Geosciences –
Geology and Hydrogeology

GEOSCIENCES BACKGROUND

Uranium was enriched at the Paducah Gaseous Diffusion Plant (PGDP) from 1952 through 2014. Trichloroethene (TCE), a manufactured volatile organic compound (VOC), was used extensively to degrease enrichment process equipment and & routinely clean more than 400 miles of enrichment process piping.

From 1953 until 1993, rail tank cars unloaded TCE at the southeast corner of the C-400 Cleaning Facility where it was stored, transferred and used for degreasing in heated liquid baths, high-pressure sprayers and vapor degreasing units.

Losses of TCE DNAPL to the shallow subsurface included: 1) Leakage along TCE transfer system piping; 2) Discharge through process wastewater; 3) spills; and 4) Cleaning process vapor releases. TCE-laden water from the C-400 cleaning baths was discharged through wastewater piping for transfer to the PGDP wastewater treatment facility. The discharged TCE dissolved the oakum joints used to seal the pipes of the wastewater transfer system and allowed TCE-laden water to enter the subsurface directly.

TCE is a dense non-aqueous phase liquid (DNAPL) and is denser than water. TCE’s density causes it to sink through porous soil, aquifer materials, and groundwater.As TCE sinks through soil and aquifer media it leaves TCE DNAPL in the interstitial pore spaces where it remains as it is slowly dissolved. When sufficient quantities of DNAPL are released, their downward movement will continue until they encounter impermeable materials such as clay. When impermeable material is encountered TCE DNAPL will pool.Once pooled, the DNAPL will remain a long-term source to groundwater contamination.

From 1953 to 1976, the PGDP feed plant reprocessed spent nuclear fuel rods containing uranium. Reprocessing resulted in the introduction of technetium-99 (99Tc or Tc-99), a man-made fission radioisotope, and other radioactive materials not associated with naturally occurring uranium. Deposition in process equipment, piping and transfer equipment as well as transfer and storage of 99Tc-bearing liquids introduced 99Tc to PGDP waste and wastewater streams.

Technetium-99 is a unique radionuclide in environmental settings because it easily dissolves in water where it forms the pertechnetate ion,TcO4.The pertechnetate ion is relatively unreactive with aquifer materials and very mobile in groundwater.

The southeast and northwest corners of the C-400 Cleaning Building have been identified as major groundwater contamination sources related to the PGDP Northwest Plume which contains TCE and99Tc.Sources of the Southwest Plume (TCE and99Tc) include uranium burial grounds, a RCRA-closure drummed uranium above-ground burial facility, an oil landfarm, and the C-720 maintenance facility. The Southwest Plume is limited to DOE property. On-site sources for the Northeast Plume have not been clearly defined.

The Northeast and Northwest TCE Plumes and the Northwest 99Tc Plume are the largest in the DOE complex and amongst the largest documented groundwater plumes of their kind in the world. The depth of the contaminated aquifer, the geochemistry of the aquifer and contaminants, and aquifer materials that range from flowing fine sands to cobble all pose challenges to geoscientists and engineers in their efforts to characterize and remediate PGDP groundwater contamination.

TCE Cleaning Baths in southeast corner of the C-400 Building
TCE Groundwater Plumes Calendar Year 2010
TCE Groundwater Contamination Source Areas

LITHOSTRATIGRAPHY 1
STRATIGRAPHIC MODEL DEVELOPMENT

KRCEE’s initial lithostratigraphy efforts began as an M.S. Thesis project to independently develop a stratigraphic model and compile historical lithologic logs collected during PGDP and vicinity environmental investigations.

Initial project activities included extensive field reconnaissance in the vicinity of the PGDP, consultation with Kentucky and Illinois State Geological Surveys to correlate the distribution of geologic units in southern Illinois with geologic units in the vicinity of the PGDP, and carbon dating analysis of (Upper) Continental Deposit material overlying the Regional Gravel Aquifer. Approximately 400 lithologic logs were gathered, compiled in Rockware @ software and used to produce stratigraphic and hydro-stratigraphic surfaces and cross-sections for the PGDP and vicinity.

Project Participants

Josh Sexton, M.S. Student, Department of Geological Sciences, University of Kentucky
Dr. Alan Fryar, Department of Geological Sciences, University of Kentucky (PI)
Dr. Stephen Greb, Kentucky Geological Survey, University of Kentucky
Dr. Steve Cordiviola, Kentucky Geological Survey, University of Kentucky
Steve Hampson, KRCEE

Field reconnaissance: A gravel exposure in a lower reach of Little Bayou Creek (Sexton, 2006)

LITHOSTRATIGRAPHIC DATABASE PROJECT

The Lithostratigraphic Database Development Project encompasses ongoing lithologic data compilation, classification, and development/updating of a hydrogeologic and lithostratigraphic database for the PGDP and its environs. Database development began in 2004 with a focus on identification of the top and bottom of the Regional Gravel Aquifer (RGA), aquitard material overlying the aquifer (HU3), boring interval depths, elevations, and descriptions.

