The disposal of human wastes is a practice that has, of course, been around as long as we have. As long as humans wandered about in small groups, nature provided disposal facilities everywhere. But as settlements grew, some form of technology was required to keep the wastes out of places that posed dangers to health and welfare. In modern societies, waste treatment is an essential part of the infrastructure of settled areas, and carries with it large environmental demands for water and places to deposit the residuals from treatment.
Low-flow toilets came into service as water consumption started to strain existing systems.
Before the 1950s, toilets typically used 7 gallons or more for each flush. By the end of the 1960s, toilets were designed to flush with only 5.5 gallons, and in the 1980s the new toilets being installed were using only 3.5 gallons. Today, a new toilet uses no more than 1.6 gallons of water in the U.S.
The flushing quantity was set by the maximum load and pretty much hit a lower limit. But this wasn’t enough for Australia with the driest climate of any continent.
In the late 1970s Caroma was awarded a Commonwealth Government industry grant to develop an effective dual flush toilet. In 1981 Caroma launched the first effective dual flush toilet. Two flush buttons operated the Caroma model – one for a full flush (11 litres) to remove faeces and the other for a reduced flush (5.5 litres) for urine. Others had previously developed a dual flush mechanism, but it was operated by only one flush button; pressed quickly for a reduced flush or held down for the full flush cycle. If the button was not depressed for long enough, the flush was not effective. Caroma also redesigned toilet bowl so that less water was required to effectively remove the waste.
The Caroma dual flush toilet was such an efficient water-saving device that all Australian states, other than New South Wales, soon introduced legislation to make the installation of dual flush toilets compulsory in all new buildings. In 1993 Caroma launched a new dual flush toilet which used only six litres of water for a full flush and three litres for a reduced flush (known as the 6/3 litre two button dual flush system).
This design has spread around the world and is even beginning to show up in the United States. It has importance to sustainability beyond its improved environmental performance. The design of this dual-flush toilet requires the user to stop, think and make a conscious choice before actuating the flush button. The interruption in what had been a transparent, automatic act opens up an opportunity for learning and changing the values that underly action. In this case, the unconscious belief is that the wastes simply go away, and so I have no responsibility for my actions. In a survey done in Metropolitan Boston years ago during the planning of a major waste treatment project, people were asked where their bathroom wastes went. The predominant answer was “away,” with no sense where away was.
Now, someone has come up with an innovation that breaks through the limits of previous designs by separating the liquid from the solids, thus keeping the nutrients–nitrogen and phosphorus–from getting to the treatment plant, and from there into the receiving waters.
There has been a steady rise of low-flow and other alternatives to the standard loo in the last few years, including stylish new dual-flush toilets, a line of toilets that flush with air instead of water, and a number of incentives and awards from governments for water efficient johns.
And a new study, published in the journal Environmental Science & Technology, finds that by and large, toilet users (aka just about everyone) are widely accepting of a new type of toilet — the NoMix toilet, pictured to the left and at bottom.
This new porcelain throne does precisely what you’d think it does — it separates liquid from solid waste, saving water by reducing the need to flush while simultaneously lowering the need for water treatment by keeping these kinds of waste separate from other, less polluted wastewater.
But from the point of view of sustainability, this improvement is a step forward, but also a step back from the dual-flush system, as technology has stepped in and done the job without creating any consciousness and subsequent responsibility on the user’s part. The critical opportunity to change beliefs and values has gone down the drain along with the wastes. Such opportunities are rare in today’s technology dominated world, especially where the devices are expressly made to avoid the need for reflection and responsibility. User-friendly usually turns out to be sustainability-unfriendly. So much for a better potty. How much better is still to be determined in any case. The developers note on their [website](http://www.novaquatis.eawag.ch/ueberblick/praxis/index_EN) that kids, in particular, have trouble aiming.