Green Remediation Focus
Delfasco Forge
Grand Prairie, Texas
Superfund, NPL
Image Gallery
TAGA Van
Crawl Space Exhaust System
Exterior Vent
Solar Panel
Cleanup Objectives: Mitigate offsite trichlorothene (TCE) vapor migrating through soil into indoor air of residential properties from a contaminated ground water plume that resulted from the site's past use as a munitions manufacturing and forge operation since the 1950s.
Green Remediation Strategy: Employ onsite sampling and analytical techniques during site investigations, and use renewable energy to power exhaust systems addressing TCE vapor intrusion.
- Deployed EPA's mobile laboratory to collect and analyze soil and air samples in the vicinity of over 80 homes and private properties overlying the estimated groundwater plume.
- Conducted passive air sampling within a targeted four-block area to further define the plume.
- Installed an exhaust system consisting of a conventional 6-inch fan, operating at a rate of 200 cubic feet per minute, in the crawl space of buildings with TCE concentrations above the 14 µg/m3 action level.
- Connected each exhaust system through exterior-wall wiring to a 10- by 16-inch 10-watt solar panel mounted on the building's roof.
- Made available to each building owner a 24-volt battery with a lifespan of 5-7 years to ensure continuous operation of the exhaust system.
Results:
- Reduced materials, time, and costs associated with offsite laboratory analysis of soil and air samples, through onsite use of equipment such as a trace atmospheric gas analyzer and summa-type canisters.
- Employed passive air sampling techniques providing continuous, real-time analytical results that optimize field decisions regarding locations for follow-on sampling.
- Installed each exhaust system within two days, including less than one hour for the solar equipment.
- Incurred equipment costs of only $200 for the fan and solar panel, plus $50 for the battery, needed for each building.
- Achieved an immediate 95% reduction in TCE vapor in each building's interior following exhaust system installation.
- Avoided a building owner burden estimated at $96 each year for electricity to power the exhaust system, through use of solar energy.
- Mitigating offsite vapor intrusion until the contaminated ground water plume at Delfasco Forge is successfully treated through technologies such as soil vapor extraction.
Property End Use: Continued occupancy of nearby buildings, while onsite Superfund cleanup progresses
Point of Contact: Hope Schroeder, U.S. EPA Region 6
Update: August 2024
