TexAmericas Center (TAC) retained Matrix to help with property transfer strategies for the former Lone Star Army Ammunition Plant (LSAAP) after it was closed in 2005 under Base Realignment and Closure (BRAC). In 2010, portions of LSAAP were transferred to TAC. In 2014, the U.S. Army entered into an Environmental Services Cooperative Agreement (ESCA) with TAC to investigate and remediate Army-retained contaminated sites that could be transferred to TAC following clean-up. Under the ESCA, Matrix performed asbestos abatement, groundwater and surface water sampling, and landfill maintenance and conducted investigation and remediation at the High Explosive Burning Ground (HEBG).
Matrix cleared the 51-acre site surface of munitions and explosives of concern (MEC) prior to using digital geophysical mapping (DGM) to identify five saturated response areas (SRA) with high metallic signatures comprising 20.4 acres. Matrix investigated the SRAs using armored equipment and identified and characterized burnt debris, ash, and MEC to a depth of eight feet. Matrix summarized the findings in a Draft Affective Property Assessment Report (APAR) indicating remediation of the SRAs would be required to protect human health and the environment.
Matrix removed 32,000 metallic anomalies spanning 31 acres to depth outside the SRAs. The Army modified the ESCA funding remediation for the four smaller SRA’s in FY2019. To date, Matrix has excavated and removed over 8,500 cubic yards of metallic debris in the SRAs using armored equipment. Once native soils are encountered, excavations were mapped and sampled to verify that all the metallic debris and contaminants had been removed. Over-belt and eddy current magnets were used to remove ferrous and non-ferrous metal from the excavated debris. Matrix’ UXO Team has inspected, demilitarized, and recycled over 150,000 pounds of metallic debris and destroyed over 10,000 MEC items via detonation. Matrix has further characterized, transported, treated, and is in the process of disposing of 2,800 cubic yards of characteristic hazardous waste and 5,200 cubic yards of non-hazardous waste.
