Toilet with rain water?

[David in Normandy]

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?

[Skipweasel]

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.

[David in Normandy]

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).

[Clot]

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!

[Lobster]

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

[Si]

In message , David in Normandy writes

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 .

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...

[RobertL]

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

[David Hansen]

On Wed, 16 Jan 2008 20:14:32 +0100 someone who may be David in Normandy wrote this:-

Rainwater harvesting is the term for this and a search engine will pull up much on the subject.

[Mary Fisher]

I don't know what French regs are but the Green Building Store sells specially designed rainwater/mains water WCs which are very efficient and switch automatically between the two water sources.

They are expensive though ...

[David in Normandy]

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]

Thanks. Google comes up with 406,000 links! That should keep me busy for a bit.

[David in Normandy]

I had a browse through their site but couldn't find the auto switching toilets. It defeats the object if they are expensive though. I don't want to spend vastly more than could possibly be recouped through using less mains water.

The downstairs loo just struck me as a fairly obvious, easy and cheap target for replacement with rain water, since the butt would be outside very near for connection.

[David in Normandy]

I guess that would be perfectly legal. May be worth=20 considering.

--=20 David in Normandy

[David in Normandy]

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.

[Si]

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.

[David in Normandy]

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.

[nafuk]

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.

[mick]

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.

[Mary Fisher]

Sorry, I can't find it either. I definitely had printed information from them but I was obviously confused about their stock.

They'll come up on the rainwater harvesting sites.

Mary

[The Natural Philosopher]

Only one caveat. Algae growth. D not havbe an anwer for that other than a capful of bleach in the tank every week.