If you are like me, the cost of new septic was too high, and you weren’t sure if one would work way out on your property anyway. That’s why I went out and found the best off grid toilets for remote cabins or eco-friendly homesteads.
How can you have an off grid toilet without a septic? The best alternative to flush toilets are composting toilet systems. This may be a high tech commercial model, or it can be a simple as a bucket based DIY composting toilet.
There are a number of things consider when choosing an off grid toilet — cost, labor involved, the number of people using, etc. Below I’ll go through the main options, and when they might be the right choice for you.
Best Toilets without a Septic System
Composting toilets are the most popular toilets for use without a septic system. While there are a wide range of options out there, including pit latrines and incinerating toilets, composting toilets are simple, safe, and don’t have to be smelly. This allows them to be used in doors, and they can be put in a relatively small space like a cabin, tiny home, or RV. Composting toilets do not need any form of plumbing, although they do need to be emptied regularly.
- Humanure Bucket Toilet Composting Toilet
- Clivus Style Composting Toilets
- Commercal Composting Toilets
- Biogas Digester
- Incinerating Toiltes
- Outhouses aka Pit Latrines
There are composting toilets that range from simple and cheap < $20, to $1000’s, and small and portable to permanent room size installations. The primary benefit of more expensive systems is that they require less maintenance (read emptying poop) and they can accommodate more users.
The primary draw back of composting toilets, which is also one of biggest benefits, is that you get compost out of them. This compost usually needs some time to “finish” outside in a bigger compost pile before it is safe to use as fertilizer. If you are in a situation where you don’t have room for this, or are in a very sensitive environment, then a
Humanure Bucket Toilet
- Cost — $20 – $60
- Maintenance – Once or twice a week
By far the simplest and cheapest way of handling your off grid toilet, the “Humanure” bucket system is a method that I have been using myself for many years. Easy to understand and robust, as there is nothing to break down, the Humanure toilet is usable in small spaces and is highly portable.
- Reference – The Humanure Handbook
The Humanure Toilet
Humanure composting happens in two stages. The first stage is the collection point, sometimes called the “pot” or “vault”. This can be as simple as a bucket with a seat on it, and another bucket with proper cover material near by. Some people also like to go to the point of having an enclosed box for the collection, with a small fan that vents directly outside. The fan establishes a negative pressure gradient, which pulls all the smell out of the room.
The key point here, is that all waste needs to be kept covered with a cover material, in order to prevent smell, absorb liquids, and keep things sanitary. This can be such things as —
- Wood chips
- Peat moss
- Dirt or clay
Whatever you have locally available is best, but it should be something that absorbs liquids and is a natural, combustible material.
A few times a week, to once or twice a month, the bucket needs to be emptied in to the outdoor compost, and well covered with dirt. Compost with human waste should be composted for two or three years to ensure all potential illnesses and parasites have been killed. The recommended way of handling this is to have three compost piles, which you rotate once a year, cleaning the next one out only when you need to use it next.
The bucket should be relatively free of remaining material after dumping, but can be scrubbed lightly with a toilet brush and soapy water to clean everything up. This can be dumped in the compost as well. Be sure to use Safe Detergents And Soaps For Grey Water Systems.
Proper use of the cover material to keep everything covered, and to absorb extra liquids, means there is very little if any smell. Likewise, keeping a good layer of dirt and plant matter on the compost keeps in the smell there as well. Emptying the bucket isn’t scent free, but isn’t near as bad as emptying a grew water tank, and is over quickly.
A quick tutorial or poster on the wall is usually enough to get guests to use the Humanure toilet properly. The biggest problem, is that many tend to over use the fill material, which means your are emptying the bucket much more than is really needed. For many quests, you can simply increase the number of buckets, although you will probably spend much more time servicing bucket toilets than you would other designs.
DIY and Where to Buy
Build yourself by putting a toilet seat over a wood or plywood box with a hole. Place a regular 5-gallon bucket below
Amazon sells ready to go bucket toilets which work well if you don’t have any carpentry skills, or want something that looks store bought.
Clivus Style Composting Toilets
- Cost — $100s – $1,000s depending on size
- Maintenance – Once or twice a year
One of the earliest composting companies on the market, Clivus toilets are designed to be permanent installations that only need occasional emptying. The biggest innovation of traditional Clivus designs is the use of a composting chamber with a slopped floor that allows you to add raw waste on one end, and take out finished or nearly finished compost on the other. Clivus designs can large enough to allow the entire composting cycle to happen inside the toilet, which makes it a less smell, less gross option to many people.
