Composting Toilets - Tell All

[Ribbit]

If I can get the right sized holding tanks that will fit the boat, to build a fully composting aerobic bacteria system (rather than a pre-composting dry system), thanks to Hopcar (trade sponsor of the forum), I'll be able to give it a thorough testing on my way home (6 to 12 months). Shouldn't be any bugs to work out, but you never know.

If I can't get the right tanks to fit, I'll get a C Head until I can get some suitable.

After experience last year, I do wonder about the speed of peat being made. I had a heck of a lot (tons) of hedge cuttings to dispose of, so I picked up a nice heavy duty wood chipper. All the chips, bark, leaves, etc., then got spread out on a tarp to air dry (to use for fuel in a multifuel stove), but it was too wet since to even bag it up as it dried, as it didn't dry.

In 5 months of lots of rain, all that woody/leafy material has pickled.

It's peat. Lumpy peat (as some is anyway), but peat.

Thinking about it, the Chinese use just water to pickle their cabbage, and that doesn't take long either.

So if you want to make your own, easiest would be to shred lots of dead leaves, put them in a big 1 ton waterproof builders bag, and like the Chinese method with cabbage, put weights on top to keep the vegetation below the water level. Then when it's pickled, just dry it out. Worth a try anyway.

[RaymondR]

Originally Posted by SebastianB

According to my reading of Marpol it is unlawful to dump ANY untreated sewage into territorial waters (3mile limit). CFR 140.3 defines as sewage as, "human body wastes and the waste from toilet and other receptacles intended to receive or retain body waste. From everything I can read of the CFR it is just as illegal to dump urine as it is to dump feces regardless of the actual ecological impact.

Whether or not it's policed seems to depend on the definition of sewage where you are. In the place I am in at the moment it is designated as classes 1, 2, and 3 and the classes rely upon the number of viable faecal coliforms in a defined volume of sewage. Urine would not have any? When and where you can dump depends upon the class.

[valhalla360]

Originally Posted by Ribbit

If I can get the right sized holding tanks that will fit the boat, to build a fully composting aerobic bacteria system (rather than a pre-composting dry system), thanks to Hopcar (trade sponsor of the forum), I'll be able to give it a thorough testing on my way home (6 to 12 months). Shouldn't be any bugs to work out, but you never know.

Can you clarify what you are proposing?

Composting is a dry process (slightly damp but no visible water).

I'm not sure how you would do a holding tank for a composter.

[Ribbit]

Originally Posted by valhalla360

Can you clarify what you are proposing?

Composting is a dry process (slightly damp but no visible water).

I'm not sure how you would do a holding tank for a composter.

Ordinary garden composting would do the same thing, but pickling is faster for a more 'peat like' substance. So for the existing 'composting' toilets, non-peat based garden compost would work just as well. In the same way that dried earth worked very well in Earth Closets (too dense for agitation, you just poured a cup full of dry soil over the contents (including urine), each time the toilet was used, once the bucket was full it was put onto a compost heap, and then used on the garden).

This is because 'composting' isn't a dry process, it's an aerobic bacteria system, rather than an anaerobic system (why it fails if it becomes too moist).

Doing it dry is actually a very inefficient and slow way, because you can't get enough air to the aerobic bacteria, for them to work effectively and efficiently. This is why 'composting' toilets are inaccurately named, they are best described as a 'pre-composting' system.

Existing holding tanks cater to slimy, stinky, anaerobic bacteria, which eventually degrade and block up the 'treatment' process.

I have done a lot of work for a Company that produces aerobic bacteria systems for on land use, to cure anaerobic bacteria caused problems with septic tanks, drain fields/soakaways, etc. As an example, a well designed and large house system that had functioned well for over 50 years, became blocked solid, and the aerobic bacteria fully restored the whole system, including the drain field, in about 10 months.

So I am going to build a marine system based on those principles, which will need 'two' tanks, so the second tank can be switched to being used until the first tank has completed its treatment cycle, when the contents will be perfectly safe to empty anywhere (I have even seen people drinking the perfectly safe runoff - but you won't catch me doing it lol!). Seven days after the last use of the first tank, should be enough, but for 'belt and braces' assurance, ten days would be fine.

The aerobic bacteria will keep all of the system internals clean, eliminate smells (because aerobic bacteria aren't making methane with a stinky process), and won't require people to lug bins of pre-compost or jugs of urine. Because the internals will be cleaned continuously by the aerobic bacteria, systems won't become clogged up (slimed up thanks to the anaerobic bacteria - the aerobic bacteria eat them and their slime), and should have a very long service life.

