Going off grid and trying to plan your toilet system? Here are some common plumbed and no-plumbing toilet options and considerations for each, so you can work out the best off grid toilet option for you.
The bucket is definitely high on the gross scale, but it’s the simplest method of creating a no-plumbing toilet. It’s great for the early days before you start building all your infrastructure. A 20L bucket with a cheap toilet seat (or a pool noodle cut a to length with a split down the length jammed on the rim) is all you need. Keep some sawdust, ash, or lime nearby to sprinkle on top periodically to keep the smell down, and it can be lined it with a bag for easy disposal.
The bucket’s slightly more sophisticated cousin, a long drop is a low maintenance option that can work great in the early days - and should be a temporary solution. You can use the same bucket seat method as before, but with the bottom of the bucket cut out over a hole, just keep it well away from any water sources to avoid contamination. As with a bucket toilet, a sprinkling of ash, lime, or sawdust will help cut down on smell.
A composting toilet is considered the best off grid toilet by a lot of off-gridders, as it offers a less gross experience than a bucket or long drop, but isn’t as expensive or complex to install as some other options. The big difference with a compost toilet is that they’re designed to separate the liquids and solids into different tanks, because the worst of the smell comes from the two mixing.
The solids tank needs a medium of some kind to absorb any excess water content and speed up composting – you can use any carbon-based material such as coconut husk, untreated sawdust, or peat for this.
You can buy ready-to-go units that have two tanks, a urine diverter, and a little handle for mixing up the solids – or you can DIY a system with the ol’ bucket, a funnel and a handful of sawdust to sprinkle on top. We've even seen one customer go so far as to make two toilets - one for liquid, one for solid! Composting toilets can be self-contained with a smaller unit that collects the output right in the toilet, or a two-part system that collects everything underneath – same as the difference between a bucket and a longdrop. E.g., you might have a simple bucket system, or a pipe down to a larger holding tank.
You will have to take out the solids and compost them, which will be more or less frequent depending on use. Typically, a 10L bucket will fill up in 4 weeks with 2 people full time. You will also have to dispose of the liquids somewhere – many people use it to fertilise certain plants.
Nature’s Head is the most common brand we’ve seen off-gridders use for ready-to-go composting toilets, but there are plenty of options out there.
As the name suggests, an incinerating toilet burns away all the waste, leaving you with ash. Like the previous methods it also requires no plumbing, but it is much more sterile. It can also be used many more times before filling up. They can be powered by electricity or gas - electricity-powered is pretty much a no-go on solar, while the gas ones just need a little electricity for a spark.
This option is very expensive (think $8000+), and requires fuel, so it is not the most popular.
Off grid, the septic system is the closest you’ll get to a normal toilet. It works the exact same way as a normal toilet, but instead of going into the mains sewage, it gets stored in a septic tank. This is the only option in this article that will also handle your greywater – for the rest you’ll need a separate solution for it.
Septic systems have two parts, a septic tank and a drainfield. The septic tank is watertight and collects the black water, separates solids and floating matter (like grease), and digests organic matter. The separated liquid then goes into the drainfield, where it is dispersed into soil or a reedbed which filters and treats it before it becomes groundwater.
These are a popular option off-grid, especially for more permanent and comfortable places, and is often required by banks/councils when they have a say. Like any plumbed appliance in the home, they'll draw power to run the water pump.
These do have their drawbacks, as they require the solids to be removed when they build up (usually after 3-5 years) and can occasionally overflow. Natural Flow is an alternative that works similarly to a septic system, but turns the solid waste into compost, cutting down on maintenance dramatically.
Things to consider:
How often will the toilet be used? Will it just be weekends (and not every weekend?), or everyday? How many people will be using it? The answers to these questions will determine what kind of toilet is most effective for you. The more usage a system gets, the more you will appreciate a more sophisticated solution.
Bank, Council, and Insurance Requirements
Check what council regulations in your area apply to how you can manage waste. If you have a connection to a mains sewer, you're legally required to use it unless the building consent authority provides a waiver. If you need a loan or have insurance, the bank and insurance companies might have requirements you have to meet too. Usually a septic system is required, but many people make the case for a composting system.
How much maintenance are you willing to do? Do you want a set and forget system, or are you willing to put in a little work every few days? Will the amount of use it gets increase the maintenance past what you’re willing to do?
Septic systems are usually the most popular for full time use for families, as they are ‘flush and forget’, while compost toilets are popular when it’s one to two people, and the bucket and long drop are used a lot in part time situations.
There are plenty of great no-plumbing toilet options for off-gridders, as well plumbed options for anyone wanting to keep those modcons! The best off grid toilet option is whichever one works best with your usage plans, situational requirements, and maintenance abilities - hopefully this breakdown has made the right option clearer!