Time Critical Removal Action Fort Huachuca Former Practice Landmine and Booby-Trap Training Area

US Army Corps of Engineers (USACE) Los Angeles District, awarded Bristol this time critical removal action (TCRA) as a task order under the Indefinite Delivery Contract for Munitions and Environmental Remediation Services (ERS) in connection with U.S. Department of Defense (DoD) Installation ERS and Range Maintenance/Services for USACE projects to eliminate the potential for an adverse human encounter with explosives of concern (MEC) and discarded military munitions (DMM) during current and reasonably anticipated future uses of the Fort Huachuca Former Practice Landmine and Booby-Trap Training Area. The site is located on Fort Huachuca, in Cochise County, Arizona, and was identified as the area of concern based on historical use and because the site is adjacent to land currently used by Fort Huachuca base. The 100-acre project site lies entirely within Area 15, which is designated as “Mines and Booby-Trap Training Range” from a historical 1955 map. 

A geophysical investigation and subsurface clearance were performed over 100 percent of the 100-acre site in order to mitigate the imminent threat to human health posed by the potential presence of MEC. All investigation areas within the site boundary were completely investigated down to 12 inches below ground surface (bgs). The results included the discovery of unexploded ordnance (UXO), and munitions debris (MD). The UXO was successfully disposed of by detonation in January 2020. The MD was certified as material documented safe and transported to a recycler. 

At the conclusion of TCRA, Bristol coordinated with USACE to develop a site-specific final report (SSFR) that documented the results of the surface and subsurface clearance of MEC and provided additional data for any potential future investigations.

UNLV Study Area MRS 02 RI/FS

US Army Corps of Engineers (USACE) Los Angeles District, awarded Bristol this project to complete a Military Munitions Response Program (MMRP) remedial investigation/feasibility study (RI/FS) at the former Nellis Small Arms Range, formerly used defense site (FUDS) (including Burial Areas, Moving Target Area, and Ordnance Jettison Area) on a 2,014-acre munitions response site (MRS) located in Las Vegas, Nevada. Project activities included preparing project plans, performing RI/FS field activities, writing RI/FS reports, and preparing and gaining acceptance of a Proposed Plan and Decision Document. 

The 2,014-acre University of Nevada, Las Vegas (UNLV), study area MRS02 was created to address land that is scheduled to be transferred to UNLV. Bristol conducted a remedial investigation to determine the nature and extent of potential Munitions and Explosives of Concern (MEC)/Munitions Constituents (MC), assess the potential risks/hazards to human health and the environment, and evaluate remedial investigation findings to determine if no further action is needed or remedial action alternatives are needed through a FS.

The Bristol team conducted field investigations from November 2017 to March 2018, using light detection and ranging survey (LiDAR) mapping, biological and cultural resource surveys and monitoring; geophysical surveys, MEC field work and MC sampling; and intrusive investigations. In all, the Bristol team completed 90 miles of geophysical surveys resulting in 12,000 geographical anomalies investigated with zero unexploded ordnance (UXO). The Bristol team identified munitions debris (MD) items to include 37mm fragments, 100-pound practice bomb, smoke grenade, heavy case fragments, and jet assisted take-off (JATO) Bottles. All MD was collected and taken to staging area for inspection, certification, and recycling, 

In addition to MD, the Bristol team found that lead and antimony exceeded residential and industrial screening criteria in the Moving Target Berm Areas and downrange from the moving target berms. Polycyclic aromatic hydrocarbons (PAHs) also exceeded residential soil screening criteria in the small area where clay target debris were identified. Based on the RI report, remedial action for military munitions was not required and no further action was needed. However, the RI report concluded the higher levels of lead, antimony, and PAHs in the soils on site posed an unacceptable risk and further evaluation was warranted through the FS. 

Through the FS process, USACE identified excavation, transportation, and disposal of contaminated soils as the alternative method of choice to ensure protection of human health, welfare, and the environment from actual or threatened releases of hazardous substances.

Community participation is a key element in the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) process, and as such USACE and Nevada Division of Environmental Protection (NDEP) provided information regarding the preferred alternatives for the MRS to the public through a public meeting, administrative record file for the site, and announcements published in local newspapers. Once the proposed plan was finalized, Bristol completed the final decision document in March 2020.