Composting heads

[dLj]

OK, quite some time ago, there was a discussion here on SBO I was a part of and the question came up about composting heads and how they should actually be classified. A lot of times they are called desiccating heads. But in actuality they are classified as mouldering heads. When I brought this point up in that thread, I was asked to provide documentation - which at the time, I thought I could put my fingers right on it but that was not the case. I've now just found that reference which I'll attach for any one who may be interested. I can't remember now who was asking - apologies. I've just spent some time trying to find that original thread but without success. In any case, the composting heads commonly used on a boat are considered mouldering heads. See section 2.5.1 of the attached document.

dj

 

[Ralph Johnstone]

I always thought that mouldering was a term restricted to John Brown's body.

John Brown’s body lies a-mouldering in the grave;
John Brown’s body lies a-mouldering in the grave;
John Brown’s body lies a-mouldering in the grave!
His soul’s marching on!
CHORUS.
Glory, halle – hallelujah! Glory, halle – hallelujah!
Glory, halle – hallelujah! his soul’s marching on!

He’s gone to be a soldier in the army of the Lord!
He’s gone to be a soldier in the army of the Lord!
He’s gone to be a soldier in the army of the Lord!
His soul’s marching on!

 

[StuartSailor]

"While both are types of waterless, composting toilets designed to manage human waste without a sewer connection, they rely on two completely opposite biological and physical mechanisms to break down waste.
Summary of Differences

• • A desiccating toilet acts like a food dehydrator: it aggressively removes water to stop bacterial action and reduce odor.
  • A mouldering toilet acts like a backyard compost pile: it preserves a specific level of humidity so that "mold" (fungi) and micro-fauna can slowly consume and break down the material in a cool, slow-managed ecosystem."

 

[thinwater]

Good posts, both. Excerpt from thesis:

Another name for this type of toilet is a mouldering toilet. “Typically, they operate at room temperature and compost a mixture of feces and bulking material such as sawdust. Some accept urine as well, though many do not. Over the course of several months they convert the humanure/bulking material mixture into a mostly-composted, odorless product that is periodically removed (No`e-Hays, 2000).” This type of composting does not bring the composting pile up to a proper pathogen-killing temperature. Due to this, it is not suggest that the compost created from this method be used on food crops or in food gardens. Instead, the compost may be used as a soil conditioner away from
food crops or may be safely used in a flower garden (Van der Ryn, 1978).

I operate the head on my F-24 as a desiccating head (for very light use, this is simpler), but it could be either. Soon, for example, it will be winter, and the temperatures will be too low for anything but desiccation.

 

[PEBI]

Straw, air born fungi such as the yeast used in bread, and fungi from your own gut. And if there's water, there's bacteria.

Good posts, both. Excerpt from thesis:

Another name for this type of toilet is a mouldering toilet. “Typically, they operate at room temperature and compost a mixture of feces and bulking material such as sawdust. Some accept urine as well, though many do not. Over the course of several months they convert the humanure/bulking material mixture into a mostly-composted, odorless product that is periodically removed (No`e-Hays, 2000).” This type of composting does not bring the composting pile up to a proper pathogen-killing temperature. Due to this, it is not suggest that the compost created from this method be used on food crops or in food gardens. Instead, the compost may be used as a soil conditioner away from
food crops or may be safely used in a flower garden (Van der Ryn, 1978).

I operate the head on my F-24 as a desiccating head (for very light use, this is simpler), but it could be either. Soon, for example, it will be winter, and the temperatures will be too low for anything but desiccation.

There was an incident some years ago near my city when raw sewage (instead of treated) was picked up by local farmers and sprayed onto local farms.

So it's a holding tank or a composting head. If it's a composting head do you use the same company to get rid of the ***** for you when you get to dry land.

 

[dLj]

Straw, air born fungi such as the yeast used in bread, and fungi from your own gut. And if there's water, there's bacteria.



There was an incident some years ago near my city when raw sewage (instead of treated) was picked up by local farmers and sprayed onto local farms.

So it's a holding tank or a composting head. If it's a composting head do you use the same company to get rid of the ***** for you when you get to dry land.

I'm not following your question. Are you asking if a composting head needs to be pumped out as a standard marine head does? That is not how they work. Maybe try asking your question in another form?

dj

 

[thinwater]

Perhaps the broader question.

How do you dispose of the waste from a composting, moldering, or desiccating head? No, they are not typically disposed of through a honey dipper. Not toilets.

Each of these has caveats. I wonder which are most common.

