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Author Topic: Collecting Rainwater & Harvesting for drinking and domestic use?  (Read 35333 times)

Andrew K Fletcher

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Latest Video now on Youtube: http://youtu.be/tEzhdUhPFn4

Effective Economical Rainwater Harvesting System to provide all water used in the home. Includes making a 32 mm water diverter and primary and secondary flush system with 25 micron water butt inlet filter sock, 5 micron filter and housing. Hope you enjoy building one of these.

Drinking filtered rainwater free of chlorine, fluoride, pesticides, fertilizers, farm animal waste, wildfowl and fish waste makes more sense to me and tastes beautiful compared to the chemically treated mains water. A Pond UV Sterilizer can be added to make sure its pathogen free. We use a Doulton ceramic candle filter and housing for bathroom wash basin cold and for an additional filtered rainwater supply in the kitchen.

A double stopcock system has been installed to switch from rainwater to mains when tank is empty.

Would have liked a 3,500 litre tank, settled for a 2,700 litre tank for £155 Ebay
B&Q best for 32 mm pipe guttering and connectors. Toolstation for MDPE Pipe and , guttering, downpipe converter, fittings, Soil Pipe, fittings. Recycle centre for patio table legs. Maplin for Junior Hippo Water Pump..

Total Outlay: £620.00  Had some amazing bargains from Ebay

A first flush system is usually a 4 inch soil pipe, capped off at the bottom with a screw cap end so it can be cleaned out occasionally. The end cap is drilled and a continuous drip tap is fitted so that the flush system drains between showers. This reduces maintenance. The top of the pipe is reduced down to 32 mm or larger to take all of the rain from the roof. Water flows from the down pipe into a Y junction. Waste Push Fit 32mm fittings are ideal for this and inexpensive. Water enters the Y junction or T junction and rapidly fills the length of 4Ē pipe, usually around 4 feet minimum. Inside there is a plastic hollow ball that floats up and closes the first flush system when filled allowing clean water to flow into the Water Butt via a filter sock,

The first flush system is a simple effective method of removing insects, bird droppings and other debris every time it rains, by washing it into the 1st Flush, where the ball float seals it in and debris settles to the bottom.

In Rural India and other developing countries, this first flush system is the only filter they use and the water collected is drank by everyone, even imported into the cities and sold to people who canít drink the chlorinated chemically treated mains water.

We could learn a lot for these people. 

http://www.youtube.com/watch?v=Yf2CUYCWgko  Here is one in action. Although no ball float was used in this design.


 


« Last Edit: 11/05/2013 11:03:24 by Andrew K Fletcher »

Andrew K Fletcher

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Modified the Hippo Pump installation, due to an oversight on my part. Drilled small hole close to the top of the 45 gallon barrel , cut plug off and pulled cable through.

Having the pump flex going through a screw on lid means when you unscrew or screw it you tend to coil the flex around the 32 mil pipe attached to the pump. Obvious really. This lid needs to be removed fairly often to wash out the 25 micron filter soc on the inlet.

Having the push fit end on the inlet as shown in the slide show makes it very easy to remove the filter sock and replace it.

The filter socks wash in cold water, turned inside out and brushed lightly to remove silt. You can tell when the filter needs cleaning because the water backs up the down-pipe due to restricted inflow.

Washed the filter socks out 3 times now and not harmed by the process.
« Last Edit: 08/10/2008 17:44:03 by Andrew K Fletcher »

lyner

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Sounds a good system and we should all be aiming at something like that. You may need to check out with the water authority about an acceptable change over system which connects with the mains. They are a bit funny about these things because of the risk of contamination. One bomb-proof method is to have a header tank with a  ball cock.

Andrew K Fletcher

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Sophie-centaur
Thanks for your input and glad you enjoyed the slide show.

