Profile on Sedlak by A.J.S. Rayl

David Sedlak was born and raised in Oyster Bay on Long Island, New York, the second child born to Burton and Arlene Sedlak. “Growing up in a town like Oyster Bay, it was hard not to be attracted to water,” he says, “and growing up in the 1970s, it was hard not to be concerned that chemicals humans were using might be having adverse effects.”

One thing he held onto from his youth was his love for being outdoors. Living on Long Island, young David spent a good deal of his childhood on the shore. “I had a lot of direct experiences with water, and that had an influence on my interest in studying the environment,” he says. “I recall that some species of birds, like the peregrine falcon, had declined through the use of chemicals like DDT and PCBs and that you weren’t supposed to eat fish from certain areas of Long Island sound, because they might be contaminated.”

The fact that a place he cared about looked clean and healthy, but wasn’t because of chemicals no one could see, made him curious. That was the spark. He wanted to understand how chemicals moved in water and whether anything could be done to alleviate the problems they caused.

As a student at Oyster Bay High School, David found encouragement from “an excellent teacher”—Lillian Murad—who introduced him to chemistry. “She got me really curious about how chemistry was important to many aspects of the environment,” Sedlak recalls. He relocated to Ithaca and the Ivy League that fall. “I went to college not really knowing exactly what I wanted to do,” he says. “Mainly, I went to Cornell with an intent to study chemicals in water and their impact on people.”

After graduating with his bachelor of science degree in environmental science in 1986, Sedlak was hired as a staff scientist at Environ International Corporation in Princeton, New Jersey. “The two Princeton professors who started the office at Environ, Joe Highland and Bob Harris, had been advocates for various citizens’ groups on issues like Love Canal in New York and [the groundwater contamination in]Woburn, Massachusetts,” he notes. At Environ, Sedlak learned about hazardous waste remediation and how contaminants in soil were difficult to clean up and could have impacts for very long times. “These experiences made me more interested in developing ways to destroy contaminants rather than move them from one place to another,” he says. Ultimately, they also directed his Ph.D. research.

Two years later, Sedlak enrolled in the doctoral program in water chemistry at the University of Wisconsin, Madison. “I went there because the water chemistry program had produced some of the best scientists and engineers who studied chemicals contaminants like PCBs and DDT. He earned distinction at Madison by taking the Graduate Student Paper Award in the American Chemical Society’s Division of Environmental Chemistry in 1990 and the Graduate Student Award in the same division the following year. With the completion of his dissertation, Abiotic Oxidation of Polychlorinated Biphenyls (PCBs), Sedlak, in just three and a half years (impressively fast for U.S. academia), was awarded his Ph.D. in June 1992.

He was already in Switzerland. Sedlak had taken up residence in Zürich in April 1992 for a two-year post doctorate fellowship at the Swiss Federal Institute for Environmental Science and Technology. When the fellowship ended in the summer of 1994, he accepted an assistant professorship in the Department of Civil and Environmental Engineering at the University of California, and moved back to the States and Berkeley that fall.

“My focus really changed when I got here to California in 1994,” Sedlak says. “It was the first time I'd ever been in a place where water quantity was a key issue. All of my life I had been in places where water quality was a key issue. There's plenty of water in Wisconsin and in New York and Switzerland. California was the first place I had ever been where water quantity was the driving issue. That got me interested in whether or not practices in which people used wastewater effluent as a water resource was a good idea and if the chemical contaminants that I knew could cause problems in wet systems could also cause problems in an arid climate.”

In 1996, Sedlak began investigating the quality aspect of water, studying chemical contaminants and looking into the fate of wastewater-derived contaminants. For that research, he developed some of the first reliable methods for measuring steroid hormones in wastewater. He reaped data that a decade later garnered notice as scientists around the world started reporting that steroids in water resources were causing feminization of wildlife.

Since his first experiments on steroid hormones, Sedlak and his students have studied the fate of other chemicals in conventional and advanced wastewater treatment systems and in engineered treatment wetlands. The found that nitrosodimethylamine (NDMA), a suspected carcinogen that can cause liver damage, is sometimes formed when chlorine is used for wastewater disinfection. Recently, they elucidated the mechanism of formation, and his group is now developing strategies to minimize NDMA formation.

