Tomorrow’s Toilets

Stephen DeAngelis

April 1, 2010

At the close of yesterday’s post about washing machines and water, I indicated that I would next discuss how new designs for toilets are also trying to cut down on water use. Although human waste is not a normal subject brought up in polite company, some people argue that it should be (see my post entitled Infrastructure and Disease). As long as people are taking in food, the waste byproducts of that consumption will inevitably come out and have to be dealt with. Dealing safely with human waste requires a lot of water. Since water is predicted to become a scarce commodity — one over which people may be willing to fight (for more on the subject read my post entitled The Coming Water Wars?). Designers and engineers are trying to mitigate the water impact of sewage disposal through new designs. I first wrote on this subject in a post entitled Sewage and Cleantech. In this post, I want to concentrate on some new toilet designs that the good people at Gizmag have uncovered. The first design addresses two areas where shortages are a concern: water and electricity [“Computerised loo generates electricity when flushed,” by Mike Hanlon, no date provided]. Hanlon reports:

“As the humble computer continues its march into every nook and cranny, it offers unprecedented capability to many household objects which one might have thought entirely adequate. Take for example the toilet … released by Japanese manufacturer www.toto.co.jp. The computerised, eco friendly toilet basin is designed to fully automate the bathroom experience … so all you have to do is sit and be serviced! Its sensor system raises the lid as the user approaches and a hand operated panel to the side of the basin enables bidet-like automatic waterjet washing for sanitary cleaning – no hands needed. When you’re finished, simply stand up and the computerized basin flushes automatically! Now this level of functionality is impressive, but by no means unique – what’s so clever about the Toto system is that it GENERATES electricity from the movement of water being flushed from the cistern into the bowl – this toilet runs on eco-friendly hydroelectric power. It stores the electricity in a dry cell battery that lasts ten years without replacement. As well as facilitating a safe and efficient bathroom experience, the TOTO computerized toilet minimizes water use to when it’s really needed, by running a voltage over the contents of the bowl prior to flushing, analyzing the minimum amount of water required to achieve the result, and hence it uses an absolute minimum of water. When used in public toilets it also ensures maximum sanitary conditions through its non contact design. Thanks to TOTO, the smallest room in the house has just become the most efficient!”

I tried to find the computerized toilet on-line; but Toto has such a dizzying array of toilets I’m not sure whether this one made it to market or not. I did, however, find a very amusing article from about how confusing high-end toilets can be [“But Do They Flush? Japan’s High-Tech Toilets Do Nearly Everything, Even Redden Faces,” by Mary Jordan and Kevin Sullivan, Washington Post, 15 May 1997]. Jordan and Sullivan wrote:

“An American diplomat was at a dinner party in a Japanese home when he excused himself to go to the bathroom. He did his business, stood up and realized he didn’t have a clue about how to flush the toilet. The diplomat speaks Japanese, but he was still baffled by the colorful array of buttons on the complicated keypad on the toilet. So he just started pushing. He hit the noisemaker button that makes a flushing sound to mask any noise you might be making in the john. He hit the button that starts the blow-dryer for your bottom. Then he hit the bidet button and watched helplessly as a little plastic arm, sort of a squirt gun shaped like a toothbrush, appeared from the back of the bowl and began shooting a stream of warm water across the room and onto the mirror. And that’s how one of America’s promising young Foreign Service officers ended up frantically wiping down a Japanese bathroom with a wad of toilet paper.”

Hanlon also wrote about another water saving toilet called the Propelair WC [“New toilet cuts water consumption by 84 percent,” 15 July 2006]. He reports:

“Here’s a brilliant idea that we think needs recognition, particularly given that water restrictions are starting to become commonplace in western countries. The Propelair WC uses just 1.5 litres per flush compared with the 9 litres used by an average UK toilet– in one household alone, this can save 5 tonnes of water per month. The Propelair system looks like a conventional toilet and is used in the same way. It has a sealable lid that allows air to force waste and a small amount of water from the bowl, giving improved flushing and drainage performance. The system generates its own air, requires no ancillary equipment and connects to existing plumbing, but can also connect via flexible waste-pipes for awkward installations … and uses one sixth of the water used by a conventional toilet system. … Garry Moore, Managing Director of Phoenix Product Development Ltd, says: ‘As properties across the country face the prospect of compulsory water metering and developers face tighter restrictions on water use in both residential and commercial buildings, the importance of water conservation technology becomes paramount.’ Phoenix believe that water conservation technology like Propelair offers a cost effective and more easily deployed solution to water shortages than major capital investment in new water supply facilities. Moore adds: ‘The Water Research Centre estimates that even a modest uptake of the Propelair system could create a saving of 140 million litres of water daily, the same volume of water that Thames Water’s recently proposed desalination plant in East London could produce in a day.'”

