Remediation, Near Surface Disposal & Long-term Stewardship

CRESP assesses, recommends and develops approaches aimed at improving the evaluation, effectiveness and efficiency of remediation and risk mitigation techniques for contaminated environmental resources. Resources include soils, ground water, surface water, sediments and biota.

Project activities range from:

  • Improving methods for characterizing contaminated environmental media
  • Monitoring the effectiveness of remediation processes and near surface disposal systems
  • Reducing uncertainty in contaminant environmental fate and transport
  • Developing improved treatment processes
  • Examines the relative risk to human, ecological and eco-cultural resources from remediation methodologies, including the effect of delaying remediationDevelops methodologies to compare the risk to receptors from different remediation practices.

CRESP also evaluates and develops approaches for more efficient and effective methods for regulatory compliance, natural resource damage assessment, end-state definition and risk communication associated with remediation and potential future use of resources.

Lead Researchers

Craig H. Benson, University of Virginia
Kevin Brown, Vanderbilt University
Joanna Burger, Rutgers University
Michael Gochfeld, Rutgers University
Jesus D. Gomez-Velez, Vanderbilt University
Kathryn A. Higley, Oregon State University
J.N. Chen, University of Central Florida

EM Sites Impacted

  • DOE Complex
  • Hanford: Richland Operations Office and Office of River Protection
  • Oak Ridge Reservation
  • Savannah River
  • Portsmouth and Paducah
  • West Valley

Current Project Areas

Landfill Partnership – Improving Performance Assessment, Monitoring Approaches, and Caps/Liners Design for Near-surface Disposal Facilities

Project Objectives
The CRESP Landfill Partnership (LP) has two primary objectives: (1) to address technical issues related to on-site disposal facilities (“landfills”) in the DOE complex that receive low-level wastes (LLW) and mixed wastes (MW) from remediation and decommissioning projects and (2) to address issues pertinent to key stakeholders that influence design and monitoring of disposal facilities (e.g., US EPA, NRC, DOE, and state agencies). The technical objective focuses on creating technical solutions that build confidence in DOE disposal operations while also resulting in lower costs, more expedient construction or operations, improved performance (in the context of DOE regulatory requirements), and more effective monitoring. The stakeholder objective resolves contrasting and/or contradictory regulatory issues that impede facility design and performance, with the ultimate goal of creating confidence in EM operations and a consistent regulatory structure for disposal facilities.

Over the past decade, the CRESP Landfill Partnership (LP) has focused its efforts on solving practical problems related to design, construction, and performance assessment of on-site disposal facilities for low-level and mixed waste in the DOE complex. The LP was formed as an outcome of a series of technical reviews of disposal issues throughout the complex and was charged with finding solutions to the key problems identified in the reviews. The LP conducts applied research, participates in reviews and assessments, and engages in technical transfer on on-site disposal issues for the broader community. Outcomes from the LP have led directly to more efficient designs and successful acceptance of PAs throughout the complex.

A complex-wide review is underway that is comparable to the review conducted a decade ago, with the objective of identifying the most important technical issues facing on-site disposal facilities for the next decade. The review consists of a series of interviews with key stakeholders within DOE: technical personnel at each of the sites, headquarters representatives, and LFRG committee members. The interviews cover the challenging issues stakeholders within DOE are facing and the knowledge needed to resolve these issues. Outcomes from these interviews will be synthesized, and a workshop will be conducted virtually with the interview group to discuss the findings and prioritize issues for the future. A report with recommendations will be prepared from the outcomes of the workshop.