Aquifer surfaces interpolated from database records were utilized in the 2008 PGDP Groundwater Flow Model Update, 2010/2012 PGDP pump and treat optimization activities, and the 2016 PGDP Flow Model Update. Newly acquired lithologic log data is included in semi-annual updates to the database. In CY 2020 a 28,000-record 10th update to the database was submitted to the PGDP.

Lithologic log data has been acquired from PGDP site & CERCLA project documents, the Kentucky Geological Survey water well data repository, U.S. Army Corps of Engineers, TVA Shawnee Steam Plant engineering documents, geologic quadrangle maps and the Illinois Geological Survey. Approximately 1700 digital lithologic log files were transferred from KRCEE to PEGASIS in 2014.

Stratigraphic surface and hydrogeologic unit surface maps, isopach maps and 3D renderings have been produced from Lithostratigraphic Database records utilizing a variety of geotechnical software packages including Surfer, ARCMap, ArcScene, Earth Vision Software (EVS), Leapfrog, Groundwater Modeling System (GMS) and Rockware.

Lithostratigraphic Database Project Team participants included PGDP personnel, University of Kentucky faculty & staff, contractor subject matter experts and Earth and Environmental Science graduate students. The Kentucky Geological Survey enlisted geological sciences graduate students to conduct a significant data input during the summer of 2009.Approximately 1,000 lithologic logs were updated and/or digitally entered by Agricultural and Biosystems engineering summer student support during 2012.

Project Team

Adam Locke, Engineer/GIS Specialist, CDM Inc., Pittsburgh
Bruce Phillips, Sr. Environmental Scientist, Navarro Engineering
Dr. Alan Fryar, Professor, Hydrogeology and Environmental Geology, Earth and Environmental Sciences, University of Kentucky
Dr. William Andrews, Geologic Mapping Section Head, Kentucky Geological Survey, University of Kentucky
Emily Eastridge, Graduate Student, Earth and Environmental Sciences, University of Kentucky
Estifanos Haile, Graduate Student, Earth and Environmental Sciences, University of Kentucky
Ganesh Nath Tripathi, Graduate Student, Earth and Environmental Sciences, University of Kentucky
Abhijit Mukherjee, Graduate Student, Earth and Environmental Sciences, University of Kentucky
David Cross, Undergraduate Student, Earth and Environmental Sciences, University of Kentucky
JoAnna Foresman, Research Assistant, Biosystems and Agricultural Engineering, College of Engineering
Ken Davis, Geologist/Hydrogeologist, Paducah Remediation Services & Four Rivers Nuclear Partnership (Paducah Site)
Mark Cross, Undergraduate Student, Earth and Environmental Sciences, University of Kentucky
Steve Hampson, Associate Director, Kentucky Research Consortium for Energy and Environment (KRCEE), Center for Applied Energy Research, University of Kentucky(PI)

3D Rendering of the top of the McNairy Formation underlying the central and western PGDP Industrial Site (ARCScene view from SSE).
3D Rendering of Hydrostratigraphic units underlying Solid Waste Management Unit 4 (EVS view from SSW).
Regional Gravel Aquifer - Gravel (HU5) Isopach Map Underlying PGDP & Vicinity (Surfer & ARCMap).

R12 KRCEE PGDP Hydrolithostratigraphic Database

RELEASE NOTES

The Kentucky Research Consortium for Energy and Environment (KRCEE) annually updates and edits the PGDP Hydrolithostratigraphic Database for use in site activities.  The twelfth revision (R12) of the KRCEE Hydrolithostratigraphic Database (Table 1) was completed for submission to DOE-PPPO September 30th, 2023.  Posted information directly supporting the database includes a column identification table describing column contents for all records, a characterization model table describing classification of hydro- and lithostratigraphic column data; a database materials column classification table and a summary of Grant Year 7 database activities (Table 1).

Table 1.   R12 Hydrolithostratigraphic Database and Supporting Information

Accompanying the R12 Database are renderings of PGDP and vicinity hydrogeologic unit surfaces and isopachs of the principal hydrogeologic units at the PGDP.  Renderings are provided in two formats: 1) .pdf for use in Adobe software (Table 2.1); and 2) .jpg for use in MS Windows Photos program and import into other document software (Table 2.2).

Table 2.1.   R12 Hydrolithostratigraphic Database and Supporting Information (.pdf)

