How do you clean up thousands of tons of contaminated soil? Conventional cleanup methods are costly and often ineffective. A newly developing technique called "phytoremediation" takes advantage of the natural abilities of plants to contain and remove toxic materials from soil and groundwater. At the Aberdeen Proving Ground in Maryland, waste pits containing toxic residues threatened the wildlife and water supply in a nearby wetland area. A field-scale pilot project at this site uses poplar trees to contain the toxic materials in ...  [click for more]