Intake for a private water supply

[jamieled]

I'm currently looking at starting to install our water supply, and so ordering the bits and bobs I need. It will be fairly simple - a blue MDPE pipe from the burn to a storage tank above the house and then another MDPE pipe to the treatment for the house.

 

I'm having trouble remembering the name of (and therefore sourcing) a bit for the intake. This will be the end of the submerged MDPE pipe in the burn. I know this as an intake rose, but builders merchants and an online search are not coming up with anything useful. 

 

It's essentially a perforated metal cylinder attached to the end of the pipe, to minimise vortexing, but mainly to minimise the ingress of any large debris.  Has anyone got anything similar - if so by what name do you know it and where did you get it from?

[Cpd]

Hahaha I used the inside of a washining machine drum ! Just drilled a hole for the pipe, I then put an additional home made stainless steel mesh filter over the end of the incoming pipe to stop other smaller particles getting in the pipe. Position  the drum on top of a concreate slab or exposed bed rock to stop silt build up. I put a concreate slab on top (where the washing used to go in) so for maintenance I just lift up the slab pull off the mesh filter, pop a cork into the pipe pull out the drum and give it a good rinse. Put your intake hole about half way up the side.  My water then goes into a sort of settlement / holding tank  where I have the outfeed halfway up, overflow pipe at the top and a small hole in the bottom of one side so that there is a constant flow of water from the base of this tank, this stops sediment building up very well.  I have not installed filters and uv yet but have been awarded a grant to do this in the next few months. The guy from council was totally impressed with my existing set up and told me to leave it all in situ as it was working very well. All my new fancy filters and stuff will be near the house. I am hoping that my washing machine drum and pre filters will prolong the life if the more expensive micro filter system still to be installed. Others with similar system complain about the cost of replacement filters all the time, this is because they take directly from a water source without pre filtration. 

[Miek]

Like this?

 

I did the same a few years back for a private water supply. Been working for 4 years without a blockage. 

 

Looks a bit messy at first

 

Edited January 8, 2019 by Miek

[Cpd]

@Miek that’s axactly the thing, I lined my muddy hole with bricks, pea gravel and geo textile six years ago,  yes it was a messy job to start with but the water is VERY clear and tastes GREAT I get no less than 8500 litres every 24 hrs from my supply. The guy from council said “Lovely spring water full of lovely things so passing except for the odd floating bit which filters will sort out.”   Water with added fibre ! But in reality the floating bits were of no concern to him as the test results were so good but to meet best practice we need uv and very fine particle filters. 

 

Edited January 8, 2019 by Cpd

[Cpd]

[jamieled]

Thanks both, food for thought. I'd need to modify this a bit for working in our burn as it's quite flashy, lots of cobbles and boulder movement which will need considered as I think something that big will get a bit battered quite quickly. But the responses so far are making me think a DIY approach is the way I'll go.

 

[Miek]

If you could completely bury the drum under the bed of the burn it might work, though appreciate that this could be difficult. 

 

If the burn is clean of debris or leaves I'd have thought a simple gauze strainer on the end of the pipe would suffice. If there is crap in it then this might get blocked. 

 

I hope you intend to treat the water in some way as surface water from streams can be nasty depending what's up stream, sheep for example, liver fluke and wot not.. 

[jamieled]

It may well be possible to bury the drum so I'll have a think. Around here it's a condition of  PP that treatment is installed and I think may well be the case nationally  as I've done a few private water supply assessments in a professional capacity. In our case it will involve a three stage cartridge filter to remove the bits, an iron filter and a UV filter.

[Jeremy Harris]

25 minutes ago, jamieled said:

It may well be possible to bury the drum so I'll have a think. Around here it's a condition of  PP that treatment is installed and I think may well be the case nationally  as I've done a few private water supply assessments in a professional capacity. In our case it will involve a three stage cartridge filter to remove the bits, an iron filter and a UV filter.

