Air Force Plant #4 (General Dynamics)

Overview

Air Force Plant #4 (AFP4) is a 760-acre military aircraft manufacturing facility in Tarrant County, near Fort Worth, Texas. Lockheed Martin Corporation operates it for the U.S. Air Force. Manufacturing has taken place there since 1942. The site was added to the National Priorities List (NPL) on August 30, 1990, and cleanup has been ongoing since a remedial investigation began that same year.

The main contamination concern is trichloroethene (TCE) and related compounds in groundwater. These chemicals reached the shallow Terrace Alluvium Aquifer and the upper Paluxy Aquifer. The lower Paluxy Aquifer, which supplies drinking water to the city of White Settlement and recharges Lake Worth, remains uncontaminated. The nearest drinking water well, a quarter-mile from the site, has tested free of contaminants. Beyond groundwater, soils contain benzene, several polycyclic aromatic hydrocarbons (PAHs), and metals such as cadmium, chromium, copper, lead, nickel, and zinc. Vinyl chloride has also been found in surface water. About 18,000 people live within a mile of AFP4, and six schools sit within a two-mile radius.

The U.S. Air Force is responsible for site remediation. Early cleanup included installing a permeable reactive barrier wall in 2002, and physical construction was completed by September 2006. A spring 2023 Record of Decision Amendment shifted the strategy from a full pump-and-treat system to monitored natural attenuation (MNA) combined with dense non-aqueous liquid recovery and surface water monitoring. The TCE plume's leading edge has pulled back roughly 1,500 feet since construction was completed. A second phase of remedial action started on January 26, 2024, with completion expected between December 2026 and February 2027. The Air Force also began investigating per- and polyfluoroalkyl substances (PFAS) in groundwater, soils, and sediments in July 2024 to determine the extent of contamination and any health risks.

Groundwater migration is currently stabilized, with no unacceptable discharge to surface water. However, human exposure status remains uncertain. EPA has not yet gathered enough reliable data to conclude whether all unacceptable exposure pathways are controlled. A vapor intrusion study inside the manufacturing building is underway and expected to wrap up in 2026. The Fifth Five-Year Review was approved by EPA and the Texas Commission on Environmental Quality (TCEQ) in October 2024, and the next five-year review is anticipated by the end of 2028.

Community members can get involved through the Restoration Advisory Board (RAB), which meets annually each September and is open to the public. The site's public documents are available at the White Settlement Public Library in Fort Worth, through EPA's online database, and through the U.S. Air Force Civil Engineer Center's online Administrative Record.