Feasibility of filtering gray water for drinking again, using a gravity-fed filter system?

Greetings.

Since most of us strive to be very conscious of our limited supplies of drinkable water, I'd like to know how feasible it is to collect gray water (from washing dishes or clothes, but only with a bio-degradeable soap such as Dr. Bronners) and run it through a gravity-fed water filtration system and back into a drinking water container.

• Would that water be safe to drink from a health and safety standpoint?
• Would that water taste clean?

Thanks!

Only a very small amount of fresh water in the world is suitable for anyone to drink and stay healthy it seems. Even the best quality gets filtered by us before we drink it. Saying that with plenty of higher quality water available to filter why would you chance using water you know is contaminated to start with and trusting only one purification system to make it safe to drink again? Nope, I’m not gonna do it. Ours always tastes the same as we always filter.

Yuck.

Please do not do this.

NASA spent millions of dollars to make this work on the ISS.

Most of us can't afford millions of dollars for a water recycling system, but we CAN afford to buy a few cases of clean drinking water every few weeks that we know is safe to drink.

Filtering common minerals, bacteria, organic material, and other solids out of drinking water is one thing, but removing all the dissolved chemicals is a lot harder to do.

Bear415 said:

Greetings.

Since most of us strive to be very conscious of our limited supplies of drinkable water, I'd like to know how feasible it is to collect gray water (from washing dishes or clothes, but only with a bio-degradeable soap such as Dr. Bronners) and run it through a gravity-fed water filtration system and back into a drinking water container.

• Would that water be safe to drink from a health and safety standpoint?
• Would that water taste clean?

Thanks!

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Plumber here, it IS possible to be filtered enough to be drinkable (say through a mult stage reverse osmosis filtration system) but it will not yield as much as goes in, the soaps you use would likely change the taste, body sludge and etc would quickly clog filters, in an emergency it's doable with enough filters but the taste may make you want to die. Boiling is a simple and effective method, but the key would be to filter it before hand. Through sand, charcoal, cloth, THEN boiling it.

I had to boil water to survive when I was stranded in the remote Arizona mountains, I recommend being prepared before hand, the amount of work required to make it potable is tremendous, but in an emergency "tremendous" is just a way of life

Bear415 said:

Greetings.

Since most of us strive to be very conscious of our limited supplies of drinkable water, I'd like to know how feasible it is to collect gray water (from washing dishes or clothes, but only with a bio-degradeable soap such as Dr. Bronners) and run it through a gravity-fed water filtration system and back into a drinking water container.

• Would that water be safe to drink from a health and safety standpoint?
• Would that water taste clean?

Thanks!

Click to expand...

I'm designing a very high efficiency solar still to make potable water from gray water. Let me know if you want to work with me in testing it.

^^^ Don’t you mean you need someone to test the results? Lol!!! Solar stills are great but distilled water really isn’t all that good or good for you, right!

Distilled water is safe to drink. But you'll probably find it flat or bland. That's because it's stripped of important minerals like calcium, sodium, and magnesium that give tap water its familiar flavor. What's left is just hydrogen and oxygen and nothing else. However having tasteless safe water to drink vs unsafe water, the choice is a very good one. Rain catchment is another option too. You can collect approx. 27 gallons of water per inch of rain on a 5'x10' area.

Drinking water as I mentioned in my response above, usually contains a few trace minerals to improve the taste.

But distilled water is normally safe to drink also.

Captured rainwater runoff from a roof or tarp, etc (if you want to go to the trouble) unless passed thru a good filter system, should be reserved for non-potable uses, unless of course you are completely out of drinkable water and it happens to rain on you!

bullfrog said:

^^^ Don’t you mean you need someone to test the results? Lol!!! Solar stills are great but distilled water really isn’t all that good or good for you, right!

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I have been testing (& tasting) the water I produce. There are additives available to add back the minerals that distilled water lacks.

I want to test the ease of use aspects of the device I've developed.

future_vandweller said:

I'm designing a very high efficiency solar still to make potable water from gray water. Let me know if you want to work with me in testing it.

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Simple science says that distillation removes almost anything from the water, and boiling the water (which happens during the distillation process) kills any organisms in the water.

The only thing left are certain chemicals like benzine which will evaporate and condense before the water does, because of the lower boiling point. These chemicals can be removed by not condensing the water until it reaches the boiling point. The chemicals will boil out first.

