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Grey Water Systems?

 
James Hogg
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Can some please explain in detail what is inside a grey water system and how they work. Can you please also keep it as simple as possible. Thanks
 
Angelika Maier
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Location: cool climate, Blue Mountains, Australia
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There are so many different systems you can setup. The easiest is a hose or even easier are buckets brought out.
 
Jennifer Wadsworth
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Greywater systems take used water from sinks (other than the kitchen sink - which is "dark grey water"), showers, tubs and washing machines and return it to the landscape. They do this in any number of ways.

Starting with the simplest (and generalizing greatly!):
--you can unhook the p-trap below a sink and place a bucket under this to collect greywater. You can then take that water outside and water your woody stemmed plants with it (trees, shrubs) - don't water herbaceous plants with this method. This is the so-called "bucket method". A variation of this is to do your dishes in tubs in the sink and then take the tubs outside....
--you can do a bit of plumbing to get your greywater out of the house. This works for sinks and sometimes tubs/showers depending on where they're located in the house. Essentially you replumb with a jandy valve so that you can switch between sewer and landscape. You need a drop of 1" to every 10 linear ft the pipe travels to get to it's ultimate destination. The destination should be some kind of mulched pit/basin and ideally, the greywater should vent UNDER the mulch.



--If you live in a climate that lends itself to having an outdoor shower part or all of the year, simply set up a hose over a tree limb and maybe make a little platform to stand on and put a curtain around the whole thing (or not - depending on your personal taste!) Or you can build something more permanent like I did. See pic below showing the beginning setup of my outdoor shower - three drains venting into three infiltration basins. The full blog post documenting this project is here: http://abundantdesert.com/2013/11/02/dolce-verde-outdoor-shower-part-1-design/



--Washing machines have pumps in them so that water is pressurized and can travel quite a distance, usually 80-100 ft, so it does not have the limitations of being gravity fed. You can set up a simple system whereby the water is diverted into a 55 gal. barrel (because it's pressurized water, this is done to stop the water from scouring the soil if it was piped directly to the landscape) and then hook up a hose to the barrel and direct the hose to the WOODY plants you want to water. OR you can attach drip irrigation to this setup (because it's pressurized). Below is a project that Watershed Management Group did at my house in Nov 2013 doing exactly this (irrigation) - it's called "Laundry to Landscape" or L2L for short.



--If you want to actually purify greywater before reusing it - you'll need to pass it through some biological systems, or multiple systems depending on how "clean" you want it. This involves things like sand, gravel or mulch filters, reed beds...all the way up to "living machines" (google John Todd Living Machines).

To define a greywater project:
--determine the water source
--what do you want to use the water for? Is it a good candidate for greywater use? (in other words - will it be used for woody plants - NOT herbaceous food plants) How far away is it from the water source?
--is the water source on an exterior or interior wall? If not on an exterior wall, can you move it so it is? Or even move it outside? (I moved my washer to my back porch and my main shower is in the backyard).
--is the greywater pressurized or not?
--what's your budget? There are some FANCY systems out there...

A really useful online source of information is Brad Lancaster's site - he is the author of "Rainwater Harvesting for Drylands and Beyond, Vol 1-2": http://www.harvestingrainwater.com/greywater-harvesting/
 
James Hogg
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Thanks Jennifer! I am in the UK so the water would not be used to water plants as the rain does that enough, it would be more for flushing toilets. What you said about purifying and cleasing it really interested me. What would needed to be included to clean the water enough to flush toilets and how would we get it to work?

Many Thanks

James
 
Jennifer Wadsworth
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Thanks for clarifying, James! (and welcome to Permies)

For that kind of setup - turn off the water to your toilet. Then remove the trap under your bathroom sink and put a bucket under it. When you need to flush, simply remove the bucket and pour the water into the tank, then flush. Because the greywater is not stored (never store greywater - it gets stinky!), there is no need to cleanse it further.

There are some fancy ways to hook up this plumbing so that it works automatically. Here are a couple of pics - from uber luxurious to a DIY hack!



Liked this one from: http://www.instructables.com/id/Hack-a-Toilet-for-free-water./


 
James Hogg
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Thank you. I'm affraid that the water I'm using will need to be stored and therefore cleansed. Sorry to be such a pain but how would I do this?
 
Jennifer Wadsworth
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Just so I can get a handle on what you actually want to do....

--where are you getting the greywater?
--what is the volume?
--for what purpose are you wanting to store it?

Personally - I would NOT store greywater - it's not a 'best practice'. Methods of cleaning greywater for storage/reuse often involve biological or living machine systems - definitely more complex.