Rendered Data Sheet 1. R12 Database Data Locations.pdf
Rendered Data Sheet 1a. R12 Database Data Locations PGDP Site & Southern Reservation.pdf
Rendered Data Sheet 1b. R12 Database Data Locations Central & SW PGDP Site.pdf
Rendered Data Sheet 1c. R12 Database Data Locations N PGDP Site to Ohio River.pdf
Rendered Data Sheet 2. R12 Top of HU6 – GW Model Domain.pdf
Rendered Data Sheet 2a. R12 Top of HU6 – PGDP Industrial Site.pdf
Rendered Data Sheet 2b. R12 Top HU6 – C-400.pdf
Rendered Data Sheet 3. R12 Top RGA – GW Model Domain.pdf
Rendered Data Sheet 3a. R12 Top RGA – Industrial Site.pdf
Rendered Data Sheet 3b. R12 Top RGA – C-400.pdf
Rendered Data Sheet 4. R12 Top of HU5 (RGA-LCD Gravel & Sand).pdf
Rendered Data Sheet 4a. R12 Top of HU5 – PGDP Industrial Site.pdf
Rendered Data Sheet 4b. R12 Top HU5 – C-400.pdf
Rendered Data Sheet 5. R12 Top of HU3 – GW Model Domain.pdf
Rendered Data Sheet 5a. R12 Top of HU3 – PGDP Industrial Site.pdf
Rendered Data Sheet 5b. R12 Top HU3 C-400.pdf
Rendered Data Sheet 6. R12 HU3 Isopach (Manual) – GW Model Domain.pdf
Rendered Data Sheet 6a. R12 HU3 Isopach (Manual) – PGDP Industrial Site.pdf
Rendered Data Sheet 6b. R12 HU3 Isopach C-400.pdf
Rendered Data Sheet 7. R12 RGA Isopach – GW Model Domain.pdf
Rendered Data Sheet 7a. R12 RGA Isopach – PGDP Industrial Site.pdf
Rendered Data Sheet 7b. R12 RGA Isopach – C-400.pdf
Rendered Data Sheet 8. R12 RGA Gravel (HU5) Isopach – GW Model Domain.pdf
Rendered Data Sheet 8a. R12 RGA Gravel (HU5) Isopach – PGDP Industrial Site.pdf
Rendered Data Sheet 8b. R12_HU5_Isopach – C-400.pdf

Table 2.2.   R12 Hydrolithostratigraphic Database and Supporting Information (.jpg)

Rendered Data Sheet 1. R12 Database Data Locations.jpg
Rendered Data Sheet 1a. R12 Database Data Locations PGDP Site & Southern Reservation.jpg
Rendered Data Sheet 1b. R12 Database Data Locations Central & SW PGDP Site.jpg
Rendered Data Sheet 1c. R12 Database Data Locations N PGDP Site to Ohio River.jpg
Rendered Data Sheet 2. R12 Top of HU6 – GW Model Domain.jpg
Rendered Data Sheet 2a. R12 Top of HU6 – PGDP Industrial Site.jpg
Rendered Data Sheet 2b. R12 Top HU6 – C-400.jpg
Rendered Data Sheet 3. R12 Top RGA – GW Model Domain.jpg
Rendered Data Sheet 3a. R12 Top RGA – Industrial Site.jpg
Rendered Data Sheet 3b. R12 Top RGA – C-400.jpg
Rendered Data Sheet 4. R12 Top of HU5 (RGA-LCD Gravel & Sand).jpg
Rendered Data Sheet 4a. R12 Top of HU5 – PGDP Industrial Site.jpg
Rendered Data Sheet 4b. R12 Top HU5 – C-400.jpg
Rendered Data Sheet 5. R12 Top of HU3 – GW Model Domain.jpg
Rendered Data Sheet 5a. R12 Top of HU3 – PGDP Industrial Site.jpg
Rendered Data Sheet 5b. R12 Top HU3 C-400.jpg
Rendered Data Sheet 6. R12 HU3 Isopach (Manual) – GW Model Domain.jpg
Rendered Data Sheet 6a. R12 HU3 Isopach (Manual) – PGDP Industrial Site.jpg
Rendered Data Sheet 6b. R12 HU3 Isopach C-400.jpg
Rendered Data Sheet 7. R12 RGA Isopach – GW Model Domain.jpg
Rendered Data Sheet 7a. R12 RGA Isopach – PGDP Industrial Site.jpg
Rendered Data Sheet 7b. R12 RGA Isopach – C-400.jpg
Rendered Data Sheet 8. R12 RGA Gravel (HU5) Isopach – GW Model Domain.jpg
Rendered Data Sheet 8a. R12 RGA Gravel (HU5) Isopach – PGDP Industrial Site.jpg
Rendered Data Sheet 8b. R12_HU5_Isopach – C-400.jpg

Discussion about changes to R10 and R11 databases and renderings are under development and will be posted as R-12 Project activities transition into R13 during the KRCEE GY7 Extension period (November – December 2023).

Project Team

Shishir Kumar Sarker, Ph. D. Student, Earth and Environmental Sciences, University of Kentucky
Steve Hampson, KRCEE (PI)

GROUNDWATER MODELING 1

KRCEE participation in PGDP groundwater modeling efforts began in 2004 as a carryover of UK-Kentucky Radiation Health groundwater modeling evaluation efforts conducted as part of the Agreement in Principle Program.

The first Project Team task undertaken by Department of Civil Engineering faculty and post-doctoral staff was an independent review of historical PGDP modeling efforts. The review encompassed the initial 1994 PGDP Groundwater Flow Model (MODFLOW) and model updates through calendar year 2000 which included development and implementation of a flow and transport model (MODFLOWT). (1998 PGDP Groundwater Flow Model)

Next, the Project Team ran the 1998 MODFLOW and MODFLOWT model simulations and evaluated results. Sensitivity analyses were then conducted on key model parameters including hydraulic conductivity and TCE degradation rates. Sensitivity analysis of TCE plume extents over a range of TCE intrinsic biodegradation half-lives, from 5 years to 26.5 years are shown in accompanying figures.

