| 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 a limited area and possibly degrade these materials into nontoxic byproducts. At a former battery manufacturing facility in Trenton, New Jersey, a field of lead-tolerant plants is removing lead from the soil around the outside of the factory building. Residents of the surrounding urban neighborhood police the site, protecting it from intruders. Running time is 15 minutes. |