Unless you are downstream from a location where solvents are used, your fine! And if you're in the woods, it's pretty much a sure thing that there's no

I'd be happy to try it.

future_vandweller said:

I have been testing (& tasting) the water I produce. There are additives available to add back the minerals that distilled water lacks.

I want to test the ease of use aspects of the device I've developed.

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As far as the water being good, there are sugar free drops that will flavor the water. No chemicals, no nothing, just flavor from the fruit. I have tried it with distilled water and it tastes very well. Certainly better than tap water..... And Future_vandweller is corred, there are additives for the minerals.

And being good for you? It is by far the safest way to purify water, and you don't have to purchase filters, salts, etc.

I've read that everything we drink now has passed through the gut of some beastie at some time or other in the past. The Earth's water cycle is just a huge recycling system. But, depending o what we have added to the water will certainly impact how well Mother Earth can do her job. Same for you. I would be awful careful doing this and would still pass on it unless it was an emergency of some sort.

Just an added thought...
I am working on a recycle shower/gray water system for not-drinking, and I'm careful to filter and sterilize even that. In my experience, the water I actually consume is less than I use for other purposes, so if I can recycle grey water for non-potable uses, I shouldn't have to worry about anything short of an apocalypse.

Drinking "gray" water just sounds bad.
Hard pass on me being the taste tester. Sorry OP...

Other than for a dire emergency (or a science experiment) I don't understand why you would want to do this and carry around all the stuff needed. A better solution would be to minimize your grey water and/or not put anything in your grey water that you wouldn't want to drink. Or carry sufficient water for your needs.

You have 3 problems:

1. removing everything that is harmful
2. testing to ensure harmful stuff has been removed
3. making the water palatable (mental and taste)

Bear415 said:

...drinkable water...collect gray water...through a... filtration...

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.
Catchment:
In this portrait of our 40'/13m semi-trailer conversion, I added 'fences' or dams to three sides of the porch roof.
Zoom in to see the break in the dams at the curbside rear of the roof.
.
Process:
During a rain, we wait a few minutes to rinse the muck off the roof, then place one of our five-gallon stainless-steel retired Pepsi kegs to harvest the drainings.
.
Result:
This fluid is adequate for worshing.
We access a RO dispenser in a store, so we are without a filter or purification system.

I run a dehumidifier vs AC during the most expensive electrical rate hours of the day. It's 110 and way cheaper to run than my 220 AC system and the drier air in the house really helps . I get a fair amount (up to a couple gallons a day) of water in the tank on humid days and though I don't drink it, I use it for watering plants mostly. In a water pinch, I'd flush the loo and wash clothes with it. Drinking it would require filtering and boiling to get the dust and such out as well as killing any bacterial population.

Cheers.

RonDean said:

Just an added thought...
I am working on a recycle shower/gray water system for not-drinking, and I'm careful to filter and sterilize even that. In my experience, the water I actually consume is less than I use for other purposes, so if I can recycle grey water for non-potable uses, I shouldn't have to worry about anything short of an apocalypse.

Click to expand...

I am toying around with the same idea, recycle grey water but only shower water, not the sink. I plan on making a tall vertical sieve with 6' x 3" PVC pipe packed with swimming pool sand and several layers of activated charcoal with filter media on bottom to keep the sand out of the exit slats. It will sit in a 5-gallon bucket with a modified lid (dust free) and have a 2 gallon top (with strainer) for pouring 1 gallon of shower water in at a time and let it take its course. Lid on top (dust free). Will probably wipe off a little before the shower, yes, no #1 in the shower pan. Maybe change out sand and activated carbon when I smell an odor. Thoughts , soap type, issues, yes, no, not no, but hell no, ??

I only use soap if I have to cut grease. And only outside the shower. I use a moist towel to remove that before actually showering. When I get in the shower I mainly just use a clean washcloth (for physical body abrasion) and I feel quite clean afterward. But, my solution is still a work in process.

It seems to me to be spending a lot of money on dead weight to lug around. Sand, charcoal, dedicated containers and pipes as well as pumps and distillery. A system like that is really feasible in large scale. I used to run a water bottling plant and the huge amount of filtration equipment is daunting. There are emergency filters for water. Otherwise personally I will continue to buy bottles.