• Backyard compost pile.
  • Large enough yard. Not near the property line.
  • Well enough covered.
  • Allowed to mature for > one year and not used for crops.
• As are baby and pet waste (bagged and landfill). Not as bad as WAG bags.
  • Not into small waste bins in parks. This has been a problem at waterside parks. A large dumpster or double-bagged with home trash is more appropriate.
  • Not in high concentrations. Some park trailheads have banned this, since when the compactor truck squeezes the waste, it's a mess.
• Buried in the woods. Only appropriate in remote areas.
  • Not near the water.
  • Same basic rules as camping waste.
• Liquid waste (most separate)
  • Over the side. Low solids and nearly sterile. High nitrogen.
  • Toilets.
  • Buried in the woods, but without the burying. Reasonably remote areas.
• Over the side. Only appropriate well offshore, similar to a holding tank.

 

[dLj]

"While both are types of waterless, composting toilets designed to manage human waste without a sewer connection, they rely on two completely opposite biological and physical mechanisms to break down waste.
Summary of Differences

• • A desiccating toilet acts like a food dehydrator: it aggressively removes water to stop bacterial action and reduce odor.
  • A mouldering toilet acts like a backyard compost pile: it preserves a specific level of humidity so that "mold" (fungi) and micro-fauna can slowly consume and break down the material in a cool, slow-managed ecosystem."

@StuartSailor Can you please provide the reference for the above? According to the paper I posted, the following was stated for dehydration:

“Dehydration – Urine and feces are managed separately. The deposited fecal matter may be dried by the addition of lime, ash, or earth and the contents are simply isolated from human contact for a specified period of time to reduce the presence of pathogens."

I've certainly never added lime, ash or earth into my heads.

dj

 

[dLj]

Perhaps the broader question.

How do you dispose of the waste from a composting, moldering, or desiccating head? No, they are not typically disposed of through a honey dipper. Not toilets.

As you are well aware - there are two components for disposal - the liquid portion and the solids portion. I've not seen a CT (using the abbreivation used in the paper I posted) for boats that does not separate the two but there could be one I guess.

For myself, it has depended upon where I'm sailing.

Each of these has caveats. I wonder which are most common.

I'm kind of chuckling - how common do you think these are currently? Given how controversial I've seen discussions, on CT's - I doubt they are very common here... But I'd love to be wrong...

• Backyard compost pile.
  

  • Large enough yard. Not near the property line.
  • Well enough covered.
  • Allowed to mature for > one year and not used for crops.

I'm not sure why you've added in the "not used for crops" since if ANY compost is properly matured you can certainly use it on crops. If it's not properly matured, then it's recommended not to be used on crops.

In any case, I would think disposing of it in a backyard compost pile would be pretty low usage. The logistics seem pretty onerous....

• As are baby and pet waste (bagged and landfill). Not as bad as WAG bags.
  

  • Not into small waste bins in parks. This has been a problem at waterside parks. A large dumpster or double-bagged with home trash is more appropriate.
  • Not in high concentrations. Some park trailheads have banned this, since when the compactor truck squeezes the waste, it's a mess.

This is likely the most common disposal for the solids side.

• Buried in the woods. Only appropriate in remote areas.
  

  • Not near the water.
  • Same basic rules as camping waste.

Neither the solids nor liquids are recommended to be buried, rather spread out unless you are putting them into a composting location.

I have spread the solids in the woods but only when I've been really remote.

• Liquid waste (most separate)
  

  • Over the side. Low solids and nearly sterile. High nitrogen.
  • Toilets.
  • Buried in the woods, but without the burying. Reasonably remote areas.

Liquid waste is an excellent fertilizer. It's really our social perception that rejects it's use in this manner.

For myself, this really depends upon where I am. I work very hard at keeping a socially acceptable behavior in all my disposal methods. Meaning if I am basically anywhere that humans can see what I'm doing, I just use public facilities to dispose of the liquids side. So using toilets would be the number one disposal method I use. The others I only do if in remote regions.

• Over the side. Only appropriate well offshore, similar to a holding tank.

I comply with regulations....

dj

 

[thinwater]

I intended post #7 as sort of a survey, without too much detail. I've used a fair few of the methods. Some of the problems I have run across.

The crops restriction is regulatory, applying only to large community projects. Irrelevant to sailors.

Overuse of waste cans next to park benches has been a problem in a few places. Of course, diapers and dog walkers were also part of the problem. The parks problem occurs in a few places out west where campers are required to carry their waste out in WAG bags; it sort of amused me, because what did the park manager expect?

