A mysterious vial of mud taken from a New Jersey swamp may end up offering a solution to several obstinate forms of water and ground pollution.

A few years ago, researchers in Peter Jaffe’s laboratory noticed that ammonium was inexplicably disappearing from a soil sample taken from the Assunpink Wildlife Management Area southeast of Princeton. Jaffe, a professor of civil and environmental engineering, suspected that an unidentified type of bacterium was breaking down the ammonia in the soil. What was truly interesting was the bacteria seemed to be converting the ammonia in the absence of oxygen – a behavior with potentially important implications for sewage treatment and other processes.