Radiological Sites

Cradle to Grave Support for Successful Site Investigation and Remediation – HGL offers a full array of services for safely and efficiently investigating and remediating sites with radioactive or mixed waste contaminants. HGL’s technical approach focuses on obtaining timely and cost-effective site closures (end states) by using innovative technologies that result in beneficial reuse of the properties. HGL can support radiological assessment and cleanup projects from cradle to grave, creating project continuity that allows for cost savings, streamlined schedules, and regulator buy-in for use of innovative remedial and decision-support modeling and optimization technologies.

HGL is an experienced federal contractor that delivers the radiological support services required to implement remedial actions and decontamination/decommissioning projects for the U.S. Environmental Protection Agency (U.S. EPA), the U.S. Department of Energy (DOE), and the U.S. Army Corps of Engineers (USACE), specifically for sites under the Formerly Utilized Sites Remedial Action Program (FUSRAP). HGL’s radiological expertise encompasses the following:

  • Complex Groundwater and Vadose Zone Flow and Transport Modeling
  • Historical Document Reviews and Records Management
  • Investigation and Radiological Surveys of Media and Structures
  • Radiological Risk Assessments
  • Feasibility Studies and Remedial Designs
  • Field Engineering, Quality Control (QC), and Safety
  • Remediation of Radiologically Contaminated Environmental Media
  • Building Decontamination and Demolition (D&D)
  • Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) Final Status Survey Planning and Execution

HGL has over 35 years of experience providing radiological support services to U.S. Government agencies, various operation and maintenance (O&M) contractors, and power generators including the following:

  • Battelle Pacific Northwest National Laboratory (PNNL)
  • Bechtel Hanford
  • CH2M Hill Plateau Remediation Company
  • Consolidated Nuclear Security, LLC
  • DOE EM-50
  • Fluor Daniel Fernald
  • Fluor Hanford
  • Los Alamos National Laboratory
  • Nevada National Security Site
  • Nuclear Regulatory Commission (NRC)
  • Ontario Power Generation, Inc. – Pickering Nuclear Generating Station
  • Ontario Power Generation, Inc. – Western Waste Management Facility
  • U.S. EPA
  • Westinghouse Savannah River Co.

HGL’s Experience at DOE and Other Federal Radiological Sites

Project Examples:

DOE Hanford Site, WA

HGL has provided services to DOE at the Hanford Reservation for over two decades under multiple projects. These services have included supporting Remedial Investigations (RIs), conducting innovative technology and remediation demonstrations, designing and developing a virtual library, designing a risk communication tool, and providing technical and modeling support for the Basalt Waste Isolation Plant. HGL has also developed multiple complex groundwater models for various sites at the Hanford Reservation.

Project Highlights
Developed the original groundwater flow and transport model for the 200 West (200W) Area using HGL’s VAM3D finite element code.
Developed a vadose zone flow and transport model for the Tank Farm sites.
Conducted 3-D regional groundwater flow and transport simulations to predict fate of tritium, uranium, Tc-99, and solvents resulting from releases in the 200 East (200E) and 200W Areas.
Supported the low-level tank waste interim performance assessment.
Developed a 2-D model to simulate impacts of Columbia River level fluctuations on contaminant migration from the 100-N Area.
Developed a risk management tool to assist stakeholders and tribal members in evaluating and optimizing groundwater remedy selection.
Developed and maintains the Hanford Virtual Library, which integrates multiple environmental databases into a data warehousing and reporting system and provides extensive data graphing capabilities that aid data analysis.

DOE Savannah River Site (SRS), Aiken, SC

Under contract to Westinghouse Savannah River Company (WSRC), HGL has provided a broad range of technical services to support site investigation and environmental restoration activities at different areas of the SRS. The SRS is a DOE nuclear materials processing center that has been operating since the early 1950s. Site contaminants include chlorinated solvents and various radionuclides (Am-241, C-14, Cs-137, I-129, Pu-238, Pu-239, Sr-90, and Tc-99). Environmental cleanup began in 1981. HGL identified, developed, and applied model simulation technologies to conduct comprehensive analyses of groundwater flow and contaminant transport in the unsaturated zone and underlying groundwater systems. The analyses supported risk assessments and engineering design evaluations.