Additional specific objectives are:

  • Develop and maintain long-term data sets that support the efficacy of methods used to predict final cover performance for PAs for on-site disposal facilities. Provide confidence in the predictions made in PAs.
  • Evaluate how contact with cementitious materials (saltstone, concrete, mudmat) affect the engineering properties and service life of barrier materials such as GCLs and geomembranes.
  • Evaluate and demonstrate efficacy of water-balance approach using natural cover surfaces for long-term management of final covers at DOE on-site disposal facilities.
  • Evaluate the efficacy of variably saturated flow models for final covers in collaboration with DOE-LM with emphasis on integrating evolution of vegetated ecosystem and impact on flow dynamics in final covers.
  • Support assessment and evaluation of waste containment and disposal initiatives at Oak Ridge, Savannah River, and other sites as needed.
  • Identify and participate in opportunities to evaluate in-service barrier systems with the objective of providing comprehensive and authoritative data on the long-term effectiveness of barrier materials used in liner and cover systems in the DOE complex.
  • Support in DOE effort to identify near-surface disposal pathways for graphite reactor cores.

Recent Project Outcomes/Results

DOE Landfill Partnership

Significance/Impact to DOE
Throughout the DOE complex, decommissioning and remediation as well as other waste management activities are contingent on the availability of an on-site disposal facility. Consequently, the ability to cost effectively design and construct on-site disposal facilities in an expedient manner has a significant effect on the cost and schedule of decommissioning projects. These factors are complicated by the notorious difficulty in achieving stakeholder acceptance for a facility meant to contain wastes on-site essentially in perpetuity. Stakeholder acceptance is also affected by contrasting and/or conflicting technical requirements in government regulations (e.g., EPA’s RCRA vs. DOE’s 435.1) as well as a lack of stakeholder confidence in containment systems, performance assessments, and monitoring systems. The CRESP Landfill Partnership conducts the applied research and facilitates the technical dialogue needed to build confidence in technologies used for on-site disposal facilities, the methodology used to design and assess the facilities, and the systems used to monitor long-term performance.

EM Sites Impacted

  • DOE Complex
  • Hanford: Richland Operations Office and Office of River Protection
  • Oak Ridge Reservation
  • Savannah River Site
  • Portsmouth and Paducah Sites
  • West Valley

Radioecological Protection

Project Objectives

The CRESP Radiological Protection effort has two primary objectives: (1) limit DOE EM’s environmental and fiscal liability by ensuring its approach to radiological cleanup is consistent with efficient, cost-effective, and sound scientific principles as well as regulatory guidance and (2) increase stakeholder’s confidence in radiological remediation actions taken by EM through ongoing analysis, public communication, and training. The issue of environmental liability is addressed through ongoing collaborative research with CRESP and EM partners on specific environmental questions of concern to EM and by dissemination of results in scientific and public settings. Stakeholder confidence requires ongoing and continued dialogue with both EM and members of the public at EM sites and will include analysis of site environmental data, development of publicly accessible content, presentation at public meetings, and in-depth support to EM.

Specific and ongoing objectives for Budget Period are to:

  • Develop a catalog of customizable and referenceable factoids on radiological background for use in communication of radiological impact for members of the public (e.g., as was needed for WIPP and Portsmouth)
  • Evaluate uptake and transfer of radionuclides in native plant species used for cover on uranium tailings impacted soils (e.g., phytostabilization, phytoremediation, transfer factors; to be coordinated with closure cover evaluations carried out under Landfills Partnership)
  • Review applicability and opportunities for machine learning / artificial intelligence capabilities in radiological safety issues such as gamma spectrometry and facilities safety programs
  • Continue development of open access software for construction of mesh phantoms and assessment of radiation dose to non-human biota
  • Collaborate with PNNL on evaluation of C-14 and Cl-36 issues related to removal of graphite cores from reactors and tank waste processing

Significance/Impact to DOE
Stakeholder confidence in DOE EM’s mission hinges on EM employing scientifically defensible, transparent, inclusive, and efficient environmental remedies during site cleanup. This confidence can be achieved through employing best practice and current guidance; undertaking ongoing evaluation of effectiveness of remediation strategies; and investigating and adapting emerging science and communicating results to a wide range of stakeholders including the general public.

