Longhorn Army Ammunition Plant

Environmental Restoration Program

LHAAP-35A (58)

Site Description/History

The LHAAP-35A (58) site, also known as the Shops Area, is located in the north-central portion of LHAAP and currently covers an area of approximately 11 acres. The surface features are a mixture of asphalt-paved roads, a parking area, and areas of wooded and grassy vegetation. The topography is relatively flat with the surface drainage flowing into the tributaries of Goose Prairie Creek.

LHAAP-35A (58) was established in 1942 as part of the installation’s initial construction. The facility was used to provide plant-operated laundry, automotive, woodworking, metalworking, painting, refrigeration, and electrical services. The site was active throughout LHAAP’s mission and became inactive in 1996-1997, along with the entire installation. The LHAAP-35A (58) site boundary has been defined differently in the past. Earlier investigations for LHAAP-35A (58) covered additional areas to the south, however the current site boundary encompasses approximately 11 acres, which also contains sites LHAAP-02, LHAAP-03, LHAAP-60, LHAAP-68 and LHAAP-69.

Remedial Activities

Between 1992 and 2008, multiple investigations were conducted in a phased approach to determine the nature and extent of contamination at the LHAAP-35A (58) site. In 2009, a Feasibility Study (FS) was completed. The findings from these investigations were that the shallow zone groundwater was impacted with volatile organic compounds (VOCs), while the soil and former sump/waste rack sump areas posed no unacceptable threat to human health or the environment. There have been no previous Remedial Actions (RAs) at LHAAP-35A (58) site. The remedy for this site was implemented in 2013 and includesd Land Use Control (LUC), Enhanced In-situ Bio-remediation (EISB) in the eastern plume, and monitored natural attenuation (MNA). The groundwater use restriction LUC boundary encompasses LHAAP-02, LHAAP-03, LHAAP-56, LHAAP-59, LHAAP-60 (Building 714), LHAAP-65, LHAAP-68, and LHAAP-69.

Contaminants of Concern

PCE, 1,1-DCE, TCE, and VC in Groundwater

Current Phase

In the Remedial Action Operation phase including MNA (sampling and reporting), well maintenance, LUC documentation, reporting, and Five-Year Reviews.

Future Phase

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