Project Highlights
Environmental Assessment
Performed a hydrogeological design evaluation of the saltstone low-level nuclear waste disposal facility in the Z-area at the SRS.
Developed a variably saturated flow and radionuclide transport model to evaluate the design of a tilted cap and drain system surrounding waste canisters.
Performed a groundwater pathway analysis at the Old Burial Ground facility to assess potential impacts of tritium releases on Four-Mile Creek.
Groundwater Restoration
Provided groundwater modeling and related technical expertise to support groundwater restoration activities at multiple areas of the SRS.
Reviewed site characterization reports, evaluated hydrogeological data, provided advice on tracer test design and implementation, assessed surface water/groundwater interactions, conducted 3-D modeling analysis and design, and evaluated groundwater extraction systems for plume remediation.
Facilitation/Public Outreach
Provided technical briefings to WSRC and assisted its personnel in preparing technical briefings and presentation materials for meetings with DOE and regulators.
Participated in DOE Integrated Technology Demonstration and Plume Focus Area work group meetings.

Santa Susana Field Laboratory (SSFL) Site, Ventura County, CA

HGL’s work at SSFL entailed conducting an RI of a 470-acre portion of the site, the location of a former research facility that included 10 nuclear reactors and testing facilities. Site characterization activities required using a variety of surface radiation scanning techniques and instrumentation to scan surface soils in 100 percent of accessible parts of the Area IV operational area and adjacent Northern Buffer Zone. Multimedia sampling of groundwater, surface water, and sediment as well as risk assessment and community relations support were conducted to support the radiological study and background evaluation led by EPA Region 9.

Project Highlights
Worked for EPA Region 9 under an expedited schedule with funding provided by DOE.
Conducted an RI to determine the extent of radiological contamination, which included the gamma scanning of over 400 acres, geophysical mapping of 100 acres, and collection of 3,250 mixed media samples for radiological analysis.
Designed, fabricated, and field-tested state-of-the-art gamma scanning systems capable of traversing rugged terrain.
Performed natural/cultural resource management, conducted in-depth historical research, and provided community involvement support.
Employed 60 on-site staff, including health physicists, geologists, radiation safety officers, and radiation technicians.
Developed innovative radiological scanning and survey techniques and instrumentation that maximized radiation surveying speed while providing high sensitivity in rugged terrain.
Successfully managed natural/cultural resources in an area rich in sensitive species and Native American history.
Provided security and maintenance of U.S. Government-owned buildings and properties.
Received the following client commendation: “[HGL has] gone beyond expectations in developing state-of-the-art radiation monitoring devices using the latest computer telemetry…HGL also has an impressive H&S program…Finally, HGL has experience and good qualifications to deal with the myriad of environmental, cultural, and endangered species laws…I believe [HGL has] saved the project and the Agency time and money.” Gregg Dempsey, EPA Senior Science Advisor.

FUSRAP Sites, St. Louis, MO

HGL is executing a large-scale remedial action to clean up low-level radioactive waste (uranium, thorium, and radium) on numerous commercial, municipal, and residential properties in two separate areas of St. Louis. The dedicated team of over 60 on-site personnel perform radiological characterization and remediation efforts, which includes using two railcar loading areas. Since beginning the project, HGL has excavated and shipped nearly 64,000 cubic yards of impacted soil. Project work is completed under CERCLA and is managed by USACE in accordance with the Clean Air Act, the Clean Water Act, the National Contingency Plan, the National Historic Preservation Act, and the Toxic Substances Control Act, as well as with Missouri Department of Natural Resource and Missouri Department of Transportation regulations. HGL has received interim CPARS ratings of “Exceptional” and “Very Good.”