EM Sites Impacted

  • Hanford Site
  • Savannah River Site

Evaluation of Radionuclide Source Terms and Transport from Disposal of Graphite Reactor Cores

(To be added)

EM Sites Impacted

  • DOE Complex
  • Hanford Site

Development of a Consistent Ecological Risk Methodology

Project Objectives
The overall objective is to provide DOE, regulators, and other stakeholders with (1) methods of identifying and evaluating  the value of the ecological resources on DOE sites, (2) methods to evaluate the risk to ecological and eco-cultural resources, 3) methods and approaches to integration of successful risk communication to DOE, regulators and the public, and 4) methods of integrating uncertainties in both ecological resources and evaluation of risk to these resources, providing consistency and transparency to increase stakeholder confidence that human health and the environment are protected. 

  • Adapt and develop ecological screening methodology that can be used at multiple sites, working with relevant site people (B. Loony and others at SRS; A. Bunn at Hanford; N. Giffen at ORR, others suggested by DOE).
  • Develop and expand a screening risk review methodology developed at Hanford and refined at Oak Ridge that will be useful at SRS or other designated DOE sites.  Work with relevant site personnel.
  • Develop a manuscript (refereed paper) on the ecological risk screening methodology that is generalizable to other sites and is relevant to evaluating contaminants of concerns and protecting eco-cultural resources and is consistent with on-going DOE human health risk assessments.
  • Develop a white paper on the bioindicators used at the major DOE sites to examine consistency and transparency with the objective of finding commonalities for complex-wide comparisons.  This will illustrate a context for bioindicator use relevant to all major DOE sites and to assure stakeholder groups that remediation is protective of human health and the environment.
  • Examine uncertainties in ecological and human risk from food chain exposure to mercury in Oak Ridge, SRS, and other sites, and how institutional and land use controls can be improved (e.g., when fish consumption advisories initially fail).
  • Edit and shepherd Risk Communication special Issue of the journal Risk Analysis.  A compendium would be useful for HQ and Sites, with a focus on DOE issues, but broadened to include other stressors and communication tools useful for stakeholders, managers and the general public.
  • Compare the protection of valuable ecological resources on DOE lands with surrounding areas, using federal land use/land cover data sets.  This will be useful to the DOE in demonstrating the stewardship of the DOE of ecological resources.

Significance/Benefit to EM
Many of the major DOE sites contain valuable and unique ecological resources of interest to DOE, EPA, State Agencies, conservation organizations, and site neighbors.  HQ and EM need a consistent, practical, transparent, and defined methodology to examine the risk to ecological resources on EM sites from that status quo and from proposed remediation practices. This would contribute to planning for post-remediation land uses and restoration. One of DOE-EM’s oft-stated goals is “protection of human health and the environment.” EM needs a methodology that can be applied complex-wide, given the range of information currently available at different sites.  This project will provide a brief inventory of what information is available and describe a methodology that can be applied complex-wide to assess risk to individual remediation units within and among DOE-EM sites.  The methodology will include two assessment approaches: 1) individual remediation units, and 2) a watershed approach.  Both provide essential data for DOE HQ, sites, regulators and the public to make informed decisions.   The assessment also provides an independent evaluation of ecological resources on DOE sites.

This project will provide an opportunity to bring together data that are already available at DOE-EM sites about ecological resources, will provide new ecological resources information data bases, and will provide managers and the public with usable information to help with science-based decision-making. Further, this research will demonstrate the positive benefits of DOE ownership of ecological resources at several EM sites, illustrating how DOE stewardship has enhanced the integrity and value of ecosystems, protected endangered and threatened species, as well as unique and rare ecosystems, and provided the public with accessible and transparent information about resource values.  One advantage of the team is that it contains expertise in ecology, ecological health risk evaluations, human and ecological toxicology, human health risk assessment, and public health, and is thus able to provide advice on remediation, resources and risk involving both human health and the environment.