Also some canal boat/narrow boat sites in the UK. Composting toilets have become popular, leading to some restrictions.

Not so much bury solids as cover with leaves. Obvious. Camper common sense. I figure the only people that would do this are experienced backcountry campers. Not at the water's edge.

----

With common sense, disposal is not a problem.

 

[dLj]

I intended post #7 as sort of a survey, without too much detail. I've used a fair few of the methods. Some of the problems I have run across.

The crops restriction is regulatory, applying only to large community projects. Irrelevant to sailors.

Overuse of waste cans next to park benches has been a problem in a few places. Of course, diapers and dog walkers were also part of the problem. The parks problem occurs in a few places out west where campers are required to carry their waste out in WAG bags; it sort of amused me, because what did the park manager expect?

Also some canal boat/narrow boat sites in the UK. Composting toilets have become popular, leading to some restrictions.

Not so much bury solids as cover with leaves. Obvious. Camper common sense. I figure the only people that would do this are experienced backcountry campers. Not at the water's edge.

----

With common sense, disposal is not a problem.

It's been a long time since I went backpacking. I live pretty close to the Appalachian Trail. Several times I've brought hikers to my house to feed them and allow them to take showers. I've had some interesting conversations on the current state of hiking, regulations and equipment. The whole field has changed so much since I was actively camping/hiking that I almost don't even recognize it.

I think an interesting survey question here would be - How many sailors that are on this site either are using a CT or would consider using a CT?

I think I read somewhere that something like only about 10% of Americans would give an affirmative to that question - but please don't ask me to get the reference to that - 1st, that might be wrong, and 2nd - I have no idea where I read it...

However, there seems to be a greater acceptance growing mainly driven by the campervan world. It appears that there the adoption of these CT units is getting stronger. Which makes a lot of sense. The space constraints on a say 17 foot campervan is notably greater than I have on my 41 foot sailboat.

I'm obviously biased. But I was exposed to CT's back in the 70's when I was an active part of off-grid living. I used to build Clivus Multrum CTs...

dj.

 

[StuartSailor]

@StuartSailor Can you please provide the reference for the above? According to the paper I posted, the following was stated for dehydration:

“Dehydration – Urine and feces are managed separately. The deposited fecal matter may be dried by the addition of lime, ash, or earth and the contents are simply isolated from human contact for a specified period of time to reduce the presence of pathogens."

I've certainly never added lime, ash or earth into my heads.

dj

Maybe a desicating head would be a sub set of moldering in that all descriptions of desicating toilets refer to drying the the waste for removal where as in moldering they go on to describe a slow low temperature composting. An AirHead might compost but a CHead does not. The goal I have on boats is usually to dehydrate the waste as quickly as possible, reducing its mass and making it easy to remove from the boat.

From Dr Branstrador's Thesis at Purdue.

«The only maintenance required for a low-temperature composting toilets is
to rake the collected pile a few months apart. This can be done through access
doors with rakes that stretch into the room that do not require the caretaker to
physically be within the compost pile. In general, two chambers are used. One
chamber sits for a year or two at a time to assure proper compost and sanitary
conditions are met while the other chamber is used by the residence. Keeping in
mind proper balance of organic compounds, carbonaceous organic matter is added
after each use to prevent a negative odor (Jenkins, 2005)."

I think a desicating heads goal is to pause composting until waste is removed to a longer-term location.

 

[dLj]

Maybe a desicating head would be a sub set of moldering in that all descriptions of desicating toilets refer to drying the the waste for removal where as in moldering they go on to describe a slow low temperature composting. An AirHead might compost but a CHead does not. The goal I have on boats is usually to dehydrate the waste as quickly as possible, reducing its mass and making it easy to remove from the boat.

From Dr Branstrador's Thesis at Purdue.

«The only maintenance required for a low-temperature composting toilets is
to rake the collected pile a few months apart. This can be done through access
doors with rakes that stretch into the room that do not require the caretaker to
physically be within the compost pile. In general, two chambers are used. One
chamber sits for a year or two at a time to assure proper compost and sanitary
conditions are met while the other chamber is used by the residence. Keeping in
mind proper balance of organic compounds, carbonaceous organic matter is added
after each use to prevent a negative odor (Jenkins, 2005)."

I think a desicating heads goal is to pause composting until waste is removed to a longer-term location.

Thanks for this - what I was hoping was to see if whatever reference you used above might clarify the difference between a mouldering head and a desiccating head. According to the Perdue papers description, the heads typically found on boats actually seem to fall more under the designation of a mouldering head.

