Humanure flushing toilets and worm farms

Steve Farmer wrote:How about throwing a few flushable chunks of charcoal into the toilet every x number of flushes? Would this save the need to open the IBC and add straw etc, or would it just end in  charcoal sludge similar to the problems of using sawdust?

Charcoal floats! You might have a problem getting it to flush. I really don't know what would happen as it's not something I've considered trying. It's possible to add it to the system, but personally I wouldn't rely on it as the only carbon component. It's not the natural habitat of worms and their associated ecosystem - that's the litter layer of the soil - so I think I would be very cautious about using it in concentration. Bottom line is that I try to imitate nature as much as possible. I think it's far less likely you'll go wrong doing that.

Just to update everyone on the system ...

It's now been approved for use by my local municipality under the provisions for 'septic tank with drainage'. (To alter legislation to give it specific approval would take far too long and the council wanted to start using the system right away.) Last summer myself and a Portuguese architect oversaw the first municipal installation of the system to replace a failed septic tank. There are more in the pipeline.

The design has been open-sourced and I've now created a website for it, including full construction details, maintenance, case studies and a forum where the community of users can ask questions and discuss problems.

Thank you Wendy for the work that you have given towards this project. It looks like a project that I will be doing on my farmstead.

I do have a question in regards to dealing with the government. What is the best way to approach this? Would working towards vermicompost or a modified septic tank approach?

Neil Stratton wrote:I do have a question in regards to dealing with the government. What is the best way to approach this? Would working towards vermicompost or a modified septic tank approach?

The Portuguese authorities I've dealt with are pretty pragmatic and open-minded. I have no idea how that all works in the 'States. I would guess a lot comes down to the individuals in your local municipality? You could certainly blind them with science by going armed with all the relevant research (I've linked some papers on the website}.

Wendy, I'm glad you're still here updating us. … ETA: And wow, your website www.vermicompostingtoilets.net is amazingly informative -- Thank you!

Our school in the Himalayas has dry composting toilets, but now that we have about 80 to 140 people living here most of the time, we are planning to install this kind of filter for the greywater before it goes to the canals along the trees. Until now, the greywater from the kitchen and from the bathing block go direct to little surface canals. The kitchen one, especially, tends to stink.

We don't have wood chips available, but all summer the local lumberyards happily give away wood shavings and sawdust. We've been trying to get sawdust for the toilets, but it tends to be mostly wood shavings and a few chunks, so I think we can use it. And I think you mentioned up-thread somewhere that it might be good to mix in a few autumn leaves (not enough to mat down) and sticks and bits, eg garden waste. Do you think that sounds good?

We had some compost worms in a big pile of drying cow manure last year -- I hope they haven't dried out or something, but I assume there are still some in there.

We got the pits dug and the stonemasonry done before winter set in, but we have to wait till March or April to finish them with the waterproof cement plaster. I hope it works!

This seems like a good thread with good info, so I'll just add in here that my worm humanure setup is one of the most amazing things I've ever done.  I've schlepped my way through handling sewage for 30 years, from RV tanks  (ugh) to septic tanks, composting toilets of several styles....and the worms handling it is beyond wonderful!

The main advantage is that there are flush toilets in the house, which makes everyone happy in the long run, especially visitors.

A funny aside, I noticed we always had Daddy Long Legs spiders in the house, up in the corners of the ceilings, couldn't figure out how they got in.  Just assumed it was because we were in a rural location.  Also lots of ladybugs got in.  After all of the compost potty weeds stopped coming inside, no more spiders/lady bugs inside.  

One observation about composting toilet height vs. flush toilet height, never realized this, but the low seat level of the flush toilet is conducive to making everything work nicely.  The composting toilets are very high, often with legs dangling straight down, which is not conducive to things working well.  There's actually something called a Squatty Potty that is said to be a preferred style.  So another plus for the flush toilet.

It's a pretty simple system, like the typical box arrangement pictured in this thread.  The ground does not freeze here, so I can't vouch for keeping the setup from freezing.  I know some friends in Canada have this method in a cesspit so the worms can go down below the frostline in the winter and survive.   Cesspits might take some special care not to pollute ground water or provide too much fertilizer for large trees that might grow shallow roots and fall over in a big wind storm.  Had friends who had this happen, not because of a septic setup, but because of grey water discharge, too much water on native trees.

Kept an eye on the gravel at the exit end for the first month to make sure it was draining properly and the worms were not drowning.  

Here are some specifics:

1.  No special worms, just worms found in my soil.  They do a great job, multiply like crazy.  Started with about 100 worms, and in just a couple spring/summer months they were everywhere in the box, and much bigger/healthier looking than when I put them in.

2.  Lined the sides of the box with native soil so the worms could recognize the environment.

3.  I use 1 1/2" rock at the outflow end of the box, wrapped in a large rectangle of chickenwire, folded over several times to make it strong, to block the end, but allow water to escape.  I am not a woodchip fan, because they break down and get into the waterline and plug it up.   Rocks worked well in my greywater reed beds, are easy to take out and rinse off and return if necessary.

4.  The water from the washing machine does not go through this box, because it seems like a lot of water in a day (sometimes 4 loads)  that might cause issues with the worms and draining too slowly, or flushing the vermicompost out too vigorously,  so we rerouted that water to come in farther down the line.

5.  The original setup of the interior of the box was to line the sides with native soil, then fill the middle third of the box with shredded paper, shredded egg cartons, about half the depth of the container.   All torn/shredded paper can be thrown in here.

6.  Added a smaller box downhill/downstream from the first main box that catches any worms that sneak out, and compost that washes out.  This is an experiment just in case using the compost in the landscape was possible, and to make sure the worms were collected and moved/managed easily without having to go into the main box.  

Six months later, the box contents looks like vermicompost, no odor, the worms are everywhere.  The contents stays at a level of about half full.  Not a lot of vermicompost gets collected in the second box.   I just can't say enough how impressive this is, and would highly recommend it over a plain composting toilet.

One more detail about the worm box....I was most worried about the heat that might collect in the box on hot days when the sun is directly on it for hours.  As great as the rock work around the box is in that photo on this thread, I don't know how thick it needs to be to be more like a cool cave rather than a hot oven.  

I put a wooden covering over the plastic box with a couple of inches of air space on all sides and top, with 2 inches of space between it and the ground, up on little blocks.  It's dark, so it won't be so obvious, but it seems to be okay, as the worms are staying there.

Thanks for outlining your experience Cristo. Great to have examples to draw on. :-)

One more note about flush toilets, we just had the experience of emergency nausea in the night, and thank heavens there was a flush toilet with clean water in it, because only having a composting toilet available....well.....doesn't get much worse than that!!