Composting toilets in an urban setting

ensuite loo web

Jeff Knowles had reservations about putting in a ‘long drop’ in his urban home, but was pleasantly surprised.

In 2001, my partner Chrissy and I engaged Strine Design to assist in the design of our new sustainable home in Queanbeyan. Under the leadership of architect and builder Ric Butt, Strine had been responsible for numerous buildings of a deeply sustainable nature in the Canberra area. Many of these included sustainable elements that were not available through other builders/architects at that time—composting toilets being a case in point.

Initially, it must be said, I had reservations (mostly to do with smell and a reputation for being difficult to maintain) about putting in a ‘long drop’, but several visits to see Clivus Multrum units already installed around the district convinced me that the idea was worth proper consideration. Chrissy was especially keen, due to the water saving and general ecological advantages.

Deciding to incorporate the unit into our home design and actually getting that design through the local council turned out to be two quite separate things. Fortunately for us, our architect Ric Butt had a lot of experience in this area. He’d pioneered the use of the units with forward-thinking councils, even in water catchment areas such as the Googong Dam where it was absolutely crucial for them to work well. He also had ready access to evidence from other composting toilet owners of the minimal maintenance required.

The eventual approval only took two weeks. With written agreement on our part to maintain and service the unit, our council agreed to pass the ‘radical design’—which, in fact, represented a return to many concepts that had previously been commonplace in Australian houses in the bush.

The house was duly built and the toilets (one CM10 unit with two separate toilets) were installed. We had them installed partly raised inside and partly submerged outside with a service hatch. This is one way of installing them—it means a couple of steps inside, but not as far to descend to do the maintenance outside.

We obtained wood shavings from the local sawmill and our learning began. Ric’s flippant suggestion was to start the composting process by just throwing in a dead possum. Not surprisingly, I couldn’t find said deceased possum lying anywhere around, so we finished up using a product from the supermarket called Actizyme.

Actizyme is designed and marketed as a natural drain cleaner but is also an excellent compost starter. It took me a while to understand that the active microbes in standard food composting systems are the same as the ones in the Clivus Multrum.

That established, we settled in to using the loos—and fielding the inevitable questions from visitors such as “Where is the button?”, “Why don’t they smell?”, “How much water do you really save in a year?”

The council came out to visit a few times in the first few years to check that the neighbours were not affected by smells etc from the toilets and that we were doing the right things by the greywater. Now they occasionally send people to us who need help with the approval or maintenance processes.

Read the full article in ReNew 128.