The following comes from a document from water companies relating to installation of modern meters by water companies:

ďThe housing for the
meter includes a non-return valve
which prevents water from
passing back into our mains.Ē

Also fitted Demand Valve on pump has non-return valve and then there are the dual manual isolation valves to alternate between two sources. and ofc the stop cock isolation valve in between the tank and the booster pump. System is already bomb proof.

The header tank and ball cock method is another brilliant method of using rainwater to feed toilets. All that is required is a pressure switch and a float operated pump in the water butt to automate the refills to the header tank. The pressure switch will turn off the pump when the header tank ball cock is closed when the tank is full. This system could be installed for as little as £100.00.( Minimum of two 45 gallon water butts, preferably-Used Fruit Juice containers costing £15.00 each. A non-return valve £9.00  all from Mole Valley Farmers) pipe work and fittings B&Q and a header tank and ball cock from your local recycle centre as most people remove these when changing to a combi-boiler so readily available. When installing header tank make sure its over a supporting wall to prevent beams from sagging in the loft. 1/3 of all water used goes down the toilet.

Sounds a good system and we should all be aiming at something like that. You may need to check out with the water authority about an acceptable change over system which connects with the mains. They are a bit funny about these things because of the risk of contamination. One bomb-proof method is to have a header tank with a  ball cock.

Andrew K Fletcher

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If itís yellow let it mellow
If itís brown flush it down
Leave the bathwater in too
And use this to flush the loo

Flushing the toilet 1 in every 5 times previous saves a lot of water.

that mad man

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Looks like a good system. 8D

One question though.

Do you collect all the rainwater or does some still go down the drains?

The reason I ask is because over the road from me they have built a new school with a sege? roof. It has gutters but the rain water is collected into a tank and recycled for the toilet system. There are no downpipes leading to rainwater drains and from what I can remember one of the other benefits was that the rates were also reduced. I think it was because the rain run-off did not use the normal rainwater drainage system which forms part of your normal rates.

It may be worth checking the legislation as you may also be able to get a reduction in rates for the same/similar reasons.

I will try and find out more details as it may be useful information.

Andrew K Fletcher

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Thanks for taking the time to have a look at this system.

Yes it does collect all the rainwater and there is a small reduction available for people that divert rainwater for use in the garden. As this soaks away and is not returned to the sewer as was the case before the water was recycled.

Looks like a good system. 8D

One question though.

Do you collect all the rainwater or does some still go down the drains?

The reason I ask is because over the road from me they have built a new school with a sege? roof. It has gutters but the rain water is collected into a tank and recycled for the toilet system. There are no downpipes leading to rainwater drains and from what I can remember one of the other benefits was that the rates were also reduced. I think it was because the rain run-off did not use the normal rainwater drainage system which forms part of your normal rates.

It may be worth checking the legislation as you may also be able to get a reduction in rates for the same/similar reasons.

I will try and find out more details as it may be useful information.

BenV

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With regards toilet flushing - it's also a nice idea to pop a brick in the cistern, or even better - invest in a duel flush system, so you can use much less water than a full flush.

Andrew K Fletcher

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Sound advice Ben.

These dual flush systems are inexpensive, relatively easy to install and as Ben says can save a considerable amount of water and money. A small bottle filled with water might be more suitable than a brick though :)

A friend and neighbour argued a full flush is better if you are flushing less because it moves everything in one go, whereas a small flush may have to go several times to move the same amount of toilet paper "woman thing after a pee"

With regards toilet flushing - it's also a nice idea to pop a brick in the cistern, or even better - invest in a duel flush system, so you can use much less water than a full flush.

Bored chemist

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Nice piece of work Andrew.
I know that you have already made sure that the rain water cannot run back into the domestic system. I know that you have done this in several ways.
However the water bye-laws a re stupid and prescriptive.
I can't fit a tap outside my house without connecting not one, but two, non return valves in series with it.
I gather this is because I might connect a hose (which I don't have) to it and the hose might somehow get to a higher pressure than the mains and the water might be contaminated and one of the valves might not work.
Since they really are that stupid, I think you need to fit the aproved double non return valve just in case they decide to play silly buggers.

