Yet NASA's attempts to improve the disposal of its crews' excreta in the skies could lead the way for the earth-bound. The Environmental Control and Life Support System (ECLSS), which controls the living environment on shuttles and on the International Space Station, doesn't have the luxury of disposal: discharging trash into space has long been judged a bad idea. In the past, astronauts' conditions were considerably more primitive. Alan Shepard set off for the first Mercury shuttle flight on May 5, 1961, with no provision for any excretion, as the flight was supposed to last fifteen minutes. When it was delayed by four hours, Mission Control gave Shepard permission to pee in his space suit.
"It was a very real problem," says Amanda Young, curator of early space flight at the National Air and Space Museum. Fecal bags were developed for the Apollo missions. These stuck to the astronauts' backside, were sealed with Velcro after use, then stored until landing. Urine could be dumped overboard, but a hole big enough to dump feces in space could make the spacecraft too vulnerable. "If you have a break in the skin of the craft," says Young, "oxygen is sucked out of the astronauts. They begin to boil. They'd die in twenty seconds." For the moon landings, all astronauts were wearing "fecal containment devices"—like padded shorts—as well as a urine collection bag attached to the suit with a valve. No one used the fecal options, but a famous photo of Buzz Aldrin is known in certain circles as "Buzz whizzing."
Asking how astronauts go to the bathroom is one of the most common questions put during NASA or space museum outreach sessions, Young says. "Interest from the public is strange. Women don't care. They think, they worked it out and that's that. Men have an almost unhealthy interest. Children are interested in the poop factor." What everybody should actually be interested in is the drinking-pee factor.
Water weighs a kilogram a liter. It is heavy and therefore expensive: it costs $40,000 to transport each gallon up to the International Space Station. They don't want to load a shuttle or space station with extra weight, but they need water. So the ECLSS does what anyone would do in straitened circumstances: it turns urine into drinking water. On future space station missions, and on the planned 2012 mission to Mars, astronauts will be drinking their own urine, sweat, breath, and tears because they have to. Officially, this process is called reuse or reclaiming, and it may be the future of the planet. In fact, it's already happening.
Water is a fixed commodity. At any time in history, the planet contains about 332 million cubic miles of it. Most is salty. Only 2 percent is freshwater and two-thirds of that is unavailable for human use, locked in snow, ice, and permafrost. We are using the same water that the dinosaurs drank, and this same water has to make ice creams in Pasadena and the morning frost in Paris. It is limited, and it is being wasted. In 2000, twice as much water was used throughout the world as in 1960. By 2050, half of the planet's projected 8.9 billion people will live in countries that are chronically short of water.
But usage is only part of the problem. We are wasting our water mostly by putting waste into it. One cubic meter of wastewater can pollute ten cubic meters of water. Discharging wastewater into oceans turns freshwater into the less useful salty stuff, and desalination is expensive.
The reuse of wastewater effluent is now being proposed in several areas. In Toowoomba, Australia, where rainfall has decreased 30 percent in the last thirty years, local councilor Dianne Thorley told a TV interviewer that if she had her way, there would be "advanced water treatment plants bolted onto every sewage plant in Australia." She was convinced that a system using advanced ultrafiltration, reverse osmosis, and UV disinfection—or the best cleansing modern science can provide—would ensure adequate safety. Not everyone takes so enthusiastically to the idea. In San Diego, the so-called "Toilet to Tap" proposal was rejected by voters, and a new and expensive reuse project in Orange County, California, continues to cause consternation. In Arizona, a case involving a leisure firm wanting to use recycled wastewater to make artificial snow for a mountain considered sacred by 13 Native American tribes may soon head for the Supreme Court, so deep do feelings run.
Yet toilets already go to taps. Countless human settlements take their drinking water from the same sources into which other countless human settlements discharge their raw or treated sewage. Several American municipalities already do this "indirect potable reuse." The Upper Occoquan Sewage Authority's effluent supplies 20 percent of the inflow into the Occoquan Reservoir, which gives the residents of Fairfax County, Virginia, their drinking water. In droughts, it can supply 90 percent, and the sewage authority maintains that its highly treated effluent is cleaner than most water sources that end up in the reservoir.
