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Topic: Flush the toilet with Gray Water (easily) (Read 5 times) previous topic - next topic
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Flush the toilet with Gray Water (easily)
Yahoo Message Number: 58336
I just saw a tv program where they designed a new office building that captured gray water and used it to flush the toilets.  What a great idea!

Calling all engineers, boondockers, and handy folks, think about this.

What would prevent RVs from using the gray water, that we already capture, and flushing the toilet with it? The benefits would be:
1. fresh water tank would last longer
2. gray tank would not fill up as quickly (which is usually faster  than the black tank)
3. you could boondock longer
4. With a dedicated pump to the toilet, you could have better  pressure

One simple design would be to install a separate water pump between  the gray tank and the toilet connection. This would only require the  pump and some water line connections.

Some possible problems:
1. There might be too much debris in the gray water to run through  the pump?
2. The configuration (pump location, 12V supply, access) would vary  with the different floor plans. Some might be simple, some not.
3. Things I have not thought of.

This seemed like the perfect group to run this by, with all of the talent we have.

Think about it,

Chris Hunter

cahunter at charter.net
Re: Flush the toilet with Gray Water (easily)
Reply #1 –
Yahoo Message Number: 58338
"One simple design would be to install a separate water pump between the gray tank and the toilet connection. This would only require the pump and some water line connections.
Some possible problems:
1. There might be too much debris in the gray water to run through  the pump?
2. The configuration (pump location, 12V supply, access) would vary
 with the different floor plans. Some might be simple, some not."

Chris

This is an interesting idea. I already have a separate pump to transfer water from the gray tank into the black. Since the gray fills at a much faster rate, this gives us the ability to use all the fresh water without running out of wastewater storage. A 'Y' valve could be added to divert it to the toilet or black water tank. It might give a stronger flush than what the stock Whisper King pump provides.
I'm going to have to take at look at it when I get off work.
Thanks for the idea.
 See the following link for the wastewater transfer pump in our 23.5' FL http://pg.photos.yahoo.com/ph/lw5315us/album?.dir=27f0&.src=ph&store=& prodid=&.done=http%3a//pg.photos.yahoo.com/ph/lw5315us/my_photos Or http://tinyurl.com/3jvx7

Larry
2001 MB
* Not to be confused with Larry W (3000 of my posts are actually from expert Larry W due to Yahoo transition mis-step)
Re: Flush the toilet with Gray Water (easily)
Reply #2 –
Yahoo Message Number: 58340
I've read of several people (including Larry) who have installed a pump to transfer grey water to the black tank.  I would think that the smell from the grey water would be pretty bad every time you flushed with it.  The grey tank smells worse than the black tank most of the time, the bacteria seems to work better on the black than the grey.
Also, you would definitely need a filter or you'd be looking at the odd piece of lettuce or a couple of coffee grounds when you flushed.

Jonna
Re: Flush the toilet with Gray Water (easily)
Reply #3 –
Yahoo Message Number: 58342
"Also, you would definitely need a filter or you'd be looking at the odd piece of lettuce or a couple of coffee grounds when you flushed."

Jonna
 You would most definitely want a filter. The small holes in the rim of the toilet would plug with small pieces of debris that would be very difficult to remove.
I used a cleanable filter on the gray to black transfer pump to prevent damage to the pump's valves. I also mounted the supply line, on the gray tank, an inch or so above the bottom to prevent picking up the solids that have sunk to the bottom of the tank.
Using gray water to flush may not be ready for prime time, due to the odor factor, but the transfer pump has proven its worth in extended times between having to dump.

Jonna, I'm up in the middle of the night because of my job.
Are you a night owl or an insomniac?

Larry

Relaxing with a snack and glass of Shiraz before going to sleep.
2001 MB
* Not to be confused with Larry W (3000 of my posts are actually from expert Larry W due to Yahoo transition mis-step)
Re: Flush the toilet with Gray Water (easily)
Reply #4 –
Yahoo Message Number: 58349
I'm a night owl.  I could blame it on my usual shift when I was working but truthfully, I always picked those hours because I hated getting up early.  I tend to stay up a lot later when I'm online using my cell phone as I don't go on until 9pm.  Now that I'm not working, I don't have to worry about getting up early OR going to bed late.... it's the best of all worlds.

Jonna
Re: Flush the toilet with Gray Water (easily)
Reply #5 –
Yahoo Message Number: 58373
We try to keep debris out of our grey water.  Fine filter in sink.
Wipe dishes with inexpensive disposable napkins to remove garbage and oil .

Coffee grounds are great compost.

best,  paul
Flush the toilet with Gray Water (ea
Reply #6 –
Yahoo Message Number: 58361
In a message dated 9/23/2005 10:00:25 PM US Mountain Standard Time,  writes: What would prevent RVs from using the gray water, that we already capture, and flushing the toilet with it?

 That's a great idea, Chris!  While we do use gray water to flush our toilets when we're boondocking, it'd be great if RV manufacturers would figure out a system such as you described.

Linda Hylton 2004 Red 23.5' TK Timer Valley SKP Park Sutherlin, OR See where we are: http://map.datastormusers.com/user2.cfm?user=1167

[Non-text portions of this message have been removed]
Linda Hylton
 
Re: Flush the toilet with Gray Water (easily)
Reply #7 –
Yahoo Message Number: 58365
"That's a great idea, Chris! While we do use gray water to flush our toilets when we're boondocking, it'd be great if RV manufacturers would figure out a system such as you described."

Linda
 As Jonna pointed out, gray water can smell very bad, especially in hot weather. The gray water tank can be treated with a holding tank chemical but that's an additional expense.  There is the additional issue of what to flush with when the gray water tank is empty. It might require double plumbing the toilet, making sure it has adequate backflow prevention. You certainly do not want to contaminate the fresh water with gray or black water.
It can be done but it would require a backflow device that can handle whatever solids, from the gray tank, that may pass through it.  It is very easy to do this improperly. This is why the UBC (uniform building code) is so tough on backflow prevention devices. Water can flow backwards in many ways, some that you may have thought of.  This may require new devices designed for the RV market. Simple check valves (one way valves) do not qualify.
 Double plumbing has become somewhat common in commercial building. At our airport, treated waste water from the sewage treatment plant next to the airport is used for flushing. It is also used for landscaping irrigation.

It's still a very interesting idea.

Larry
2001 MB
* Not to be confused with Larry W (3000 of my posts are actually from expert Larry W due to Yahoo transition mis-step)