Southwest of Chicago, 100 million gallons of sewage churn in the open air. Soupy and turbid, the brown muck comes through the Stickney filtration plant, the largest wastewater-treatment facility in the world, at a million gallons a minute. Few Chicagoans think about what happens after they flush, sending their refuse through a maze of sewers that could stretch from here to Toronto. Fewer still know their own shit could come right back to them, after the nutrient-dense slop is turned into fertilizer and used to nourish their produce. The circle of life. It rules us all.
Biosolids is a euphemism for processed shit. The circumlocution dates to 1991, when the Water Environment Federation (a national group of water and wastewater industry associations) formed a committee called, no joke, the Name Change Task Force. The task they forced was coming up with a polite term for excrement. Whatever the moniker, humans have used their own product as manure for centuries. The Chinese have recycled human waste since at least 500 B.C., building significant infrastructure to ferry “night soil” from cities to farms. The nutrient-rich fertilizer helped China build one of the most efficient farming operations in the ancient world. Mariners kept scurvy at bay by growing fruit plants in deposits of their own feces. Even today, gathering night soil is a full-time occupation for hundreds of thousands in India. It’s no overstatement to say that human manure helped colonize the world and then feed it.
In the United States, night soil waned with the rise of the Industrial Revolution. Today in Chicago, biosolids are on the rise. The biggest biosolids game in town is the Metropolitan Water Reclamation District of Greater Chicago, the utility with a name so long even its acronym leaves off a few letters. The MWRD, which manages all the wastewater in Cook County, is a collection of almost incomprehensible numbers. It filters 1.1 billion gallons of wastewater every day, flowing through 550 miles of sewers. Put another way, it pulls in 2,000 Olympic-size swimming pools of waste each day through a sewer system that could reach from Chicago to Toronto. It operates 105 miles of overflow tunnels that crisscross Cook County, underneath the district’s 883 square miles, serving all of Chicago and 125 other municipalities.
“The average water rec facility in the U.S. can treat 1 million gallons of wastewater a day,” explains Reed Dring, manager at the Stickney Water Reclamation Plant. Medium height and medium build, Dring would fade into a crowd if not for his enthusiasm. His dark eyes, shaded by a hardhat emblazoned with his name, flash behind his glasses. “Today’s an average day; I’ll see about 500 times that. On a rainy day, when we’re at capacity, this facility treats 1.44 billion gallons of water.” A smile flashes across his face when he gets to the big reveal: “So what an average plant can do in a day, I can do in a minute.”
All this comes at a phenomenal cost. The MWRD has one of the largest budgets in the state, at $1.2 billion dollars. The electricity bill alone is $27 million every year. To cut back on some of these costs, the agency tries to use wastewater as a resource, running a hydroelectric dam southwest of the city and using reclaimed heat to warm the Stickney compound. But biosolids are the MWRD’s biggest new frontier.
Of the 2,000 employees at the Stickney plant, the overwhelming majority wear weathered Carhartt jackets and Timberland work boots. There is no official uniform, but this getup, give or take a McDonald’s coffee cup, is the unofficial one. So a man in a turban stands out, especially when his office is a greenhouse.
Meet Dr. Lakhwinder Hundal, the district’s environmental soil scientist and head of the biosolids program. A wiry man, height accentuated by an olive-drab turban, Hundal explains in his soft Indian accent that biosolids aren’t exactly popular on the consumer market. It’s his job to turn that around. “We’ve been producing biosolids for centuries but still, for some reason, not everybody is aware of it. That’s why we’re doing so much educational work.”
The greenhouse is an oasis in the center of 440 acres of industrial machinery, used to show the difference between plants grown with biosolids and those cultivated in soil. Even under a steel-gray sky on a typical wintry day in Chicago, the greenhouse is warm and bright. Two dozen pots of green grass line one long steel table. Another holds small shrubs. A row of flowers dominates the center of the room. Two pots of each plant line the table, nearly identical, except in each case, the one on the left is larger, healthier, brighter. Those are grown with biosolids; the others are raised in standard topsoil.