A summary of Project Team findings is provided in the GW Modeling Efforts FFA Summary Presentation below.

(Above: Description of biodegradation half life sensitivity analyses.)

Project Participants

Dr. Srinivasa Lingireddy, Associate Professor, Civil Engineering, University of Kentucky (Co-PI)
Dr. Chandramouli Viswanathan, Adjunct Faculty, Kentucky Water Resources Research Institute/College of Engineering, University of Kentucky (Co-PI)
Dr. Alauddin Kahan, GW Model Services, Scientific Applications International Corporation, Knoxville, Tennessee
Dr. Lindell Ormsbee, PE, Director, Kentucky Water Resources Research Institute (KWRRI); Director, Kentucky Research Consortium for Energy and Environment; Professor, Department of Civil Engineering, University of Kentucky
Dr. Alan Fryar, Professor, Hydrogeology and Environmental Geology, Earth and Environmental Sciences, University of Kentucky
James Kipp, Associate Director, Kentucky Water Resources Research Institute (KWRRI), University of Kentucky
Steve Hampson, Associate Director, Kentucky Research Consortium for Energy and Environment (KRCEE), Center for Applied Energy Research, University of Kentucky

(Figures: Biodegradation Half-life Model Runs: Blue TCE plume extents are the baseline model at time zero, black line is the TCE plume extent after specified model run duration. Half Life is specified on each slide)

GROUNDWATER MODELING
ALTERNATIVE GROUNDWATER MODEL DEVELOPMENT

Faculty, staff and graduate student modelers at the Kentucky Water Resources Research Institute (KWRRI) and UK College of Engineering developed an Artificial Neural Network (ANN) model to supplement the use of MODFLOW groundwater flow and MODFLOWT transport models at the PGDP site.

The purpose of an ANN model for the PGDP is to forecast TCE concentrations as accurately as the MODFLOWT model so that it can be incorporated with an optimization technique and integrated into a management model.

An optimization model requires numerous evaluations of the objective function, and this is not feasible with a MODFLOWT model that can take hours (to days) for one simulation. A properly trained ANN model could give results of the objective function in seconds.

Three distinct groundwater modeling tasks were accomplished for the Project. Results are discussed in the reports below.

PROJECT TEAM

Joshua Kopp, Graduate Student, Department of Civil Engineering, College of Engineering, University of Kentucky
Dr. Lindell Ormsbee, PE, Director, Kentucky Water Resources Research Institute (KWRRI); Director, Kentucky Research Consortium for Energy and Environment; Professor, Department of Civil Engineering, University of Kentucky (PI)
Dr. Chandramouli Viswanathan, Adjunct Faculty, Kentucky Water Resources Research Institute/College of Engineering, University of Kentucky

Locations of existing and simulated pumping wells used in ANN model simulations.

GROUNDWATER MODELING
PROPERTY ACQUISITION REPORT (LAND STUDY) GROUNDWATER MODELING

The PGDP Property Acquisition Study (Land Study) was conducted in accordance with a Congressional Directive to DOE in the Energy and Water Development Appropriation Bill, 2006 (Senate Report 109-084).

“Within the funds provided the Department shall undertake a study of the potential purchase of property or options to purchase property that is located above the plume of contaminated groundwater near the facility site. The study shall evaluate the adequate protection of human health and environment from exposure to contaminated groundwater and consider whether such purchase, when taking into account the cost of remediation, long-term surveillance, and maintenance, is in the best interest of taxpayers.”

The Land Study required a groundwater modeling evaluation for a complete range of groundwater remedial alternatives identified in PGDP decision (regulatory program) documents. Five alternatives were identified, No Action and four remedial scenarios (Table 3.4.1 below). For each alternative, the temporal as well as maximum extent of plume impacts was modeled over a 100-year period.

A KWRRI & UK-Civil Engineering Project Team applied experience in site groundwater modeling (see Groundwater Modeling 1) to conduct MODFLOW and MODFLOWT simulations of each remedial action scenario using the 1998 PGDP Flow and Transport Models (Bechtel-Jacobs, DOE, 1998*).

Further project groundwater modeling information is available in the text and Appendix A of the Property Acquisition Study Final Report.**

*DOE (U.S. Department of Energy) 1998. Ground Water Flow Model Recalibration and Transport Model Construction at the PGDP, Paducah, Kentucky, DOE/OR/07-1742&DO, United States Department of Energy, Paducah, KY, June 1998.

**The findings of the PGDP Property Acquisition Study are presented in greater detail with PGDP Future Use, Public Outreach & Education Projects

Modeled maximum TCE plume contours (5 µg/L) over time assuming source reductions at C-400, C-720, SWMU 1 and SWMU 4 (including dissolved phase treatment of Southwest Plume and PTZ at facility fence) (Scenario 4)
Table 3.4.1 Potential Response Action Scenarios
Scenario ID Description
1 P&T Continuation of existing pump and treat action
2 C400 Source reduction of contamination at C-400 building using direct heating technology
3 URD Source reduction of UCRS and RGA sources using direct heating technology, and treatment of Southwest Plume using ozonation (i.e. C-Sparge) technology
4 URD-PTZ Source reduction of all sources, treatment of Southwest Plume, and PTZ technology at the PGDP security fence.

