Urine redirect to gray tank

[ahattar]

Getting a little ahead of myself here since I don't take delivery until early 2020, but thought I'd throw it out there.  I'm sure somebody has redirected urine from the composting toilet to the black tank, I'm wondering if anybody has looked into going to gray?  The only benefit to this would be to use the brand new black tank as a second fresh water tank.  Its possible its not a potable tank, but it could be used for outdoor showers and such.  I have no clue if it will be way too tight under there to do any sort of mods since I've spent all of 15 minutes looking at an Oliver in person.  

 

 

[John E Davies]

It would be super easy to convert the 18 gallon black tank to potable water, it can gravity feed into the main fresh tank when that one is depleted, since the black tank sits about thee inches higher.... I am unaware of anyone who has done this yet. The access should be fine, the only tricky part would be blocking the vent pipe where it connects to the main vent under the bathroom sink. After blocking the vent you would have to install a large overflow pipe, going from the top of the tank to the belly. Access is OK since there is a big hole in the floor under the toilet.... And of course you would need a home built adapter with a ball valve at the outlet of the tank, under the front dinette seat.

I personally would not want any urine going into the grey tank. That would make it way more stinky than it already is, and it would not be appropriate to water a sage bush with it.... you could buy a second pee tank and cap ($40), and stash either the empty one, or a full one, behind the toilet, I think it would fit fine but I haven’t tested it there.

John Davies

Spokane WA

Edited November 23, 2019 by John E Davies

[ahattar]

Great info, thanks John.  Once I can get my hands on the trailer I'm sure this will all make perfect sense.  Do you know, are the black tanks made from the same potable material as the fresh tank?  

I've never had an issue with grey odors.  I will look into it more of course, but I figure actually taking a pee on the sage brush would be more harmful than the very diluted grey tank.  When we do wilderness river floats, we're instructed to pee in the river because it dilutes so quickly.  This prevents a bunch of burn marks and stink at camp.  We use all natural soaps but I would still guess the soap would hurt the environment more than the urine.  

I installed a composting toilet in my truck camper a long time ago.  it wasn't a natures head and the pee tank was horrible.  If the natures head is quite a bit better then just having a second tank sure would be an easy solution.  

Thanks 

  

[John E Davies]

The black tank is indeed black ABS, not poly, which is actually fine for potable water. The main reason the factory cannot do this mod is that their “RV whatever” certification requires that sewer and fresh have to remain completely separate, but there is no reason an owner cannot modify it, as long as you get rid of the connections to the nasty parts.

The pee tank in the Natures Head is fine, you add a few ounces of vinegar to it when empty, and rinse the urine each time with a couple of squirts of vinegar from a spray bottle. Smells are a non issue as long as your toilet vent fan keeps running. You need to keep the filters clean. Removing a full tank is pretty painless. Just be careful about spills. There is a big Natures Head thread here, I can get you a link if you like.

John Davies

Spokane WA

[Overland]

There have been quite a few threads here on repurposing the black tank, but to date I don’t think that anyone has actually done anything. I removed mine for extra storage but I don’t think that counts. 
I suspect the reason no one has followed through on any of the ideas is that at the end of the day it’s a lot of work for little gain. The p tank on the toilet is large enough that diverting it isn’t really worth it and fresh water is more easily stored in the truck than trying to add capacity in the trailer. 
But if you do come up with something once you get your trailer, then please post about it as there’s been a lot of interest over the years. 

[ahattar]

I'm pretty familiar with composting toilets.  I forget the brand we used last time but I'm sure its pretty darn similar to NH.  Emptying the urine tank on the other one was not fun though if you were just barely too full.  I got rid of the urine tank and plumbed it to my black tank on the truck camper which made it all pretty painless.  

Thanks again for the info.  

[ahattar]

1 minute ago, Overland said:

There have been quite a few threads here on repurposing the black tank, but to date I don’t think that anyone has actually done anything. I removed mine for extra storage but I don’t think that counts. 
I suspect the reason no one has followed through on any of the ideas is that at the end of the day it’s a lot of work for little gain. The p tank on the toilet is large enough that diverting it isn’t really worth it and fresh water is more easily stored in the truck than trying to add capacity in the trailer. 
But if you do come up with something once you get your trailer, then please post about it as there’s been a lot of interest over the years. 