DOE-EM Sites Impacted

  • DOE Complex
  • Hanford Site
  • Major EM sites (Hanford, INL, SRS, Oak Ridge, Los Alamos)

Assessment and Remediation of PFAS in Soils, Groundwater, and Wastes

Project Objectives
The overall objective is to provide DOE-EM with treatment technologies and insights into remediation of per- and polyfluoroalkyl substances (PFAS).  Currently, through related federal support (e.g., through Department of Defense, Strategic Environmental Research & Development Program (SERDP) and support from EPA), CRESP researchers are investigating (i) techniques to mobilize PFAS to facilitate more efficient recovery from the vadose zone and groundwater (Guelfo), (ii) membrane separation approaches to concentrate PFAS from groundwater to make subsequent destruction technologies more efficient by providing a smaller volume and more concentrated feed (Lin), (iii) development and demonstration of EPA leaching test and evaluation methods (Garrabrants and Kosson), and (iv) testing the efficacy of reactive liner systems for retaining PFAS when used in landfill disposal containment systems (Benson).  However, the majority of PFAS work in progress is focused on aqueous film forming foam (AFFF) typically used at federal facilities for firefighting, which has a different distribution of specific PFAS compound than anticipated at EM sites where other forms of PFAS were used in processing. The specific objectives for Budget Period 13 are to:

  • Conduct batch and unsaturated column experiments to evaluate the ability of oxidative pre-treatment to mobilize precursors under conditions relevant to the vadose zone and conditions at DOE sites.
  • Evaluate use of customized nanofiltration membranes for concentration of PFAS at concentrations and PFAS mixtures found in groundwater at EM sites.
  • Engage EM and EM labs in the interlaboratory validation of EPA leaching tests for PFAS as part of the Leaching Environmental Assessment Framework (LEAF) and extend LEAF testing and demonstrations to cases relevant to EM sites.
  • Evaluate reactive barrier membranes under development for the ability to retain PFAS in background simulants of leachate from low activity waste disposal sites.
  • Continued CRESP participation in the DOE PFAS working group.

Significance/Benefit to EM
PFAS, which recently have become a high priority contaminant of concern for EPA, have been used extensively throughout the defense legacy complex (now EM field sites).  Thus, there is high likelihood that significant groundwater contamination with PFAS will be identified throughout the complex as well as PFAS presence in wastes requiring treatment and disposal.  The regulatory framework and requirements for remediation, treatment and disposal of PFAS containing environmental media and wastes is rapidly evolving.  This project is to advance research underway to the benefit of EM by evaluating promising technological approaches for PFAS recovery, treatment, assessment and disposal under conditions specifically relevant to EM PFAS challenges.

DOE-EM Sites Impacted: Major EM sites (SRS, Oak Ridge, INEL, Los Alamos, Hanford, others)

All Publications: Remediation, Near Surface Disposal & Long-term Stewardship,
2006-2019 (pdf)

Highlighted Publications & Reports

CRESP Remediation and Near Surface Disposal

Yesiller, N, Hanson, J, Risken, J, Benson, C, Abichou, T & Darius, J 2019, ‘Hydration Fluid and Field Exposure Effects on Moisture-Suction Response of Geosynthetic Clay Liners’, Journal of Geotechnical and Geoenvironmental Engineering, vol. 145, no. 4, p. 04019010.

Suttora, L, Rosenberger, K, Benson, C & Hughes, F 2019, ‘Reducing Risk to Enable End States, Panel’, WM ‘2019, WM Symposia, Phoenix, Arizona.

Setz, M, Benson, C, Bradshaw, S & Tian, K 2019, ‘Lithium Extraction to Determine Ammonium in the Exchange Complex of Bentonite’, Geo Testing Journal, vol. 1, no. 42.

Scalia, J, Benson, C & Finnegan, M 2019, ‘Alternate Procedures for Swell Index Testing of Granular Bentonite from GCLs’, Geotechnical Testing Journal, vol. 5, no. 42.

