Pump and treat systems, however, are energy and capital intensive endeavors. Alternative clean up technologies are needed. While plants have often been noticed at sites with shallow TCE contamination, they were only recently considered to play any significant role in the remediation of the solvent. Research in various university labs, such as the University of Georgia-Athens, Kansas State, Iowa State, and the University of Washington, have found that several plants possess the enzymatic capability to degrade TCE and its decomposition products such as dichloroethylene. Trees under consideration are hybrid poplars and cottonwoods.
Field trials are under way at sites in Florida, Maryland, New Jersey, Texas, and Utah.
The Air Force's Aeronautical Systems Center Environmental Management Directorate is leading a multi-agency demonstration project in Fort Worth, Texas. The DOD's Environmental Security Technology Certification Program and the U.S. EPA's SITE Program are also involved in the project. A year later, NATO's Committee on the Challenges of Modern Society accepted the project as part of an ongoing technology transfer process within the NATO scientific community. Data are being collected to determine the ability of the trees, planted as a short-rotation woody crop, to perform as a natural pump and treat system. Although the trees were transpiring water from the contaminated aquifer, they were not hydraulically controlling the plume.