How often should you empty your composting toilet?

A composting toilet is a great tool to save water, but it requires some maintenance: you need to empty your composting toilet from time to time and this is a task that shouldn’t take you much time.

For two people, full-time usage, you need to empty your composting toilet every 3 weeks. If you have more people using it, is one week less per person. If you only use it on weekends, every two months is enough. The urine bottle needs to be emptied every 2-3 days.

Emptying the liquids

As the urine bottle is the first one to get full, I will start with it. Usually, the urine bottle is transparent so you can watch for the current level. Try to empty it before it gets full. It’s a better experience.

Most of the composting toilets have overfill protection, the urine won’t get overboard, but I’m sure you don’t want to clean all the mess thereafter. So, my rule of thumb is when the bottle gets 3/4 full, it’s time to empty it, and usually, it’s about 3 days to get to that stage.

The urine tank should be emptied frequently and washed every time with water and vinegar if possible, if not, use some biodegradable detergent. Washing every time you empty the urine tank will provide you an odorless composting toilet and your experience will be much more pleasant.

Emptying the solids

It’s a bit harder than emptying the liquids, but it’s by no means something epic to do, it’s pretty easy and you’ll get used to doing this in no time.

First of all, if you have a mobile composting toilet there are only 3 little steps:

  • Open the seat and put a garbage bag around the rim, the fit should be tight to prevent spillage
  • Invert the unit so the waste will fall on the bag, this is especially useful for mobile composting toilets like the ones present on RVs and boats.
  • Don’t clean the unit with chemicals. This will kill all the good bacteria.

And that’s it! Now you have a clean composting toilet almost ready to use again.

I’ve found this video on YouTube from Our Tiny Mess that shows how to dump the waste from your composting toilet in a proper way.

Refill the composting toilet

Now that you have a clean toilet, it’s time to refill it. You can use sawdust, coconut coir, or peat moss. Fill the deposit until the agitator bar is covered in a horizontal position.

If the coconut coir or the peat moss is dry, put some water to help moisturize the medium so it can do its job in a proper way.

Be sure you don’t overfill the tank after the agitator as when using it you’ll have a tough time agitating the compost as you need to move more material and it’s heavy. Also, don’t put less than recommended because the waste will not compost so efficiently and can lead to bad smells.

Avoid at all cost water ingress in the tank, water will slow down the composting process and will also make a bad smell. If you have water entering your tank, inspect visually the whole tank look for possible gaps, and fix that as soon as possible.

What is the best material to refill the toilet?

The best material to refill your composting toilet is what you have access to. Sawdust, coconut coir, or peat moss are the most used. Sawdust usually is the cheaper one and the most available, you can find it in every corner. My favorite is coconut coir because of the smell it leaves and the package I buy locally is resealable so I don’t bother with that after the use. It is plug and play as it can be.

The advantages of using one material over the other are availability and price. Before you buy, take a look at the stores nearby, watch out for the cheapest by the pound and make your decision.

Also, it’s important to store the filling material in a proper way, some bags have ziplock to reseal the package for future use. It’s more practical. Some that don’t have this mechanism, you can put it in a bucket or two with a cover for storage.

Where to dump the waste?

The liquid waste can be disposed of in RV Dump Stations that allow it, most of them allow liquid waste disposal.

Don’t dispose of it in a public area! This can upset a lot of people as this leaves smells and it’s gross, especially when it is not our own. Empty the bottle on a dirt road or on soil away from water that animals could drink and away from plants.

Usually, the solid waste that comes from the composting toilet is not completely composting yet. It’s good to inform locally if your town has a compost pile, this is free of charge and it’s a good way to get rid of your waste if you don’t have a garden.

If you are mobile on an RV, you can dispose of the waste on a garbage can as it is no different from disposable diapers and you if have no other choice, you can bury the waste in a wilderness area. Be sure to dig a hole at least 12 inches deep and don’t put all the contents in one hole only. Also don’t do this near a river, lake, or any water body. It can be hazardous for wildlife. Don’t bury the plastic bag, dispose of it in a proper way.

Independently of your situation, remember to Leave No Trace, your actions matters.

Cleaning and Maintenance


If necessary, a quick spray of water and white vinegar is enough to keep your composting fresh and without odors between uses. For more intensive cleaning, moisturize a paper towel with water and vinegar and you are good to go. The ratio of water to vinegar is 1:1 and it’s recommended to use a spray bottle. This way you do your business, spray one or two times and it’s clean again for the next use.

Just don’t use any chemical cleaning product as it kills all the good bacteria that the composting needs to process the biological waste. This may lead to bad smells and they’re hard to get rid of.


At least, once a month, inspect visually your composting toilet for any cracks or leaks, inspect all the seals because it is important that there is no water ingress on the composting toilet nor smell leaks.

Inspect the privy shelter and vent pipes, if you find any damage, fix it whenever it is possible so your composting toilet can continue to work in a proper way.

With proper maintenance and operation, a composting toilet will last years and your carbon footprint will be minimal as you don’t waste water anymore doing your daily business.

Related questions

What is the cost of a composting toilet?

A composting toilet will cost you at least $800 and the price will go up to $3,000. Some are really simple, others are fancy with electric agitator. You can also save some money by doing yourself. This requires you to have space and the tools to do a composting toilet by yourself.

A good self-contained composting toilet from Nature’s Head will cost you about $1,000. That is a good brand and I recommend to anyone who is RVing, van-living, or even living off-grid.

Another good brand is Sun Mar, they are more heavy-duty and also more expensive, they start at $2,000. But they are a league of its own. Sun Mar sells complete solutions for house, mobile, RV, off-grid, you name it.

As those solutions are self-contained you only need to dispose of the waste every 3 weeks and squirt it 2 or 3 times with water and vinegar every time you use. Independently the brand you choose, it will last years.

Can I have a composting toilet if I live in a van, boat, RV, off-grid?

Sure you can! As composting toilets don’t need water they are ideal for mobile usage. It’s widely used by van-lifers and people who live off-grid. If you live off-grid, you sure have a compost pile and it’s a great way to dispose of the waste from your composting toilet. The principal brands on self-contained composting toilets are Nature’s Head and Sun Mar.

You can also have a composting toilet if you live in an apartment or in a house, there are lots of people who have made their own composting toilet outside and use the compost material as fertilizer in their garden or crops.


Hi, I'm Sérgio and I'm passionate about saving the environment reducing my carbon footprint and making better choices. Here I will share some tips that I'm learning on my journey of having a way of live that is more sustainable.

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