Project Team

Dr. Srinivasa Lingireddy, Associate Professor, Civil Engineering, University of Kentucky (Co-PI)
Dr. Lindell Ormsbee, PE, Director, Kentucky Water Resources Research Institute (KWRRI); Director, Kentucky Research Consortium for Energy and Environment; Professor, Department of Civil Engineering, University of Kentucky (Co-PI)
Dr. Chandramouli Viswanathan, Adjunct Faculty, Kentucky Water Resources Research Institute/College of Engineering, University of Kentucky (Co-PI)
Teri Dowdy, Instructor, Biosystems and Agricultural Engineering, University of Kentucky

Project Documents

PROPERTY ACQUISITION STUDY MODEL UPDATE

A faculty and staff project team from the Kentucky Water Resources Research Institute (KWRRI), the Kentucky Geological Survey (KGS), KRCEE and the UK College of Engineering utilized the updated 2008 PGDP Groundwater Model to reevaluate the Property Acquisition Scenarios GW modeling responses to remedial actions.

Project Team

Dr. Junfeng Zhu, Hydrogeologist, Kentucky Geological Survey, University of Kentucky (Co-PI)
Dr. Lindell Ormsbee, PE, Director, Kentucky Water Resources Research Institute (KWRRI); Director, Kentucky Research Consortium for Energy and Environment; Professor, Department of Civil Engineering, University of Kentucky (Co-PI)
Dr. Kelly Pennell, Associate Professor, Civil Engineering, University of Kentucky
Dr. Alan Fryar, Professor, Hydrogeology and Environmental Geology, Earth and Environmental Sciences, University of Kentucky
Steve Hampson, Associate Director, Kentucky Research Consortium for Energy and Environment (KRCEE), Center for Applied Energy Research, University of Kentucky

Project Documents

PGDP GROUNDWATER MODEL SUPPORT INDEPENDENT MODEL REVIEWS

A groundwater modeling project team from the Kentucky Water Resources Research Institute, Kentucky Geological Survey, UK Earth and Environmental Sciences and the UK College of Engineering executed and evaluated the 2008 and 2016 PGDP Groundwater Model Updates.

The project team reviewed project documents and model inputs for each updated model. Following execution of the MODFLOW models for each update, the project team provided an independent review of model results and recommendations for future model improvements.

Project Team

Dr. Lindell Ormsbee, PE, Director, Kentucky Water Resources Research Institute (KWRRI); Director, Kentucky Research Consortium for Energy and Environment; Professor, Department of Civil Engineering, University of Kentucky (Co-PI)
Dr. James Dinger, Water Section Head, Kentucky Geological Survey Water Section, University of Kentucky
Dr. Junfeng Zhu, Hydrogeologist, Kentucky Geological Survey, University of Kentucky (Co-PI)
Dr. Kelly Pennell, Associate Professor, Civil Engineering, University of Kentucky
Dr. Alan Fryar, Professor, Hydrogeology and Environmental Geology, Earth and Environmental Sciences, University of Kentucky
Estifanos Haile, Graduate Student, Earth and Environmental Sciences, University of Kentucky

Project Documents

GROUNDWATER-SURFACE WATER INTERACTION

UK Earth and Environmental Science PGDP projects conducted from 2000 – 2013 evaluated the extent, concentrations, and trends associated with groundwater seeps that discharge TCE and technetium-99 contaminated groundwater to Little Bayou Creek approximately 3 miles down-gradient of contamination sources on the PGDP industrial site. The projects have included research for and authorship of independent journal articles as well as in-depth thesis and dissertation work.

Preliminary site and seep characterization and assessment work was conducted independently (journal article: Fryar et al., 2000) and as part of thesis (Mukherjee, 2003) and dissertation work (LaSage, 2004) with funding from the University of Kentucky Water Resources Research Institute (KWRRI) Federal Facilities Oversight Unit (FFOU).

Subsequent publications, thesis and dissertation work built upon earlier works.

Newly emerged spring along study area reach 2 in 2012
Overview map of the PGDP and environs, including the study area where offsite TCE groundwater plumes discharge through seeps to Little Bayou Creek
LBC seeps study area detail (Tripathi, 2013)

Project Team

Dr. Alan Fryar, Professor, Hydrogeology and Environmental Geology, Earth and Environmental Sciences, University of Kentucky (PI)
Joshua Sexton, Graduate Student, Earth and Environmental Sciences, University of Kentucky; Geologist, Marshall Miller and Associates & J.L. Sexton and Son
Ganesh Nath Tripathi, Graduate Student, Earth and Environmental Sciences, University of Kentucky
Abhijit Mukherjee, Graduate Student, Earth and Environmental Sciences, University of Kentucky
Danita LaSage, Doctoral Student, Earth and Environmental Sciences, University of Kentucky
Dr. Stephen Greb, Adjunct Professor Geology, Kentucky Geological Survey, University of Kentucky

