e. coli in drinking water

[Katherine]

We have water from a private borehole. Its just been tested and has come back with e. coli present in an unacceptable level. (Total colicforms (cfu's) 41 in 100ml, e.Coli 20 in 100ml). The letter says to get a UV filter but I just wondered if we need to be boiling etc. Have been looking to see what the acceptable level is as don't want to worry my neighbours if we are only just over etc. Can't find any info on the actual levels though.

I know its not likley to be dangerous as we were told the hospital would phone if there was anything dodgy and they haven't but my neightbour nearly fainted when I mentioned e. coli so I'd like to be able to reassure her. I know not all e. coli is dangerous too.

Any water testers out there that know what the results mean?

Am in a mad rush so will come back to this if no-one else helps.

There are some standards details here .

Gut instinct is that if coliforms are present at all you should be boiling the water. Also have vague recollection that e.Coli 20 is not the scary one.

Have a look at Drinking Water Inspectorate site too.

Sorry but must go out now.

Thankd twink. Good sites. Don't know why I never managed to find them. The advice was to boil so at least I can tell my neighbours that. However the DWI site also states that they have a duty to identify the source of contamination and the tap used for the sample needs to be checked (crigne - do I have grubby taps). Would seem that they should at least take a smaple from a neighbouring property before we are faced with having to install a UV system. Have to admit I was surprised that this was the only advice in the letter. At least I know what action to take now. So thanks.

Katherine, I just picked up this:

If my well is contaminated with E. coli, what can I do to protect myself?

If your well tests positive for E. coli, do not drink the water unless you boil it for at least one minute at a rolling boil, longer if you live at high altitudes. You may also disinfect the well according to procedures recommended by your local health department. Monitor your water periodically after disinfection to make certain that the problem does not recur. If the contamination is a recurring problem, you should investigate the feasibility of drilling a new well or install a point-of-entry disinfection unit, which can use chlorine, ultraviolet light, or ozone.

from a US site (here ). But it's actually talking about e coli O157:H7, presumably different? (I didn't realise there were different strains, I would have reacted like your neighbour too!) Don't think it gives levels, but says under-5's are more vulnerable - boiling would be safest anyway. (You could do it in batches and then refrigerate in containers.)

Have just looked at Twink's first link - clean INSIDE the tap??? What???

I don't think it means that there is a strain called E.coli 20, I think it means there are 20 cfus (colony forming units??) in 100 ml. You're right that not all E.coli strains are dangerous, Katherine, but I would deinitely boil the water if children are involved unless they know for sure that the strains are non-pathogenic ones.

Sorry Tamum, I was in such a hurry I misread Katherine's original post & I had a recollection that e.Coli had numbers associated with it (but I've not been in the industry for 4 years now and have mummy 'brians' It's e.Coli 0157 to look out for, some details are here

This US site has some useful information too.

Katherine, feel free to do the 'contact another talker' thing if you want any more information; I worked in the water industry for a long time, most of it in the 'process' side (ie engineering stuff to make it safe to drink) rather than the quality testing but still have useful contacts.

Well, you were dead right about the numbers, I can see completely where the confusion lay

JanH, when I first did my training we got sent to the 'labs' to test water from customers taps, that was an eye-opener ! I had never realised how much contamination can come from the tap...

Frankly I wish I had never learned, so although my cleaning prowess regularly hits new Mumsnet lows, I do keep a toothbrush specifically for cleaning taps.

So do you just scrub with water, Twink, or washing-up liquid, or do you use a cleaner or bleach or something? (I clean round the outside of the tap - occasionally! - it would never have occurred to me to clean inside. Obviously! )

Hi all. Am going to phone up this morning and ask for another sample to be tested from one of the other houses so we can rule out the tap. I'd hate for contamination from us to results in everyone shelling out for a UV system.

DH had just moved the taps so we are wondering if he distrubed the pipes or something at the time. Also we've just replaced our filter and the old one was horrible. Although it had a new filter DH didn't sterilise the holder. My washing machine has been playing up too. Hasn't been pumping the dirty water away properly. When the engineer fixed it yesterday he spilt some water and it STANK! Well I was washing nappies in there. It does mention on the DWI site that contamination can come from dishwashers and washing machines too. I'm just worried that if it is the tap then we'll get a filter fitted at source but we will all still be at risk from it.

DD has had a really poorly tummy all week. I'd put it down to a virus as there is so much around at the mo but it makes you wonder. Although of course the last water test was 5yrs ago so who knows how long its been like that. Better get on the phone......

I start with descaler either a proprietary one or vinegar because our water is so hard. Then I just spray a blast of bathroom cleaner or similar and scrub as much as I can with my tap toothbrush.

The real inside of the tap is kept clean by the water itself, it's only the last bit which is open to the air which gets manky. Most of our taps have a sort of crisscross grid in the end which is where gunk can collect.

I get the impression you're all laughing at me now

I'm not, Twink, honestly! (If I put a smile or a winky now you'll think I am really, so I won't!)

Katherine, it certainly sounds as if there was a high chance the sample could have been contaminated after it came out of the borehole !

You're right to get another sample done at another house. Then sterilize as much of your stuff as you can and get your main tap retested for your own peace of mind (assuming the second sample comes back ok, otherwise you'll obviously have to go down the secondary treatment route).

Hope it is easily dealt with, good luck.

It's ok Jan, I think I know you're not - but I'm off to do my taps right now as they've been neglected !

just checked my taps in the bathroom.....am going to do twinks tootbrush idea.....yuk!!