Project Highlights
Coordinate with property owners to safely remove radiologically affected soil and sediment.
Excavate contaminated soil around utilities, buildings, parks, and commercial and residential properties, as well as within roadway rights-of-way, while minimizing impacts to local property owners.
Apply the principles of MARSSIM to implement Final Status Surveys for site closure.
Operate and treat over 1 million gallons of site-generated water each year for permitted discharge.
Maintain staff on-call 24 hours per day, 7 days a week to both support local utility companies if underground repair work is required in contaminated areas and to support water management during storm events.
Operate two material staging and loadout areas, which include stockpile management, railcar loading, inspection, and manifesting.

Safety Light Superfund Site, PA, and Peck Iron & Metal Superfund Site, VA

Under its 10-year remedial action contract (RAC2) with the U.S. Environmental Protection Agency (EPA), Region 3, HGL has executed work assignments at Superfund sites located throughout the mid-Atlantic region. Sites have included landfills, former manufacturing, dry cleaning, pesticide, metals recycling, and wood treating facilities, and sites with munitions and radiological contamination.

Exterior View of Main Building at Safety Light Superfund Site

Interior View of Main Building at Safety Light Superfund Site

At the Safety Light Site Superfund Site in Bloomsburg, PA, a former manufacturing facility contaminated with radioactive materials including Cobalt-60, Cesium-137, Radium-226, Actinium-227, Neptunium-237, and Lead-210, HGL first searched the site buildings for documents pertaining to the site’s history and operations. HGL subsequently conducted a structural integrity assessment of the main building at the site to assess its safety prior to demolition.

Estuarine Tributary at
Peck Iron & Metal Superfund Site

For the Peck Iron & Metal Superfund Site, HGL is conducting a comprehensive RI to determine the nature and extent of PCBs, metals, dioxins, and radionuclide contamination at this former scrap metal processing facility and to assess the potential risks to human health and ecological receptors. The work included conducting a comprehensive investigation of soils, surface water, groundwater, tidal and non-tidal wetland sediments, and aquatic biota tissue (fish and oysters); performing an aquatic invertebrate toxicological study of Paradise Creek; surveying for munitions and explosives of concern (MEC); conducting a multimedia background study and a building hazard analysis; and evaluating the need for a MARSSIM investigation and conducting a gamma radiation survey with biased sampling of radiation anomalies for isotope identification. HGL performed baseline human-health and ecological risk assessments that included a food-chain analysis to assess potential hazards to on- and off-site human receptors and ecological communities. The risk assessments will be used to establish preliminary remediation goals and to evaluate remedial alternatives for the Site.

Project Highlights
Safety Light Site Superfund Site
Collected historical site operations documents in an abandoned building with radiological contamination.
Implemented a process designed by HGL’s Certified Health Physicist to electronically scan documents at the site and ensure that no radiologically contaminated material was physically removed.
Provided decontamination and demolition (D&D) support by conducting a structural condition assessment of the main building at the site.
Peck Iron and Metal Superfund Site
Conducted a gamma-radiation survey
Identified and assessed human and ecological risks for 14 radionuclides species.
Completed and sampled on- and off-site soil borings and installed and surveyed groundwater monitoring wells.
Inspected three on-site buildings for structural integrity and the presence of asbestos-containing material and collected wipe samples from within the buildings.
Conducted acoustical profiling of the Paradise Creek channel bottom.
Completed a wetland delineation survey.

FUSRAP Niagara Falls Storage Site (NFSS), Lewiston, NY

HGL was contracted by the USACE, Buffalo District to provide environmental remediation support services at the NFSS located on the former Lake Ontario Ordnance Works. Beginning in 1944, this FUSRAP site was used by the Manhattan Engineer District for storing radioactive residues and wastes from uranium ore processing conducted during the development of the atomic bomb. Historical activities at the site have resulted in radiological and chemical contamination in soil and groundwater.  Services included environmental and hydrogeological assessment, data management, analysis and visualization, advanced GIS development and application, groundwater flow and solute transport modeling, remedial alternative analyses, long-term monitoring support, risk communication, and a potentially responsible party (PRP) investigation.

