thinking outside the closet

Millions of people still don't have clean drinking water, yet in modern cities we flush literally gallons of it down the toilet every time we go for a pee. This should be a crime.

There are lots of examples of low water toilets, dual-flush toilets, composting toilets, and waterless urinals. There are even incinerating toilets for those who dare. Here and there, these end-user technologies are adopted voluntarily or with incentive subsidies, but they are not being used in sufficient numbers to offset growth in demand for water. We seem to be stuck in the pilot project stage, meaning "Hey, I wonder if this thing works?". Of course it bloody works. Just do it. We don't have to go completely waterless, but there is no reason for any toilet to use more than six litres a flush.

But we should be beyond that by now, and here's why.

The challenge is not just the volume, it's also the quality of the water we waste. Sanitation engineers classify water into three general categories: potable (for drinking), grey (waste water from sinks, baths, showers and washing machines) and black (the nasty stuff). In modern cities, treated potable water is piped into buildings, and all the used (or wasted) water leaves the buildings through sewers. This is wasteful because it uses a one-size-fits-all approach. We are paying to treat water so that it's drinkable, then flushing 30% of it down the toilet.

People living in areas without municipally treated water have always understood the value of untreated rain, well, river or lake water. They collect it and use it for irrigation, washing and even drinking. Two old Canadian houses I have lived in were designed with a dual water system: one set of pipes distributing untreated rainwater to baths and toilets, and another set of pipes sending clean well water to basins for drinking and cooking.

In the modern urban version of a dual piping system, municipal authorities would go apoplectic just thinking about the health risks. Some cities have managed to mix drinking water and raw sewage without any help from meddling residents. Just imagine what could happen in the privacy of your own home...

Still, it isn't too difficult to set up a system to collect water from sinks and washing machines, send it through a filter, and flush toilets with it. If tree huggers can do it, surely municipalities can specify appropriate standards to appease their fear of litigation. It would increase indoor plumbing costs, but if municipalities can afford to give away low water toilets in order to avoid developing new water supplies, it should be worth their while to subsidize water recycling systems. Am I dreaming?

Footnotes:

1. In some countries it's relatively easy to find a toilet that not only uses 6 litres instead of 13, but actually does the job with that little water. The bowl is designed for it. You can go to Home Depot in Canada and find toilets labelled with the volume of water they use, and in some cities they are also rated for effectiveness by the local municipality. (If you follow the previous link, you'll see that there are some that don't work, but it's just a matter of weeding out the poor performers.)
2. In South Africa, go to any sanitaryware supplier and ask how many litres a toilet uses, and they'll have to phone the manufacturer. Lack of awareness is the first problem. The second is that the bowls aren't designed to flush solids with 6 litres, which may be why dual-flush toilets are supplied instead of low water toilets. Get the designs, manufacture the ones that work best, and make them mandatory.
3. The second link in the first paragraph of this post is to an independent Canadian study finding that, on average, dual-flush toilets saved more water than six-litre toilets. This is not surprising, given that the dual flush toilets used either 3 or 6 litres - no more. On the South African models, I'm not sure what the maximum flushing volume is.