volume of water required m3 per hour

[scottishjohn]

1 minute ago, SteamyTea said:

You don't normally drink from the loft header tank though.

good point 

I forgot cold main was direct  LOL-

[SteamyTea]

Just now, scottishjohn said:

forgot cold main was direct

Will make your tea and porridge taste funny as well.

[scottishjohn]

13 minutes ago, SteamyTea said:

Will make your tea and porridge taste funny as well.

probably not as bad as hard water down south tastes .

 HMMM --maybe need to fit UV on main house --will check with water board ,maybe the amount of chlorine and other things they add is enough  when not storing for long

Edited December 18, 2019 by scottishjohn

[scottishjohn]

37 minutes ago, scottishjohn said:

good point 

I forgot cold main was direct  LOL-

on hunting  this article  would suggest i have no worries providing break tank is not too large 

EG a days supply max in storage,which was what i was proposing anyway

http://dwi.defra.gov.uk/consumers/advice-leaflets/tanks.pdf

Edited December 18, 2019 by scottishjohn

[Jeremy Harris]

The way mains water treatment usually works is that it relies on what they call residual disinfection.  The water is treated at the supply end and usually a tiny amount of residual chlorine is left in the water, enough to stop any bugs from multiplying in any static parts of the distribution system (and there will always be some static pipes, somewhere).  as long as there's no exposure to air, the chlorine remains in the water, but as soon as there is an open, ventilated, surface it comes out of solution (it's why you may sometimes smell it near an open running tap).

 

As a consequence of this, the water in the break tank will very quickly lose any residual disinfection, and because of air movement into the open air space above the tank, bacteria, spores etc will get into the water.  With no residual disinfection, the water has no means to prevent these bugs from multiplying.  Add in that there will then be some static legs within the house, and with no residual disinfection there is nothing to stop bugs from multiplying.

 

Any mains water supply that has a break tank has to be considered to be similar, as far as disinfection requirements are concerned, to water from a borehole or spring supply.  The simplest way to disinfect such water is with a UV disinfection unit, fairly cheap to buy, and reasonably cheap to run.  The only real limitation is that such a system does not provide any residual disinfection, so the unit needs to be placed as close to the point of use as practical (ours sits upstairs, in the services room, just before the water distribution system for the house).

 

As @SteamyTea rightly says, there was a very good reason why water coming from vented cold water tanks in houses was classified as non-potable, and not to be used as drinking water.  With cold tank systems, at least one tap in the house (usually the one in the kitchen) would be mains fed, to provide a safe drinking water supply, whilst the other taps were for washing, flushing toilets etc, and were not drinking water.

[ProDave]

21 minutes ago, Jeremy Harris said:

As @SteamyTea rightly says, there was a very good reason why water coming from vented cold water tanks in houses was classified as non-potable, and not to be used as drinking water.  With cold tank systems, at least one tap in the house (usually the one in the kitchen) would be mains fed, to provide a safe drinking water supply, whilst the other taps were for washing, flushing toilets etc, and were not drinking water.

Though I spent my childhood cleaning my teeth with such water, oblivious to the issues, and got away with it,.

[SteamyTea]

32 minutes ago, ProDave said:

cleaning my teeth with such water, oblivious to the issues, and got away with it

 

[joe90]

The bungalow I replaced with our build used groundwater (very shallow well) and had iron and copper in it but the old fella that lived here lived to a ripe old age with no health problems, later it was fitted with a filtration system to meet regs for it to be rented out. @scottishjohn could you not add rainwater harvesting fir the non potable uses to help cost?

[Jeremy Harris]

TBH, I think the real risk of not disinfecting the water is probably very low, but we live in litigious times, and if thinking of having rented-out accommodation, then there is a legal requirement (at least here in England and Wales) to ensure the water is potable, with mandatory (annual, I think) water testing/analysis for any supply that is not directly connected (i.e. without an air gap) to the mains.

 

I grew up in houses that had cold water tanks in the loft, and I'm pretty sure the bathroom cold supplies came from those tanks (just so the hot and cold were at the same pressure at the bathroom taps).  I remember my mother telling me to never swallow the water when cleaning my teeth from the bathroom basin tap, though, so there was an awareness even in the 1950's and 60's that tank-fed cold water wasn't potable.

 

I'd have no problem in using our borehole water without disinfection, as I'm pretty confident it's fine, but I did run a tap to my neighbour's vegetable patch (she had to unreel a hose around 50m or so to get to it, so I felt she might find it easier having free water to hand), taken off from before the UV unit, and felt the need to both tell her that it wasn't drinking water and fit a label to it stating this.  The reason I did this is because she's in her 80's, and although she's in very good health I didn't want to take the risk of her believing that the water from that tap was safe to drink.

 

Much the same goes in our house.  I'd be happy to use the water without the UV unit running, but I wouldn't feel happy for my nearly 90 year old MiL to do the same when she comes to stay.  The risk may be very small, but imagine how you'd feel if someone became seriously ill from drinking your water, let alone the financial impact if someone chose to sue.

[scottishjohn]

you are probably correct -- fit a uv and have some overkill,was going to do that on rented  chalets anyway - if they ever get built .

first problems first --get house sorted with them in mind 

[scottishjohn]

I sent an email  to dwi-defra 

a very nice woman came back to me and we discussed things 

If stored water volume is only a 1-2 supply in the break tank then --she sees no problem as the rate of the chorine etc coming out of the water will be much slower  than the usage ,so no need for UV

 In fact as the water is coming from a reservoir --eg surface collected water,then adding UV could in extreme cases cause conversion of dissolved organics into nasties 

not normal ,but possible --so her advice was --no UV

 drain down chalets at end of each season and just flush plenty of clean water through at beginning of next one along with careful cleaing of all spouts and taps  and shower heads --normal good practice basically