pros-and-cons-of-composting-toilet

When building a homestead from scratch, almost anything goes. This is especially true when your homestead is away from city building codes. While I can’t address every state, in most rural areas in Texas, the building codes are just about “anything goes”… just about! When it comes to poop, everyone has rules. Know the rules for your homestead area. This article is about composting toilets, not regulations.

Nobody likes to talk about their own waste. That’s what this article is about because homestead waste is a reality. We deal with animal waste all the time. We have to find a way to deal with garbage, as well, if we don’t have municipal garbage service. The last piece of the puzzle is dealing with human waste.  It’s a crappy job, but somebody has to talk about it. (Sorry, I couldn’t help myself.)

Nobody would use a composting toilet if they had access to a regular toilet… well almost nobody. If you are living off of rainwater collection, then toilet flushing is a major use of water each day.  Believe it or not, the toilet uses more water than anything else in your house. It uses a third more water than the shower each day. Toilets use 25% of the water in a house, even when that house has a dishwasher and a clothes-washing machine. If you don’t have those, then a toilet uses 33% of household water. Living off rainwater is far more practicable with a composting toilet than with a standard toilet.

If you are building a homestead cabin on a budget and cannot afford a septic system at first, or live in an area where a septic system doesn’t work, then a composting toilet is probably the best choice left.

Building a Cabin or Homestead

Put together a floor, four walls, and a roof and you have the basics for a shelter. Add insulation, electrical power, and water for modern conveniences. As long as the structure has a door, then the rest is up to you. I recently built a 690 square foot one bedroom, one bath cabin on my property. Everything was simple enough. It even has a dishwasher and laundry room. The problem was what to do for the toilet.

Building an Off-Grid Toilet

In the city, all of the wastewater is highly managed. In the country, where there is no municipal sewer system, almost every home uses a septic system. Standard septic systems consist of two tanks to separate and break down solids and a “leach field” where the resulting liquid is absorbed into the ground. Septic systems have very strict rules and requirements. They can also be expensive.

Depending on the location of your homestead, the rules and requirements of a septic system might also be a real problem. With my cabin build, I had problems with both the location and the cost of the system.

First, as the old saying goes “poop goes downhill.” If your home is at the bottom of a hill right next to the property line or road, then where will the septic system be located? You can’t put it on your neighbor’s property, and you can’t make poop run uphill.

Second, septic systems cannot be located too close to natural water systems, like creeks. My new cabin is located next to a creek on the low area of my property. So I was starting literally in a hole.

If the water table is too high or the ground is not right, then the normal “leach field” for a septic system must be replaced with a sprinkler system that uses a pump to spray the water onto the ground. This adds to the complexity and the expense.  Both the groundwater and the clay layer near my new cabin are very shallow.

For those reasons, a septic system for my cabin was going to be an expensive, complicated pain to install. For those reasons, and the fact that I don’t want to walk outside to a cold, spider-infested outhouse, I decided to go with a composting toilet.

Indoor-Composting-Toilet
Complete DIY indoor composting toilet.

The Basics of a Composting Toilet 

A quick search online will find lots of ways to turn a simple bucket into a composting toilet. If you put a toilet seat on a bucket you can certainly use it.  Just put leaves or sawdust in the bottom and keep adding more after each use.

That’s what composting is: using natural materials and processes to break down human waste so it can then be disposed of safely.

Some people set up a nice-looking indoor composting bucket system in their home. They build a nice cabinet to hold the bucket with a comfortable seat and built-in tray for holding dry sawdust. On a regular basis, they take the bucket out and dispose of the contents in whatever way suits them for their area.

I thought about doing that, but there is one major issue. That issue is urine.

Separating Urine from “The Rest”

urine diverter for composting toilet
Urine diverter kit. Image credit and product link here.

When I decided to start using a composting toilet I learned one counter-intuitive reality regarding human waste. It turns out that poop doesn’t really stink as much as you think it does… once it is mixed with a composting material. Urine, on the other hand, stinks to high heaven as it ages. I always thought the opposite to be true. I thought urine was sterile, thus less smelly. It turns out it stinks.

A basic bucket system for a composting toilet allows both the urine and the poop to stay in the bucket. This is a recipe for disgust.

If I were to build my own bucket system for composting waste I would make sure to order a “urine diverter.” A urine diverter is a small bowl that attaches to the inside of the bucket and— as indicated—diverts the urine to a secondary container, like a jug. This keeps things more acceptable from a smell perspective.

If one were to build their own bucket-based composting toilet, I think a urine diverter would be mandatory. I also think it would work, but I don’t think it would be perfect.

Managing Smells

I don’t think anyone but the most rugged person would find the idea of having a fairly open bucket of poop and sawdust in their home to be a pleasant one. I certainly don’t. But there are solutions to this.

