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lowri

ultra-violet filters

I'm having trouble with contaminated water, nothing too frightful but the bacterial count at source is too much. Has anybody any advice about fitting an ultra-violet filter? I know there has to be a filter before it, to take any bits out, the only place to put the 2 units seems to be where the water enters the house, under a trap.
Is it an expensive thing?
I've also been advised to extend the fence round the spring (2 X 3 foot concrete rings sunk onto a gravel bed and covered with concrete, with an inspection cover fitted) to 4.5 metres from the centre of the capping.
The only stock in the field are sheep, and that's all there ever are. I imagine that with the high rainfall this summer the whole area is now saturated, hopefully not as far down as the aquifers otherwise we're all doomed - aren't we?
I only had the water tested out of curiosity and because of something mentioned on a Downsizer forum - or was it in the press?
mochyn

Lowri: I'll try to remember to get the old chap to look at this post this evening. We have similar filters for similar reasons. He knows all about them...

As does james, I think: he might pop along later...
James

Re: ultra-violet filters

lowri wrote:
I'm having trouble with contaminated water, nothing too frightful but the bacterial count at source is too much. Has anybody any advice about fitting an ultra-violet filter? I know there has to be a filter before it, to take any bits out, the only place to put the 2 units seems to be where the water enters the house, under a trap.
Is it an expensive thing?


cant add much more to that. Yes, pre-filter: UV will only work on clear water. I suppose all I'd suggest is that both filters should be easily accessible.
I've heard that UV lamps for UV filters are quite pricey. This is because its got to be a very specific wavelength.

lowri wrote:
I've also been advised to extend the fence round the spring (2 X 3 foot concrete rings sunk onto a gravel bed and covered with concrete, with an inspection cover fitted) to 4.5 metres from the centre of the capping.


Is the spring discharging at surface into a catchpit? or do you have a few concrete rings buried into a gravel bed with a pump raising the water to surface?
This will dictate the way you're surface structure should be constructed, so let me know & I'll be able to advise

With regards to fencing distance, definitely increase the distance to at least 4.5m. In fact, Id go further- try to increase the distance by as much as you can afford.

Bacteria cannot live for very long without a host, hence the further away the source of bacteria is, the greater the reduction in bacterial load.

If you can keep stock 50m from your source, you're very likely to have very low bacterial counts. so consider changing your land-use to accommodate this .
I'd strongly recommend considering the economics of whether its cheaper to do this or to buy & run a UV filter. It need not be wasted land- just land on which stock isn't kept.
I very much doubt that any private water supply vendor would advise you this (because they're selling UV filters & equipment), but its true.
If you chose to go down the route of a larger stock-restricted area, be aware that your water will still be 'live' (unlike after a UV), and may have low counts of bacteria...but there's a very high chance that they'll be very much reduced to the point were its really not a problem (see note at bottom)


lowri wrote:
The only stock in the field are sheep, and that's all there ever are. I imagine that with the high rainfall this summer the whole area is now saturated, hopefully not as far down as the aquifers otherwise we're all doomed - aren't we?


With regard to the high rainfall causing a flush-through: your exactly right. You will get an increased bacterial count/ nitrate level after heavy rain if your groundwater source is in continuity with the surface.

With regard to the integrity of your water supply- No, your not doomed. Far from it. Bacteria doesn't live that long and just like us they need both oxygen and food to thrive. While you cant reduce the oxygen in your water, land management and good cleanliness around your source can greatly reduce the food that bacteria will live off (normally dissolved solids of shit).

Bacteria has a short life and groundwater is naturally flowing, so following a few simple housekeeping jobs, your bacterial count will reduce rapidly.

lowri wrote:
I only had the water tested out of curiosity and because of something mentioned on a Downsizer forum - or was it in the press?


Yep, that was here.

{note: personally, I prefer live water with a low bacterial count from well managed land than a UV sterilised water from land on which stock has contaminated the water. Small doses of bacteria are good for you}
SheepShed

We installed a UV filter after getting a water analysis which showed that we had just about everything going in our water. As you say you need a particle filter first then a UV filter afterwards. Both will need servicing once a year. We paid something like 250 for both fitted in 2000.