Project Documents

Journal Article Fryar, A.E., Wallin, E.J., Brown, D.L., 2000. Spatial and temporal variability in seepage between a contaminated aquifer and tributaries to the Ohio River. Ground Water Monitoring & Remediation 20, 129–146.
Thesis Mukherjee, Abhijit, “Identification of Natural Attenuation of Trichloroethene and Technetium-99 Along Little Bayou Creek, McCracken County, Kentucky” (2003). University of Kentucky Master’s Theses. 293. https://uknowledge.uky.edu/gradschool_theses/293
Meeting Presentation and Poster Mukherjee, A., Fryar, A.E., Evaluating Natural Attenuation of Contaminants Along A First Order Coastal Plain Stream, Presentation to Geological Society of America, Paper 152-4, 2003.
Dissertation LaSage, D.M., 2004. Natural attenuation along a first-order stream recharged by contaminated ground water. Ph.D. Thesis, University of Kentucky, USA, 238p. (unpublished)
Journal Article Mukherjee, A., Fryar, A.E., LaSage, D.M., 2005. Using tracer tests to assess natural attenuation of contaminants along a channelized Coastal Plain stream, 2005 Environmental & Engineering Geoscience 11 (4), 371–382.
Meeting Poster Sexton, J., Geologic Mapping of Near-Surface Sediments in the Northern Mississippi Embayment, Poster Session,, Geological Society of America, Knoxville, TN. April 2005.
Thesis Sexton, J., Lithologic and Stratigraphic Compilation of Near Surface Sediment, 2006. (Sexton MS Thesis)
Journal Article LaSage, D.M., Sexton, J.L., Mukherjee, A., Fryar, A.E., Greb, S.F., 2008. Groundwater discharge along a channelized Coastal Plain stream. Journal of Hydrology 360 (1-4), 252–264.
Journal Article LaSage, D.M., Fryar, A.E., Mukherjee, A., Sturchio, N.C., Heraty, L.J., 2008a. Groundwater-derived contaminant fluxes along a channelized Coastal Plain stream. J. Hydrology. 360, 265-280. (KRCEE_4.5_2008d)
Meeting Presentation Tripathi, G.N., Fryar, A.E., Spatio-temporal variability in groundwater discharge and contaminant fluxes along Little Bayou Creek , KRCEE Quarterly Meeting Presentation, June 2011.
Meeting Presentation Tripathi, G.N., Fryar, A.E., Thermal profiling of focused groundwater discharge along a channelized stream in western Kentucky, Presentation, October 2011.
Dissertation Tripathi, G.N., 2013, Spatio-temporal variability in groundwater discharge and contaminant fluxes along a channelized stream in western Kentucky, Ph.D. dissertation, University of Kentucky, Lexington, Kentucky, 127 p. https://uknowledge.uky.edu/ees_ etds/13/.
Meeting Poster Hampson, S., Little Bayou Creek Seep Studies, PGDP GW Modeling Team Poster & Discussion, February 2015.
Meeting Poster Tripathi, G.N., Fryar, A.E., Spatial and seasonal variability in groundwater discharge and contaminant fluxes along a channelized stream in western Kentucky, September 2011.
Journal Article Tripathi, G.N., Fryar, A.E., Hampson, S.K., Mukherjee, A., Seasonal to Decadal Variability in Focused Groundwater and Contaminant Discharge along a Channelized Stream. Groundwater Monitoring and Remediation, January 2020.

PGDP GROUNDWATER MODEL INTERIM TRANSPORT MODEL EVALUATION

The ITM activity consisted of the development of an Interim (Groundwater) Transport Model utilizing flow parameters from the 2016 Update of the Paducah Gaseous Diffusion Plant Sitewide Groundwater Flow Model (DOE, 2017) and transport parameters from the 2008 Update of the Paducah Gaseous Diffusion Plant Sitewide Groundwater Flow Model (DOE, 2010).

ITM outputs for several time frames through CY 2018 were compared to 1) transport outputs from the 2008 Update of PGDP Groundwater Flow Model and 2) published interpretations of PGDP trichloroethene (TCE) plume extents based on field measurements

Recommendations regarding the development and refinement of a transport model to supplement the 2016 Update of the Paducah Gaseous Diffusion Plant Sitewide Groundwater Flow Model are included in the Report and Presentation below.

Project Team

Dr. Junfeng Zhu, Hydrogeologist, Kentucky Geological Survey, University of Kentucky (PI)
Steve Hampson, Associate Director, Kentucky Research Consortium for Energy and Environment (KRCEE), Center for Applied Energy Research, University of Kentucky

Interim Transport Model TCE plume results for 1995 data (shaded) plotted against 1995 TCE field monitoring results (lines)

TCE FATE & TRANSPORT
OVERVIEW

The TCE Fate and Transport Project (TCEFT) was undertaken to determine if degradation mechanisms were reducing trichloroethene (TCE) concentrations in the PGDP Regional Gravel Aquifer (RGA). After nearly fifteen years of PGDP groundwater field and geochemical data collection, assessment, publications and reports, the presence or absence of TCE degradation processes acting in the RGA remained unresolved.

