Site Cleanup: Your Goal, Our Goal – HGL has consistently demonstrated its ability to complete effective investigations, design innovative remediation systems, and successfully and safely complete soil and groundwater restoration efforts. Throughout each project, HGL seeks to optimize the design and operation of remediation systems to reduce cleanup times and associated costs.

HGL offers a full array of services for safe and efficient remediation of sites contaminated with hazardous, toxic, radiological, and munitions-related contaminants. HGL’s multidisciplinary staff has the experience needed to design and implement remediation approaches that focus on obtaining prompt and cost-effective site cleanup. Using both innovative treatment technologies and proven methods, HGL develops sustainable remedies that, to the extent possible, allow for beneficial re-use of site property. HGL’s remediation expertise encompasses the following:

  • Landfill Cap Construction
  • Pesticide- and PCB-Contaminated Soils Remediation
  • Soil Vapor Extraction/Biosparging
  • Optimized Pump and Treat
  • In Situ Oxidation/Enhanced Bioremediation
  • Operation and Maintenance and Long-Term Monitoring Optimization
  • Permeable Reactive Barrier Construction
  • Regulatory Negotiation
  • Contaminated Soil/Sediments Removal
  • Long-Term Monitoring/Long-Term Operation
  • DNAPL/LNAPL Remediation
  • Enhanced Product Recovery
  • Explosives-Contaminated Soils Bioremediation
  • Community Relations Support
  • Construction Support

Performance-Based Remediation (PBR) – Over the past 15 years, HGL has become a PBR industry leader, successfully managing  and executing single- and multiple-installation PBR projects ranging in size from $5 million to $45 million under both RCRA and CERCLA. HGL has completed these projects for Department of Defense clients, including the U.S. Army Corps of Engineers, Army Environmental Command, and Air Force, and it has successfully managed performance risk and liability for them using various remedial technologies. Additionally, HGL has 27 years of experience executing firm fixed price projects with challenging milestone performance schedules. With their extensive experience executing PBR projects, HGL’s staff has developed expertise in negotiating and securing consensus on all aspects of environmental remediation projects from the investigation through closure (end state) phases. HGL’s strong performance on these PBR projects is evidenced by the “Very Good” and “Exceptional” ratings below.

The following six projects demonstrate HGL’s expertise providing remediation services:


PBR 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).

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.

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.


PBR at MacDill Air Force Base and Avon Park Air Force Range, Florida

HGL is providing PBR services, ranging from assessment through final cleanup, at 54 Defense Environmental Restoration Program (DERP) sites within MAFB, headquarters of U.S. Central Command, and APAFR, Florida. HGL has exceeded the contract minimum performance objective of 23 site closeouts (SCs) by advancing 31 sites toward SC, meeting no further action conditions at 18 sites, and achieving final regulatory SC at 23 sites in under 4.5 years.

Work includes completing source removal actions for soils contaminated by polycyclic aromatic hydrocarbons (PAHs), metals, petroleum products, and munitions debris (MD); constructing biosparging systems to treat volatile organic compounds (VOCs) in soil and groundwater; and using in situ remediation technologies to treat groundwater contaminants. Project complexities include addressing sites with challenging karst hydrogeology and dense non-aqueous phase liquid (DNAPL) sources, adjacent to active taxiways, within an active bombing range at APAFR, and near sensitive wetlands and estuaries.

Project Highlights
Conducted site remediation and developed and implemented an Optimized Exit Strategy.
Implemented in situ remedies, including in situ chemical oxidation, bioremediation, biosparging, and enhanced reductive dechlorination (ERD) at 15 sites to treat POL contaminants, VOCs/semivolatile organic compounds, PAHs, and pesticides.
Implemented innovative thermal ERD and deep soil excavations using large-diameter augers to remediate DNAPL beneath the water table.
Excavated over 75,000 tons of source materials, including POL- and DNAPL-contaminated soils.
Completed over 65,000 hours of work without a safety incident.
Received National Safety Council Perfect Record Awards for 2014 through 2017.
Received “Exceptional” ratings in all categories in 2017 CPARS evaluation.

Performance-Based Environmental Remediation Services at Scott Air Force Base, Illinois

HGL conducted work at Scott Air Force Base with an initial performance objective of achieving remedy in place (RIP) at 20 separate sites. Work included contaminated soil excavation and debris removal at six sites; on-site treatment of lead-contaminated soils; construction of a 36-acre landfill cap with a passive landfill gas venting system; installation of an in situ Submerged Oxygen Curtain (iSOC) to treat POL contamination; and completion of a pilot study for in situ enhanced reductive chlorination to remediate TCE in groundwater. HGL exceeded contract objectives by obtaining RIP or better at all 20 sites, including site closure at 11 sites.

