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An End to "Unsightly Floatables"

composting toilet

 “Unsightly floatables.” That was an engineering term that I’d learned years ago when I was a city planner in Burlington, Vermont. It was a phrase used by municipal wastewater engineers when referring to the “floaters” on the surface of Lake Champlain when a rainstorm would create a stormwater surge large enough to overwhelm the sewage treatment plant and shunt the sanitary sewer directly into the lake. Those occasional system overloads were not good for water quality, for sure. In fact, they were the primary reason why we invested $52 million dollars to upgrade our municipal wastewater system.

All my life, I’d hardly questioned the practice of filling a porcelain bowl with potable water, dropping our bodily waste into it, then using another large quantity of drinking water to whoosh it out of sight and out of mind - straight into the lake on occasion, as it turns out. Even in a properly functioning wastewater systems, does that method of waste disposal continue to make sense in this world of increasingly scarce potable water?

I've known about composting toilets for residential use for decades, but it wasn't until the Gypsy project that I had the opportunity to put one in my own home. We bought our composting toilet nearly a year ago and tucked it into a corner of Gypsy while we slowly began finishing the interior.

When we moved Gypsy here to the maritime museum we discovered an unexpected convenience – a guest bathroom on the outside of the nautical archaeology lab building, 30 feet from our front door. Rather than immediately installing our composting toilet, we took advantage of the “facilities” next door.

I’ll admit, I was dragging my feet on the composting toilet installation. Why was I so reluctant to make the switch?

Well, there were two primary reasons. The first had to do with cutting a hole in a perfectly good roof. The non-electric version of the composting toilet we bought from Sun-Mar requires the installation of a 4-inch vent running straight up from the rear of the unit. In Gypsy, it meant cutting a hole in the bathroom ceiling, then through the loft ceiling, then through six inches of foam insulation, then through the plywood roof sheathing, and then, finally, through my beautiful green metal standing seam roof. Taking a drill and a pair of tin snips up the ladder to make the cut was one of the hardest things I’ve had to do yet.

The second reason why my motivation was lacking had to do with my seemingly insurmountable fear of the unthinkable. What if it stinks?

I struggled to put that fear aside. Even though I’d read the marketing literature – “No odor” – and scoured the internet for testimonials – “No odor” – I just couldn’t bring myself to hook our new toilet up.

“What if ours is different?” I wondered. I couldn’t bear the thought of coming into our tiny home and feeling as if I had just stepped into an outhouse. The bathroom is right next to the kitchen, after all. What if . . .?

Then, as usual, Marion talked some common sense into me – “We really don't have another alternative – just do it and we’ll see what happens.”

Okay, here goes . . .

composting toilet

What could have been more fitting than to unveil the new throne on New Year’s Day. Once the vent and the urine drain were installed there really wasn't anything more to do except pour in a few gallons of composting mix (hemp stalks and peat), a bit of the starter microbe mix, and a little warm water. There you have it. Ready for use!

Fingers crossed, we went about our “daily business,” so to speak. We waited. We sniffed. We cranked the drum through its six revolutions twice a week. (I get Fridays and Marion gets Tuesdays. It’s really fun!)

We sniffed some more.

No smell!

We did have one “adjustment,” however. After about a week of use we had a day or two with very strong south winds. The length of pipe that had come with the toilet only brought the vent to a level even with the roof peak. Hoping to keep the profile of the pipe low, I decided to see how much “roof effect” we’d get without the specified two feet of pipe above the ridge. Well, when those south winds blew hard, we had downdrafts (creating positive pressure inside the toilet), and pew, we had "odor" in Gypsy Rose. Oh, no!

I quickly installed a two foot extension on the vent and instantly the problem was solved. We’ve been using our composting toilet for nearly three weeks now. It's great! The transition from a flush toilet to a composting model was completely painless. As it turns out, the only difference between our composter and a flusher (aside from lack of a flush) is the cupful of compost mix that gets sprinkled in after each poo.

Now that I’ve finally made the switch, my only regret is that I didn’t do it decades ago.

composting toilet

Comments

It's good to read this as we are thinking about putting in a composting toilet when we renovate our house.