Will do for sure.  We generally camp right on a river or lake and have always pumped water, so water is easy to come by.  Its the desert hunting trips and what not where the water is more sulfur than water where it would be nice to have an extra 18 gallons for a couple weeks.  Loading up the pickup is definitely an option but since the black tank is there, unused and out of the way I figure I might as well try to make it work.

[Overland]

I made some small modifications to our water system that have proven successful in stretching our water supply to over a week for two people, including daily showers. Simple stuff like low flow faucets.  We carry 15 gallons in the truck, and I’ve considered buying a tank that’s sized to fit the floor of the rear of our F150. I believe that 30 gallons seemed to be the most practical size. Maybe someday, but so far water has only been a minor inconvenience on any of our trips. 
 

I know of at least one owner who carries a large water bag in the bed of their truck, which holds an enormous amount of water. That seems a bit inconvenient to me, and I like having water split among more than one container in case one leaks, but it’s an idea. 

Edited November 23, 2019 by Overland

[ahattar]

Thats pretty good getting a week with two daily showers.  I'll for sure check out your mods, thanks.  We use a solar shower a lot during the warmer months so the water inside is mainly for all the little things.    

We're going to be traveling full time with a lot of toys and a couple of dogs one of which weighs as much as 15 gallons of water but takes up more space.  I like to be able to drop the trailer and go play pretty quick so having as much as possible loaded on/in the trailer is pretty handy.  I have one of those truck bed drawer systems, Decked I think its called.  Jury is out on if its worth having.  It takes up almost half the bed height as it is.  We've traveled in everything from a 45' pusher to a truck camper.  Every time we change it up we just try to live with less and less stuff.  For me the hassle of loading and hauling everything usually outweighs the convenience of having it along.        

[BackofBeyond]

From my experience the urine tank is not an issue. Its easy to empty and replace. For me its not worth the effort to redirect. I did look at using the black water  tank as a water storage, but as Overland commented, water has not been much of an issue. I carry a spare 8 gallon container in the truck,  which has worked out well.  I have repeatedly used it to transfer H2o into the trailer tank (it is very easy on the Oliver).  If there was ONE thing I would change on the O it would be the 3 power source fridge - I'd go DC compressor- but until the  current one really pisses me off or finally quits, it will stay. Next would be the jet engine on the roof called the ac. 

Urine tank never comes to mind.

Happy Thanksgiving all.

[ahattar]

2 hours ago, BackofBeyond said:

From my experience the urine tank is not an issue. Its easy to empty and replace. For me its not worth the effort to redirect. I did look at using the black water  tank as a water storage, but as Overland commented, water has not been much of an issue. I carry a spare 8 gallon container in the truck,  which has worked out well.  I have repeatedly used it to transfer H2o into the trailer tank (it is very easy on the Oliver).  If there was ONE thing I would change on the O it would be the 3 power source fridge - I'd go DC compressor- but until the  current one really pisses me off or finally quits, it will stay. Next would be the jet engine on the roof called the ac. 

Urine tank never comes to mind.

Happy Thanksgiving all.

Doesn't seem like a lot of effort to me but I won't know until I have the trailer.  How often do you have to empty your urine tank?  I guess I just see the perfectly good and out of the way 18 gallon tank sitting there so why not use it.  Having extra water rarely hurts and not taking up space in the truck is good too.  

Why DC compressor?  I had a 3 way fridge in my truck camper that worked fine.  Took very little propane if needed but the vast majority of the time the solar more than covered it.  My biggest complaint with the Oliver fridge is the lack of freezer space.  

[John E Davies]

The NH pee tank is 2.2 gallons but you need to empty it before it gets completely full or you will have a real mess. You definitely don't want urine to go into the main composting area. The average adult pees 1 to 2 quarts per day. The average wife pees way more than that.... 😉

Naatures head

I drilled a couple of 1 inch "sight holes" in the enclosure so I could easily see the level as it fills. I also drilled some 3/16" drain holes in that enclosure since it traps shower water otherwise....

