For centuries, rivers have sustained human civilization. From the Nile to the Indus, these blue-green and brown waters have been invaluable sources of irrigation. Unfortunately, they are equally convenient for waste disposal. Over time, cocktails of industrial effluents have caused these rivers to acquire much darker hues. Fortunately, Prof. Juan Hinestroza, fiber science, has created a pollutant-absorbing fiber that could help restore rivers to their former glory.