The biggest advantage of the Clivus is that it can be sized to work for a household with many people, and yet only need yearly emptying. And, they only need occasional additions of brown plants, like leaves or wood chips, to help with the composting process. Many Clivus composting toilet designs also have an exterior access port, here you can use a shovel and wheel barrow behind the house to unload the cargo all at once.
Unlike the other composing toilet options on this list, the Clivus is not portable, and is a rather large permanent construction. What you gain in convenience is made up for by increased construction time and up front cost. But, if emptying a bucket twice a week doesn’t seem right for you or your family, then a DIY Clivus can be a good alternative.
Clivus style composting toilets don’t need any skill from the user, you just do your business and go. Guests don’t have any problems as there isn’t anything for them to mess up.
Commercial Composting Toilet
On the market, there are a number of commercial, ready made composting toilets. Usually made of plastic, and about the size of a 5-gallon bucket, they sit some where in between the bucket toilet and the Clivus in terms of cost and usability.
Here are some of the most popular commercial composting toilets on the market:
Nature’s Head Composting Toilet
- Cost — ~ $1,000
- Maintenance – About every 80 uses, liquids once or twice a week
Popular among the boating and RV crowds, these premium composting toilets are meant to be portable and smell free. Like most commercial composting toilets, the feature internal venting fans, a mechanical peat moss addition system, and a urine separator.
This composting lasts longer than a bucket toilet, mostly because you need much less peat moss since the urine is separated in to a separate bucket. The process of adding cover material is semi-automated, you just spin the handle.
This model is battle tested. It works without water or electricity, which makes it my recommended off grid commercial composting toilet —
Separett 9215 Composting Toilet
- Cost — ~ $1,000
- Maintenance – About every 80 uses
A similar design in many ways to the Natures Head composting toilet, the Separett has two big advantages — an motorized peat moss adding system and a urine drain that can be plumbed to a drain or outdoors. This means there is less maintenance to do and there is nothing for the user to mess up.
Separett toilets work both with traditional AC outlets and 12 V DC systems, which means they pair well with a off grid solar setup.
However, the down side to the Separett is that there is no manual way to agitate the bucket, which means they don’t work unless you have consistent power. Because of this, and because of the added complexity of design compared to the Nature’s Head, this is my #2 recommendation for an off grid commercial composting toilet.
Sun-Mar Composting Toilets
- Cost — ~ $2,000
- Maintenance – About every 100 uses
Sun-Mar toilets ar different than the other commercial composting toilets in that they do not have a urine separator. Instead, they use electrical heat to evaporate extra liquid from the storage chamber. This ultimately makes the toilet rely on power to operate effectively. Without power, is is essentially an over-priced bucket with a vent pipe out the back.
Given that it is the most expensive option, and ultimately less effective that the others on this list, I do not recommend a Sun-Mar toilet.
- Cost — ~ $800 + plumbing costs
- Maintenance – Once or twice a year
A bit of an odd ball on this list, biogas systems are an up and coming waste management system world wide. Used for more than half a century by German farmers as a way to process farm waste, Biogas is the waste management system that produces free heat and cooking gas while composting the refuse.
Unlike other composting toilets, which try to limit the amount of water in the system, biogas digesters compost as a liquid slurry. This type of composting is inherently smelly, since it makes methane (the biogas), which is why commercial digesters are completely enclosed to contain smell and store the usable methane gas.
The best thing about a biogas system is that it can be used with a traditional flush toilet, since excess water is not rely a problem. Occasionally, biogas digesters will need the “compost tea” drained out. For use with human waste, which should be completely composted before taking out, I recommend having two or more digesting chambers on hand that you switch out once full. Let the full one continue to digest for 6 mo – 1 year before emptying.
Methane produced by biogas digesters is order less after filtration and can be used for cooking with like propane or natural gas.
Bio gas digesters use the hot compost process, which means they kill pathogens much more quickly than heap type composts will. The down side is that they need to be kept warm, about 80 – 90 internal, in order to work. In cold climates, that means they will probably need to be insulated and or heated in the winter.
