Remediation

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
  • Enhanced Product Recovery
  • Permeable Reactive Barrier Construction
  • Regulatory Negotiation
  • Contaminated Soil/Sediments Removal
  • Long-Term Monitoring/Long-Term Operation
  • DNAPL/LNAPL Remediation
  • Operation and Maintenance and Long-Term Monitoring Optimization
  • Perfluorinated Compounds Remediation
  • Explosives-Contaminated Soils Bioremediation
  • Community Relations Support
  • Construction Support

 

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


 

Environmental Remediation Services at Scott Air Force Base, Illinois

HGL began its work at Scott Air Force Base with an initial performance objective of achieving remedy in place (RIP) at 20 separate sites. Work included excavation of contaminated soil and removal of debris at six sites; treatment of lead-contaminated soils on site; 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 petroleum, oil and lubricants contamination; and completion of a pilot study for in situ enhanced reductive dechlorination (ERD) to remediate TCE in groundwater. HGL exceeded contract objectives by obtaining site closure at 11 sites, response complete at two sites, and RIP at four sites. At the remaining three sites, the contract objectives were modified to achieve regulatory approval of a feasibility study or record of decision.

 

Project Highlights
Completed CERCLA remediation at 20 separate sites, including construction of groundwater and soil remedies, use of source treatment (excavation and soil amendment to stabilize lead), and use of in situ technologies (iSOC® and bioremediation).
Effectively negotiated the disposal of soil from removal actions at the on-base landfill to eliminate off-base disposal, limit on-base truck traffic, minimize the carbon footprint of the removal actions, and accelerate the project schedule.
Designed and implemented a pilot study to evaluate ERD through injection of EHC® (an amendment that combines controlled-release carbon, zero valent iron, and nutrients) and after the study had demonstrated the amendment’s effectiveness, provided the design parameters needed to prepare the full-scale remedial design.
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.

 

Point of Contact

Jeff Dick, PE
Vice President
E-mail: jdick@hgl.com