Period Water

[DJH]

A lot of us Period Property owners have private water supplies either in the form of wells, springs and I know at least one of us collects rainwater from the roof for domestic use. The prolonged heavy rainfall here has caused the water in quite a few wells to succumb to contamination in the form of silt and sandy clay like material washed in from surface groundwater and increased water table levels.

Some friends who are suffering from this problem asked if I could help out. We had the water tested for both bacteria and chemicals with one friend’s results quite good except for slightly low PH and fitting a sediment filter has proved an adequate solution.

My other friends’ situation was more of a problem. From the first day the well has a history of fine sand/silt contamination (known as rabbit sand here for some reason) and a settlement tank (an enclosed tank with three sections in it to allow material to sink to the bottom of each section) was fitted to help filter out some of the sand. However the well is now almost completely silted and the water is coming up like grog.

Luckily they live in an old mill and a nearby watercourse is an alternative source of water so we had the water from the well and the stream tested and the result of the stream water unsurprisingly, showed contamination by both coliforms and e-coli although at the lower scale. The well was bacteria free but along with the stream has a low level of Manganese present and high turbidity. We had the well water from the settlement tank tested a few months ago and although the well was bacteria free there were bacteria in the tank water. The PH from both sources was just over 7 which is fine.

We took the decision to abstract water from the stream to use until or if, it ever stops raining, and the level drops in which case they will revert to the well in which hopefully the silt may have settled after 6 months or so.
I fitted a low level well pump connected with a foot valve in the stream with a 20 micron filter to take out any lumps before it made it to the settlement tank.



On the left is a Filter-Ag which removes suspended solids and clears the turbidity and the water passes to the greensand filter to remove any iron and manganese. (The white container is the regenerant tank for the greensand filter which has potassium permanganate in it to recharge the greensand after back washing has taken place) After the greensand filter a sediment filter removes any medium which might be disturbed during the backwash operation and then an Ultra Violet light kills off bacteria. Before the treated water passed to the house I flushed the supply pipes with Milton Sterilising fluid to kill off any residual bacteria.

The well water supply to the tank is against the right hand wall with a sediment filter fitted to it.

The water is now crystal clear and tasteless. We will have it tested in a month’s time for bacteria to ensure all the treatment is working.

Disclaimer. This worked for us but other treatment systems are available…

Doug

 

[worms]

Doug, interesting set up. With the heavy rain, if the stream is through any pasture land or grazed moorland, then there is a high probability of cryptosporidium in the water. Depending on the techniques used by the lab and your sampling technique it would be possible not to have found this in the sample. It will pass through your 20 micron filter, but should be amenable to uv if the set-up is correct.

 

[eezageeza]

How much did the gear in the photo cost Doug?

Our water comes from a borehole, completely untreated, and while it's been fine for the last 20 years (the ground water levels move quite substantially, but the water quality seems to be pretty constant) I'm always worried that one day we might have to add some treatment to make it potable.

It would be interesting to have a ball park number for the plant required.

 

[CliffordPope]

Interesting thread. I'd never considered the possibility of silt being washed into a well. I assumed that if the well was properly constructed with a suitable wall around it then surface water or silt never entered. But it seems that in periods of heavy rain there can be underground silting too.

Our well is affected by rain water, but there is a time delay of over a month. It usually goes rather low in summer, has twice in the last 30 years dried up, but always refills eventually after the rains return.
An old man I talked to said the main influence on water level was barometric pressure - it was lower over summer because air pressure was highjer, but with the generally lower pressures in autumn the water levels rose again.
In our case there appears to be some kind of underground reservoir, with a threshold lip that has to be topped before some kind of syphon starts again. It's hard to visualise what's going on down there.

We don't treat the water, but some years ago had it tested. It was absolutely fine on all counts. The tester said he had to tick the box for 0-5 coiliforms per whatever, and then issue a formal advice that these should be treated. But unofficially he said ours was in fact zero, so it was pointless doing anything.

It is a bit acid, which I counter by dangling a bag of lime in the well and renewing it occasionally.

 

[DJH]

Luckily Worms, the stream comes directly down from the mountain through a forest and few fields in my friend's ownership with horses on them and sheep in a neighbouring field. The stream is fast flowing and storm water passes through quickly. Using a sediment tank with the pump operated by a float switch the tank is not replenished frequently but at least once a day depending on use in the house of course. That's a good point about cryptosporidium and I'll raise it with the lab when we submit a sample in a few weeks time. As you say the UV should zap all the nasties...

The total cost including VAT at 23% ( :roll: ) eezageeza of the filters and uv etc was €2300

Included in this cost were the two filters (preloaded with medium and the valves set to the correct time and backwash programme) the UV filter and control, the regenerant tank and 1 kilo of Permex (potassium permanganate) which from experience is a years supply and 100 PH indicator strips. Installation costs were dinner everyday and a Big Thank You...

I expect prices may well be cheaper in the UK and there are cheaper vessels over here but again, from experience, these filters have a long life (mine have been installed now for just under nine years) and have so far needed just the PH media changed about every 12 to 18 months and the injector on the greensand filter about every 24 months. The greensand Is the original loading.

You would assume Clifford, that the well lining would prevent anything getting into the well but the bottom sections have holes or slits cut in them to allow water to enter the well and I suppose sand or silt can come in that way as well. It can also enter up through the well washed in by ground water.

That's interesting about barometric pressure having an effect on water levels in the well. I recall from memory that suction pumps won't raise water more than about 28 feet.

Dangling a bag of lime down the well to reduce acidity is a new one on me as well (no pun intended ) does it work?

Doug

 

[CliffordPope]

I think the lime works, but it's hard to get an accurate pH reading with the cheap meter I've got. It certainly has reduced the tendency for the bath to get blue stains.
It's perhaps a bit hit and miss, because it will depend on the rate of flow of whatever underground stream feeds the well, compared with the rate of draw-off.
More recently I've put some small lumps of broken up concrete into the attic storage tank. That apparently is a trick used in the Australian outback. Rainwater is naturally acidic, from atmospheric CO2, and traditional storage tanks were made of concrete. With the change to plastic tanks they found their water pipes being dissolved and baths going blue. But the remedy was to break up the old tank and put some bits in the new one.

 

[DJH]

Lime will make the water alkaline which raises the PH but will make the water hard with the addition of calcium carbonate. Water with high or low PH can have an unusual taste but hardness can improve the taste of water apparently. No doubt your bottle blond hair doesn't turn green either Clifford...

My friend's well is situated in limestone country (hence the number of stud farms and stables in the vicinity) which explains the PH of 7.68 and the hardness of 227 which makes it moderately hard between the range of 151-250 mg/l CaCO3. They were advised by the original installer to retro fit a water softener ( the outline of which you can see in the photo where the wall is unpainted) but unfortunately this sent softened water to the kitchen tap which is a no no as softened water is not as good for you as hard water (or wine ) The sodium content of the potable (treated) water was 125 which is about mid range and not harmful apparently :shock:. This level of sodium is noticeable where water has come into contact with metal such as screws and fixings in wc cisterns which are now very rusted and stains at the back of the bowls on the close coupled wc's where small leaks weeping from where the siphon is made into the cistern has rusted the connecting bracket and bolts...

We have taken the softener out of the system..

Doug