Poop is not a dirty word to UW soil scientist

A chef-turned-professor digs into a new crop — turning recycled waste into better soil, better food and better health.

From Manhattan chef to UW soil scientist, Sally Brown’s career path took a few zigzags before she became one of this country’s leading experts on cleaning up damaged soil. Along the way, she has also become an unwavering advocate for the use of bio-solids—a.k.a. treated human poop—to cure hurt dirt and give everyday gardeners the biggest green thumb on the block.

Sally was named after the character in Charles Schultz’s famous Peanuts cartoon—mainly because her parents enjoyed the comic strip. But Schultz called the straight-talking Sally “the complete pragmatist,” and it’s obvious that’s a trait she shares with the UW researcher.

Research without practical use holds no interest for the real Sally Brown, who has cleaned up contaminated soil throughout the country. She worked on restoring the former Bunker Hill Superfund site in Idaho, which was contaminated by mining and smelting ores that were rich in lead. She also dealt with zinc associated with cadmium and arsenic contamination from a smelter and tailings from the milling of the ores. To combat those nasty elements, she employed bio-solids as well as wood ash and log-yard waste to reduce erosion, correct the soil pH and provide a vegetative cover at the site.

Brown also worked to mend land at a Superfund site in Jasper County, Missouri, that was poisoned by mine tailings. Today, you would have no idea how that area was ruined by lead, zinc and cadmium from smelter deposits and mining waste, given how it now sports lush vegetation and has attracted animals to what had been their previous habitat.

Brown—who first got involved in Superfund site cleanups during postdoctoral studies at the United States Department of Agriculture (USDA)—is a kind of dirt alchemist who knows how to turn bio-waste into a soil amendment that can improve damaged or poor-quality soil. She advocates for the use of bio-solids to complete a cycle in which waste is used to increase crop yields of everything from wheat in the nation’s breadbasket to pumping up a backyard green bean harvest.

We make about six million tons of bio-solids a year, and half of it goes to waste. That drives me nuts.

Sally Brown

The Peanuts’ Sally annoyed Charlie Brown because she didn’t always do the right thing. The UW Sally Brown is often annoyed that so many people don’t do the right thing when it comes to solid waste, often dubbed pejoratively as “sewer sludge.” Take, for example, the kerfuffle with Whole Foods Market this past autumn. The market banned produce farmed using “sludge” as of September 2014, a ban that remains in effect today. Brown strongly disagrees with the market’s ban and she has good company: the mayors of Seattle, Tacoma, Madison, Wisc., and the King County Executive have all urged Whole Foods to change its position.

Brown got involved in the Whole Foods situation at the invitation of the Wastewater Treatment Division of King County, which asked if Brown could prepare a response to counter the retailer’s position.

The Whole Foods ban came about when a small group of activists claimed that crops grown with bio-solids could make people sick. The Center for Media and Democracy claimed the ban was a victory for consumers since there was little scientific research on the safety of using bio-solids. But that wasn’t quite accurate; Brown and colleagues have done extensive research on this subject, and they say food grown with biosolid mulch is safe for human consumption. So, too, they say, is treated wastewater. “In many cases,” Brown wrote in an 2012 article for Biocycle magazine, “effluent from wastewater is easily treated to make water that is safe for growing grass, irrigating crops, and making ice cubes.”


Brown’s route to a career as a soil scientist touting the good that can be made of waste was a bit quirky. She grew up on Long Island, went to Williams College in Massachusetts, and was on track to be a reporter. She even got a job writing for a fledgling paper in New York City. “But I realized I wanted to do stuff, not write about it. In a way it’s connected to how I do my work now. I like to get my hands dirty, see how things work.” After college, she traveled to Israel and worked on a kibbutz in a chicken house. Then she moved back to the states and went to work as a prep cook in a Manhattan restaurant called Soho Charcuterie.

“I remember feeling very glamorous watching Warren Beatty chewing the French toast I had made. He was with Diane Keaton when they were filming Reds,” she recalls of that time in 1980. Her time at that restaurant was short-lived, however, as HIV/AIDS felled half of the crew, and the business closed.

Her next adventure involved a move to New Orleans. “I wanted to train with a great American chef,” she says. “I opted for New Orleans and went to work for Paul Prudhomme.” But when Prudhomme’s sister directed her to go to the kitchen and retrieve a hog’s head, “It was the death knell for my culinary aspirations,” Brown recalls.

While kitchen work was out of the question, her interest in food continued to blossom, but in a different direction. Ahead of her time, she began thinking “farm to table” was the way to go and began providing Long Island-grown produce to Manhattan chefs. Starting out in 1986 with her mother’s Chevy Nova, she drove 200 miles a day delivering freshly grown produce. Prudhomme, who by then was cooking in New York City, became her first high-profile client. Eventually, the seasonality of the business, long hours on the road and the unfortunate penchant of restaurateurs to go out of business without paying their bills put an end to that chapter of her life.

Her decision to become a soil scientist and her advocacy for bio-solids sprouted from her experience in the food world. “I went to graduate school [at the University of Maryland] to connect farms with cities by way of poop,” says Brown, who has a way of explaining things she takes quite seriously with a bit of humor.

Early in her academic career, Brown discovered something curious and astounding: When bio-solids are added to soil poisoned by substances like cadmium, the soil actually becomes much less toxic. In her eyes, that has incredible potential to cure toxic land—and do great things for things that grow in the ground. “We make about six million tons of bio-solids a year,” she says, “and half of it goes to waste. That drives me nuts.”