In the RV world, everyone carries their poop around with them. They do so in a tank under the RV. This tank can be emptied, but it is never clean. The smells from this tank cannot be allowed to come back up through the toilet into the RV. To stop this from happening, RV toilets have a flap that seals the hole in the bottom of the toilet bowl. That simple flap with a rubber seal is all it takes to keep the smells out of the living area.

I would want my composting toilet to be designed with the same idea in mind: a bowl with an opening for the poop that can be closed when not in use. Combine that with the urine diverter, and now we are starting to get somewhere.

Composting toilet ventilation kit.
Composting toilet ventilation fan kit. Image credit and product link here.

The problem with having a hole with a flap is that it makes it hard to add more sawdust between uses. We will come back to that later.

Another way to deal with any smells is to have a forced-air ventilation system. Imagine the above-referenced cabinet with a bucket inside it. If one installed a well-sealing toilet-seat lid, then one could contain any wandering odors. If one were to then install a small fan (like a computer-cooling fan) to vent the air from the cabinet outside, then one could have a pretty effective system.

Vents need screens. Even a small 1″ or 2″ hole for a vent requires a fine screen. “Happy as a fly on poop.” Ever heard that one? It is important to keep gnats and flies from coming into any composting toilet bay. Any small screening material will do.

Components for a Modern In-Home Composting Toilet

Now we can imagine a solution: a nice seat with a seal (either on the seat or via a flap), plus a urine diverter to keep the urine separate from the poop, and a screened forced-air ventilation system to keep any random smells out of the house. Those are the elements of a good composting toilet.

No matter the method you use to make your composting toilet, if it has those elements, I think you will be successful.

One idea would be to start with the bowl from an RV toilet, that way you have a flap. Or at least use the lid from an RV toilet, that way you have a nice sealing lid. If you build a sitting cabinet into your bathroom make sure the cabinet is well sealed and has a small low-voltage ventilation fan with a screen. This will create steady negative pressure inside the cabinet and take any errant smells outside where they belong. Make sure you use a urine diverter that puts the urine into a fairly well-sealed gallon (two-gallon is better) jug. That is a recipe for success.

I don’t see any problem with that set-up at all.

Let’s Talk About Urine

Before I tell you about my composting toilet, I have to talk about urine. My composting toilet has a urine diverter that goes to a well-sealed jug. The jug is 2.2 gallons, and that sounds like a lot.

The average person pees about a pint each time they go. There are two pints in a quart and four quarts in a gallon. That means that my “really large” jug has a capacity of about 18 trips to the bathroom. But, you don’t want the jug completely full, so it has a functional capacity of 15 trips to the bathroom. That means one person going three times a day will fill the jug in 5 days.

This is the unforeseen aspect of a composting toilet. A family of three would fill a 2.2-gallon urine jug in less than two days. Who will empty the urine jug every other day in this instance? Make sure it’s not you and make sure it’s actually done.  Little Johnny won’t look before he pees. You don’t want an overflow!

I don’t consider urine to be “black water.” I consider urine to be dark-grey water. Why? Because when I empty the urine jug, I do it outside.  So, for my own personal use (I’m a guy), I have an alternate urinal that feeds into my greywater system. I use this when I just have to pee. This means that I only use the urine jug on my composting toilet when I actually have to sit down to go. Assuming that’s once a day, then I have to empty the urine bottle, for myself alone, only twice a month.

These are the important details of using a composting toilet.

Dealing with Poop

As I said before pretty much no one would use a composting toilet if they had the ability and cash to install a septic system. When you don’t have that ability, then dealing with poop is a real thing. Don’t let a little poop stand between you and your homestead.

In a composting toilet, the poop is either covered by, or mixed with, composting material. Here’s the truly amazing thing: in a properly-made composting toilet there is no smell. The big thing everyone is afraid of is the smell, either when using the toilet or upon cleaning. I can open my composting toilet—and leave it open—and there is no smell. When I’m using my composting toilet, there is no smell.

A composting toilet is not an outhouse. Perhaps in your youth, you went to summer camp and used an open-pit latrine and remember how gross it was. That is not a composting toilet. That’s just a hole in the ground where poop and pee were piled up in the summer heat. Disgusting!

Or you may have used a port-a-potty or chemical toilet as an adult. These are more sanitary than an open pit latrine, but they are still pretty gross compared to a proper bathroom. A proper composting toilet is nothing like that.

With the exception of having to empty the urine jug on a regular basis, a composting toilet is just like any other, but without the water mess.

How Often Do I Empty the Poop Part?

I’m pretty sure I empty the main chamber of my composting toilet more often than I need to. I empty it about every ten weeks, so, five times a year. I have a commercially-built composting toilet. So, I take the top off, dump the contents into a plastic trash bag, and put the top back on it. I do this in my bathroom. There is no smell

This is with one person using it, and I could probably empty it four times a year with no difference. A five-gallon bucket design might need to be emptied sooner, but you can easily just carry it outside and replace it with a clean bucket.