Once I have the system running efficiently, fully fine tuned it, and worked any bugs out, I'll license it for production very cheaply. So all rights reserved.

[valhalla360]

What you describe isn't composting (composting is at most a damp process) but it has a similar effect in relation to eliminating odor. Unless there is more to it than you said, it won't do anything to break the material down faster than a standard holding tank.

More importantly, I don't think it solves the average boater's situation. I'm pretty sure the authorities will still consider your treated waste as sewage and subject to all the limitations of standard holding tank discharge. That means you will still be limited to the amount that you can store in your holding tanks and then you are searching for a pump out or need to take an offshore run. (I'm not saying it isn't perfectly safe to dump overboard. Just that the authorities won't buy it.)

The advantage of a composting toilet is in the reduced storage space needed drastically and allows easy disposal of the urine in any shoreside head (or for reasonable people dumping overboard with no regrets).

PS: By the way, I'm not sure where you are getting yoru information but anaerobic bacteria break down waste very efficently. The only real downside is the smell. Switching to aerobic will not clear out a plugged septic system.

[Ocean Girl]

Originally Posted by Ribbit

Ordinary garden composting would do the same thing, but pickling is faster for a more 'peat like' substance. So for the existing 'composting' toilets, non-peat based garden compost would work just as well. In the same way that dried earth worked very well in Earth Closets (too dense for agitation, you just poured a cup full of dry soil over the contents (including urine), each time the toilet was used, once the bucket was full it was put onto a compost heap, and then used on the garden).

This is because 'composting' isn't a dry process, it's an aerobic bacteria system, rather than an anaerobic system (why it fails if it becomes too moist).

Doing it dry is actually a very inefficient and slow way, because you can't get enough air to the aerobic bacteria, for them to work effectively and efficiently. This is why 'composting' toilets are inaccurately named, they are best described as a 'pre-composting' system.

Existing holding tanks cater to slimy, stinky, anaerobic bacteria, which eventually degrade and block up the 'treatment' process.

I have done a lot of work for a Company that produces aerobic bacteria systems for on land use, to cure anaerobic bacteria caused problems with septic tanks, drain fields/soakaways, etc. As an example, a well designed and large house system that had functioned well for over 50 years, became blocked solid, and the aerobic bacteria fully restored the whole system, including the drain field, in about 10 months.

So I am going to build a marine system based on those principles, which will need 'two' tanks, so the second tank can be switched to being used until the first tank has completed its treatment cycle, when the contents will be perfectly safe to empty anywhere (I have even seen people drinking the perfectly safe runoff - but you won't catch me doing it lol!). Seven days after the last use of the first tank, should be enough, but for 'belt and braces' assurance, ten days would be fine.

The aerobic bacteria will keep all of the system internals clean, eliminate smells (because aerobic bacteria aren't making methane with a stinky process), and won't require people to lug bins of pre-compost or jugs of urine. Because the internals will be cleaned continuously by the aerobic bacteria, systems won't become clogged up (slimed up thanks to the anaerobic bacteria - the aerobic bacteria eat them and their slime), and should have a very long service life.

Once I have the system running efficiently, fully fine tuned it, and worked any bugs out, I'll license it for production very cheaply. So all rights reserved.

This is great. The more sailors experiment the more we learn. Most research on these types of heads are from third world country sanitation solutions research, nice to see some boat/marine research.

From what I've researched, to compost, not desiccate, the temp needs to reach a certain degree and for a certain length of time. The size of the compost tank would have to be substantial, so that is why we desiccate aboard recreational vessels. You sound very knowledgeable and I'd love to hear your trials and results.
Thanks for posting
Erika

[Ocean Girl]

PS
I came to the thread to post this tip. For stray peat that can get on the seat when adding to poo tank, I use a disposable painters brush. After adding peat to the tank I just swipe the brush all around to sweep any stray peat into the toilet. I douse it with Lysol every once in a while, but it only touches the dry clean peat.
Was pic necessary? Prob not

[Scout 30]

Originally Posted by valhalla360

What you describe isn't composting (composting is at most a damp process) but it has a similar effect in relation to eliminating odor. Unless there is more to it than you said, it won't do anything to break the material down faster than a standard holding tank.

More importantly, I don't think it solves the average boater's situation. I'm pretty sure the authorities will still consider your treated waste as sewage and subject to all the limitations of standard holding tank discharge. That means you will still be limited to the amount that you can store in your holding tanks and then you are searching for a pump out or need to take an offshore run. (I'm not saying it isn't perfectly safe to dump overboard. Just that the authorities won't buy it.)

