5 stage sediment filtration for rainwater

[JoceAndChris]

A long shot, this, but is anyone filtering rainwater for domestic supply? I don't mean for the garden but to create clear, good water for the loos and showers. Ours is yellow and full of bits of worm and wasp ( the worms live in the rainwater chamber, the wasps live in the attic)

Having bravely come to terms with the fact we are unable to afford mains and the borehole idea is a no-go we are now getting our plumber in to change the tanks in the attic, which have no overflow pipe!!! And are filthy. Our well water is filtered below sink but we're planning to instal a 5 stage sediment filtration system at £699.96 for the rainwater. It's the bottom one in the linked page. Apparently it can deliver 45-50 litres per minute. It wouldn't be drinking water, but it would put brighter water into a lovely new clean tank that would then be used in toilets and showers and I would then be able to have a new bathroom which I have waited nearly 6 yrs for!!!
http://www.eastmidlandswater.com/m/prods_m.asp?c=153&cat=Rainwater%20Solutions


Just would really love to know if anyone has done anything similar and what filtration they used.

 

[DJH]

Where's the link Joce? :?

Doug

There it is... you put it in while I was typing...

 

[DJH]

It's the bottom one in the linked page.

Which one at the bottom???

Doug :?

 

[DJH]

This one maybe?

http://www.eastmidlandswater.com/Details.asp?ProductID=1397

Doug

 

[JoceAndChris]

That's it! Thanks for clarifying that Doug!

 

[DJH]

Not a bother Joce. I think that might be overkill or belt an braces solution which I'm all for in almost everything. I'd consider using an Ultra Violet light as well to kill any nasties in the water even after going through all those filters. You will be showering in it after all and you don't want to be taking in droplets of contaminated water... :shock:

Doug

 

[agbagb]

That seems ridiculously expensive to me. You should be able to get the 10" filter housings for less than £20 a piece and the filters should only be a few £ a piece. You might also consider if going down to 1 micron is necessary and filter socks may be more useful at the low pressure collection end in the 100 50 micron range. Have a look on ebay for what's used to filter WVO (waste vegetable oil).

The flow rate will vary according to pressure and how clogged the filters are.

 

[DJH]

Yes, they know how to charge don't they?

This one might be better as it has a carbon filter which your first choice doesn't, to take out odours from the water...

http://www.eastmidlandswater.com/Details.asp?ProductID=899

and this one backwashes which should save a few bob on filter ellements but need a UV light to go with it...

http://www.eastmidlandswater.com/Details.asp?ProductID=2752

You do need to store the water in a container suitable for potable water with screens on any overflow pipes.

Doug

 

[Flyfisher]

I wonder if it's really necessary to have a filtration system with a flow rate of 45-50 litres per minute?

If you have an adequately-sized 'holding tank' for the filtered water then surely the actual filtration system only needs to be able to provide a suitable average flow rate, which should be far, far lower than that needed to supply a running tap or shower.

(Not that I have any experience of such things, so just thinking out loud really.)

 

[JoceAndChris]

Thanks for your thoughts! I'll mull all that over with Chris tonight. It's a bit hard, this purchase. I tend to think that the more money you chuck at a problem the more fixed the problem is, but I accept that isn't always the case, as last week so resoundingly proved.

 

[JoceAndChris]

My last yellow bath! Yes this is before bathing!

 

[DJH]

Hmm. Must save a bob or two on tanning salons Joce... :lol:

Can you describe exactly how you are saving rainwater at the moment? The 5 filters you are thinking of fitting are unlikely to take the colour from your water. Are you thinking of storing your rainwater in one tank and then filtering it as you use it or filtering it into another tank and using it straight from there maybe?

Doug

 

[JoceAndChris]

Chris is home now and says the filter seller at East Midlands says the pump has got to match the filter, the pump is 35 l per minute so that one you linked to Doug, isn't enough.


The rain falls on the roof and then down through lead guttering and lead down pipes, down into a brick built 19th C underground chamber under the garden, which is all exceedingly filthy. From there is pumped into our scullery where the filtration will live. From there up through the pipes into the tank in the attic. And from there down to the bathrooms which are on our ground floor and taps in the kitchen basement. So, the filtration would only happen in the scullery before the water gets to the header tank in the attic.

I would be really upset to spend 700 and still bathe in what looks like pee.

 

[ChrisD]

My last house had a filtration system similar to what has been linked to here. The well water could still be quite rusty coloured especially a day or so after rain. It was tested and declared safe to drink but I used a reverse osmosis unit for drinking water, just to be sure. That only yielded a couple of pints a day though. I hope your experience is better but I'd be very wary about spending a lot of money without any guarantee of achieving what you wish for.
Best of luck.

