A highly toxic water pollutant, known as perfluorooctanoic acid (PFOA), last year caused a number of U.S. communities to close their drinking water supplies. PFOA contamination also is a pervasive problem worldwide. A research team now reports an inexpensive and renewable material that rapidly removes PFOA from water. The novel treatment effectively eliminates the micropollutant to below 10 parts per trillion, far below US Environmental Protection Agency and all state health advisory limits.