In fact, I can't find a good definition of a desiccating head. It is mostly found in the marine focused literature and all of those are simply saying that the CT's on boats are desiccating heads. No actual definition establishing the technical difference between mouldering heads and desiccating heads have I found to date. The closest I have found is the reference I quoted above from the Perdue paper where it talks about the addition of lime and such.

I'm starting to think that the term dessicating heads on boats is a misnomer. That term applied to CTs on boats seems to have no basis in the technical literature on composting systems.

dj

 

[dLj]

I thought it was quite clear in the article.

but google says: View attachment 240403






The thing to ask is View attachment 240404
2.2 gallons is 8L of liquids. I drink 2L of water a day. And urinate between 1 and 2L of urine. Depending on activity level. On a boat sailing I'd urinate 1L or 1 `1/2 L or urine.

My question, what is the reference you use above quoting the difference between those heads - that is NOT in the article I posted. In fact the term "desiccating head" is not even used in that article. So I don't know what article you are using to pull up those definitions. However, whatever document you are quoting clearly looks like it is coming from the marine based literature, not the scientific based composting literature. So, please provide the specific reference so that I can actually look at the source.

There is a huge body of scientific work that has been done on composting systems over many decades. The term "desiccating heads" seems to have only appeared fairly recently with the advent of small composting heads starting to be implemented on boats. I have not found any scientific basis for the term "desiccating head" within the scientific literature on composting systems. The description you have provided above on mouldering heads is technically inaccurate in many aspects of it's definition of a mouldering head. Likewise, the description on desiccating heads also has a number of significant gaps and incorrect statements - from a scientific composting viewpoint.

I'm interested the fundamental details - not the political, marketing BS.

dj

 

[PEBI]

scientific basis for the term "desiccating head" within the scientific literature on composting systems.

The description you have provided above on mouldering heads is technically inaccurate in many aspects of it's definition of a mouldering head.

Likewise, the description on desiccating heads also has a number of significant gaps and incorrect statements - from a scientific composting viewpoint.

I'm interested the fundamental details - not the political, marketing BS.

dj

Good point.

Post #5. Was not directed at user DLj. But I was discussing temperature and introduction of fungi for composting. The scientific article did not mention all the ways fungi was introduced when it talked about mouldering toilets.

Your saying Desiccating head isn't a term used in your article or any scientific paper. So it should not be used in your thread.

From what I found. Desiccating is actually taken from Latin word: Desicare. Which means to dry out. Google translate.

On wikipedia they call Desiccating heads: Urine diverting dry toilet or UDDT for short.
Click this.

In biology and ecology, desiccation refers to the drying out of a living organism. Microorganisms cannot grow and divide when desiccated, but can survive for certain periods of time, depending on their features. After the addition of water, the bacteria will start growing again, so desiccation does not provide complete sterilization.

Reference
Click this.

I'll say this but I don't know if you will be able to understand what I mean other then what I typed "literally."

Dish soap. Anti bacterial dish soap kills bacteria in soap water in your sink. Normal dish soap is marketed as it washes bacteria away.

If you air dry after washing away bacteria and there is still a little bacteria on the plates the bacteria will stop replicating and stop deposting poison on you plate when it dries out.

The hotter the water is, the better the dish soaps work in water to remove oils and fats. But most food born bacteria (that cause food poisoning) love 40'C water which is water most wash at. Fungi also love this temperature range. 60'C holding because most bacteria slow down replication significantly.

Moulderiing toilets: low temp. Does not kill bacteria. Dangerous to add to lettuce gardens.

High temperature composting. Normal compost piles in other words. As the pile gets bigger so does the energy inside and the temperature kills the bacteria.

Desiccating or Urine divergent dry toilets should also not be used on lettuce gardens as the bacteria remain dorment without water. But from my second reference when water is added it starts to replicate again. Which could cause an outbrake if lettuce is sold to a restaurant of food borne illness.

_______________________________________________________


I asked if anyone knew if the waste from Desiccating (uddt) toilets or Mouldering toilets are deposited with the same company that would take raw sewage at the harbour. Or is there a seperate waste company that would take that specific dry waste. But maybe that's for a different thread.

 

[thinwater]

I thought it was quite clear in the article.

but google says: View attachment 240403






The thing to ask is View attachment 240404
2.2 gallons is 8L of liquids. I drink 2L of water a day. And urinate between 1 and 2L of urine. Depending on activity level. On a boat sailing I'd urinate 1L or 1 `1/2 L or urine.

