EPA Region 6 is involved in a project that uses solar power to help mitigate vapor intrusions.

The project is being conducted at the Delfasco Forge site in Grand Prairie, Texas, to address trichloroethene (TCE) vapor migrating from a groundwater plume. EPA and the state of Texas had determined after extensive site investigations that technologies such as soil vapor extraction or natural attenuation would require several years to remove or significantly reduce the plume. The removal now under way involves installing exhaust systems in off-site buildings with TCE vapor concentrations above the action level. Long-term, inexpensive operation of the systems is enhanced through use of solar energy to generate the electricity needed by the exhaust fans.

From 1981 until 1997, the Delaware Forge and Steel Company used less than 2 acres of the site for metal forging and fabrication that applied degreasing agents containing TCE. Studies indicated that degreaser spills and releases had led to contamination of shallow groundwater extending below an adjacent 65-acre area with approximately 500 homes and six light industrial businesses.

Post-installation sampling of two exhaust systems indicated an immediate 95 percent reduction in TCE vapor in each building's interior. Exhaust systems will be offered to additional homes in the area defined by soil-gas sampling.