John Davies

Spokane WA

Edited November 23, 2019 by John E Davies

[ahattar]

Its pretty much the same exact toilet I installed in our truck camper.  We had the Airhead.  I guess you guys have more fun emptying urine than I do!  I got tired of the airhead tank almost immediately and diverted to my black tank.  Only downside was I dropped a 7/16 socket in there!  Still makes me mad today.  Like you said, if you fill it anywhere near full, its a nasty balancing act.  We did the vinegar thing plus the diluted vinegar spray bottle and all that jazz it still gets gross when you're living full time with it.

My first choice will be to divert to grey and then use the black tank to expand the fresh.  I hope to find a simple elegant way to do it since the toilet is basically in the shower.  Grey tanks smell because of food particles and funky stuff that comes off your stinky body, I really don't see urine making any of that worse.  I also think if you're dumping grey water in the wild, its worse than dumping straight urine or the same as dumping urine mixed in with the grey.  Back to wilderness rules.  We can pee in a river but we are not allowed to dump dish water in the river without first straining the particles.  We can pee in the river but we can't bathe in the river with soap regardless of the type.    

Now if only Oliver would hurry up with my damb trailer so I could get started! 

[BackofBeyond]

17 hours ago, John E Davies said:

The NH pee tank is 2.2 gallons but you need to empty it before it gets completely full or you will have a real mess. You definitely don't want urine to go into the main composting area. The average adult pees 1 to 2 quarts per day. The average wife pees way more than that.... 😉

 

As stated above, I usually empty every day, not waiting until full. I try to use a waste station, but if not available, any out of the way spot works. I did the JD mod of sight holes to visually see urine level, that's a mod worth the time. In retrospect, the compost toilet has been a great choice. If I was to start camping for long stretches in remote places, I would consider a convert of the black tank to H2o storage. It is doable. 

As for the fridge, the OEM works "OK" but it has a hard time in hot weather, and on propane, likes to shut itself off every now and then. (its been bombproof on ac) I have an ARB portable with the Danfoss compressor, we use  it for drinks and overflow. The thing is great, draws little current, and is bombproof. There is another owner on the site that has replaced his with a dc unit.  His long term results are worth monitoring.

 

RB

[Overland]

Just put a 12v fridge freezer in your truck and you’re set. We can keep 3 weeks of food between our truck and trailer.  But I think that there may be four of five of us now with 12v fridges in the trailer - they’re great. 
 

I’ve never heard of anyone being able to run an absorption fridge with solar.  Maybe at 12 noon in July in Arizona. 200w of solar on my truck is sometimes iffy even for my 12v fridge and 125Ah battery. 

Edited November 24, 2019 by Overland

[ahattar]

Thats what I was thinking on the cooler style freezer/fridge in the truck.  Glad to hear you like it, I've heard good things.  We won't use it all the time, just when we're packing a bunch of salmon from the north or seafood from the south.  Our Yeti cooler packed right can keep things cool for 10+ days so we use that for extra fridge space.  

Don't know what to tell you on the fridge.  I had 3 160w panels if I remember correctly with quality controllers and proper wire sizes with 4 6v mediocre cart batteries.  Almost never had to switch to propane.  Granted we didn't have anything else other than led's and the toilet fan using DC.  The nice thing about a 3 way fridge is in the winter when there isn't enough sun, propane will run the fridge forever.  

[ahattar]

On 11/22/2019 at 6:26 PM, John E Davies said:

It would be super easy to convert the 18 gallon black tank to potable water, it can gravity feed into the main fresh tank when that one is depleted, since the black tank sits about thee inches higher.... I am unaware of anyone who has done this yet. The access should be fine, the only tricky part would be blocking the vent pipe where it connects to the main vent under the bathroom sink. After blocking the vent you would have to install a large overflow pipe, going from the top of the tank to the belly. Access is OK since there is a big hole in the floor under the toilet.... And of course you would need a home built adapter with a ball valve at the outlet of the tank, under the front dinette seat.