Burger, J, Gochfeld, M, Kosson, DS, Brown, KG, Salisbury, JA & Jeitner, C 2019, ‘Evaluation of ecological resources at operating facilities at contaminated sites: The Department of Energy’s Hanford Site as a case study’, Environmental Research, vol. 170, pp. 452-462.

Burger, J, Gochfeld, M, Kosson, DS, Brown, KG, Bliss, LS, Bunn, A, Clarke, JH, Mayer, HJ & Salisbury, JA 2019, ‘The costs of delaying remediation on human, ecological, and eco-cultural resources: Considerations for the Department of Energy: A methodological framework’, Science of The Total Environment, vol. 649, pp. 1054-1064.

Burger, J, Gochfeld, M, Kosson, D, Bunn, A, Salisbury, J, Brown, K, Downs, J & Jeitner, C 2019, ‘Comparing Ecological Risk between D & D Facilities and Operating Facilities at the Hanford Site – 19531, Poster’, WM ‘2019, WM Symposia, Phoenix, Arizona.

Burger, J, Gochfeld, M, Jeitner, C, Bunn, A, Downs, J, Kosson, D, Salisbury, J & Brown, K 2019a, ‘Comparing Ecological Risk between D & D Facilities and Operating Facilities at the Hanford Site – 19531, Presentation’, WM ‘2019, WM Symposia, Phoenix, Arizona.

Burger, J, Gochfeld, M, Jeitner, C, Bunn, A, Downs, J, Kosson, D, Salisbury, J & Brown, K 2019b, ‘Comparing Ecological Risk between D & D Facilities and Operating Facilities at the Hanford Site – 19531, Panel’, WM ‘2019, WM Symposia, Phoenix, Arizona.

Benson, C & Tian, K 2019a, ‘Stress-Induced Porewater Pressures in the Vadose Zone Beneath a Mixed Waste Landfill ‘, WM ‘2019, 2019 Symposia, Phoenix, Arizona.

Benson, C & Tian, K 2019b, ‘Stress-Induced Porewater Pressures in the Vadose Zone Beneath a Composite-Lined Landfill – 19001, Panel’, WM ‘2019, WM Symposia, Phoenix, Arizona.

Benson, C, Black, P, Walker, S, Rosenberger, K, Seitz, R & Brown, K 2019, ‘Interagency Community of Practice in Risk and Performance Assessment, Panel’, WM ‘2019, WM Symposia, Phoenix, Arizona.

Benson, C 2019, ‘Applying Lessons Learned on Engineered Barrier Service Life to Performance Assessment, Presentation’, WM ‘2019, WM Symposia, Phoenix Arizona.

Benson, C 2019, ‘CRESP’s Land Fill Partnership: Applied Research to Solve Challenging Problems for On-Site Disposal Facilities, Presentation’, WM ‘2019, WM Symposia, Phoenix, Arizona.

Tian, K, Benson, C, Yesiller, N & Hanson, J 2018, ‘Evaluation of a HDPE Geomembrane from a Composite Liner after 12-yr of Atmospheric Exposure’, Geosynthetics 2019, Industrial Fabrics Association International, Houston, Texas.

Tian, K, Benson, C, Yang, Y & Tinjum, J 2018, ‘Radiation dose and antioxidant depletion in a HDPE geomembrane’, Geotextiles and Geomembranes, vol. 46, no. 4, pp. 426-435.

Tian, K & Benson, C 2018, ‘Containing Tc-99 using a multisorbing barrier material’, Waste Management ‘18, WM Symposia, Phoenix, Arizona.

Scalia, JI, Bohnhoff, G, Shackelford, C, Benson, C, Sample-Lord, K, Malusis, M & Likos, W 2018, ‘Enhanced bentonites for containment of inorganic waste leachates by GCLs’, Geo synthetics International, vol. 25, no. 4, pp. 392-411.

