One of the most-asked questions I get about tiny living is about having a composting toilet.
Once I supply my usual-and-not-super-intriguing: “I have a composting toilet because it saves clean drinking water, etc.,” I don’t always get asked too many follow-up questions on it.
At that point, one of three things have happened:
- I have already lost their attention with the implied subject of environmental sustainability
- They don’t want to discuss anything that has to do with going to the bathroom
- They do have questions but feel they are too embarrassing to ask
Whether you are simply curious, really want some in-depth knowledge to impress your friends or are seriously interested in transitioning from a traditional toilet to a composting one, I’m going to do my best to break it all down while also putting your mind at ease: it’s not disgusting—just different.
What is a composting toilet?
First, it doesn’t compost sh*t. Literally, it really doesn’t. The name is a bit misleading as human waste takes about one year to biodegrade safely and fully (more on that in another post down the road).
A composting toilet in general is a toilet that does not use water and therefore does not need to be connected to a sewer system. It is also commonly referred to as a dry toilet.
Why use a compost toilet instead of a traditional one?
Anywhere from 1.6 to 7 gallons of fresh water is used to flush a toilet, depending on what decade your toilet was built in. And yes, that’s right—we use clean drinking water to flush bodily fluids and solids away so we can’t see it anymore.
After crunching some numbers, we realized this:
“Our composting toilet saves over 10,000 gallons of clean drinking water per year. That’s enough drinking water to last 15 years for two people.”
Does it smell?
On most days, it doesn’t smell. On some days, it smells like wet soil. And for hours here and there, yep, it smells like somebody sh*t in dirt.
One awesome thing is that this toilet has a small fan attached to a venting hose that we hooked up to its own solar panel (they typically require a 12-volt source and can also be hooked up directly to a battery). The fan accelerates the air flow and helps to suck some of the odor out through a vent in the side of the house.
Where does the urine go?
Composting toilets have a urine diverter that funnels the liquid into a holding tank. The tank can easily be removed when full and the liquid disposed elsewhere (outdoors, someone else's toilet, down a drain--not a storm drain btw).
Most of them also have the option of a setup that will drain the liquid straight out through the bottom of the tank so there is never any sitting urine in the tank. We did this by connecting a hose to the bottom of the urine tank that drains out at the back of our tiny house and is mixed in with our grey water (more on that in a future blog).
Where does the solid waste go?
When ready to . . . well, you know . . . the user must manually flip a handle that opens up to the receptacle in the bottom of the toilet. You can use various composting aids in this tank including peat moss, saw dust or coconut coir.
How do you physically use it?
In simple terms, you sit forward a bit to pee so the liquid goes into the diverter. You scoot back a few inches for . . . well, you know . . . which is when you use the flip-handle to open and close the opening to the solids receptacle.
After you make a deposit into the solids receptacle, you get to give the turn-style crank handle a few whirls and you are good to go!
What do you do with the toilet paper?
All our toilet paper goes into a small trash bin with a lid next to the toilet. The bin is lined with 3-gallon compostable trash bags. With two of us in the house, we usually empty this trash a couple times a week.
We use bamboo toilet paper from a brand called Who Gives A Crap (affiliate link). They specialize in toilet paper made from 100% bamboo fibers that they claim feels “. . . as soft and strong as a unicorn’s mane (minus the split ends). . .” which I can personally confirm is true.
Not only is this magical TP sold at a price competitive to traditional tree toilet paper, they also donate 50% of their profits to help build toilets and improve sanitation in the developing world. Talk about eco-warriors!
Ummm…. does it take any special coordination to use?
Why yes, it does take bodily coordination. Thanks for asking! The coordination comes in not only on where you are situated on the seat, but also in . . . well, you know . . .what is coming out!
Let’s just say that you can only perform one action at a time.
How do you clean it and how often?
Once turning the handle on the solids container begins to meet a bit of opposition, I know it’s time to change it out. This tends to be about every three to four weeks.
The process is not a super-complicated task. While it usually ends up on my chore list, my 9-year old can also easily complete the entire process on her own.
We unscrew and remove the top part of the toilet, bring the bottom part outside and dump it in a compostable bag to that goes into the trash, fill up the bin halfway with compostable material, and done! No need to even wipe the compartment out. Before I transition to actually composting the material safely to use in our garden, I've got a little bit more research to do!
I also wash out the urine tank with hot water and vinegar at this time and take advantage of the process to deep-clean the entire bathroom (which is only 7.5' x 2.5'). The entire process ends up being about 30-minute from start to finish.
Can you only have a composting toilet in a tiny house, boat or RV?
Anyone, anywhere, can own (or make) and use a composting toilet in place of a traditional one. You don’t have to live in a small place to own one—in fact, you don’t even have to own your own place to have one!
If you rent an apartment/house/studio/garage/shed you can always opt to not use the plumbed toilet in your rental unit, and just place a compostable one right next to it. It will take a bit of brainstorming for the setup of the ventilation fan—and also how to explain to guests why you have two toilets side-by-side in your bathroom.
Where can I buy a composting toilet?
There are a few main composting toilet brands out there that specialize in models for RVs, boats and tiny houses. Two of them are:
I personally own an Airhead model as I preferred the aesthetics of it. It will ultimately come down to your preference of style, but both these brands make composting toilets that look like traditional toilets. Please feel free in the comments below to add any other brand you know of and/or like!
If you'd rather make your own composting toilet, you can do that too. While I haven't made one yet, I will post the DIY process when we ramp up for camping weather and make our first on-the-go toilet.
Is it an inconvenience having a compost toilet?
Never. Ok, it was daunting for the first three weeks. And a serious transition for both my daughter and I. But after that, it became our norm. It even feels weird to flush a traditional toilet when we are out and about.
Now that I know I’m saving tens of thousands of gallons of drinking water with little inconvenience, I would never go back to a traditional one. Even if there was a bigger inconvenience, I wouldn’t go back. So nope—no regrets! It’s a small price to pay for a HUGE impact.