- Biogas Reference — The Biogas Handbook
- Cost — ~ $2,000
- Maintenance — About once a month
Instead of composting and reusing waste, like the previous options on this list, incinerating toilets burn the refuse in to an ash. The companies Incinolet and EcoJohn both produce popular incinerating toilets
Incinerating toilets require a lot of energy input, and come in either gas powered models or electrical models. Both types use the input energy to heat up and “burn” the waste, leaving almost nothing left. Burn cycles take about an hour, although most models allow you to use the toilet while they are burning.
This type of toilet is not great for off grid use, because of the high energy input. Electrical models are very expensive to run off solar power, and gas would need to be trucked in. But, if you have access to plentiful micro-hydroelectric power or are connected to grid power, and then this could be an option for you if composting is out of the question.
- Cost — FREE – $1,000s depending on if you dig your own
- Maintenance – Rebuilding every several years
The oldest method of waste handling on the list, and one you’ve probably used before, is just a big hole in the ground with a building and seat above.
While not the most ascetically pleasing option on the list, pit toilets have two reading qualities — they can take a large amount of waste and they are cheap to build DIY. If you plan on hosting a large amount of guests that would tax your composting toilet set-up or your patience for emptying buckets, then a latrine is a good backup option.
Latrine pits are still legal in some states, so check with your county health department to see if one is possible in your are.
How Do Composting Toilets Work?
Human waste has a natural ability to turn back in to dirt, and composting toilets are designed to help that along. The biggest problem with collecting everything in one bucket is the smell and excess moisture which slows down the composting process and produces extra smelly gasses.
Every form of composting toilet has some way of taking out extra water. Bucket toilets just use a dry absorbing material to sop it up, and to become the base for later composting. Commercial toilets either physically separate urine, or use heat to evaporate it from the mix while adding dry materials. Clivus toilets have a physical separator inside the vault and venting to allow natural evaporation.
Eventually the waste compost will need to be mixed with brown compost additions like leaves, and regular dirt. Research shows that an potentially harmful diseases or parasites in human waste in completely destroyed on 2 – 3 years of composting for low temperature compost processes, and in less than a year for high temperature compost.
After the composting process, the product can be used to fertilize. In Asia relatively unprocessed human waste is used to fertilize vegetables directly, but in Western countries most sources recommend only using well composted material, and then only using that compost on trees or other edibles that don’t grow directly in th ground.
Are Off Grid Toilets Legal?
I have yet to find a district where off grid waste management techniques are explicitly illegal, although be sure to double check with a knowledgeable authority in your area.
Usually, the issue comes up with getting a permit to build a building. Most county health offices have some requirement for a septic, with the ultimate size of the building being limited by the size of the septic.
Many states explicitly allow for various off grid toilet alternatives if a septic is not viable on your property, usually because the ground percolation is too slow. Some areas allow you to opt for alternative systems even if you could build a septic. Again check with your county for details in your area.
However, even if your county requires a septic on your property you probably still have the option of implement a composting toilet system. While many laws require a septic to be present to build, using is not required by law. Building the septic to build within the law, and then primarily using a composting system to get the benefits of additional compost while saving on septic pumping costs, might just be the right compromise in your situation.
Can You Have a Sink without a Septic?
Composting toilets systems don’t “grey water” that comes from sinks, baths, showers, or other drains around the house. Even the biogas digester wouldn’t do well with that much liquid.
In order to have a sink without a septic, you should look in to a grey water system for your living condition. Grey water systems take in water that did not come from a toilet, potentially store it for later, optionally provide some amount of natural purification, then return it to the environment.
Grey water systems can be used to partially irrigate plants, lawns, or to flush toilets, and can drastically reduce overall water usage.
One thing to consider with grey water systems is that you must be careful to not flush chemicals down the drain, and to only use appropriate soaps and cleaning supplies —
Do tiny houses have toilets?
Yes. Tiny houses can function with many toilets, although small form factor composting toilets are a great match for tiny houses. Nature’s Head toilets are a great option for tiny houses, as they are designed for use on yachts and in RVs.
Do I need a septic tank if I have a composting toilet?
No. Composting toilets do not require a septic or running water, and are designed to function completely independently. Composting toilets are perfect for off grid land, boats, RVs, or tiny homes when septic is not available.
Can you put toilet paper in a composting toilet?
Yes. Paper can actually aid in the composting process by providing much needed fiber. Unbleached or chlorine free toilet paper is preferred, to prevent slowing of the composting process.