The TCEFT Project deployed a structured multi-step approach to evaluate aquifer physical properties, geochemical properties, and contaminants in order to identify degradation mechanisms in the RGA, investigate those mechanisms, and document their active presence utilizing 3 or more lines of supporting evidence: 1) The stepwise major components of the TCE Fate & Transport Project were: 1) TCEFT Natural Attenuation Review; 2) TCEFT Attenuation Scenario Selection Evaluation; 3) TCEFT Phase I, II, and III – Biodegradation; and 4) TCEFT Phase IV – Abiotic Degradation and Site Workplan for Degradation Mechanisms.

TCE FATE & TRANSPORT REVIEW

The review was a formal evaluation of PGDP in-situ groundwater degradation processes based on existing site data, reports, and journal articles. The review concluded that specific TCE degradation mechanisms in the PGDP RGA were not well supported (Fryar, 2006).

PROJECT TEAM

Dr. Alan Fryar, Professor, Hydrogeology and Environmental Geology, Earth and Environmental Sciences, University of Kentucky (PI)
Todd Mullins, Kentucky Division of Waste Management, Commonwealth of Kentucky
Steve Hampson, Associate Director, Kentucky Research Consortium for Energy and Environment (KRCEE), Center for Applied Energy Research, University of Kentucky

Project Documents

TCE FATE & TRANSPORT ATTENUATION
SCENARIO SELECTION EVALUATION

The scenario selection process was implemented by the PGDP TCE Fate and Transport Project Team and led by subject matter experts from Savannah River National Laboratory (SRNL) and Idaho National Engineering Environmental Laboratory (INEEL).

The scenario selection process, developed by SRNL, was utilized to evaluate PGDP groundwater conditions in order to identify the physical, chemical and biological fate and transport processes actively occurring and impacting TCE concentrations in PGDP groundwater.

The attenuation scenario selection process considered PGDP aquifer physical properties, groundwater chemistry, TCE concentrations, TCE degradation products, and TCE source/plume geometry.

The results of the scenario selection process indicated that aerobic co-metabolic TCE degradation was likely to be occurring in the Regional Gravel Aquifer.

Project Team

Bryan Clayton, Hydrogeologist, Paducah Remediation Services & Four Rivers Nuclear Partnership (Paducah Site)
Ken Davis, Geologist/Hydrogeologist, Paducah Remediation Services & Four Rivers Nuclear Partnership (Paducah Site)
Dr. Bryan Looney, Senior Advisory Engineer, Savannah River Laboratory, United States .S. Department of Energy
Dr. Hope Lee, Environmental Microbiologist, Pacific Northwest National Laboratory, U.S. Department of Energy
Dr. John Volpe, Kentucky Research Consortium for Energy and Environment, Kentucky Water Resources Research Institute, University of Kentucky
Steve Hampson, Associate Director, Kentucky Research Consortium for Energy and Environment (KRCEE), Center for Applied Energy Research, University of Kentucky

Primary Factor Example Pages for the PGDP Scenario Selection Screening Process (PRS, 2007)

TCEFT PHASE I, II & III – BIODEGRADATION

TCEFT Project Phases I, II, & III –Biodegradation addressed Facilitation, Scoping, Data Collection, Data Assessment, and Reporting for an investigation focused on Trichloroethene (TCE) biodegradation and abiotic TCE Fate & Transport (TCE-FT) processes in the Regional Gravel Aquifer at the PaducahGaseous Diffusion Plant (PGDP).

TCEFT Project Phases I, II, & III – Biodegradation addressed facilitation, scoping, data collection, data assessment, and reporting for an investigation focused on trichloroethene (TCE) biodegradation and abiotic TCE fate and transport (TCE-FT) processes in the Regional Gravel Aquifer at the Paducah Gaseous Diffusion Plant (PGDP). The TCE-FT Project explicitly pursued process characterization for aerobic co-metabolic TCE degradation based on the results of the scenario selection degradation screening process (above)

The TCE-FT Project included collection of microbial samples and calculation of preliminary degradation rates based upon evaluation of TCE concentrations and stable carbon isotope distributions along the Northwest Plume centroid.

The Biodegradation Project was a focused investigation into the occurrence of aerobic biodegradation processes and the compilation of historical PGDP data available to characterize additional TCE degradation pathways that might exist at the PGDP.

Based on multiple lines of evidence, the Project concluded that aerobic co-metabolic biodegradation is occurring in the NW Plume at the PGDP with a half-life of 11 years that is limited by the lack of a dissolved organic carbon source.

