Calling Composting Toilet Veterans

[Yankeesouth]

I pose the following to those of you who have experience, either recent or past, with composting toilets.

In the 20/20 hindsight we all possess, as far as your personal experience goes what are the top 3-5 pros about having a composting toilet and top 3-5 cons?  I'll be honest......I am still wavering on putting one in.  My concern is the 8-10 times I will use the cabin from November to March. (Temps won't get much above 50 often during that time.)

What real world worries and/or problem can I expect?  If you had to do it over would you go with a dry flush or low flush?   Basically would you do anything different or choose a different model/system?  I am leaning towards a dry flush system.   I think many folks have seasonal cabins and, as with mine, are unable to keep a composter in a heated place therefore it functions as a holding tank.....no composting in winter months.   Thoughts?

[MountainDon]

The big plus is no septic tank. But that can be negated if your location identifies kitchen waste water water as "black" water.

The main negative is cold temperature non-performance, IMO. A self contained unit like the Sun-Mar works well in a warm indoor environment. If winter temperatures are low and the cabin left unheated between the occasional use through the winter that can be worked around. In late fall make sure the drum is as empty as you can make it. For us that means having to remove drum contents before the composting is completed. I've been disposing of that material by burning it off in slash piles. An alternative would be to transfer the material to a pit toilet or external composting drum as those with 5 gallon pail systems will use. The sporadic use over the winter will be of low enough volume that the drum in the toilet will simply store it until it's warmer.

Dry flush for me as that was one of the advantages that attracted us. No water use is even better than low water use for us. YMMV. Water can exacerbate the freeze problems as will any bends in the waste pipe used in systems with remote composting drums.


When everything is looked at I would actually like to have a small septic tank using the infiltrators, couple with a good sized underground cistern and rainwater collection system. In our case that would probably still be less expensive than a 600 foot deep drilled well. 

[Squirl]

I will start this with the caveat that I have not yet installed mine.  I have the low flush cetrex unit approved for my septic permit.  I hopefully be able to give better first hand knowledge this spring.  I believe OlJarhead has a central unit also and has been pretty happy with his.

Pros so far. 
No septic tank ($725). No digging a septic tank.  No hiring someone to pump the septic tank ever few years.
Low water flow.  It saves me enough that I can do rainwater catchment and a cistern.  No $10,000 well.  Smaller offgrid electric system ($500) because I don't need to pump water from a deep well.
Cheaper than any other alternative septic design.  Since I failed the deep hole test, I would have had to get a different property because of the cost of all other alternatives.
Better than an outhouse.

Cons so far.

Explaining it to people/future guests.  I get the ick factor that they would have to flush a toilet and it goes to a box attached to the house.  Still imagine explaining an outhouse in comparison.
Lower resale value - again same as above.
More work than a toilet.  You don't just flush and everything goes away.

I am building mine in a central unit attached to the side of the house in its own little insulated box.  Hopefully if it needs auxiliary heat, the amount of insulation and the small cubic footage would require very little btu's to keep above 50 degrees.

[Erin]

This is our composting toilet:

It is in daily use at our house as it's the only toilet we have.  This is how you "flush"--


There is a 5 gallon bucket under the seat that serves as the receptacle.  Emptying consists of dumping it on a compost pile and covering with straw.  There is no smell of any sort with either the toilet itself OR the compost pile. 

Do some reading on "Humanure"
http://humanurehandbook.com/instructions.html

I had done quite a bit of research on composting toilets before we went this route and found a lot of mixed reviews for the commercial options.  For a basic sawdust toilet, on the other hand, I found almost no negative comments.  Better than that, I built in an afternoon and it cost us about $50. 

[rick91351]

Erin I really like your set up and certainly might use it this summer.  I think it would be great to build a privy up at the ranch near the orchard and where our kids and grand kids camp.

If we do not choose to add the product to a compost pile.  We could discard it in a slash pile and incinerate in the late fall early winter.

Used by us when working the orchard or by the campers, it certainly would not produce a huge amount discarded materials.  You could do the same in a shop area where you could make a partition but no plumbing to winterize or freeze. 

[Tinga]

I'd like a bit more input from users as well. My husband is very iffy about it and automatically assumes it will stink.
Our plan is to build stacking bathrooms with a SunMar Centrex system. The unit will be outside in an insulated shed and on a heated slab (hydronic heating)
Since we don't get freezing weather here too often (Coastal Oregon Valley) using a Sumar type toilet instead of septic seemed like a good compromise.

[comanche]

I use the sawdust method as well. As long as it gets emptied every couple of uses there's no stink. We've gone longer than we should have with it a few times and it will stink when the lids opened but the smell is contained with a closed lid.

Erin- yours looks great. I'll be mimicking that design when I get around to making mine a bit more permanent.

[Erin]

We've gone longer than we should have with it a few times and it will stink when the lids opened but the smell is contained with a closed lid.

Really??  A 5gallon bucket will last us about 2-3 days. 
No stink, lid up or down...