My Composting Toilet

After doing all the research into the proper way to build a composting toilet for maximum comfort and ease of use, I decided to just buy a commercially built one. I bought a Nature’s Head composting toilet. I spent the money because I will never install a septic system for my cabin.

The Nature’s Head has all the requirements mentioned above plus it has a crank to mix the composting material after each use. It has a tank of composting material (I use coconut coir, which is a brick that is bought online). The composting material gets hydrated by soaking it in a bucket with a gallon of water. That makes a fluffy brown fiber that is then poured into the main chamber.

On top of the main chamber is a toilet seat with a flap and a nice seat and lid. The chamber has a urine diverter that directs the urine into a 2.2-gallon plastic tank that can be easily changed. The Nature’s Head urine tank is not as quick release as one of the competitors called “Air Head.”  I would compare the two before purchasing.  I still preferred the Nature’s Head.

Nature's Head composting toilet
My Nature’s Head composting toilet.

My composting toilet has a small fan that connects to a vent hose that you can run through a wall or the floor of the house. I run mine through the floor. Surprisingly, the Nature’s Head does not come with the plug for it. You have to buy that on your own. (I’m not sure about the Air Head.)

For me, that covered all of the bases. It has: a flap, crank to mix the composting material so that I don’t have to keep adding sawdust, odor control, easy urine management; and it’s all compact and nice.

The toilet cost about $1,000. That seems like a lot compared to a bucket with a toilet seat on it. But it is nothing compared to installing a proper septic system where my new cabin is located. This toilet will last forever. I might have to replace the electric fan every few years, but it just screws on. Generally, I’m looking at $50 per year (over 20 years) to poop. I think that will be cheaper than what I spend on toilet paper per year.

You can always make your own composting toilet for under $100. I noticed one for sale on eBay that was bucket-based. The only thing it seemed to be missing was a fan, which could be easily added. It only cost about $325 including shipping. $1,000 is the most you would spend if you bought a high-end commercially produced unit.

Conclusion

If you can have a flushing toilet, that’s great. When you can’t have a flushing toilet there is no reason not to use a composting toilet. A properly designed one is perfectly fine. You can build it yourself or buy a commercially built version.

Hopefully this article outlined the different aspects of a properly built composting toilet so that you can make good choices if you ever need—or want—to use one. They work great. The urine-emptying is the only real inconvenience. If you have ever cleaned a cat’s litter box then you’ve dealt with more disgusting things than emptying a composting toilet.

The two main reasons to use a composting toilet are:

  1. You can’t install a septic system, due to cost or other considerations
  2. You are operating your house on rainwater harvesting and want to cut your water use by 25-33% to make sure your water storage will last through the dry spells.

Even if you only use the composting toilet until you save enough money to add a septic system, it’s a great option. Commercially-made composting toilets really hold their resale value, so you should get at least 75% of your initial cost back if you later decide to sell it.

As an added benefit, a commercial composting toilet is portable. Going camping? You can throw it in the back of the truck or SUV and take it with you!

Comments

  1. To continue the discussion started in your article, I have found that LEAVES, yes, the same stuff that falls for free every autumn, are the perfect solution to a composting toilet system. I’ve used a homemade 5-gallon bucket system for years (I couldn’t justify the cost of Nature’s Head for my own budget), so I know what I’m talking about, too. I don’t mess around with urine diverters, as the liquid component can actually be quite crucial to the composting process. Instead, I add a handfull of leaves in the bucket after every use, and there truly is no smell. I also keep my bucket covered, no matter what the season, to keep flies from finding it. Sawdust, when used in the same way, stunk to high heaven, but leaves? You’ve got to try it to believe it.

    All that said, good on you for using a composting toilet instead of the mainstream flush-wasters. I have a hard time getting folks sold on the virtues of composting toilets, even if they agree with all my points. Something about those ingrained, learned patterns that is jsut really hard for many people to overcome.

    1. I knew a woman with a homestead in South Dallas who used a bucket with no urine diverter and only leaves. She said the same thing that you are saying. She was an amazing person. She homesteaded by purchasing abandoned lots in what can only be described as a suburban ghetto in the south part of Dallas. She had a giant chicken coop made of those heavy mesh wire panels used under concrete on highways. She said she regularly had to shoot coyotes and wild dogs that would climb on them to try to get into it. She had vast gardens. I’m not sure if she used any electricity and lived on less than 5 gallons of water a day total. I met her when I trained her dog 13 years ago. Fascinating person. But yes, she said she had zero issues with leaves in a 5 gallon bucket.

  2. Hurray for composting toilets! Don’t poop in the water! We live full time in our skoolie (school bus turned tiny house) and the bucket method has worked amazingly well for us! It’s pretty common among our tribe especially when $1000 for the NH is not practical. We have all the components, urine diverter, (game changer) and a fan. No smells unless the pee jug is full. That’s worse than the poo! Thanks for posting! Looking forward to more great articles.

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