Life with a Composting Toilet

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Its been quite the adventure since I got distracted, enjoying my new found freedom. (Check out our map to see where 2016 took us!) I’ll tell you all about it soon enough, but today I want to give you the straight poop about our composting toilet! Ba-dum tch!

Brace yourselves people. There will be a LOT of toilet humor in this article.

Look at our lovely new throne!

In order to keep to our single-income budget, we needed to get away from expensive RV parks and out into the (free) wilderness! When dry camping (aka. boon-docking) we do not have onsite access to fresh water or dumping facilities. Filling or dumping our water means moving our entire rig. This is a minimum 3-hour process, depending on how far the nearest dump station is. So we’d prefer to do this as little as possible. Our goal is to reduce our intake to 100 gallons per 14 days. That’s one slight overfill of our 90-gallon fresh water tank lasting the common day limit to stay on public lands. This way, our dump trips coincide with our location changes.

Before the composting toilet, we would output to two separate tanks. Our sinks, showers, and washer emptied into our 70-gallon grey tank. Our toilet emptied into our 50-gallon black tank. Whichever one filled first required us to immediately pull up stakes to hit a dump station. This could be a real bummer if there was still plenty of room in the other output tank.

Not our exact tank set, but just to give you an idea. The white tank on the bottom is fresh water. Above are the smaller black tank and larger grey tank.

Eliminating our RV-style flush toilet benefits us in two ways. First it reduces our 14-day usage by approximately 20-30 gallons. This adds up to 3-4 loads of laundry, 4-6 navy showers, or 10-15 days of dishes. It will significantly extend our fresh water availability. On the other end ba-dum tch! it allows us to repurpose the black tank to extend our grey water output. Our combined tanks now provide 120 gallons of grey water storage, and all sources can be combined for full use of that capacity.

I will write up a separate article for the detailed installation process. But for those of you who are new to the composting toilet conversation, I want to talk about what it is, what it isn’t, and our first reactions to our new elimination experience. Fair warning: the rest of this article goes into detail about the full toilet experience. I will do my best to be tactful, but if this is not your cup of tea, feel free to join us again in the next article about mobile gardening!

Our old, RV-style toilet. At the bottom of the pedestal is a lever to fill and flush the bowl. On the wall is a sprayer for the ultra-low-flow flush assist. Basically useless. It will not be missed!

Our previous RV-style flush toilet was very similar to a standard household flush toilet with three notable exceptions. First, you determined the toilet fill level using a foot lever. This gave you control of your water savings. Very little water for liquid deposits, at least a gallon for solids. You see similar options in public restrooms and high-end residential toilets now. The water reduction is significant in all applications. Second, rather than being whisked of to a far off location for mysterious treatments, the waste water is stored in your “basement”. (It does eventually get whisked off for treatment, but the temporary holding gives one a dramatically different perspective on wastewater production.) Third, and this is somewhat superficial, the RV-style toilet lacked any kind of water pressure, which can be a frustrating post-potty experience. I’ll leave that one to your imagination.

There is a fourth exception, which I’m torn to assign to all RV-style toilets. That is the off-and-on, stomach-turning stench that would invade our home. Despite all of our online research, scientific data-plotting, hypothesizing, or tank-cleaning experiments, we could never pinpoint or eliminate the source of sewer smell into the bus. We might have a three month reprieve before the mysterious stench again reared it’s ugly head. Undoubtedly coinciding with visitors and causing untold embarrassment. We are optimistic that this issue will be resolved with the elimination of sewage from our RV lifestyle.

The newly installed replacement. You can see the jug in front, to captures liquids, as well as the lever on the right, to open the flap for solids.

The composting toilet replacing our RV-style flush toilet is not such a far cry away from a standard toilet experience, but it is an adjustment. The key element is the separation and proper storage of liquids and solids to prevent the creation of “sewage”. This is what makes it different and infinitely superior to a port-a-potty or vault toilet.

A view of the western-style bowl. The front area captures liquids. The back opens up to the solids containment.

The toilet is comprised of 3 main parts. On top is a standard Western-ish toilet. I say “-ish” because, while it has a lid, it does not have a fold up seat. Instead, the seat and bowl are one moulded piece. This allows for a more snug fit of the lid, which encourages proper ventilation.It also makes for a cleaner toilet in general. (Less nooks and crannies.)

The sitting experience is quite similar to a standard residential toilet. The standing experience can be more challenging, although not entirely infeasible. It is recommended that one considers adopting a seated position for all liquid deposits, to avoid “splash back”.