“The whole idea is to see side by side the outcome you’re going to get using biosolids,” he says. “The nutrients in biosolids are released at the rate the plant needs. If you use a synthetic fertilizer, you put it in your pot and most of it washes down out of the reach of the plant. So the plant gets nutrients for the first couple days, then there’s nothing left. With an organic source of nutrients, you get sustained supply for the long term. You know how humans prefer organic food? It’s the same with plants. They prefer a natural source of food to a chemical food.”
Dring sees Hundal as a secret weapon for biosolids. “We send him out to talk to the farmers, with the long beard and turban, and they all look at each other like, ‘Who’s this guy?’’’ explains Dring. “But he’s so good that a half hour later they’re saying, ‘Wow, this guy’s sharp.’”
Biosolids have a complicated history in the United States, driven by the understandable aversion to spreading feces on your vegetable garden. Hundal’s most important goal is to reverse decades of stigma attached to the natural fertilizer. Water reclamation facilities have been producing biosolids for as long as they have been reclaiming water, but it wasn’t until the 1970s that production ramped up. Filtration techniques weren’t what they are now, and biosolids contained high levels of heavy metals like lead and arsenic. Though the technology behind biosolids has improved, Hundal says, he has to fight this legacy if biosolids are to become a useful fertilizer. Hundal insists the fertilizer is not only safe for humans, but beneficial to the environment. “Anytime you use a [synthetic] fertilizer, it was produced using a lot of fossil fuel. [Biosolids are] an already-existing source of nutrients, so it’s the best way to recycle those nutrients without producing new ones,” he says. “Think of it as a factory that makes bread. Once we have the bread made, we only need a toaster to warm it up. We have the ready product, now we are finding more applications.”
Right now, that application is producing 170,000 tons of biosolids fertilizer and giving it to farmers, schools, and park districts in the Chicago area. For Hundal, the next step is to focus even closer to home. “Our goal is to produce locally. We don’t want to go 50 miles away to give this to farmers who aren’t Cook County constituents. Our goal is to give it to our own constituents so they get the benefit back.”
One of Hundal’s concerns is that synthetic fertilizers aren’t just inefficient and expensive. When chemicals such as phosphorus and nitrogen hit the water table, they push out oxygen. This low-oxygen water runs off farms and courses through rivers and streams, wending southward to the Gulf of Mexico. After decades of pesticide and fertilizer runoff, the Gulf is left with over 5,000 square miles of ocean with too little oxygen to support life. For fish and wildlife, it’s a field of poison the size of Connecticut. “It’s not only a financial decision, it’s also being stewards of the environment,” he says.
Biosolids sound like the perfect environmental solution, then, providing an efficient new product by reusing an old one. But it’s more complicated than that. While biosolids can effectively deliver nitrogen and phosphorus to a plant, activists worry about what else they might carry. “I think the EPA’s regulation of biosolids is based on science from the ’70s and is testing for things that might have been more of an issue then, and not for things that are more of an issue now,” says Rebekah Wilce of the Center for Media and Democracy’s Food Rights Network in nearby Madison, Wisc. While water treatment agencies may have improved their methods for cleaning up heavy metals, Wilce contends there are plenty of new dangers lurking behind the euphemisms, from common chemicals to pharmaceutical residue. Take triclosan, an antimicrobial ubiquitous in hand soaps. “What’s left behind, the solids, what the industry calls biosolids and what most activists call sewage sludge – because that’s what it is – becomes more and more concentrated the more liquid is taken out and cleaned.” As the concentration of triclosan rises, it could pose an increasing risk to humans. “So if you’re washing your hands over a sink and you’re using antibacterial soap, triclosan is going down the drain, and that’s going into the sewage system, and that’s getting concentrated in the solids when they separate the water out. And those are contaminants of growing concern, these are contaminants that weren’t around 15, 20 years ago,” Wilce says. The EPA has established limits for heavy metals and pathogens in biosolids, but not for much else. “They’re not testing for things like triclosan or nanosilver or Prozac, for example.”
For decades, the arguments over biosolids were confined to environmentalists and soil scientists. In January, Whole Foods pulled the night soil argument from obscurity when it banned the use of biosolids for any of its produce. For Hundal and his quest for widespread acceptance of biosolids, it’s a major blow. The activists may get their wish, and the EPA could start regulating biosolids more heavily. In that case, Hundal would just spend more time here in the greenhouse, improving upon his creation, burning the midnight oil to reduce the amount of actual oil burned to make fertilizer.