Project Highlights
Completed CERCLA remediation at 20 separate sites, including construction of groundwater and soil remedies, source treatment (excavation and soil amendment to stabilize lead), in situ technologies (iSOC and bioremediation). Exceeded contract objectives by obtaining RIP or site closure at all 20 sites.
Excavated and disposed of and/or stabilized 24,000 cubic yards of hazardous/nonhazardous waste, including PAH/PCB-contaminated soils and sediment and small arms (lead)-contaminated soils from six sites.
Effectively negotiated the disposal of soil from additional removal actions at the on-base landfill to eliminate off-base disposal, limit on-base truck traffic, minimize carbon footprint, and accelerate schedule.
Designed and implemented a pilot study to evaluate enhancing reductive dechlorination through injection of EHC, an amendment that combines a carbon substrate with ZVI. The field test results demonstrated the amendment’s potential effectiveness, and provided the data needed to prepare and implement the full-scale RD.
Received the “USACE Project Safety Recognition Award” for safe execution of all work without a single lost time incident.

Environmental Remediation Services at Former Blaine Naval Ammunition Depot, Hastings, Nebraska

The Blaine Naval Ammunition Depot was a load, assemble, and pack munitions facility during the 1940s and 1950s, and included a main production area and 2,000 storage buildings/bunkers across 48,800 acres. Site contaminants of concern include volatile organic compounds (primarily trichloroethene) and explosives (primarily RDX). HGL has been tasked with the following:

  • Conducting remedial construction;
  • Conducting operation and maintenance (O&M) of a groundwater treatment plant and extraction system;
  • Installing water lines and hookups;
  • Implementing erosion and storm water controls;
  • Collecting and analyzing groundwater, process water, and air samples;
  • Conducting O&M of monitoring and extraction wells; and
  • Preparing a work plan, as-built drawings, an O&M manual, periodic monitoring reports, and an O&M report.
Project Highlights
 Extracted, treated, and discharged 4.25 billion gallons of groundwater at 3,700 gallons per minute while operating at 97% efficiency.
Designed/constructed a 91,000-gallon wet well that required deep excavation and installation of 2,900 linear feet of piping within budget and schedule despite losing 12 days to extreme inclement weather.
Constructed the south irrigation system and grade control structures, which involved excavating approximately 116,000 cy of soil and placing 6,000 cy of riprap for erosion protection.

Removal Action at Umiat Test Well No. 9, Umiat Air Force Station, Alaska

Umiat Test Well No. 9 is located in the Alaskan foothills of the Brooks Range, more than 100 miles from the nearest road system. It is one of 11 petroleum exploration wells drilled by the U.S. Navy between 1945 and 1953 in the Naval Petroleum Reserve No. 4, a remote exploration drill site now known as the National Petroleum Reserve-Alaska. The well was cored with a rotary drill with an oil-based drilling mud that contained polychlorinated biphenyl (PCBs), resulting in the ground surface surrounding the well to become contaminated with PCBs. The U.S. Army Corps of Engineers (USACE) has been conducting cleanup activities at the site since 2009 to remove PCB-contaminated soils around the well.  HGL, under contract to USACE, excavated, transported, and disposed of 2,270 cubic yards of contaminated soil under austere and Arctic winter conditions in an area situated within a fragile tundra ecosystem.

Project Highlights
Completed removal of over 2,000 tons of Toxic Substances Control Act-classified waste from the site during winter, and sequenced transport of the waste by snowcat, truck, railcar, and ship over 2,200 miles to the disposal facility.
Obtained approval for 10 different permits/authorizations from numerous federal and state government agencies in fewer than 90 days to facilitate an accelerated schedule.
Established and operated an on-site lab that achieved both Environmental Laboratory Approval Program and Alaska Department of Environmental Conservation certification for PCB soil analysis, saving over $250,000 in project costs.

Groundwater Treatment Plant and Extraction System Operations at South Jersey Clothing Company/Garden State Cleaners Superfund Sites, Atlantic County, New Jersey

The South Jersey Clothing Company (SJCC) and Garden State Cleaners (GSC) facilities manufactured military clothing and provided dry cleaning services from the 1940s to the 1990s, contaminating regional groundwater with the volatile organic compounds (VOCs) trichloroethene (TCE) and perchloroethylene (PCE). Under this project, HGL operates a groundwater treatment plant and extraction/injection systems; samples and analyzes soil, groundwater, surface water, air, and sediments; installs, monitors, and maintains monitoring, extraction, and injection wells; and provides public relations support.

The 550-gallon-per-minute groundwater treatment plant extracts VOC-contaminated groundwater from a network of 22 extraction wells. The VOCs are removed using both liquid- and vapor-phase granular-activated carbon, sulfuric acid pH adjustment, and sodium hypochlorite disinfection. The treated water is discharged to a network of 24 injection wells and an injection trench system upgradient of the groundwater treatment plant. Operations and maintenance activities performed by HGL’s licensed plant operators include routine monitoring, preventative and non-routine maintenance of groundwater treatment plant components; plant process and groundwater monitoring sampling; and maintenance of extraction and injection well systems to maximize contaminant removal and plant production.

Project Highlights
Extracted, treated, and discharged 650 million gallons of groundwater, averaging 485 gallons per minute while operating at 96% on-stream efficiency.
Reduced plant operations staffing by 50% through effective management of project resources.
Completed a time-critical connection of a new extraction well before fall session began at a nearby elementary school.
Earned New Jersey Department of Labor Safety Awards in 2013, 2014, and 2015; and National Safety Council Safety Awards in 2014, 2015, and 2016.

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