Bio-solids have even played a role in Brown’s love life. She met her partner of 17 years, Chuck Henry, at a USDA conference on the topic, and then they worked together on the Bunker Hill Superfund site in Idaho. “Poop brought us together,” she says.

It also energized Henry’s career at the UW. After earning his doctorate in 1989 from the UW, he spent the next 27 years as a research professor and lecturer in the College of Forest Resources. Like Brown, he is up to his eyeballs in bio-solids. While he was teaching, he endured teasing from his graduate students who said he lectured about composting toilets but had never developed one. That teasing inspired him to design and build his own while on a three-month design-build study abroad program with students from the Architecture Department. With parts of the world desperate for improved sanitation—such as a place like India, where nearly 600 million people don’t have toilets, according to The Economist magazine. (Worldwide, 1 billion people don’t have access to toilets.) To put things in perspective, get this: While 6 billion of the world’s 7 billion people now have cell phones, only 4.5 billion have toilets, according to UNICEF.

The food supply may become precarious. We have taken the importance of soil for granted, but you can’t have a symphony if you can’t eat.

Sally Brown

Thus inspired, Henry and his students developed a composting toilet that they called “The Poo Screw.” Later, Henry and his students took their idea to Costa Rica, where they installed a composting toilet on a farm. By 2006, it was clear to Henry that the composting toilet was commercially viable. That year, he brought the project to the UW Center for Commercialization (C4C), whose role is to propel research out of the UW’s laboratories and into the world. They connected him with a mentor, Michael Tobiason, who is vice president and general counsel for Dale Chihuly. “The center put a lot of resources into figuring out where this was going,” Henry says. With C4C’s help, Henry launched a company called Critical Practices, LLC. The composting toilet itself is called the Earth Auger Composting Toilet.

Since 2011, the company has received more than a half million dollars through an Ecuadorian nonprofit and the Bill and Melinda Gates Foundation. To date, more than 500 composting toilets have been delivered to Ecuador for installation in primarily rural communities. Although there are other composting toilets on the market, the one developed by Henry, which costs $150, is among the cheapest to operate. The compostable toilet, if applied on a global scale, could dramatically reduce mortality and sickness from lack of sanitation. In 2002, for instance, 3 million people died from water-borne communicable diseases caused by a lack of sanitation.

The beauty of the new compostable toilet is its elegant simplicity. “It’s like backyard composting,” he explains. “You put your food waste together and turn it a couple of times and then you put it in your yard. Composting toilets are a lot the same. You are not using water to convey the waste.” So it’s clear the technology isn’t the problem. The real obstacle is how people react to the idea of using bio-solids for municipal and home-garden use. “People are terrified of bio-solids,” Brown explains. “They flush the toilet and it goes away, and that’s what they’re used to. They don’t want to think about it.”

But one thing may make people start thinking about it: climate change. Brown says that climate change will bring extreme variability in weather, so resources like bio-solids and water will be even more important than they are today. “The food supply may become precarious. We have taken the importance of soil for granted, but you can’t have a symphony if you can’t eat. You can’t have an iPod if you can’t eat,” she says.


Both Brown and Henry have made the world a better place not only through their research and innovative inventions, but because of the students they have taught over the years. One star student, Mark Cullington, is the former head regulator for bio-solids in the state of Oregon. Now he’s a lead scientist and consultant for Kennedy/Jenks, a civil engineering and environmental sciences firm in Oregon. Serving as a research assistant studying bio-solids, Cullington, ’00, worked under Henry’s supervision as he pursued a master’s degree at the UW. His student experience involved hands-on research and a thesis in which he looked at the use of bio-solids on an old mine site in Pierce County. “I evaluated soil and groundwater chemistry on that site,” he says.

“Chuck is super smart and it was his personality that drove into his students the idea that what you are doing at the UW needs to apply to the real world,” Cullington says. “He said that to all of his students. Chuck wasn’t an absent-minded professor. He was very driven to have us apply our science outside of academia. His first language was math. He had us learn math and work in his lab. I credit Chuck with where I am today,” he says, adding, “I don’t know one of his students who isn’t employed doing fun, challenging and important work.”

Kristen McIvor, of Seattle, worked with Brown from 2005 until 2011, when she completed her dissertation. She is now program director for Harvest Pierce County, supporting community gardens throughout Tacoma and Pierce County. From the ground up, McIvor, ’11, built a community garden system in Tacoma that’s connected to the bio-solids program. “When I first met Sally she took me to meet the TAGRO team.” TAGRO, short for Tacoma Grow, is a product made from a blend of pasteurized wastewater byproducts, a.k.a. bio-solids, and is delivered to all the community garden sites. Tacoma now has more community gardens per capita than Seattle, thanks in large part to McIvor’s work.

“My education was totally worth it,” she says of her student experience. “The whole idea was Sally’s. I had never been to Tacoma or heard of bio-solids. The community garden program is different because of my soil degree from the UW and because of my comfort and familiarity with soil science. Without the UW degree my work here would have been a lot harder,” she says.

Brown and Henry are making contributions that are rippling out into the world. It can be frustrating at times because people just want to keep doing what they’ve always done—wasting water and ignoring bio-solids—in a world that desperately needs to conserve and carefully leverage these resources for humanity. Today, the bottom line is that most people just don’t want to think about poop. However, with contributions from Sally Brown and Chuck Henry, that bottom line is beginning to change.