PROJECT TEAM

Dr. Bryan Looney, Senior Advisory Engineer, Savannah River Laboratory, United States .S. Department of Energy (Co-PI)
Dr. Hope Lee, Environmental Microbiologist, Pacific Northwest National Laboratory, U.S. Department of Energy (Co-PI)
Beth Moore, Project Manager, Office of Groundwater and Soil Remediation, Engineering and Technology Environmental Management, United States Department of Energy
Dr. Richard Bonczek, Technical Project Manager & Risk Assessor, Portsmouth-Paducah Project Office, U.S. Department of Energy
Bryan Clayton, Hydrogeologist, Paducah Remediation Services & Four Rivers Nuclear Partnership (Paducah Site)
Ken Davis, Geologist/Hydrogeologist, Paducah Remediation Services & Four Rivers Nuclear Partnership (Paducah Site)
Bruce Phillips, Sr. Environmental Scientist, Navarro Engineering
Dr. Edward Winner, Kentucky Division of Waste Management
Todd Mullins, Kentucky Division of Waste Management, Commonwealth of Kentucky
Brian Begley, Manager, Kentucky Division of Waste Management
Dr. Scott Little, Chemist, Kentucky Division of Waste Management
David Williams, RPM, Region 4 United States Environmental Protection Agency
Dr. John Wilson, Principal Scientist, R.S. Kerr Environmental Research Center (Ada), United States Environmental Protection Agency
Dr. R. Paul Philp, Professor, School of Geology and Geophysics, University of Oklahoma
Dr. John Volpe, Kentucky Research Consortium for Energy and Environment, Kentucky Water Resources Research Institute, University of Kentucky
Steve Hampson, Associate Director, Kentucky Research Consortium for Energy and Environment (KRCEE), Center for Applied Energy Research, University of Kentucky (Co-PI)

Wells sampled to support the assessment of attenuation processes in the Northwest Plume, PGDP (KRCEE 22.6 2008)

TCEFT PHASE IV ABIOTIC DEGRADATION AND
SITE WORKPLAN FOR DEGRADATION MECHANISMS

The Phase IV TCE FT Abiotic Degradation investigation compiled site data related to abiotic degradation processes.

The data was evaluated relative to the likelihood that abiotic processes were actively degrading TCE in PGDP’s Regional Gravel Aquifer. As part of Phase IV TCE FT activities the TCE FT Project Team reviewed available data and made recommendations for future monitoring to identify the occurrence of TCE degradation mechanisms at the site.

Project Team

Dr. Kevin Henke, Geochemist, Center for Applied Energy Research, University of Kentucky (PI)
TCE FT Biodegradation Project Participants (above)

Project Documents

PGDP GROUNDWATER REMEDIATION TECHNOLOGY EVALUATION

Faculty and graduate students from the University of Louisville Civil Engineering and Chemical Engineering Departments evaluated the nature and extent of groundwater contamination at the PGDP and evaluated remedial technologies for their potential to appropriately manage the contamination.

The U of L Project Team’s report, “Evaluation of Groundwater Management/Remediation Technologies For Application to the Paducah Gaseous Diffusion Plant”, identifies and discusses the applicability of remedial technologies to address groundwater source remediation and remediation of general groundwater contamination.

PROJECT TEAM

Dr. D.J. Hagerty, Professor, University of Louisville, Civil Engineering (Co-PI)
Dr. J.C. Watters, Director, University of Louisville, Chemical Engineering (Co-PI)
J.N. Uhl, Graduate Student, University of Louisville, Civil Engineering

PGDP GROUNDWATER ACCOMPLISHMENTS POSTER BOARDS

PGDP Groundwater Accomplishments Poster Boards were developed by a team of graduate and upperclassman College of Design students in collaboration with KRCEE, DOE PGDP Public Relations and groundwater project managers from site contractor Los Alamos Technical Associates of Kentucky (LATA KY).

The 4’ x 6’ posters display details of PGDP’s groundwater characterization and remediation accomplishments from 1988 to 2012. Detail of site infrastructure include existing and new monitoring well installations, TCE and 99Tc plume characterizations (circa 2010), pump & treat containment system optimization modeling, and installation of remedial measures.

The posters also summarize CoD’s construction of scale 2D and 3D physical models of the PGDP and its environs including detail of site infrastructure, subsurface environmental impacts. The models were featured and displayed at public events to support discussions about ongoing PGDP environmental activities, decontamination and decommissioning and PGDP future use.

GW Accomplishments Poster 1 of 4. Click to view this poster’s detail.
GW Accomplishments Poster 3 of 4. Click to view this poster’s detail.

Project Team

Anne Filson, AIA, Associate Professor, Architecture, College of Design, University of Kentucky (Co-PI)
Gary Rohrbacher, AIA, Associate Professor, Architecture, College of Design, University of Kentucky (Co-PI)
Robert ‘Buz’ Smith, Public Relations, Paducah Site Office, Department of Energy
Jeff Carmen, PGDP Groundwater Projects Manager, LATA KY
Carolyn Parrish, Graduate Research Assistant, College of Design, University of Kentucky
Joe O’Toole, Graduate Research Assistant, College of Design, University of Kentucky
Sydney Kidd, Graduate Research Assistant, College of Design, University of Kentucky
Steve Hampson, Associate Director, Kentucky Research Consortium for Energy and Environment (KRCEE), Center for Applied Energy Research, University of Kentucky

Project Documents

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KRCEE is a collaborative effort of Kentucky universities and is administered by the University of Kentucky.