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.
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.
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.
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.
September 23, 2020: "Evaluation Approaches for Transitioning from Active to Passive Remediation," presented by Earth scientist Katie Muller and environmental remediation advisor Mike Truex.
August 11, 2020: Understanding Environmental Site Conditions: What do we need to know to select and implement effective remedies? Presented by Mike Truex.
June 18, 2020: "Implications of Uranium Behavior in the Subsurface for Environmental Remediation," presented by Jim Szecsody and Hilary Emerson
Supplemental Materials for Implications of Uranium Behavior in the Subsurface for Environmental Remediation, June 18, 2020
- Efficacy of Acetate-Amended Biostimulation for Uranium Sequestration: Combined Analysis of Sediment/Groundwater Geochemistry and Bacterial Community Structure - Jan. 2, 2018
- Abiotic Reductive Immobilization of U(VI) by Biogenic Mackinawite - April 6, 2017
- Uranium Fate in Hanford Sediment Altered by Simulated Acid Waste Solutions - Nov. 12, 2015
- Influence of Carbon and Microbial Community Priming on the Attenuation of Uranium in a Contaminated Floodplain Aquifer - 2015
- Uranium in Framboidal Pyrite from a Naturally Bioreduced Alluvial Sediment - Aug. 19, 2014
- Geochemical and Mineralogical Investigation of Uranium in Multi–element Contaminated, Organic–rich Subsurface Sediment - April 28, 2014
- Geochemical, mineralogical and microbiological characteristics of sediment from a naturally reduced zone in a uranium-contaminated aquifer - July 26, 2012
- Advective Removal of Intraparticle Uranium from Contaminated Vadose Zone Sediments, Hanford, USA - Oct. 7, 2011
- Kinetic Desorption and Sorption of U(VI) during Reactive Transport in a Contaminated Hanford Sediment - May 11, 2011
- Interactions of aqueous U(VI) with soil minerals in slightly alkaline natural systems - Sept. 3, 2010
- Effect of Extent of Natural Subsurface Bioreduction on Fe-mineralogy of Subsurface Sediments - May 17, 2010
- Advective Desorption of Uranium (VI) from Contaminated Hanford Vadose Zone Sediments under Saturated and Unsaturated Conditions - March 6, 2009
- 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.