I heard that those "double flush" cisterns went out of fashion because they typically used more water than normal ones. People used the "half flush" and, when that didn't do the job they used the "full flush". Net result 1.5 flushes where 1 would do.

Andrew K Fletcher

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Thanks BC
I know you are right about this regulation. The hosepipe makes sense bacause it could theoretically be high enough to cause a siphon back into the mains should the business end be left in a pond or something, though this would require the mains to be off and lets face it, it is far less contaminating that the tanker load of aluminium sulphate dumped in the Camelford water supply causing untold health problems in Cornwall by the water company :)

I am sure my system is water tight so to speak but I have taken on board what you have said and as you say the bye-laws may be in need of updating due to the inclusion of the valves on meter instalation. So to air on the side of caution, I will be fitting a double check valve, which is a simple task to keep everyone happy.

The double check valve is £2.82 Toolstation, for a 15mm fitting, to comply with regulations not much point in ignoring your advice, even though a double check valve is fitted with all modern metres for this very purpose, as the water companies also have to comply with the same rules when fitting a meter these days. 



Nice piece of work Andrew.
I know that you have already made sure that the rain water cannot run back into the domestic system. I know that you have done this in several ways.
However the water bye-laws a re stupid and prescriptive.
I can't fit a tap outside my house without connecting not one, but two, non return valves in series with it.
I gather this is because I might connect a hose (which I don't have) to it and the hose might somehow get to a higher pressure than the mains and the water might be contaminated and one of the valves might not work.
Since they really are that stupid, I think you need to fit the aproved double non return valve just in case they decide to play silly buggers.

I heard that those "double flush" cisterns went out of fashion because they typically used more water than normal ones. People used the "half flush" and, when that didn't do the job they used the "full flush". Net result 1.5 flushes where 1 would do.

that mad man

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Unfortunately any rebate will only be around £25-£30 but its better in you're pocket than theirs.

I believe the Anglian water authority were forced to pay out a £30 rebate to consumers in similar circumstances.


Andrew K Fletcher

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Modification to 32 mm rain barrel inlets. This was essential because the filter sock works fine for a few days of rain, then restricts the flow causing loss of water due to it backing up. So came up with the idea of introducing twin filter socks on 32mm manifold. Must say for £5.40 at B&Q it was well worth the time and trouble. Works great now and not lost a rain drop since :)





 

Andrew K Fletcher

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New video showing a system with pumped mains pressure and first flush system. http://youtu.be/tEzhdUhPFn4

chris

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Really good new video, Andrew! Great project too; you should market it; you've solved all the problems of what to use and where to source reliable materials, which is 99% of the challenge.

Chris

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Mom & Dad installed a rainwater system for their coastal property.  Much of it was installed underground.

A similar "first flush" system that slowly leaks down, so they only collect the rainwater from heavy downpours. 

They do use a gravel/sand filter, also underground in their system.  I don't think there are any "socks". 

One of their concerns was the asphalt roof.  Mom will probably replace it with steel once it gets old, but they didn't have a choice when it was first installed, and chose not to replace the new roof.  So, they just carry a couple of gallons of drinking water, and just use the rain water system for the sinks, toilets, showers, etc. 

chris

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I collect the water off the roof of my studio building, but I use it only for watering the pot plants that are obligatory rain-water only recipients (like blueberries).

The roof has asphalt shingles and the water that is collected is always frothy and discoloured. The plants don't seem to care, but I'd be worried about the tars that are clearly getting into the water if I were to drink this...

Mazurka

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Chris, experimenting on oneself is slightly old fashioned, but it has resulted in numerous breakthroughs in the past  :0 ;)
(and presumably you eat the blueberries, bioaccumualted toxins and all?)

chris

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I like to think that the soil has at least some filtering effect, as do the plants themselves. Let's hope so! If I begin growing breasts and my testes shrink, we'll know I was wrong and there are some endocrine disruptors making it through after all...

C

 

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