Everyone’s Poop: Video 
A Charred Life 
Everyone’s Poop
“Down the drain, off the brain” is how most people think about it, but human waste—or effluent, as the professionals call it—has a lot to tell us about how we live, what we eat, and who we are.
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If, on the other hand, the bacteria have a steady flow of oxygen, as they get in the aeration basins, something else happens. By way of explanation, Bhattarai hooked a tall plastic beaker onto the end of a long pole and dipped it into the frothing liquor in the basin. After a few minutes, the mixture in the beaker had separated into a top layer of clear liquid and a bottom layer of what looked like a loose pile of watery brown snowflakes. These were bundles of microscopic bacteria, known as flocs, gathered together in such huge numbers that they could actually be seen with the naked eye. “They are providing the treatment,” Bhattarai said. “And also the product of the treatment.” The flocs form around soluble and colloidal (greaselike) particles in the sewage, which have little weight and don’t tend to separate from the water on their own. Over time the flocs drag these particles to the bottom of the basins and form a layer of sludge, which is sucked out and piped away.
This is known as “activated sludge.” To make sure the microorganism population in the tanks remains vigorous, a portion of it is returned to the tanks, to act as a kind of yeast or roux for the next mixture. Once the process is up and running, it is relatively maintenance-free. “Salesmen will call from time to time pitching a new kind of bug, one that will do this or that for your plant,” Bhattarai scoffed. “The bugs we have are easy to keep happy.” Rarely, a bad batch of bacteria—for instance, one that forms flocs that tend to float instead of sink—will inhabit the aeration basins. When this happens, the offending tank is drained, and activated sludge from another tank is dumped in, to begin a fresh batch.
Bhattarai spends most of his time thinking up ways to make the plant run more efficiently. At the end of our tour, he took me to visit his pride and joy, a sludge thickener that he had helped redesign, resulting in a much more effective device and an award-winning paper in an engineering journal. Bhattarai had also redesigned the signage, since the original plaque, which was still there, had misspelled the word “thickener.”
“I wasn’t strong enough to pull the old one out, so I just had a new one made,” he said, pointing to a sign a bit higher up the hill. “If I die and they name something after me, I want it to be this.”
“A sewer is a cynic,” wrote Victor Hugo in Les Misérables, much of which takes place in the sewers of Paris. “It tells all.” Designed to collect both wastewater and rainwater from street-level storm drains, the original sewers of Europe, like those in older cities in the American north and Midwest, tended to have enormous tunnels, big enough to serve not only as metaphor-rich settings for novelists but also as unofficial repositories for anything anybody felt like getting rid of. In addition to the sewer men who mucked about in the tunnels under London and Paris, there was an entire caste of unfortunates—including an army of neglected children—who made their livelihood off things they found in the sewers: bits of copper, lumps of coal, even bone fragments, anything that could conceivably be resold.
Today there is a strange kind of anthropology available to students of sewage. One thing our sewers are telling us, for example, is that we are a self-medicating society. Last August, researchers at Oregon State University announced that they had studied the raw sewage of ten U.S. cities and ranked them according to the recreational drug of choice in each town: cocaine, methamphetamine, ecstasy, and so forth. The researchers would not give the names of the towns, citing promises they’d made to plant managers who granted them access, but the Drug Enforcement Administration is reportedly interested in the technology, which essentially amounts to urine testing an entire city with one sample. In a country where federal highway funds are dispensed or withheld according to the purity of air samples, it’s not too difficult to imagine a scenario in which cities that flunk their urine tests—say one part per million of crystal meth—might be similarly punished.
Many of the compounds found in recreational drugs and medicines actually survive the final chlorination and filtering process in a wastewater treatment plant and make it into nearby rivers and streams, where they flow into the water systems of other cities downstream. In this way, a dose of acetaminophen consumed in a mountain town in the Sierra Nevada eventually turns up in the digestive tracts of people living hundreds of miles away in Southern California. In 2002 the U.S. Geological Survey published the first comprehensive survey of pharmaceutical compounds found in the nation’s rivers. Some of the most common they discovered were the insect repellent DEET; triclosan, an antiseptic; and caffeine. Caffeine is a particularly good anthropogenic marker. Wastewater treatment plants remove about 99 percent of it from the waste stream, so if it is found in higher concentrations in a sample of river or lake water, you know there is a sewage leak occurring at some point in the system. Some of the most popular barbiturates of the fifties and sixties are also among the longest-lived pharmaceutical compounds. In all likelihood, some of the downers Elvis swallowed are still out there, somewhere, floating around in the ocean.