Beneath the bowl are two compartments. (pictured below) In the front is a simple jug, into which liquid deposits are, well… deposited. The two holes in the bowl are nicely positioned for maximum capture of seated liquid deposits. If the depositor is standing (or if one makes a liquid deposit with a gusto), a flap at the back of the bowl redirects the liquid to the front for capture. A few spritzes of vinegar water from the included spray bottle rinses down any remnants and eliminates any possible odors. I prefer to keep a cup in the bathroom and “flush” with an ounce of water from the sink. This makes me feel cleaner. I also add a few drops of orange oil to combat the vinegar smells. This works nicely!

The liquids jug fills in 2-3 days with two people. It is slightly transparent, to see the current “fill line” status. Pay close attention to the level! Especially before bed. You don’t want to have to empty during a midnight run. I’ve already made the rookie mistake of forgetting to check on it. Luckily, the results were not fully disastrous. The jug nestles into an 8″ basin on the front of the base. When I lifted the bowl, the excess liquid flowed over the jug, but into the basin, which reasonably contained the mishap. The jug, basin, and bathroom were all thoroughly cleaned and sanitized. It was not a pleasant experience, but I’d venture to say that anyone with kiddos has dealt with something similar (or worse).

As I am writing this, I had the compulsion to check on the levels again. I may be slightly traumatized.

We dispose of the liquids into the grey tank. There are a few options to accomplish this. I’ve settled upon the shower drain as my preferred location. I try to time it right before one of us showers. That way, I can clean with my standard vinegar/Dawn shower cleaning mix and rinse with the warm-up water, avoiding too much water waste. Despite what others may have told you, this is not a fully pleasant experience. There are strong odors involved, although they are short-lived. Insert asparagus joke here. Long-term we are considering running a drain tube out of the jug, directly into the pre-existing plumbing below the toilet. This will require some thoughtful engineering. We have a solid plan, ba-dum tch! but have not yet found the custom parts we would require.

Here you can see inside the solids compartment with the agitator. Note the (2) gallon baggies of damp coco coir propped on the back.

The back of the base is a compartment for solid deposits. You start with a couple of gallons of dampened peat moss or coco coir (the brown hair off of coconut husks). When making a solid deposit, a lever on the side of the toilet opens the flap at the bottom of the bowl and bombs-away. Ba-dum tch! Close the flap and turn the agitator, using a separate handle on the outside of the base. This begins the composting process. A tiny fan helps to regulate the moisture and exhausts odors through a vent tube, out of the RV. It is absolutely true that no sewage smells emanate from this compartment, even when it’s open! All you get is a gentle soil smell, which is not at all unpleasant.

This compartment takes much longer to fill, at 60-80 uses. Depending on frequency of use, full-timers can go up to a month before dumping into a trash bag which can go into any public dumpster. Alternatively, you might use a composting bag, which breaks down more quickly to complete the composting process. Refill the compartment with dampened coco coir and you are good to go. Ba-dum tch! My first time changing this compartment was a general success. Maneuvering the large base was tricky, especially as I was solo. But I managed to handle it without any hazardous spills.

In this view, you can see the spider handle, which turns the agitator in the solids compartment. You can also see the vent exhaust tube, which runs behind the toilet and out the bottom of the RV.

Too much toilet paper can dry out your compost and make the compartment fill up faster. So we go by the general guideline that if you have to open the bottom flap, TP goes in. If not, TP goes into a trash can under the sink. This is working well for us so far.

Another thing worth mentioning is the increased number of potty conversations spurred by this change. I have to say, I am truly surprised at the general positive response and curiosity from people when we mentioned our plans. Even potential guests! It has inspired an unexpected number of discussions about toilet mechanics, sewage, human anatomy and positioning, etc.

My favorite quote so far…
*Matt and I discussing dogs vs cats*
Matt: But a cat poops in a box inside.
Me: Well, now you do too…

So how do we enjoy this new era in our adventures? So far, it’s a mixed bag. While it is definitely cleaner than a standard toilet, we are struggling to keep the proper moisture levels in the solids bin. Also, I’d like to get a spout for the liquids jug to prevent any back dribbling, which seems to happen anytime it’s more than half full. The top has a threaded lip for a cap. Surely we can rig something to screw on.

All in all, it’s worth the adjustment to be able to get out of the expensive RV parks and extend our freedom. But I will happily switch back to a nice residential low-flow toilet if and when we ever put down roots again. Until next time, you stay classy San Diego!

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