The advantage of a composting toilet is in the reduced storage space needed drastically and allows easy disposal of the urine in any shoreside head (or for reasonable people dumping overboard with no regrets).

PS: By the way, I'm not sure where you are getting yoru information but anaerobic bacteria break down waste very efficently. The only real downside is the smell. Switching to aerobic will not clear out a plugged septic system.

I think it does solve the average boater's situation. Much easier to bag it & treat it like trash or dump it on land.

[valhalla360]

Originally Posted by Scout 30

I think it does solve the average boater's situation. Much easier to bag it & treat it like trash or dump it on land.

If you are talking about a standard composter...I agree and that's why we got one.

If you are talking about the twin aerobic digester tank system described by Ribbit, that should result in a liquid slurry, which while harmless will almost certainly still be considered sewage by the authorities...and I do not agree.

[Scout 30]

Originally Posted by valhalla360

If you are talking about a standard composter...I agree and that's why we got one.

If you are talking about the twin aerobic digester tank system described by Ribbit, that should result in a liquid slurry, which while harmless will almost certainly still be considered sewage by the authorities...and I do not agree.

My mistake. I missed who you were responding to. I agree that the twin tanks do not make sense for boats. You would still have to pump out in no discharge zones to be legal. Plus, why take a system that's already too complicated & make it more complicated. Composting heads are really as simple as it gets.

[Ocean Girl]

Originally Posted by Scout 30

My mistake. I missed who you were responding to. I agree that the twin tanks do not make sense for boats. You would still have to pump out in no discharge zones to be legal. Plus, why take a system that's already too complicated & make it more complicated. Composting heads are really as simple as it gets.

Yes, we are definitely happy with our dry head, but I like people who are trying new options to the same old wet system. Just looking at the marine head from different angles is good.

[Scout 30]

Originally Posted by Ocean Girl

Yes, we are definitely happy with our dry head, but I like people who are trying new options to the same old wet system. Just looking at the marine head from different angles is good.

Having rebuilt my old bronze Wilcox Crittenden Junior head several time I can honestly say I've looked at that head from every angle. It's a neat old classic but I'm glad I don't have to do that again.

[wooden head]

I like the twin digester idea. As a plumber I have looked at this in household use. The new engineered bacteria make for a difference. The volume and time needed needed are far less than old systems. Yes they will have to be pumped or dumped in a leagal zone they still will be far more ecological. My biggest concern is with a wood hull and a damp bilge i wory about digestive bacteria added to the boat.

[Ribbit]

Originally Posted by valhalla360

PS: By the way, I'm not sure where you are getting yoru information but anaerobic bacteria break down waste very efficently. The only real downside is the smell. Switching to aerobic will not clear out a plugged septic system.

Yes anaerobic bacteria DO break down waste efficiently. But relatively slowly and with undesirable side effects (methane production, associated stink, plus their coating of slime blocking everything in sight).

Aerobic bacteria are way faster, don't make methane, don't make a stink, and clean up everything in sight.

I 'get it from' hands on experience (including helping to draft approval of an EU specification because they didn't have any prior - and the system IS now approved by the EU) with land based anaerobic and aerobic systems.

By the way the runoff isn't a slurry. Put it in a glass and it's clear, transparent water - I've seen someone drink it to prove how safe it is (no you will not catch me doing that! lol!).

So really it is even beyond a composting system, because there isn't even any compost left at the end.

As voracious for consuming 'stinky stuff' as the aerobic bacteria are wooden head, I don't think they consume cellulose (wood). But if they do, there's things available (cheap) that kill 99.9% of household germs (you do have to watch you don't put bleach into an aerobic system, but that's true for anaerobic systems as well). Eta: In fact anaerobic are really touchy even with things like coloured toilet paper, as the dyes can badly affect them. The aerobic bacteria are much more tolerant of that sort of thing.

Interesting that you have seen these systems in use.

PS It's a bit serendipitous (even though I was well and truly gutted) that the purchase of the boat I was after, fell through (it had a head and holding tank system that worked). The boat I have now lined up is a little bigger, and has no head fitted, so I can put the system straight in. If it doesn't pan out, I can use it as a holding tank until it needs major maintenance, and I'll put a composting head in at that time. So not exactly a lot lost to try it out. Until approval is widespread (I think the existing EU specification standard would cover it), for sure, each tank needs to be able to be pumped out, though the period for necessary major maintenance should be greatly extended, and no stink problem in the meantime.