffee made with r/o water does taste much better than when made with hard water, the reason why Merlins are popular in American kitchens.