 

[Flyfisher]

I can understand that the filter and pump should be matched, but I still don't understand why it's necessary to have such a high pump/filter flow rate. Surely the filtration system can be separate from the actual water usage? You could filter the 'raw' storage water into the attic 'clean' tank at a much lower flow rate than you need for taps and showers, subject to the size of the 'clean' storage tank of course.

Also, is it know what is causing the yellow colouration? I'm assuming it's not a physical thing (suspended solid matter etc), in which case I'm guessing it would might need some form of chemical treatment to remove the colour. At the back of my mind is some form of chemical interaction between the raw ground water, the mildly acidic rain, the lead guttering and the copper pipes, but I always preferred organic chemistry at school so didn't pay enough attention to the inorganic lessons!

It does sound like you need some sort of expert water engineer/consultant type chappie to have a look at things rather than just a 'filter seller'. Your point about being upset to spend more money and still have yellow water is well made and should be high on your list of requirements when getting someone to do the work. So, rather than asking a plumber to install a filter system (which I'm sure they will do perfectly well), the emphasis should be on the end result rather than the specific work to be done.

Basically, you want X litres of clear, solids-free drinkable water each day (or whatever) and you want someone to install whatever is required to achieve that. If they don't deliver that list (or whatever you finally decide) then they've not met their side of the contract and you don't pay them. If a company declines such conditions then it's a sign they may not be confident, in which case you probably shouldn't use them anyway.

Apologies for rambling on - I'm sure you know all that anyway, but I feel your frustration.

 

[JoceAndChris]

Thanks for the kind posts! It's very nice to have a sounding board and hear some feedback!

It wasn't very easy buying the pump for the rain Flyfisher, but we're pleased with it and don't really want to replace it. If we went for a smaller rate of flow filter, we'd need to change that pump.

Chris thinks that having a rate of flow system that's surplus to requirements will be good as it will mean less maintenance and cleaning of the cartridges.

As for what causes the yellowness, interesting thoughts! I had just thought it was rotting leaves and moss ( because our guttering is all rather shallow lead lining chestnut, we are unable to fit standard meshes at the tops of downpipes - we have home-made meshes and they tend to blow off), but you may be right about it being a chemical reaction! I'll email those pump people tomorrow with my photo and ask what they think will make the water clear.

We did have a water engineer, he was the one who did the well work for £5000 last week. :evil: He wants to continue and do more for us, but his last quote, which was £10,000 to create a new well and pump it up to the house, was just off putting. Also he said he would increase the yield and he couldn't. The whole experience just makes me think there aren't any guarantees with harvesting water.

 

[Flyfisher]

Ah, I didn't realise you were trying to use an existing pump, which makes perfect sense of course, and yes, a high flow rate is not a problem as such, I was only thinking about keeping the costs down. That's the trouble with half-baked musings - sorry!

 

[JoceAndChris]

Not half baked at all - thanks for your always wise words!

Hard choosing this sort of thing. Decorations are so much more straightforward!

 

[DJH]

I would be really upset to spend 700 and still bathe in what looks like pee.

Naturally Joce. It only goes that colour when you're in the bath peeing... 8)

Anyway, the fact that the water passes through lead gutters and pipes and copper piping has insignificant effect upon it's colour. I'd be inclined to have your cistern pumped out, cleaned and disinfected and at the same time any caulking or repairs done to the structure prior to refilling. I doubt if this has ever been done and is quite possibly, along with FF's suggestion of ground water seeping in, the cause of discolouration.

I doubt very much that even the filtration you intend using will remove either the turbidity or odour from the water. The only way to resolve this is to filter it through a sand filter and then a UV filter to disinfect it. This method will require less filtration (and decrease the flow restriction for you pump) and the sand filter is self cleaning by pre set backwashing.

You don't say what tank or cistern you have in the roof but if it is in good condition and is a galvanised one, then that can be cleaned out and given a good coating internally of a bituminous paint suitable for potable water. It should be fitted with a good and as far as possible airtight cover and insulation.

I'd hold back on buying those filters. There are cheaper ones and £700 would nearly pay for a sand type filtration set.

Doug

 

[agbagb]

down into a brick built 19th C underground chamber under the garden, which is all exceedingly filthy.

That sounds like the source of the problem. If you could cure that, then any other additional filtration would be minimal.

Could the chamber be emptied and lined with pond liner?
Then adding filtration to the inflow to hold back most organic matter entering so it doesn't build up so fast again. I think these are available to fit downpipes as well as in-line.

Just as a quick test to see what filtration would do - a paper coffee filter is about 10 - 20 micron. To go lower you should be able to get laboratory filter paper down to 1 micron.