I'm not sure how you'd fit them in a trap though - the UV filter is pretty big (say 3" diameter and 30" high) and needs mains supply.

I can't see how a fence round the spring tank is going to make any difference, it might stop the stock but it's not going to stop run off from the fields seeping in.

Hope this helps.
dougal

SheepShed wrote:
... I can't see how a fence round the spring tank is going to make any difference, it might stop the stock but it's not going to stop run off from the fields seeping in.

Much would depend on how flat the land might be.

It makes great sense to keep animals off 'nearby' land level with, or especially uphill of, your spring.

Ideally, you should be capturing groundwater - completely eliminating surface runoff and if at all possible seepage through topsoil.

So, AFAIK, there three should be three barriers. Furthest out, a stockproof fence (further back on the uphill side), then a runoff diverter and lastly something akin to a well lining to help keep out the seepage through the topsoil. In some situations the runoff would be stopped by the well simply continuing above ground for a couple of feet...
lowri

Thank you all for comments so far.
SheepShed - mains electricity for the UV filter is no problem. The "trap" is a covered area 4 foot square with a lid, it is just outside where the alkathene water pipe enters the house.
James - the spring has 2 concrete rings and a gravel bed, making it 6 feet deep, covered over with concrete and an inspection cover.
I think you gave me loads of advice on an earlier thread, several months ago! Sorry for duplicating the enquiry but I never printed it out!
Re the stock fence problem, the spring is not on my land, there is a Deed of Grant which allows me a fence (size unspecified.) The spring is on a plateau, sheep grazing land, the usual.
The Council are sending me the final results, also their recommendations, i e fence, filters, etc., and a list of recommended contractors. I await this with interest.
The nearest mains water (which I don't like the idea of) is nearly 2 miles away. I know that to bring it to the end of my lane (9/10ths of a mile) is 20,000! (A friend has a building project there so I know the sum is accurate. Think I prefer my own supply!)
James

As dougal says, your main aim is to stop infiltration & runoff from the surface. So once the fence (as big as you can get away with) is up, you need to:

1)stop any surface water getting to the concrete rings. I've seen different ways of doing this, an low earth bank is good (maybe a foot tall), a brick or concrete low wall is better. Draw a shallow trench out on the downslope side of the concrete well.

2) clear any weed away from around the well- this encourages the build up of silt, which (along with rotting vegetable matter) provides organic carbon which can feed bacteria

3) If not already, try to make the seal between the top ring and the lower ring water proof. This could be a tricky job and you may need a type of putty that'll dry in water, but it would stop infiltration straight from surface.

However, these housekeeping things wont stop the bacteria as much as a very large fenced off area would, so its probably still going to be the case that you'll need a UV filter.

You'll still end up with far tastier water than if you went on to mains!
lowri

The spring (2 concrete rings on top of each other) is actually a 6 feet deep tank nearly always full of water! The outlet to the house, through the concrete ring (down nearly one/sixth of a mile of alkathene pipe) is about 9 inches above the gravel bed at the bottom. I had trouble a few years ago with frogs in the tank - local belief is that if there are frogs in it, it is the purest water possible - I found that the frogs were getting in through the overflow, a bit of pipe leading out at the top - into thin air! At the time there was a spot of bother with the water being coloured, this was due to standing water round the concrete capping flowing back in!. I had work done to slope the surrounding ground well clear of the capping. A plastic drainage pipe now leads into an adjacent ditch, with wire netting scrunched up in it and nylon gauze tied over the end - result: no more frogs!
(There was an additional hazard with the frogs, occasionally one (or 2 in tandem!) would go down the outlet and get wedged in the ball valve in the holding tank behind the house, only diagnosed when the water supply to the house suddenly ran out! We never had the spring dry up sufficiently to get down to the outlet and put a gauze over it - not necessary now!)
But these hazards are nothing to the overall horror and expense of having to go on the mains, which I intend to avoid at all costs!
Thank you all for your help.
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