Human Nature: Science, Technology, and Life.

Fecal Fuel

Several days ago, we looked at "toilet to tap," the increasingly useful art of turning sewage into drinking water. Orange County, Calif., which is pioneering the practice, is proud to tell you how thoroughly its filtration purges the sewage: "Thousands of microfilters, hollow fibers covered in holes one-three-hundredth the width of a human hair, strain out suspended solids, bacteria and other materials."

But what if the water isn't what you want? What if you want the sewage?

Who would want these lovely "suspended solids," you ask? Why, you would. Apparently, they're a fine source of environmentally friendly fuel. Agence France Presse reports that in Oslo, Norway,

city officials soon plan to introduce buses that run on biofuels extracted from human waste. ... The biofuel, which is methane generated by fermenting sludge, will come from the Bekkelaget sewage treatment plant which handles waste from 250,000 city dwellers. "By going to the bathroom, a person produces the equivalent of eight litres (2.1 gallons) of diesel per year. That may not seem like a lot, but multiplied by 250,000 people, that is enough to operate 80 buses for 100,000 kilometres (62,000 miles) each," [one official] says.

Fecal fuel is, if you'll pardon the expression, green:

In addition to being carbon neutral, it emits 78 percent less nitrogen oxide and 98 percent fewer fine particles—two causes of respiratory illnesses—and is 92 percent less noisy. ... "If our entire fleet switched to biomethane, carbon dioxide emissions would be reduced by around 30,000 tonnes per year," according to [an Oslo official].

It protects the food supply:

Contrary to first generation bio-ethanol, made from grains and plants, biomethane has the added advantage of not impacting food supplies, nor does it require fertilisation or deplete precious water resources.

In other words, instead of turning corn into fuel, which prevents you from eating the corn, we should feed you the corn first and then collect your droppings so that your sustenance becomes part of the fuel production process.

And it's cheap:

All included, the cost of producing biofuel equivalent to one litre of diesel comes to 0.72 euros (98 cents), while diesel at the pump in Norway currently costs more than 1.0 euro.

In fact, as a fuel supplier, maybe you should get a cut of the savings. Remember that pilot project in India I mentioned last year? The one where villagers get paid to use public toilets while their urine is tested for use as a fertilizer? At the time, I proposed that

we could try our own version of the Indian experiment. To do that, we'd need to devise an efficient method of converting public-toilet waste into something productive, such as fertilizer, without endangering public health. ... I bet somebody will figure out pretty soon how to monetize toilet waste. ... Restaurant grease [is] being illegally siphoned from filthy bins and barrels. Bandits are selling it for conversion to biodiesel. When bandits start siphoning public toilets, maybe governments will wake up and get in on the action. And you'll stop having to pay.

Nine months later, Oslo may have worked out the last piece of the puzzle. You go to the bathroom. We filter the excrement from the water. We recycle the water so you can drink it again. Meanwhile, we turn the excrement into fuel. All of this helps the environment, protects the food supply and saves money. And if you play it right, you get paid.

Anyone got a problem with this?

Crap and Trade, Revisited

Last week, I looked at the economics of pay toilets and argued that the toilets should pay you. In India, a pilot project is cleaning up the environment and trying to generate fertilizer by paying people to use "eco-sanitation" toilets. Meanwhile, American cities are charging people to use expensive, high-tech, energy-consuming Automated Public Toilets (APTs). Does the American approach really make sense?

Now it turns out that in at least one city, we're not even getting nicer toilets for our money. Two days ago, Seattle dumped its APTs. Reason No. 1: They'd been taken over by druggies and hookers. Reason No. 2: They were "less cost-effective than regular public restrooms."

And how. Unlike other cities, Seattle wasn't charging APT users. But the eye-popping number is the cost of its units. The Seattle Post-Intelligencer reports that according to the manufacturer, "A single stall automated toilet now goes for $200,000 to $220,000 plus on-site installation." And that's not even the real number, by a long shot. The total cost to the city, including maintenance, has been about $1 million per toilet.

How can toilets cost that much? Read the reviews. They have "handsfree washing and drying ability and an emergency button that automatically dials 911." They have "automated floor scrubbers" and are "cleaned by jets of water between each use." They have "metal doors that open at the press of a button and stay closed for up to 20 minutes. The units clean themselves after each use, disinfecting the seats and power-washing the floors."

Nice, huh? So how did they get taken over by junkies and prostitutes?

One reason seems to be that Seattle put them in places where that was likely to happen. Another reason could be that the toilets were free. I doubt it, since free APTs on skid row in Los Angeles haven't suffered the same fate. A third explanation is privacy: 20 minutes to yourself in a sealed chamber is perfect for taking care of your next fix or giving a blow job.

The toilets ended up so gross and scary that even homeless people wouldn't use them. One woman supplies this fantastic quote to the New York Times: "I used to smoke crack in there. But I won't even go inside that thing now. It's disgusting."

As a result, the APTs failed at the basic job of any public toilet: curbing outdoor excrement. A city spokesman ruefully tells the Seattle Times: "Even when these restrooms were running, we were still getting reports of people urinating and defecating in public." The spokesman says that at this point, Seattle "doesn't have a plan for providing public-restroom services" and is still "trying to figure it out."

Here's a wild idea: Bag the high-tech fetish. Put up plain old public toilets. That seems to be the lesson from yesterday's New York Times:

Rather than automated toilets, some cities are looking for cheaper alternatives that would be cleaned by human attendants. One prototype, to be installed next month in Portland, Ore., would cost $50,000 each, compared with some $300,000 for an automated unit. Randy Leonard, a Portland city commissioner, helped design that toilet, which in addition has open gaps at the top and bottom of the door, a feature discouraging drug abuse, prostitution and the like. But given that lesser privacy, it is unclear how popular such a toilet might be ...

Sorry, folks: Lesser privacy is the price you have to pay to keep out the druggies and hookers. And human attendants are the price of keeping toilets affordable. For the cost of one APT, you could put up six to 20 of those low-tech Portland units.

Now, if the Indians can just figure out how to monetize the waste, we can start paying users. Eco-san, anyone?