Performance-Based Remediation at the Former Fort Ord, California


From 2003 through 2017, HGL worked with the U.S. Army Corps of Engineers under multiple contract vehicles and changing regulatory guidance to complete a challenging PBR project at the former Fort Ord. Fire training exercises had resulted in a contaminant plume (Operable Unit [OU]-1) that migrated under the ecologically sensitive Fort Ord Natural Reserve. The project mission was to achieve the cleanup levels for trichloroethylene (TCE) and other volatile organic contaminants identified in the OU-1 Record of Decision (ROD).

Chemical of Concern Plume Based on Post-2004 Investigations

HGL developed an Exit Strategy to reach site closure that included attainment monitoring for the ROD contaminants of concern (COCs) and the emerging contaminants perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). After demonstrating that the ROD requirements for the COCs had been met, HGL presented information showing that the existing Institutional Controls, absence of an exposure pathway, and limited PFOA/PFOS extent would provide protectiveness from these contaminants if the OU-1 site was closed. In February 2017, the regulators concurred with the Army’s recommendation to close OU-1.

Winner of the Prestigious Grand Prize Award from AAEES

Based on its achievement of the project goals and elimination of future groundwater monitoring and remediation costs, HGL earned a Grand Prize in the 2017 Excellence in Environmental Engineering and Science™ competition organized by the American Academy of Environmental Engineers & Scientists® (AAEES). AAEES has been identifying and rewarding the best in current environmental engineering and science since 1989.

Project Highlights
Addressed groundwater site with large, diffuse plume in multilayered geological setting and sensitive ecosystem.
Constructed a hydraulic containment barrier that halted off-post plume migration.
Constructed and operated a 200-gpm pump and treat groundwater remedy that achieved ROD cleanup goals and received EPA Region 9 and state regulator concurrence that “…all remedial actions have been implemented and completed at this site.”
Optimized the pump and treat remedy using HGL’s innovative Physics-Based Management Optimization (PBMO) software in conjunction with a calibrated HGL MODFLOW-SURFACT groundwater model, reducing the cleanup time for the 4,200-foot plume by approximately 2 years and saving approximately $310,000 in projected costs.
Reduced carbon dioxide emissions by 59,000 pounds per year through optimization of the groundwater sampling program and operation of the groundwater treatment plant.
Implemented measures including mapping plant populations and using temporary mats on roadways to avoid affecting State and Federal threatened and endangered plant and wildlife species in the project area.
Completed over 21,000 labor hours without a health and safety incident.
Received client ratings on 4 completed task orders in 24 total categories (6 per task order: Quality, Schedule, Cost Control, Regulatory Compliance, Business Relations, and Management). HGL was rated “Exceptional” in 22 categories and “Very Good” in 2.
Received in 2017 a Central Coast Regional Water Quality Control Board (CCRWQCB) letter stating “…you are to be congratulated that your work has been professional, honest, timely, and most cooperative with all cleanup team members, as well as the greater Ft. Ord community. This is no small accomplishment for a site that’s both technically challenging and has a high public profile.” John M. Robertson, Executive Officer, CCRWQCB.