composting toilet research.

[mrsbrown]

According to the BCA, we probably need about 1 toilet per 20 people, so 5 toilets for 100 people.

According to this site, people produce about 520ml per person per day, including the "dry matter" (sawdust) required.

I like this bucket technique - the buckets have good firm lids (they make great nappy buckets), they are light enough to carry when full, and the resulting toilet is a standard sitting height.  OTOH, I can only find white buckets in Australia, so it's really obvious what's inside.  A dark internal colour is recommended.  There's another good description of this method here.

Those buckets are advertised on ebay and are 20litres each.  You don't want to fill them more than 3/4 full, so each bucket will be enough for 30 people each day.  For 100 people, for 5 days (being generous), I would need to collect 17 buckets.  Need some extra buckets for sawdust, so 30.  This will also provide buckets to be demolished to fit toilet seats.

Alternatively, there are a number of people selling larger plastic barrels with lids.

Ceres sell worm bins.  When I looked at them, they had aeration holes on the side, and a tap at the bottom.  That could be useful for the "store for 12 months option".  Because I think we need to drain the leachate into a trench.  The bucket method above relies on an open compost system to provide sufficient oxygen.

Ideally, we would use a container with a piece of mesh steel in the bottom and a tap to drain leachate.  Over the mesh we would put several layers of newspaper and some sawdust.  The container would be large enough that it doesn't need emptying or moving for 5 days. The seat  would sit on top of the container and would be at using height without needing steps.  Everybody using it would be amazed that it doesn't smell and remember to both cover their deposit and close the lid. The container would have a pipe with holes in it that won't clog but will allow for oxygen to get into the pile. When full, the container would have a tightly fitting lid with a few more, insect proof, holes.  It will be small enough that it's easy to move. In a years time we would open the lid and empty the pathogen free [1], non smelly humus into a trench which we would cover with 100mm of dirt for further aging and/or use as fertiliser.  And the process would start again.

[1] Actually, according to my reading, you don't need perfect composting conditions to achieve pathogen free in 1 year.  That just happens with time.