 

We have a private water supply that I installed, drawing from a borehole we had drilled.  I was surprised that we weren't required to do anything to treat the water at all, as the requirement for treatment and testing only applies to private supplies that feed more than one household.

 

I tested the water a few times  before and during the commissioning (which was a bit of a long drawn out saga, related to the way the borehole had been drilled) and found that it had a high ferrous iron content, plus a tiny bit of dissolved H₂S and some manganese, so I built and installed an ozone injector,  vented oxidising chamber, followed by a backwashing sand filter to remove the ferric iron precipitate.  I also added a 5µ filter and UV disinfection unit, just as belt and braces, but may well end up taking the UV unit out, as it costs a bit to run and maintain.  The ozone injection is more than sufficient to disinfect the incoming water, as well as very quickly oxidise the ferrous iron, H₂S and manganese, and the raw water has been free of coliforms every time it's been tested (we're drawing from an aquifer that's trapped beneath a ~40m thick gault aquitard).

 

The only downside of the ozone injection treatment method is that it doesn't provide residual downstream disinfection, but then neither does UV treatment, the only difference being that the UV unit is closer to the point of use.

 

I did also pay to have the supply tested by the local authority public health people, really just so I had some form of official lab report for building control, if they asked for it (they didn't, weren't interested at all in it).  I'll probably test a sample every year or so, for as long as I can still get access to the lab, but I'm not expecting anything to change, as the borehole now has a pretty good sanitary head and a good seal around it to prevent surface water contamination.

[jamieled]

14 minutes ago, JSHarris said:

I was surprised that we weren't required to do anything to treat the water at all, as the requirement for treatment and testing only applies to private supplies that feed more than one household. 

@JSHarris there are separate private water supply regs in Scotland and I've not yet come across  a private supply here that the local environmental health officer didn't want tested at planning application stage (in order to understand what, if any treatment is required). Following construction, it is as you note above - commercial premises or multiple houses on the same private supply that need routine testing .

 

Interesting about the ozone injection - I'll look into it some more as I'd not considered it, but I suspect your supply (in microbiological terms) is a bit healthier than ours.

 

For anyone else needing water testing in Scotland, I'd recommend using the Scottish Water labs. They have a  logistics service if you need it for transporting samples (you can just drop off at the labs but there's only two)and it's a lot cheaper than the LA or  commercial lab. Our tests were around £50 each for a fairly broad range of parameters.

[Jeremy Harris]

Environmental health weren't the slightest bit interested in testing our supply, and it was only when I pushed them, saying that I wanted to have a chit from them, rather than my unofficial report, that they agreed to test a sample.  Even then they refused to accept a sample I'd collected.

 

LA testing is a bit of a scam here, as they are required by law to undertake private supply testing for a set fee, which is less than any of the local labs charge.  To get around this they refuse to accept samples and insist on coming out to the premises to take samples themselves, so they can add on a sample collection fee that is way higher than the mandated test fee.  I was fortunate in that I had access to an exceptionally good, world renowned, lab...

 

There's a long saga surrounding our borehole, but one major problem is that in this neck of the woods there is an almost total absence of available expertise when it comes to private water supply treatment.  I ended up getting a great deal of help from a forum in the USA, where private water supplies are far more common.  Oxidation of ferrous iron, manganese etc seems understood here at the commercial water treatment scale, but I only found one company that really knew much about it, and they were up in Lancashire, so could advise over the phone about kit and supply it, but I was left having to design the treatment system and learn from experience.  My first degree was in chemistry, but that was over 45 years ago now, and I've forgotten more than I ever learned!  With the help of some people in the US I did get a very good treatment system put together, but with what I know now I wouldn't opt for the sand and aquamandix filter, due to it's high backwash requirement.   If starting from scratch now I'd opt for the same  air dryer, ozone generator and injector system that I ended up building, probably a slightly smaller contact vessel, and a backwashing Turbidex filter.  The running cost of this would be a fair bit less, due to the much lower backwash requirement of the Turbidex, plus Turbidex filters down to around 5µ so there would be no requirement for any further fine filtration.