Reuse works better when it involves camouflage. This technique is used, appropriately for a militarized country, in Israel. During a presentation at a London wastewater conference, a beautiful woman from Israel's Mekorot wastewater treatment utility, who stood out in a room full of gray suits, explained that they fed the effluent into an aquifer, withdrew it, then used it as potable water. "It is psychologically very important," she told the rapt audience, "for people to know that the water is coming from the aquifer." This is a clever way of getting around fecal aversion. Not having wastewater—and not wasting water—would be better still.
Devotees of ecological sanitation—"eco-san"—think that composting or urine-diverting toilets are the solution. Though it only makes up 5 percent of the flow, urine contains 80 percent of the nitrogen and 45 percent of the phosphorus that has to be removed at treatment works. Separating it at source would cut down treatment processes and costs. A urine-separation toilet also cuts water use by 80 percent. In the remote Chinese village of Gan Quan Fang, a schoolteacher named Zhang Min Shu extolled the virtues of his urine-diverting toilet to me with a big grin. "It's very scientific. There are two solid waste containers. We only need to clean it once a year. Once it's full, we swap the containers around." The contents of the full container are removed, hopefully now safely composted and pathogen-free, and applied to fields. The empty container moves into the full one's place, and another year should go happily by. Done properly, eco-san turns waste into safe, sowable goodness. Done properly, there's little argument against it. It is sustainable. It closes the nutrient loop, which sewers and wastewater treatment plants have torn open by throwing everything into rivers and the sea, damaging water and depriving land of fertilizer.
Yet eco-san provokes hostility. I hear references to the "eco-mafia" or to those "damned Germans and Swedes," the two leading eco-san nations. Sanitation experts who have tried and failed for years to persuade people to invest in a $50 basic cement slab and pit understandably wonder how they'd persuade people to spend $300—the average cost of an eco-san latrine—instead.
Petter Jenssen is an agricultural professor at the Norway University of Agriculture and a confirmed proponent of eco-san. I ask him why eco-san fans annoy everyone who isn't one. "The way people present eco-san is often a bit religious," he says, meaning the fundamentalist kind. "It's eco-san or nothing but. That can trigger people's resentment. Also, early systems did have drawbacks and they didn't see them." If done wrong, eco-san can leave pathogens in the composted or dehydrated excreta. Even if done well, it may not get rid of worm eggs. Also, it can require huge behavior changes that are notoriously difficult to achieve. Urine diversion toilets, for a start, require men to urinate sitting down, a shock to anyone used to the ease of what Germans call stand-peeing. Not every man, I suspect, would be as amenable as Mr. Zhang in Gan Quan Fang, who is serene about such things. "For me," he tells me with a big, satisfied smile, "whatever the toilet is, I use it. For example, here we eat wheat. When we go to the south of China, we eat rice. Otherwise we starve."
The flush toilet needn't be the holy grail of hygiene. Canadian academic Gregory Rose points to the example of cell phone technology. Developing countries without phone systems didn't bother with telephone poles and underground cables. They vaulted directly to cell phones and satellite communications. Similarly, in sanitation, Rose writes, "[t]he opportunity I see for developing countries is to leapfrog over the dinosaur technologies we have funded and implemented in the North and move to these advanced technologies," such as composting latrines or waste stabilization ponds. It is time for appropriate sanitation technology, not blind faith in flushing.
The concept of sustainability, as promoted by eco-san fans, has now penetrated even the rich world of engineering certainties and infrastructurally invasive sewers and wastewater-treatment plants. A large sewage-treatment plant uses a quarter of the energy of a coal-fired power station. As the United Kingdom's environment minister recently realized, "there's a carbon impact here that simply has to be tackled." David Stuckey, an engineering professor at London's Imperial College, thinks change must come, and it will be through economics. "People are looking to invest in wastewater treatment," he tells me. "You don't have to be a genius—just look at the price of resources and the cost of nitrogen and phosphorous. Once costs go up, people change."
Other things will also have to be tackled. Hospital pharmaceuticals in wastewater will be the next headache. In a recent investigation, the city of Philadelphia utility found 90 percent of the drugs it tested for, including evidence of medicines used for heart disease, mental illness, epilepsy, and asthma. A senior EPA official admitted that "there needs to be more searching, more analysis."
Petter Jenssen sits on the other side of the waterborne sewerage and ecological-sanitation divide, but he agrees. "We've invested so much in conventional sewerage. There are many economic interests tangled up in it. It depends on what politicians dare to do. Maybe it will take another fifty years to reach a sustainable system. But things can happen. Fifteen years ago I was considered a romantic scientist. Now I'm chairman of the national Water Association."