Can you tell me a bit more about the "cupful of compost mix"? Is this something you have to buy specially?

That's cool! Thanks for sharing your composting toilet story. I'm envious. I don't know about the potential for one in our urban home, but maybe someday.

I found your link on Crunchy Chicken's blog. I love your little house!

Lisa in MN

Sounds great, Kevin. I'm encouraged by your enthusiasm and testimonial. I may be buying an old fixer-upper house with an unknown septic tank condition -- I'm thinking that if there is more than minor repair needed to it, I'll just get a composting toilet, and rig greywater systems for the other house water. Can you explain to us neophytes how the urine drain works and also what the procedure/timeframe is for producing usable compost? Thanks so much!
Sue in the Western Great Basin

Sue,

The toilet has three components - the composting drum, the evaporation chamber, and the finishing drawer. In the electric models, a heating element under the the evaporation tray takes care of the excess moisture. In the non-electric version that I have, passive venting helps to evaporate the liquid, but a urine drain must be connected to take care of the remainder. The drain can be tied into a sewer system, a holding tank (to be emptied periodically into a sewer system), or a small, stone-filled trench outside of the house. The toilet in Gypsy Rose is connected to a 1-inch pipe that passes through the floor to the outside. At the moment, we are collecting the urine in a container. When we move Gypsy to mid-state for the summer months, it will be piped into a stone-filled trench (French drain) beneath the house.

As for removing the finished compost, we haven't gotten to that part yet. Composting action speeds up dramatically with temperature, so I'm guessing that winter microbe activity will be slow. According to the manufacturer, the unit will need to have a portion of the finished compost removed three or four times a year for toilets in continuous use.

All the best,
Kevin

Jessica,

The composting mix purchased through Sun-Mar is a mix of peat and hemp stalks. The claim is that hemp stalks are better for controlling moisture, but a mix of peat and wood chips/shavings can also be used.

All the best,
Kevin

So, it's been a year...

Any chance for an update on your composting toilet, Kevin?

I'm wondering about using one in a small houseboat (not yet built). Thanks.

Darin,

Overall, the composting toilet has worked very well. I cannot ever foresee myself installing another flush toilet.

We have made a few adjustments over the year, though. To begin with, we found that the non-electric version of the toilet does not evaporate all of the fluid and we had to regularly empty the container that catches the excess. As with other users of this model, we've stopped "sending" all urin into the toilet, but rather use a small bucket to "collect" it. From there we pour it out on the land around us. (During the summer months, I simply go outside to pee.) If we lived in a more urban or suburban environment we'd have to come up with an alternative.

The other thing about the composting toilet is its sensitivity to temperature. It really needs to be kept in a spot that stays above 50 F in order to keep things active during the winter. Here in Vermont, with temperatures regularly falling to 10 or 20 below zero, our bathroom floor is sometimes pretty cool and I've wondered how that affects the compost.

We've had no odor (a sure sign of a problem with poor venting) and the finished compost is spread on the land nearby. Overall, a very positive experience - so much so that I'd love to replace the toilet on my boat with a composter.

All the best,
Kevin

Kevin, thanks a lot for the update.

I've wondered about the non-electric type for the same reason. Fortunately, I'm (and guests are) already used to "bucket and chuck it" for number one when sailing, so don't view that as a big obstacle.

Thanks also for creating this blog in general. It's an inspiration - presented as thoughtfully as the house was crafted.

cheers-
Darin

thank you Kevin for your very informative Blog. I have for years thought about installing a composting system in my cabin situated on the shores of Lake Champlain.

Well now it appears, for various reasons, this many be the best overall approach.

I have a couple of questions to ask that would help me considerably as I will be completing this project in the near future.(cabin is only used May - mid October.

After reading your thought and experiences I plan on purchasing an Electric model.
(1)Can you tell me the make of your system? (2) since I will be replacing the flush toilet is installation difficult? (3) The really, really important questions is how does this type of system mesh with state laws? Do you have a web address that would address my last concern?


I appreciate the time and effort that you took in writing this blog. To me this approach to waste disposal is very logical.
thanks again

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