I personally would not want any urine going into the grey tank. That would make it way more stinky than it already is, and it would not be appropriate to water a sage bush with it.... you could buy a second pee tank and cap ($40), and stash either the empty one, or a full one, behind the toilet, I think it would fit fine but I haven’t tested it there.

John Davies

Spokane WA

Ok, so I'm finally digging around exploring the options here.  I think diverting urine to the grey tanks is going to be pretty straightforward.  I'm thinking I'm going to cut an access hole behind the toilet where the unused cold water supply line pops through.  This should hide things somewhat.  There should be enough room between the black tank and the exterior wall to run some pvc.  Its going to have to cut in downstream of the shower trap so I'll add a second trap for the toilet under the dinette access.  I'll have to do some digging for fittings so that the toilet can be easily removed for dumping/cleaning.  

Side note, the Airhead composting toilet I installed in my truck camper did not have the seat attached to the tub by a hinge.  This allowed us to carry a second tub in the trailer to swap in and put the full one in the trailer for a week or once we got to warmer weather to promote better composting.  Made it a shit-ton easier to clean!  Was that a pun?  

Ok, so on to converting the black tank to extra fresh water storage.  I agree that it would be super easy to use a gravity system but I'm not sure how you thought you would be able to tie the fresh and black tanks together.  Is there easy access to the fresh tank that you were thinking about?  I'm gonna go get under the bed and see if maybe I can snake a tube through somewhere but thought I'd ask what you had in mind.  

As far as plugging the black tank vent.  Looks like the storage shelf deal under the sink should be pretty easy to remove.  Do you know what it looks like in there before I pop it out for nothing?  

Thanks

  

[John E Davies]

3 hours ago, ahattar said:

Ok, so on to converting the black tank to extra fresh water storage.  I agree that it would be super easy to use a gravity system but I'm not sure how you thought you would be able to tie the fresh and black tanks together.  Is there easy access to the fresh tank that you were thinking about?  I'm gonna go get under the bed and see if maybe I can snake a tube through somewhere but thought I'd ask what you had in mind.  

As far as plugging the black tank vent.  Looks like the storage shelf deal under the sink should be pretty easy to remove.  Do you know what it looks like in there before I pop it out for nothing?  

There are a number of fresh water lines near the water pump, the line at the very bottom of main fresh tank   would be my choice to tee into. You might have to disconnect and move some other lines to get in there. You will need a manual ball valve where you can reach it easily, say under the front dinette, so you can leave that closed until the big fresh tank is nearly empty. Otherwise the black tank will just drain and empty into it, and the excess will flow right out the fresh vent hose...

I haven't opened up the bathroom vanity, but others have. There are pictures floating around. It is pretty straight forward, you should have no trouble at all reaching the black tank vent. You will need to cut it and cap it, and also cap the main waste vent that you removed it from.

While you are under there, disconnect and cap the fresh water hose that goes to the unused flush toilet, so you no longer have to winterize that part. Leave it to where somebody could easily hook it back up in the future...

Have fun, please start a new thread with pics.

John Davies

Spokane WA

Edited March 8, 2020 by John E Davies

[SeaDawg]

Fwiw, if I had a composting toilet ( and I  don't), and I wanted to utilize the black tank, I  think I would look at directing the urine to the black tank, along with the grey water from the bathroom sink.

Understanding that I would run the risk of voiding some warranties, i think it would likely be the simplest plumbing, and most hygenic use of a tank designated and situated for black contents. A number of rvs dump vanity sink to the nearby black tank, as do many boats.

Adding the sink water to dilute the urine could possibly minimize the odor. Keep the vent. Dump less frequently.  My thoughts.

Sherry

 

[Mike and Carol]

I’ve had the front off of the bathroom vanity a couple of times.  Four screws.  Just pry off the covers, unscrew and break the caulking.  What’s in there is what you would expect, hot and cold fresh water lines, HVAC ducting, black vent pipe and electrical connections for the water pump.