Ng, G & Higley, K 2018, ‘Application of US EPA SWMM 5 to a radionuclide-contaminated urban catchment with Low-Impact Developments’, Health Physics Society 63rd Annual Meeting, Cleveland, Ohio.

Neville, D & Higley, K 2018, ‘Faster, Sharper and Open’, Cascade Chapter Health Physics Society, Olympia, Washington.

Neville, D, Condon, C & Higley, K 2018, ‘Improving Methodology for Biota Radiation Dosimetry, Poster Session’, CRESP Annual Meeting, Nashville, Tennessee.

Neville, D, Condon, C & Higley, K 2018, ‘Improving Methodology for Biota Radiation Transport’, Applicability of Radiation-Response Models to Low Dose Radiation Protection Standards, American Nuclear Society and Health Physics Society Joint Topical Meeting, Tri-Cities, Washington.

Higley, K 2018a, ‘Radiation Protection: It’s Not Just the Numbers’, Applicability of Radiation-Response Models to Low Dose Radiation Protection Standards, American Nuclear Society and Health Physics Society Joint Topical Meeting, Tri-Cities, Washington.

Higley, K 2018b, ”Integration of radiological protection of the environment into the system of radiological protection”, Annals of the ICRP, vol. 47, no. 3-4, pp. 270-284.

Gomez-Fernandez, M, Higley, K & Tokuhiro, A 2018a, ‘Heuristics and Machine Learning Approaches to Radiation Protection’, Health Physics Society 63rd Annual Meeting, Cleveland, Ohio.

Gomez-Fernandez, M, Higley, K & Tokuhiro, A 2018b, ‘Heuristics and Machine Learning Approaches to Diagnosis and Prognosis’, Spring 2018 E. Dale Trout Meeting of the Cascade Chapter of the Health Physics Society, Portland, Oregon.

Elder, C & Benson, C 2018, ‘Performance and economic comparison of PRB types in heterogeneous aquifers’, Environmental Geotechnics, pp. 1-11.

Condon, C, Neville, D & Higley, K 2018, ‘Site Specific Environmental Fate and Transport of Radionuclides Through Field Work’, CRESP Annual Meeting, Nashville, Tennessee.

Condon, C & Higley, K 2018, ‘Sectional 3D Model Development for the Reference Tree’, Health Physics Society 63rd Annual Meeting, Cleveland, Ohio.

Burger, J, Kosson, D, Powers, C & Gochfeld, M 2018, ‘An Information Template for Evaluating the Relative Priority of Remediation Projects that Pose a Risk to Receptors – 18674’, WM’2018, WM Symposia, Phoenix, Arizona.

Burger, J, Gochfeld, M & Jeitner, C 2018, ‘Risk valuation of ecological resources at contaminated deactivation and decommissioning facilities: methodology and a case study at the Department of Energy’s Hanford site’, Environmental Monitoring and Assessment, vol. 190, no. 8, p. 478.

Benson, C, Albright, W, Waugh, W & Davis, M 2018, ‘Field Hydrologic Performance of Earthen Covers for Uranium Mill Tailings Disposal Sites on the Colorado Plateau’, DOE-LM Long-Term Stewardship Conference, Grand Junction, Colorado.

Benson, C 2018a, ‘Water Balance Covers for Waste Containment: Engineering with Unsaturated Soils from Theory to Practice’, Dr. Arthur T. Corey Distinguished Lecture Series, Colorado State University, Fort Collins, Colorado.

Benson, C 2018b, ‘Sustainability in Geoengineering: A New Paradigm for Engineering with Earthen Materials’, 8th International Congress on Environmental Geotechnics, Hangzhou China.

Benson, C 2018c, ‘Field Evaluation of Radon Fluxes from In-Service Disposal Facilities for Uranium Mill Tailings’, DOE-LM Long-Term Stewardship Conference, Grand Junction, Colorado.

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