RemPlex Seminars

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Flyer with information about a Jan. 26, 2021, seminar on soil vapor extraction for environmental remediation

January 26, 2021: "Hanford 200-PW-1 Operable Unit Soil Vapor Extraction Endpoint Evaluation" will be presented by Chris Johnson, PNNL senior development engineer, and CH2M Hill Plateau Remediation Company project manager Mark Byrnes.

The seminar starts at 12:30 p.m. PST via ZoomGov (Meeting ID: 160 304 1646) and is open to the public. It's part of the Center for the Remediation of Complex Sites (RemPlex) Seminar Series.

Release of carbon tetrachloride (CT) from 1955 to 1973 into the soil column in the 200-PW-1 Operable Unit at the U.S. Department of Energy's Hanford Site resulted in vadose zone and groundwater contamination. Starting in the early 1990s, soil vapor extraction (SVE) was the defined remedy for vadose zone CT contamination, while pump-and-treat was used for groundwater contamination. 

After over 20 years of SVE operations, PNNL collaborated with site contractor CH2M Hill Plateau Remediation Company and consultants Freestone Environmental Services to evaluate observed data, Subsurface Transport Over Multiple Phases(STOMP) numerical model results, and Soil Vapor Extraction Endstate Tool (SVEET) estimates of the impacts of the vadose zone contaminant source. 

This information was evaluated in the context of SVE System Optimization, Transition, and Closure Guidance to provide multiple lines of evidence to demonstrate that the SVE remedy could be terminated. Johnson and Byrnes will discuss the process involved with assessing performance data and following the SVE guidance to present lines of evidence for a path forward to terminate the SVE remediation system.

 

Save the Date: Upcoming Seminars

February 23, 2021: "Modeling and measuring the transport of foam in porous media in the presence of nanoparticles," will be presented by Valentina Prigiobbe, assistant professor, Department of Civil, Environmental, and Ocean Engineering at the Stevens Institute of Technology.

 

December 1, 2020: "Calcium carbonate minerals as scavengers of metals and radionuclides for natural attenuation and remediation," presented by Earth scientist Amanda Lawter and Laboratory Fellow Nik Qafoku.

Calcium carbonate interactions affect contaminant fate and transport in the subsurface environmental systems. Earth scientist Amanda Lawter and Lab Fellow Nik Qafoku provide insights on the use of calcium carbonate natural attenuation mechanisms and their application to remediation. Their presentation on December 1, 2020, is part of PNNL’s Center for the Remediation of Complex Sites (RemPlex) Seminar Series.

 

October 27, 2020: “Integrating Key Capabilities for the Remediation of Complex Sites,” presented by Environmental Management sector manager Tom Brouns, Earth scientist Inci Demirkanli, and project manager Vicky Freedman.

PNNL integrates a range of capabilities in multi-scale experimentation, modeling and simulation, and characterization and monitoring to translate science innovation into practical, cost-effective solutions for field implementation. Environmental remediation experts Tom Brouns, Inci Demirkanli, and Vicky Freedman describe how PNNL applies these capabilities to address the needs of complex sites through all phases of development and remediation, from complex site characterization and conceptual site model development, through remedy selection and implementation, adaptive site management, and long-term stewardship. The October 27, 2020, presentation was part of PNNL’s Center for the Remediation of Complex Sites (RemPlex) Seminar Series.

 

 

September 23, 2020: "Evaluation Approaches for Transitioning from Active to Passive Remediation," presented by Earth scientist Katie Muller and environmental remediation advisor Mike Truex.

In the context of managing complex sites and phased remedies, there is a need to defensibly support decisions to transition between remediation elements, in particular for transitioning from active to passive remediation. Available tools and guidance for evaluating transitions are presented and discussed in terms of how they can be applied to support transition decisions. Earth scientist Katie Muller and environmental remediation advisor Mike Truex highlighted the application of approaches under case study field site conditions. Their presentation was September 23, 2020, as part of PNNL’s Center for the Remediation of Complex Sites (RemPlex) Seminar Series.

 

 

August 11, 2020: Understanding Environmental Site Conditions: What do we need to know to select and implement effective remedies? Presented by Mike Truex.

Technical information about contaminants, exposure pathways, and factors that affect how candidate remedies perform at a specific site are used to support selecting and implementing environmental remedies. How do we determine the type and extent of information that is needed to support remediation decisions? What resources and approaches are available to facilitate obtaining the appropriate technical information? Mike Truex, senior project manager, explores these questions using some case study examples. “Understanding Environmental Site Conditions: What do we need to know to select and implement effective remedies?” was presented August 11, 2020, as part of PNNL’s Center for the Remediation of Complex Sites (RemPlex) Seminar Series.

June 18, 2020: "Implications of Uranium Behavior in the Subsurface for Environmental Remediation," presented by Jim Szecsody and Hilary Emerson

Environmental engineer Jim Szecsody and Earth scientist Hilary Emerson share insights gathered from uranium characterization and remediation efforts at the Hanford Site in Washington and at the Rifle Mill Site in Colorado. “Implications of Uranium Behavior in the Subsurface for Environmental Remediation” was presented June 18, 2020, as part of PNNL’s Center for the Remediation of Complex Sites (RemPlex) Seminar Series.

Supplemental Materials for Implications of Uranium Behavior in the Subsurface for Environmental Remediation, June 18, 2020

Flier with a photo of the Columbia River and pictures of speakers Hillary and Jim, text describes the seminar

 

 

  1. Efficacy of Acetate-Amended Biostimulation for Uranium Sequestration: Combined Analysis of Sediment/Groundwater Geochemistry and Bacterial Community Structure - Jan. 2, 2018
  2. Abiotic Reductive Immobilization of U(VI) by Biogenic Mackinawite - April 6, 2017
  3. Uranium Fate in Hanford Sediment Altered by Simulated Acid Waste Solutions - Nov. 12, 2015
  4. Influence of Carbon and Microbial Community Priming on the Attenuation of Uranium in a Contaminated Floodplain Aquifer - 2015
  5. Uranium in Framboidal Pyrite from a Naturally Bioreduced Alluvial Sediment - Aug. 19, 2014
  6. Geochemical and Mineralogical Investigation of Uranium in Multi–element Contaminated, Organic–rich Subsurface Sediment - April 28, 2014
  7. Geochemical, mineralogical and microbiological characteristics of sediment from a naturally reduced zone in a uranium-contaminated aquifer - July 26, 2012
  8. Advective Removal of Intraparticle Uranium from Contaminated Vadose Zone Sediments, Hanford, USA - Oct. 7, 2011 
  9. Kinetic Desorption and Sorption of U(VI) during Reactive Transport in a Contaminated Hanford Sediment - May 11, 2011
  10. Interactions of aqueous U(VI) with soil minerals in slightly alkaline natural systems - Sept. 3, 2010
  11. Effect of Extent of Natural Subsurface Bioreduction on Fe-mineralogy of Subsurface Sediments - May 17, 2010
  12. Advective Desorption of Uranium (VI) from Contaminated Hanford Vadose Zone Sediments under Saturated and Unsaturated Conditions - March 6, 2009
  13. Scale-dependent desorption of uranium from contaminated subsurface sediments - Nov. 4, 2008

 

May 15, 2020: "Introducing the Center for the Remediation of Complex Sites," presented by Dawn Wellman. 

Director Dawn Wellman discusses how RemPlex fosters technical stewardship, builds partnerships, and advanced the R&D needed to translate science and engineering innovation into practical, adaptive, operational solutions to address complex site remediation. This seminar was held via Zoom on May 15, 2020.

Slides: Introduction to RemPlex, May 15, 2020