Clivus Multrum at the Bronx Zoo
by Lloyd Alter, Toronto on 03.15.07
We look forward to the upcoming launch of Dave Praeger's Poop Culture: How America is Shaped by its Grossest National Product. The author has a blog where we learned about a new installation of Clivus Multrum composting toilets at the Bronx Zoo, avoiding construction of a huge septic system or expensive sewer construction, and saving over a million gallons of water a year.
Clivus Multrums are big, and usually used in commercial installations. Where we have tried them we have found them to be odour free. However, people used to a normal flush toilet don't like the idea of sitting on an open pile of compost, even though in a Clivus it can be a long way down. They have developed a system where it looks and functions like a conventional toilet using a mixture of bio-compatible soap and water to carry toilet waste to the composting system below via a conventional 4” drain line. From Justin's earlier post, it looks like a valve toilet design.
It is supposed to work with as little as three ounces of water, and they suggest that one can even put an offset into the drainpipe. I have previous experience with a design that used a porcelain valve toilet and an offset pipe going into a central composter; I spent a lot of time with a disgusting wire snake, trying to keep it clear, and my family used a lot more than three ounces of water to flush. If this works in a public milieu where you can't beat up the customers for using too much paper, it is an amazing advance.
Dave Praeger questions the design of the flush button, in a hole on the top of the tank.
"Whenever I’m in a public toilet, my inclination is to flush with my foot. That’s what my dad taught me, and the lesson stuck. No matter how clean-smelling these toilets may be, they’re still public toilets, and public toilets are disgusting. No one wants to touch anything in a public toilet.
I didn’t want to touch the toilet lid, which I had to move to access the flush button. And I certainly didn’t want to touch the flush button — never mind touching it twice, as the sign implores. Enlightened pooper though I may be, I can only imagine all the disgusting fingers that have been jabbing into that hole."
We have mentioned before how perhaps we should be considering using composting toilets in houses, rather than having city-wide collection of waste. People talk about going off-grid; we should now talk about going off-pipe. If this system can cope with the needs of the Bronx Zoo, it can certainly cope with the needs of a family at home. Clivus Multrum also has an interesting gray water processing system; put them together and stop exporting your waste to somebody else's backyard. And I agree with Dave about the flush button ::Poop Culture via ::Green MNP
That's really aI didn't know there were toilets like that. really interesting. That book looks great.
How come it doesn't smell, though? You'd think the smell would drift right back up through the toilets.
LA: like all good composting toilets, there is a exhaust fan that sucks all incoming air through the toilets so none gets back up.
"LA: like all good composting toilets, there is a exhaust fan that sucks all incoming air through the toilets so none gets back up."
I'd hate to think what happens when the stuff hits that fan!