 
John Elliott
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I'll agree with Jennifer that you shouldn't really store 'grey water', but there is no limit to how long you can keep your 'compost tea' bubbling. And what is the difference between grey water and compost tea? Time and the maturation of some aerobic bacteria. Grey water is anaerobic, and as long as it sits in a tank with no air exchange, it's going to get more fetid and smelly as the anaerobes have a field day. No, if you don't have a place to put it right away, keep it in a tank, but bubble air through it. That converts it in short order to aerobic compost tea, which as long as it has a source of food and air, can sit there stewing away until you are ready to use it to water some plants. In fact, the longer you keep compost tea stewing away, the more dominated by fungal microorganisms it becomes. Float some leaf litter in it and let it sit for a couple weeks, and it's really a sea of bubbling hyphae ready to colonize some soil.
 
Jennifer Wadsworth
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John - excellent points! Never quite thought of it that way.

We'll have to wait to hear back - but I get the impression that the water was to be reused in toilets, not the landscape.
 
Rebecca Norman
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The Oasis website has a lot of information about grey water. oasisdesign.net
Especially: http://www.oasisdesign.net/greywater/misinfo/index.htm
I bought their book too and love it.

First and foremost decide WHY you want a grey water system. Is it because you need to water your landscape? (In your case, no). Or do you just want to do something green and conserve a resource, but in fact don't have a water shortage? In which case you should stop and look elsewhere first for more appropriate and effective ways to conserve resources.

Art Ludwig on the link above about common greywater errors says:
Error: Automated reuse systems for flushing low usage (e.g., residential) toilets

Automated systems for flushing toilets with grey water are complex and expensive. Flushing with untreated grey water will result in fouling of the tank and fetid anaerobic smells (see "Error: storage of grey water"). Treatment is fabulously expensive. The cost for a typical system touted on the web is $10,000. Even at the punitive water rate of $0.01 a gallon, that's 5 years of 325 flushes a day to recoup your investment, not counting lost interest, electricity, or system maintenance. The $650 Homestead Utilities system (s16), which is the cheapest I’ve heard of, would take 23 flushes a day—if you had a restaurant it could earn its keep.
Extreme economic unfeasibility can indicate extreme ecological unfeasibility; the earth could be way better off if you just wasted the water than if you wasted all the plumbing, pumps, tanks, filters, and electricity needed to make this sort of system work.

Preferred practice
First, put in a low flush toilet (or a waterless composting toilet—see inside back cover). Then, "if it's yellow let it mellow, if it's brown flush it down." Third, toilets can be flushed with grey water by simply bucketing it from the bathtub/shower directly into the toilet bowl (not the tank, where it will fester). An added plus of reusing bathtub water in this way is that due to flush volume always being under direct intelligent control it is always less. Also, in cold climates you get a primitive but highly effective sort of grey water heat recovery as the bath water sits there and cools.
Once again, the Mexican housewife's system soundly outperforms the US engineer's system! If none of these preferred options appeal to you, you're probably better off just forgetting about flushing your toilets with grey water.

Exceptions
Every toilet should have a lid that routes clean drinking water en route to bowl-scouring flush through a basin where it can be used for washing hands.

Multifamily, institutional or any other high use installations can benefit from flushing toilets with highly treated grey water, especially when incorporated in the original design of the building. If you have highly treated water already and don’t know what to do with it, say from a constructed wetland, it may be worth supplying it to the toilet. An important advantage is that toilets need flushing every day, whereas irrigation need is usually seasonal.
"Clearwater” such as air-conditioner drip, reverse-osmosis water purifier reject water, and fixture warm up water is a natural for flushing toilets. It needs no treatment and can store indefinitely. Steven Coles of Phoenix, Arizona suggests that if you have an evaporative cooler, supply the toilet from its reservoir and you’ll keep the mineral concentration in the cooler water from rising.
 
James Hogg
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Jennifer Wadsworth wrote:Just so I can get a handle on what you actually want to do....

--where are you getting the greywater?
--what is the volume?
--for what purpose are you wanting to store it?

Personally - I would NOT store greywater - it's not a 'best practice'. Methods of cleaning greywater for storage/reuse often involve biological or living machine systems - definitely more complex.



It's going to be stored mainly because in the location there will be taps on their own (some of them anyway) so it would be better if all the water is in a ass collection area and can then be put back into the system to be used to flush the toilets. There is quite a lot of water but I'm not exactly sure on the volume.

Many Thanks

James
 
Jennifer Wadsworth
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For something like that, it's going to get expensive, FAST.

Check out these systems below.





 
I agree. Here's the link: https://richsoil.com/wood-heat.jsp
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