Of more concern is a class of chemicals known as endocrine disrupters, which mimic the actions of hormones and have been associated with sexual abnormalities in fish found in urban watersheds. The best-known source of such chemicals in treated wastewater is birth control pills, but a host of other chemicals, including perfume and soap additives, have now been identified as potential endocrine disrupters as well. Researchers are studying whether the presence of such chemicals in our drinking water is contributing to higher rates of diseases such as cancer and diabetes.
What we put into our bodies also has a direct effect on how well our sewers run. For instance, there is a sense in the pipeline world that concrete wastewater pipe is not lasting as long as it used to, though nobody is sure exactly why. The general consensus is that there is nothing necessarily wrong with the pipe, but that something we are doing differently aboveground is causing the waste stream to become, as the engineers say, more “aggressive.” Garbage disposals are at least partly to blame. They increase the amount of grease in the system, which slows the rate of flow in the pipes, which in turn allows more time for corrosive sewer gas to form. Other engineers point to the increase in protein consumption after World War II, when Americans began eating a lot more meat. A few years ago, during the Atkins diet craze, millions of Americans switched to a heavy-protein diet, so much so that it affected the futures market for commodities like cattle feed. If increased protein consumption really does make wastewater more aggressive, then our eating habits during the Atkins era must have put quite a stress on the nation’s sewers as well, something like putting 50,000 miles a year on your car instead of the usual 10,000.
Roy Bedichek, the great Texas naturalist, preferred to relieve himself out of doors. He believed that the advent of sewerage had broken a link in the ecological cycle, depriving the soil of vital nutrients contained in human excrement. Legend has it that even after he became an administrator at the University of Texas, he would seek out quiet places on campus to relieve himself, carrying a small trowel with him, as though he were on a camping trip. Citywide sewage collection presents an ancillary problem, one that may not have been obvious in Bedichek’s day, when Texas was still largely a rural state: Once you collect all the waste in one place, where do you put it? It’s a problem that gets worse as an area gets more urban and real estate gets more precious. New York City, for example, exports hundreds of tons of sewer sludge a year; in the nineties a good deal of it was shipped to far West Texas (on a train that came to be known locally as the “poo-poo choo-choo”), where it was spread on fields near the town of Sierra Blanca.
In the late eighties, Austin became the first city in Texas to try a new solution to this problem, in part by restoring the link Bedichek worried about decades earlier. Sludge from Walnut Creek and a second treatment plant is piped to the Hornsby Bend Biosolids Management Facility, located along a wide curve in the Colorado River, where a portion of the sludge is mixed with yard trimmings and turned into a compost known as Dillo Dirt. (Treated liquid from the two plants, meanwhile, goes into the Colorado River.) The compost is sold by the truckload, mostly to retailers and landscaping firms, which use it as a topsoil supplement. The organic content of topsoil—that is, the portion that sustains growing things—has declined in Central Texas, as it has everywhere in the U.S., in response to the pressures of farming and ranching, as well as erosion caused by development. Increasingly, topsoil has become a nonrenewable resource. “People look at it as gravel, instead of as a living thing,” said Jody Slagle, a manager at the Hornsby Bend facility.
Hornsby Bend also has a series of lagoons where excess liquid from the sludge is naturally—and gradually—treated by plants and animals that live in the water. Located on the site of Travis County’s first white settlement, it is a quiet and peaceful place, one that has become unexpectedly appealing to wildlife and observers of wildlife. Researchers from the University of Texas study leaf-cutter ants and dragonflies along the banks of the river, and thanks in part to the efforts of Slagle and a geographer named Kevin Anderson, the facility has become one of the top bird-watching sites in the state. Meanwhile, Anderson, who is writing his dissertation on what he calls “marginal nature,” is compiling a photographic record of all the organisms found in the soil.
Currently, approximately one third of Austin’s sludge is turned into Dillo Dirt; the rest is applied to hay fields surrounding Hornsby Bend. But Slagle would like to see all of it go to compost. “It could be one of the biggest keys to our future—if we can seamlessly integrate our waste into these cycles,” he said. Many Austinites are still leery of using human waste to fertilize their own yards, however. It’s the old instinct kicking in. “The closer it gets to their house,” Bhattarai explained, “the more they say, ‘I don’t think so.’”
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