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Former Atlas "E" Site 11 Missile Groundwater Remediation
| Client: | USACE Omaha District |
| Role: | Prime Contractor |
| Location: | Northeastern Colorado |
| Dates: | 2011 - 2020 |
Arrowhead served as the prime contractor for the full-scale groundwater remediation effort at the Former Atlas “E” Site 11, a decommissioned Cold War-era missile silo located in northeastern Colorado. The project was performed under a task order issued through the U.S. Army Corps of Engineers (USACE) Omaha District’s Environmental Remediation Services (ERS) MATOC and addressed legacy groundwater contamination caused by trichloroethylene (TCE) used during missile maintenance activities.
Arrowhead implemented a comprehensive remedial approach centered on in-situ chemical oxidation (ISCO) to treat volatile organic compounds (VOCs) in the surficial aquifer. The full-scale system employed a network of dual-use wells for oxidant injection and groundwater extraction to promote contaminant reduction via hydraulic recirculation. Arrowhead was responsible for the design, installation, and operation of over 120 injection/extraction wells and the construction of centralized chemical batching and pumping facilities.
Prior to system implementation, Arrowhead completed site investigations to verify the conceptual site model, including a bench- and pilot-scale ISCO study, seismic surveys, well installation, aquifer mapping, and plume delineation. These efforts supported a tailored remediation design, allowing for focused treatment and minimizing unnecessary oxidant usage.
Throughout the project, Arrowhead conducted all required monitoring and reporting, including weekly system performance checks, quarterly groundwater sampling, and ongoing plume tracking. Site data was validated and incorporated into project databases and technical deliverables such as construction completion reports, remedy optimization updates, and regulatory submittals. Regulatory coordination included routine engagement with the Colorado Department of Public Health and Environment and the EPA.
The ISCO remedy resulted in a documented 98% reduction in VOC mass in treated areas. All work was completed without safety incidents and in accordance with CERCLA requirements. Upon completion of remediation activities, Arrowhead began phased demobilization, including well abandonment and site restoration.
This project reflects Arrowhead’s technical strength in groundwater remediation, ISCO system design and operation, and long-term environmental compliance under federal contracting.
Arrowhead implemented a comprehensive remedial approach centered on in-situ chemical oxidation (ISCO) to treat volatile organic compounds (VOCs) in the surficial aquifer. The full-scale system employed a network of dual-use wells for oxidant injection and groundwater extraction to promote contaminant reduction via hydraulic recirculation. Arrowhead was responsible for the design, installation, and operation of over 120 injection/extraction wells and the construction of centralized chemical batching and pumping facilities.
Prior to system implementation, Arrowhead completed site investigations to verify the conceptual site model, including a bench- and pilot-scale ISCO study, seismic surveys, well installation, aquifer mapping, and plume delineation. These efforts supported a tailored remediation design, allowing for focused treatment and minimizing unnecessary oxidant usage.
Throughout the project, Arrowhead conducted all required monitoring and reporting, including weekly system performance checks, quarterly groundwater sampling, and ongoing plume tracking. Site data was validated and incorporated into project databases and technical deliverables such as construction completion reports, remedy optimization updates, and regulatory submittals. Regulatory coordination included routine engagement with the Colorado Department of Public Health and Environment and the EPA.
The ISCO remedy resulted in a documented 98% reduction in VOC mass in treated areas. All work was completed without safety incidents and in accordance with CERCLA requirements. Upon completion of remediation activities, Arrowhead began phased demobilization, including well abandonment and site restoration.
This project reflects Arrowhead’s technical strength in groundwater remediation, ISCO system design and operation, and long-term environmental compliance under federal contracting.