I went to the Propelair website and it looks like the toilet has yet to come to market. Another exploratory toilet is called the NoMix [“NoMix toilets make a splash in European study,” by Ben Coxworth, Gizmag, 14 March 2010]. As its name suggests, the NoMix toilet separates liquid and solid human waste in order to reduce water usage. Coxworth explains:

“If you’ve ever considered the humble urinal, you might have noticed that it uses much less water than a toilet. It only makes sense – since they don’t receive any feces, urinals don’t need all the water necessary to carry such solid waste through to the sewer line. When you use a toilet and just urinate, however, you’re still flushing away just as much water as if you, uh, went ‘Number 2.’ If you were using a NoMix toilet, however, the Number 1 and Number 2 would go separate places, with the flushes being needed for solid waste only. It’s a good enough idea that in a recent pilot project, users in seven European countries gave the device a thumbs – or should that be bottoms? – up. The NoMix has what is essentially a urinal in the front half of the bowl, near the top. The urine runs from there to a storage tank. The back half of the bowl is like a conventional toilet, where the solid waste lands and gets flushed away. … The obvious advantage of such a system, as already mentioned, is the conservation of the water that would have been used in urine-only flushes. Its good points don’t stop there, however. By keeping urine out of the sewage system, wastewater treatment plants would reportedly have 80 percent less nitrogen and 50 percent less phosphorous to process… or more accurately, to try to process. The pharmaceutical residues present in urine would also be largely kept out of the waterways, where they presently pose a threat to fish and other wildlife. Instead of being flushed, it is proposed, the urine could be used as an agricultural fertilizer. What, you think that sounds kind of gross? Apparently, 85 percent of the NoMix users don’t think so. Farmers, however, aren’t so keen on the concept – only 50 percent of them liked the idea, while only 34 percent said they would use or purchase such a fertilizer. Indeed, there were some noted drawbacks to the NoMix. For the waste separation to work most effectively, men needed to sit down to pee – God forbid! And when women were finished with a urine-only sitting, they needed to do something with their used toilet paper other than flush it. Overall, 60 percent of the users encountered problems of some sort, most notably phosphate precipitate blockages in the urine drainage system.”

It doesn’t sound like the NoMix is ready for primetime. The next toilet is a good one if you are both short on space and ecology-minded [“Home Core all-in-one toilet aims to save H2O,” by Jeff Salton, 21 February 2010]. Salton reports:

“Integrating the toilet bowl, basin, mirror and a vanity table into one, the Home Core concept has a storage tank that can be used to flush the toilet with water saved from the hand-washing basin. The All in one toilet 03 water pressure on the unit can also be controlled to four different levels to help conserve potable water. Some might see it as taking the idea of all-in-one a step too far, but we think this unit would be great aboard high-end campervans, yachts, even aircraft, where space is at a premium and fresh water can be scarce. Actually operating the design by Dang Jingwei may take a little getting used to because the controls on the device are not as intuitive as some standard fixtures … and in case you are wondering, the orange interior is said to reduce the frequency of cleaning.”

The Home Core toilet is simply a design concept and not on the market. The ultimate in water-conserving toilets, however, may be one that advertises itself as near-waterless [“EVOLUTE – the near-waterless toilet,” by Ben Coxworth, 25 February 2010]. Coxworth reports:

“Toilets use a lot of water. And once they’re done with that water, well, it’s very … used. So, any time anyone can suggest a way of limiting water usage in toilets, Mother Nature wants to hear about it. Recently, Australian inventors Tom Trainor and Mark Hutton came up with a product that they claim uses up to 90% less water than a regular toilet. The EVOLUTE’s patented new technology offers a greener, drier alternative to our current ‘swimming pool for Evolute toilet your doo-doo’ model. The heart of this new toilet is a rotating metal sphere, that seals off the opening to the sewer line at the bottom of the bowl. The top of this sphere has a hollow bored into it, creating a cup-shaped depression. Your waste runs into this cup, then when you flush the EVOLUTE, the metal sphere is rotated upside down, releasing the waste into the drainage pipe. One jet of water rinses out the cup before the sphere rotates back up, while another rinses the sides of the bowl. And yes, there is a small pool of water that sits in the cup when you’re using it. Both the rotation and the water jets are powered by the hydraulic pressure of your water mains, so no electricity is required. Because sewer gases are blocked off by the sphere, and not by water, no S-bend or cistern is necessary – the EVOLUTE simply dumps (sorry) straight into the sewer line, eliminating the larger volume of water required for a conventional flush. According to its website, it uses less than one liter of water per flush, as opposed to the usual 6 to 12. It also take up 30% less floor space than a regular toilet. The EVOLUTE is still in the development phase, and is not expected to be available to the public until 2012.”

The challenge with these new toilet designs might be as much cultural as technological. In the United States, homeowners started complaining about low-flush toilets from the minute they were mandated by the U.S. Department of Energy in 1992. Because they used less water they have less flushing power. A survey in the late 1990s by the National Association of Home Builders Research Center reported that nearly 80 percent of people using low-flush toilets claimed they had problems with them. “There are four common complaints: multiple flushes are needed to clear solids from the bowls; residue remains in the bowl even after multiple flushes; the units clog easily; and they require more maintenance than 3.5-gallon models and cause more damage when they overflow” [“An Update on Low-Flush Toilets,” by Mike McClintock, theplumber.com, 14 October 1999]. Fortunately, toilets have gotten better over the last decade and complaints about low-flush have declined; however, I suspect that as people see less and less water in their toilet bowls the more skeptical they will be about them. The late Lewis Mumford wrote, “Today, the degradation of the inner life is symbolized by the fact that the only place sacred from interruption is the private toilet.” During those “private” times, you might want to ponder the importance of the lowly toilet and the sanitation system to which it attaches. With the world’s population predicted to rise by another 50 percent, wisely and safely dealing with the waste all those people are going to produce will become increasingly important in the decades ahead.