Separating (composting) toilet pee tank?

Ramdough

Adventurer
Sink water is often considered black.

Unine without feces IS considered grey water.

However, (typical) grey water left for just a few days will turn into black water due to growth.
Adding Urine into the mix just feels like asking for trouble.
Is old grey water legally grey water always even when old?

My understanding is that bathroom sink is Grey water and kitchen sink is sometimes considered black.

I plan to have strainers on all sinks so that the waste tanks never have large solids. That way the drains are always liquid only. I would like to carry just a garden hose for dumping with a small booster pump. That way I can dump fast and easily.


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DiploStrat

Expedition Leader
Grey water is an interesting subject. I suspect, without knowing, that most of the rules against dumping grey water start with the assumption that it has passed through the black water system, as is common in most RV's. (The usual rule is to dump black first and then grey to flush the system.)

The second reason is, of course, that you don't want a lot of closely spaced vehicles dumping grey water in a camp ground as you will quickly produce a smelly swamp.

And, finally, grey water may have bits of food and fecal material from washing dishes and showering.

With a composting toilet, aka, urine separating toilet, we do dump grey water in the bush, but never when close to water courses (other than storm drains) or other campers. In other words, only in places where we would be comfortable
digging a cat hole.

Grey water will "age' gracelessly, so stuff that has been in the tank a while is more aromatic, especially in hot weather. (A shot of white vinegar helps a lot.)

As to mixing urine into your grey tank:

-- Not a problem if you then treat it like black water - no one can complain. (Never done it enough to see if it creates odor problems.)

-- You can arrange a valving system, but it is easy enough to simply dump a urine bucket into the shower drain, if, for example, you need an emergency dump.

Whatever you do, you want, ideally, at least two days autonomy, and, with two adults, that argues for a tank of at least one gallon. And a one gallon tank is small enough to dump in a public restroom without gagging everyone. (In contrast, for example, to a cassette toilet.)

In public areas, a pit (not chemical) toilet is great for dumping a composting toilet.
 

Ramdough

Adventurer
Right now, I am leaning towards having a drain plug in my shower so I can plug my Grey water tank line and drop shower water on the ground (which I believe is fine if you are allowed to outdoor shower, this is the same thing). In close quarters or places water can’t be dropped, the drain to Grey tank.

For the toilet, I am leaning towards having the bathroom sink flush through the toilet p trap and into a urine tank.

For the kitchen sink and future clothes washing machine, drain to Grey water tank.

Any flaws?

Again, not sure I want a jug.....


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Verkstad

Raggarkung
Kitchen sink counts as black water anyway
Years of exposure to plumbers and pipefitters, I learned a thing or two and like many subjects in building trades, definitions vary.
”Sullage” is what they call greywater and that supposed to be any drain thats not intended for bodily waste.
Process waste and stormwater for example are different topic.
Others consider greywater is only ’grey’ for limited time until it turns ’black’ due to bacteria growth.
But I think sinks get considered by some as ’blackwater to acknowlege the number of sinkpissers in the world and you all know who you are.

Btw.
Were I building another camper I would call it a two tank system. Greywater and piss. There would be no ’black’ because I like the poopdryer/composting system.
Depending on location would dictate when & where tanks are drained.
 
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john61ct

Adventurer
The food wastes in kitchen sink water is putrefying enough to qualify as black

for harm to a sensitive ecosystem.

Much more so than pure urine.

Shower runoff is in between, that alone really is grey afaic.
 

Ramdough

Adventurer
Btw.
Were I building another camper I would call it a two tank system. Greywater and piss. There would be no ’black’ because I like the poopdryer/composting system.
Depending on location would dictate when & where tanks are drained.
I m plan to have a poop dryer/composting toilet. I will have a bathroom sink, shower, and kitchen sink. I could easily do two tanks. One piss and one everything else. I contemplated flushing my urine p trap with the bathroom sink (not too much water, maybe some toothpaste, soap, and bacteria from hand washing).

So far I have not heard any real negatives to this plan. Only one so far is I can’t Carry a jug into a portapotty.



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Ramdough

Adventurer
I would not bother with a p-trap. Without flushing, its still contains stinky juice and potential to empty whilst in motion. But use a ballvalve, much like a submarine toilet uses. Rinsing the funnel after use will take far less water than clearing a p-trap.
I think I will go this way. Much simpler. Have a pee tank and grey tank. The volume to clear a p trap sold me. Now just need to figure out where to put the valve handle.


You still use p traps for the sinks and shower...... right? Or ball valve then too?


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john61ct

Adventurer
Since living in Asia for decades I've grown to be disgusted by TP, bumgun for the win.

But no go with drying loos. . .

Combo bidet / sitting urinal!

If space a concern, place it in the shower, basically just a sturdy funnel-seat.

Us oldies need a place to sit in there anyway. . .
 
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