If you add urine to your gray water tank is it still a gray water tank?  Or does it become black?  If you have urine in your gray tank and your traps go dry is there a sanitary issue since it’s a direct connection with your sinks and shower?   If you have urine in your gray tank and forget to close the gate while traveling and have a back up in the shower pan, would that be acceptable?   Also, is the plastic that forms the black tank rated for drinkable fresh water?  How do you fill the “black” tank with fresh water, through the black tank flush port?  These are questions that popped into my head as I read through this thread again.

[Landrover]

I think there are many different ways to carry extra water than turning the black tank into a fresh water source. If i needed to carry extra water. My idea would be to buy a Atv spot sprayer from northern tools. They have various sizes and prices.  They have onboard 12v pump and would be a easy mount to many different applications.  Just a thought.

[ahattar]

2 hours ago, SeaDawg said:

Fwiw, if I had a composting toilet ( and I  don't), and I wanted to utilize the black tank, I  think I would look at directing the urine to the black tank, along with the grey water from the bathroom sink.

Understanding that I would run the risk of voiding some warranties, i think it would likely be the simplest plumbing, and most hygenic use of a tank designated and situated for black contents. A number of rvs dump vanity sink to the nearby black tank, as do many boats.

Adding the sink water to dilute the urine could possibly minimize the odor. Keep the vent. Dump less frequently.  My thoughts.

Sherry

 

How is it anymore or less hygienic if you have two closed systems?  Its already been confirmed that the black tank is made from the same material as the fresh tank.   

[ahattar]

1 hour ago, Mike and Carol said:

I’ve had the front off of the bathroom vanity a couple of times.  Four screws.  Just pry off the covers, unscrew and break the caulking.  What’s in there is what you would expect, hot and cold fresh water lines, HVAC ducting, black vent pipe and electrical connections for the water pump.

If you add urine to your gray water tank is it still a gray water tank?  Or does it become black?  If you have urine in your gray tank and your traps go dry is there a sanitary issue since it’s a direct connection with your sinks and shower?   If you have urine in your gray tank and forget to close the gate while traveling and have a back up in the shower pan, would that be acceptable?   Also, is the plastic that forms the black tank rated for drinkable fresh water?  How do you fill the “black” tank with fresh water, through the black tank flush port?  These are questions that popped into my head as I read through this thread again.

All good questions, thanks.  Thanks for the info on the vanity, thats kinda what I figured once I popped off one of the screw covers.  Figured one of you guys would have already been in there for something.  

Black does not become black until its the combined liquid and solids.  Thats actually the great thing about a composting toilet, its just dirt and you can dump it anywhere if its well composted.  I don't see my traps going dry and I will "T" in downstream of the shower trap.  If someone was really worried about it you could possibly add a check valve after the urine line trap if it doesn't need pressure.  I pee in the shower all the time!  Grey water is actually dirtier than urine so I wouldn't worry about it.  Yes, black tank is potable.  Filling through flush port is an option though probably slow.  It appears to be easily accessible under the dinette so I would probably remove the spray head for higher flow.  

Thanks for the input.    

 

[ahattar]

16 minutes ago, ahattar said:

How is it anymore or less hygienic if you have two closed systems?  Its already been confirmed that the black tank is made from the same material as the fresh tank.   

Also, you guys do realize that your composting toilet is basically an open urine tank with no trap.  If you don't smell that, you're highly unlikely to smell the grey tank especially through a couple of traps.  

[ahattar]

1 hour ago, Landrover said:

I think there are many different ways to carry extra water than turning the black tank into a fresh water source. If i needed to carry extra water. My idea would be to buy a Atv spot sprayer from northern tools. They have various sizes and prices.  They have onboard 12v pump and would be a easy mount to many different applications.  Just a thought.

But if you had an 18 gallon tank that was out of the way and could be converted to a fresh tank in an hour or two, would you do it?  Having 60 gallons of onboard fresh water is pretty awesome, not sure why I'm the only one that sees it that way.