Toilet with rain water?

I want to reduce our metered mains water usage. So I'm considering using rain water collected from the roof via a huge water butt outside for flushing the downstairs toilet. I've heard of others that have done this. I just wondered what issues I need to think about?
Has anyone else here done this or know of any associated plumbing diagrams?
Ideally if the butt runs dry then the supply needs to switch back to mains water (either manually or automatically).
Presumably the rain water would need to be filtered to remove any small debris that could block the ballcock valve?
The rain water must be plumbed in so there is no possibility of it feeding back into the mains supply.
I need to check for any associated building laws (here in France).
Advice or suggestions anyone on this project?
--
David in Normandy

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snipped-for-privacy@nospam.nospam says...

I thought about doing that, but it was ridiculously hard to comply with the water regulations. If it were as simple as a double non-return valve I'd have done it, too.
But instead I decided that since the loo uses /very/ little water - about a litre on low-flush about about three on full flush that in the unlikely event of ever emptying the butt in Slopshire's sunny climes I'd just sling the hose into it and fill it up again. 222 litres is a lot of flushes - and the simplicity outweighed the expected effort.
--
Skipweasel.
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Skipweasel says...

I was thinking along similar simple lines of a none-return valve on each supply coupled into a T and feeding the loo. With a stop tap on each feed so I could manually switch over from mains to butt water (or turn off the water completely).
In theory it would be quick and simple to do. I still need to look into the French water regulations which I expect are murky as hell (like the tap water sometimes).
--
David in Normandy

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Does it need to comply with the water regs if it is not directly connected to the water supply? I mean, does connection to the sewer mean it has to comply?
Suppose you fed the loos ONLY from the water butt and also had a ball valve in the water butt so if it got very low it was filled form the mains.
Robert
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RobertL says...

I guess that would be perfectly legal. May be worth considering. -- David in Normandy
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On Thu, 17 Jan 2008 13:03:39 +0100, David in Normandy wrote:

Especially if the ball valve was fed via a n/r valve or 2. With the ball valve near the bottom of the butt it would make a very nice automatic changeover system.
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Mick (Working in a M$-free zone!)
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mick says...

Yes, I think I'd need to buy a quality UK ball cock & valve though, not one of those plastic / polystyrene French ones which seem to fail after six months.
The thing is, most of the time the ball cock would be submerged under several feet of water, so there would be quite an up-force on it which could sprain or snap a cheap mechanism. -- David in Normandy
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David in Normandy wrote:

I assumed that was what was intended..
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The Natural Philosopher says...

There is legal and assumed legal. I could find out exactly what the legal building requirements are in France in this respect which frankly would be complicated as my grasp of French is not fluent yet. Or I could do as suggested which I would *guess* would not be illegal. :-)
--
David in Normandy

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David in Normandy wrote:

Just a thought. Are you likely to run into problems when the ball valve gets covered in rainwater. They are not normally used in a mode where there is any alternative supply. I don't know if the regs would have anything to say about this.
One solution might be to put the valve at the top of the water butt, opposite the overflow but engineer a long reach ball that floats at a much lower level.
Andrew
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David in Normandy wrote:

Unfortunately, I can't recall which part of Belgium was pushing the use of rainwater a few years ago. Planning regulations required capture of rainwater and its use prior to the use of mains water for certain uses. Woe betide you if you were caught washing your car with mains water whilst your rainwater tank was full!
Might be worth trying some Belgian sites - I assume the French if OK? I.d struggle with the other!
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Clot wrote:

Someone I know who visited New Zealand recently told me that this was quite big out there, so that might be another avenue to explore - plus New-Zealandish is easier to understand than French...
David
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Lobster says...

Yes, New-Zealandish is definitely easier to understand than French. If you think the UK income self-assessment forms are bad you should see the ones in French!!! France has a passion for lots of complicated forms and paperwork. Nation of bureaucrats etc.
--
David in Normandy

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Here in New Zealand, I can tell you that NZ's largest water supply company (and sewage treatment plant) takes a dim view of you putting water that they have not supplied down their sewer system. Rainwater is fine for washing cars and watering the lawn and garden as long as it doesn't go down the sewer. So if you wish to use rainwater for flushing the toilet, I suggest a hidden pipe is best. :) And the rainwater tank would seldom be empty. It's easier and much cheaper to walk around and turn taps on or off a few times a year rather than have an automatic changeover system which may go wrong.
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Simpler, cheaper and more reliable, if you want to reduce your mains water usage why not build a composting loo and use none at all? The only water mine uses is when I rinse the collecting buckets each week after their contents are added to a compost heap at the end of the garden and for that I use rain water.
See <http://www.jenkinspublishing.com/garden_gallery.html .
The system certainly works in this London suburb. We've been using it since March/April last year and I've had no complaints from neighbours. The only briefly malodorous part of the process is the weekly emptying. Out of consideration for the neighbours I try and ensure I empty early morning at the weekend. Once the heap is recovered (with organic material) there's no smell.
The only organisational problem is needing a regular supply of fine organic plant matter to use as covering material but our garden is organised on a wildlife-friendly basis so there's plenty of that. I did ask tree surgeon who lives nearby whether he could supply me with fine wood chippings on a regular basis (saving him paying to dump them too) but after initial interest he refused. :(
If you have any questions do ask...
--
Si

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Si says...

This would be a practical (and cheap) solution. We've got a large garden and plenty of vegetable waste that could be mixed with it. On the down side the Mrs would definitely not be keen on the idea. Some ideas I can "sell" to her, but not this one. Personally I've no problem dealing with the poo or smell - I was brought up on a farm and also worked on a couple of sewage farms during Summer breaks many years ago when I was a student at college, so I've shovelled more s**t than most people.
--
David in Normandy

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In use, composting toilet (in reality the part of it indoors is only a collector) makes no more offensive smells than a flushing loo - ie when a human is actually making their solid deposits.
Whereas with a flushing loo the flushing process removes the solids to elsewhere (for others to deal with - not DIY at all :) with the composting toilet collector the solids stop emanating a smell once they're covered with shredded vegetable matter. In between use the toilet produces a gentle aroma of woodland and is not offensive at all. My better half was very sceptical initially and would only allow it on a trial basis but now she's very happy we have the extra toilet available.
Joseph Jenkin's book (which is available for free download from the site I quoted but is also available to buy in the UK) has much detail about the possible human parasites/toxins in human faeces and how the composting process breaks them down and renders them safe. As a result, not only do we have an additional toilet we will also have (in another year or so) perfectly safe to handle organic humanure to use in our garden. No more need for chemical fertilisers either. :)
Incidentally, commercially made composting toilets seem much less eco-friendly than the home-made one. They generally use electricity to run a fan to remove the offensive smell (and need a pipe running up through the roof) and dry the solids. They are also expensive to buy.
--
Si

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Si says...

Hmmm. You've got me thinking. During the Summer months we spend lots of time outside, usually working in the garden or just sitting in the evening. An outside loo would be of benefit. It can be irritating to remove muddy boots just to come indoors to the loo. Perhaps an outdoor prototype is in order, I doubt she'd object to that. We've certainly got the space and no near neighbours to worry about.
--
David in Normandy

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Don't forget, if it's yellow, let it mellow. If it's brown, flush it down! We are not on a meter but do this to save water/energy etc.
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Number 1s can go direct on the compost heap, no need for a toilet.
MBQ
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