Sedlak did make time to marry and have a family. He met his wife, Meg, in graduate school in 1988, and together they are raising two children, Jane, 12, and Adam, 9.

Life progressed professionally too, and in 2000 Sedlak was elevated to associate professor at Berkeley. His research broadened to include pollutant metals in wastewater. He documented, for example, how EDTA, a common chemical compound [ethylene diamine tetraacetic acid], which is added to everything from shampoo to food—it keeps metals in dissolved form—actually impedes the removal of copper, nickel, and zinc during secondary wastewater treatment. His research may lead to improved metals removal in treatment plants.

He and his students have also found measurable concentrations of human-eliminated pharmaceuticals, such as propranolol (Inderal) and over-the-counter medications such as ibuprofen and naproxen in places like the Trinity River in Texas.

In the summer of 2003, Sedlak headed “Down Under” on a Fulbright Fellowship to spend a year as a visiting associate professor in the School of Civil and Environmental Engineering at the University of New South Wales, in Sydney, Australia. “The Fulbright- objective was mainly to see how some of what I had learned about water shortages and water recycling in the U.S. looked in Australia and what we could learn by comparing these two systems,” he says.

“This started an ongoing collaboration, and I am heading back down there for three months early next year.” There is considerable interest in Sedlak’s work Down Under because Australia, like California has a very high population growth and with climate change is expecting even less water in the future; consequently, these two countries have become “leaders in the world in water reuse issues,” he says.

Sedlak wrapped his year in Oz as chair the Gordon Research Conference, Environmental Sciences (focusing on water in 2004), which brought together some of the leading scientists in the world to discuss issues related to chemical contaminants in water and their impact on humans and aquatic ecosystems.

It was a good conference and a good year. Not long after that, Sedlak became a full professor at Berkeley.

These days, when he’s not immersed in his research or service, Sedlak is in the classroom. He currently teaches graduate courses in environmental chemistry, water quality engineering, and ecological engineering. He also teaches an introductory class in environmental engineering, and is the lead graduate adviser for the environmental engineering program.

Additionally, he serves as an executive committee member for the UC Toxic Substances Teaching & Research Program, the Berkeley Institute for the Environment, and the Berkeley Water Center. He also served as group leader of the Environmental Engineering Program from 2003 to 2006.

Sedlak, an associate editor of Water Research and Environmental Science & Technology, has authored or co-authored 80 total papers to date and has presented his findings throughout the world. He also serves as a reviewer for various science journals, and has completed hundreds of reviews in recent years. He has served numerous times as a review panel member for organizations including the National Science Foundation, National Institute of Environmental Health Sciences, and the U.S. EPA.

The long-term goal, Sedlak says, is to develop cost-effective, safe, and sustainable systems to manage water resources. He is particularly interested in using municipal wastewater effluent to sustain aquatic ecosystems and augment drinking water supplies. “What I see is that water resources have been allocated to different users and when there’s a drought or when population growth outstrips the ability to provide water, that’s a real impediment to our way of life and it’s something that we’re going to have to come to terms with in the next decade,” he says.

“There are a number of possible solutions to these kinds of problems and they all involve tradeoffs between cities, farms, and wildlife,” he continues. “Wastewater effluent represents an important tool for addressing this problem, because it’s a source of water that we aren’t using now. In the future, wastewater effluent may be a valuable commodity that people pay to have instead of pay to get rid of. If this can be done safely and cheaply, it has tremendous environmental and economic benefits.”

More than a decade after he delved into his first study of wastewater contaminants, Sedlak is now noticing the rest of the country and other parts of the world catching up to the idea that set him on his course so many years ago—water quantity is connected to water quality.

A.J.S. Rayl is a freelance science writer based in Malibu, Calif. She has written on assignment for a variety of magazines, including Air & Space, Astronomy, Discover, Reader’s Digest, and Smithsonian, as well as online ventures including the Planetary Society’s website, http//planetary.org.