Parkersburg, W.Va., is a city of 33,000 on the Ohio River. For decades, a DuPont plant 7 miles upstream has polluted the local waters with ammonium perfluorooctanoate (APFO), a surfactant used to make Teflon. As debate raged about possible health effects, Parkersburg South High School student Kelydra Welcker, now an 18-year-old college freshman, took action. “There was little being done to discover ways to remove this chemical from the environment,” Welcker says. “I knew there had to be a solution, and I wanted to be part of it.”

She devised a simple test for the presence of the chemical in water, which involved measuring the foam on a shaken sample of boiled water. Then, using hand-me-down chemistry equipment in a makeshift lab set up in a trailer behind her house, Welcker developed a way to remove APFO from water by combining granular activated carbon, the stuff that cleans fish tanks, and electrosorption, which draws remaining APFO ions to a pair of electrodes. She has made a desktop unit for treating small quantities of domestic drinking water, and she hopes the local utility company—with assistance from DuPont—will scale up her technique to treat water on a community-wide basis.

“I hope people understand that science isn’t just people in white lab coats speaking gibberish,” says Welcker, who has been winning science awards since she was 13. “Scientists are real people who want to make a positive impact on their world.”