Is the first part an article or AI (pretty sure it is AI summary, because it is an image paste, because of the style, and because of the links). If yes, forum rules say you must identify AI summaries as such. They are not really a source. Pretty sure I wrote one of the source links.

I do think we have flogged this horse to death. Obviously, there is a continuum of processes in these heads, depending on both design and operation. Most can be operated in more than one mode, depending on load, products used, installation details, and season.

 

[dlochner]

I asked if anyone knew if the waste from Desiccating (uddt) toilets or Mouldering toilets are deposited with the same company that would take raw sewage at the harbour. Or is there a seperate waste company that would take that specific dry waste. But maybe that's for a different thread.

For small recreational boats there is no company that "takes raw sewage." Marinas pump the raw sewage from the boat and deposit it into the municipal sewers. Or more accurately, marinas had the boat owner the hose and the boat owner pumps the holding tank. In the absence of a municipal sewer it goes into whatever ever waste system the marina uses.

 

[dLj]

Your saying Desiccating head isn't a term used in your article or any scientific paper. So it should not be used in your thread.

I am not saying you can't use that term in this thread. What I'm saying is that the definition of a desiccating head in the specific field of composting has eluded my research.

I can't find what the definition is - scientifically/compost specific speaking. Meaning, at what percentage of moisture does one enter into the realm of a desiccating head? What are the full composting methods required if using a desiccating head to achieve safe and useful compost? What exactly are the requirements to meet the designation of "desiccating head" vs a "mouldering head". I have not found a solid data-based definition. From all the data I've seen, all the heads currently used on boats and RVs are mouldering heads.

The paper I attached actually talked about additives needed to go into a dehydration mode. Something I've never done, don't know anyone that has and is not normally done with these kinds of systems. But no mention of desiccating heads or whatever technology is required to be classified as that specific system.

Moulderiing toilets: low temp. Does not kill bacteria. Dangerous to add to lettuce gardens.

This is wrong. You really need to read the actual literature. In the utilization of a mouldering compost system, the time frames required for safe compost are much longer than higher temperature methods. There are also other constraints. Your statement here is one of the cultural mis-informations surrounding this technology. I'm not going to sit here and write the complete explanation as it already has been given in the attached document. If more detailed information is needed, I probably have that also. I'm happy to discuss.

High temperature composting. Normal compost piles in other words. As the pile gets bigger so does the energy inside and the temperature kills the bacteria.

It's much more complicated than this.

Desiccating or Urine divergent dry toilets should also not be used on lettuce gardens as the bacteria remain dorment without water. But from my second reference when water is added it starts to replicate again. Which could cause an outbrake if lettuce is sold to a restaurant of food borne illness.

Please read the attached paper - there are several steps in creating compost. You cannot achieve the final stage of safe compost buy using what directly comes out of these CT's because they have not been fully composted at that point. Don't confuse the full composting process with taking the solids receptacle and using it directly.

I asked if anyone knew if the waste from Desiccating (uddt) toilets or Mouldering toilets are deposited with the same company that would take raw sewage at the harbour. Or is there a seperate waste company that would take that specific dry waste. But maybe that's for a different thread.

Pretty sure this question has been answered by others.

dj

 

[dLj]

I do think we have flogged this horse to death.

@thinwater - I'm fine with that.

But honestly - there appears to be no such thing from a scientific/composting point of view that identifies what a desiccating head actually is. It appears to be nothing more than a current marketing term prevalent in the marine industry - might also be in the RV industry as well but I don't really care a whole lot about that sector.

It seems to be more of a term that detractors to CTs like to use when objecting in on-line forums to say "Oh, it's not even really a composting head, it's a desiccating head..." As if that were in some way negating the value or usefulness of these units...

dj

 

[thinwater]

For small recreational boats there is no company that "takes raw sewage." Marinas pump the raw sewage from the boat and deposit it into the municipal sewers. Or more accurately, marinas had the boat owner the hose and the boat owner pumps the holding tank. In the absence of a municipal sewer it goes into whatever ever waste system the marina uses.

In fact, any portable toilet service company will pump a boat's holding tank, if the boat is near a bulkhead or on dry land. This happens occasionally, when a boat is on the hard and needs to replace the holding tank or similar. Some live-aboards get regular service from a porta-john service company. Some areas operate mobile water-borne pump-out services.

In Baton Rouge and several surrounding parishes, and some areas of Florida, by law, all waste from porta-johns, septic tanks, and holding tank systems must go to a commercial 3rd party site for pre-treatment (biological) before going to the municipal sewer (POTW). [Probably other places as well, but these I have designed treatment equipment for.]