Microplastics, or tiny fragments of plastic worn away from the products we use and discard every day, are a common environmental problem. They’ve been found in the deepest oceans and on the highest mountain peaks, and in our bodies, too—researchers in Australia estimate that the average person swallows and breathes in a credit card’s worth of plastic every week. The health hazards of microplastics aren’t conclusive, but they’ve been linked to cancer, dementia, and reproductive disorders. And while there are ways to remove microplastics from the environment, these are generally expensive and can result in other types of pollutants.

Now, inspired by a visit to a water treatment plant and the realization that the U.S. Environmental Protection Agencey (EPA) doesn’t regulate microplastics, 17-year-olds Victoria Ou and Justin Huang of Woodlands, Texas, have invented an inexpensive, clean device that extracts microplastics from water. The process, which uses ultrasonic sound waves, is still being developed, but the pair are working to make it remove plastics from drinking water and industrial and residential wastewater. To help them continue their research, Ou and Huang won the Gordon E. Moore Award for Positive Outcomes for Future Generations, with a prize of $50,000.