Project Highlights
Reviewed historical documents to compile site-specific and regional hydrogeological and environmental data.
Developed a comprehensive database that included analytical, geological, and hydraulic properties as well as water-level elevation data.
Developed and calibrated a regional 3-D groundwater flow and solute transport model to gain insight into the regional and local groundwater flow conditions and the impact of climatic changes and waste management strategies on groundwater flow conditions.

  • Used the model to predict the transport of radionuclides from the Interim Waste Containment Structure (IWCS), a capped containment structure that contains high-activity radium residues.
  • Utilized the model to assess the effectiveness of the remedial alternatives, including a range of enhanced containment and waste removal options evaluated as part of a Feasibility Study.
  • Integrated a GIS/database and advanced numerical model with 3-D animation to characterize a complex hydrogeological setting and to predict radiological transport.
  • Conducted simulations of the transport of radiological contaminants from the IWCS up to 10,000 years in the future.
Assisted USACE in optimizing its groundwater long-term monitoring program.
Provided engineering recommendations to mitigate waste transport and extend the operating lifespan of the waste containment.

Welsbach & General Gas Mantle (Welsbach/GCM) Superfund Site, Camden, NJ

Loading Railcars with Radiologically Contaminated Soil for Disposal

Under a 5-year, $110 million contract through the U.S. Army Corps of Engineers Philadelphia District, a HydroGeoLogic, Inc. (HGL)-led Joint Venture (JV) consisting of HGL and APTIM Federal Services, LLC (APTIM) of Baton Rouge, Louisiana ( is conducting environmental remediation in support of the cleanup of the Welsbach/GCM Superfund site for the U.S. EPA, Region 3. The site includes two former manufacturing facilities as well as about 1,000 residential, commercial, industrial, and recreational properties.

The Welsbach Company and the General Gas Mantle Company made gas mantles at the site from the late 1890s to 1941. The companies used radioactive elements during production to help the mantles glow more brightly when heated. In the early 1990s, the New Jersey Department of Environmental Protection (NJDEP) found elevated levels of gamma radiation at the locations of the manufacturing facilities and in many nearby residential areas. EPA added the site to the Superfund program’s National Priorities List (NPL) in 1996. In 1999, EPA selected a cleanup plan. The cleanup involves disposal of contaminated soil and waste materials from residential and industrial properties.

Aerial View of the Gloucester Marine Terminal

In addition to industrial and residential properties, cleanup is ongoing at the highly active Gloucester Marine Terminal (GMT), a commercial property that includes an active port, warehouses, and a logistics complex adjacent to the Delaware River. The HGL-APTIM JV’s tasks include excavating contaminated material, relocating utilities, dewatering areas and treating the wastewater, conducting radiological testing of soils and water, importing clean fill, and manifesting and shipping waste, all in coordination with shipping schedules and shipyard traffic associated with the GMT. Owing to the site’s proximity to the river, water management, logistical coordination, and climate change adaptation are significant components of the construction activities. In addition to dewatering areas and treating the wastewater using a portable wastewater treatment facility (WWTF), the HGL-APTIM JV is designing and constructing a larger, permanent WWTF. The facility is scheduled to be completed in 2023.

Project Highlights
Daily coordination with the GMT to minimize the impact of remediation activities on the terminal’s operations. This is one of the busiest terminals in the United States for refrigerated goods.
Operation and treatment of over 1 million gallons of site-generated water each year for permitted discharge.
Excavation of contaminated soil around utilities, buildings, and commercial and residential properties while minimizing impact to property owners and facility operations.
Operation of a material staging and loadout facility, which includes stockpile management, railcar loading, inspection, and manifesting.

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