A Model of Contaminant Transport, Saline Valley Aquifer, Gallatin County Illinois Ryan William Cox Southern Illinois University Carbondale, [email protected]
Total Page:16
File Type:pdf, Size:1020Kb
Southern Illinois University Carbondale OpenSIUC Theses Theses and Dissertations 12-1-2013 A model of contaminant transport, Saline Valley Aquifer, Gallatin County Illinois Ryan William Cox Southern Illinois University Carbondale, [email protected] Follow this and additional works at: http://opensiuc.lib.siu.edu/theses Recommended Citation Cox, Ryan William, "A model of contaminant transport, Saline Valley Aquifer, Gallatin County Illinois" (2013). Theses. Paper 1319. This Open Access Thesis is brought to you for free and open access by the Theses and Dissertations at OpenSIUC. It has been accepted for inclusion in Theses by an authorized administrator of OpenSIUC. For more information, please contact [email protected]. A MODEL OF CONTAMINANT TRANSPORT, SALINE VALLEY AQUIFER, GALLATIN COUNTY ILLINOIS By Ryan W Cox B.S. Northern Illinois University, 2010 A Thesis Submitted in Partial Fulfillment of the Requirements for the Master of Science, Geology Department of Geology in the Graduate School Southern Illinois University Carbondale December 2013 THESIS APPROVAL A MODEL OF CONTAMINANT TRANSPORT, SALINE VALLEY AQUIFER, GALLATIN COUNTY ILLINOIS By Ryan W Cox A Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science in the field of Geology Approved by: Steven Esling, Chair Ken Anderson Liliana Lefticariu Graduate School Southern Illinois University Carbondale June 11, 2013 AN ABSTRACT OF THE THESIS OF RYAN W COX, for the Master of Science degree in GEOLOGY, presented on July 11, 2013, at Southern Illinois University Carbondale. TITLE: A MODEL OF CONTAMINANT TRANSPORT, SALINE VALLEY AQUIFER, GALLATIN COUNTY ILLINOIS MAJOR PROFESSOR: Dr. Steven Esling The Saline Valley Conservancy District (SVCD) formed in 1980 to provide a stable source of water to many communities in Southern Illinois. The SVCD well field located in the thickest, most productive region of the Saline Valley Aquifer lies directly adjacent to a reclaimed coal mine. Subsurface movement and surface discharge from the mine has been shown to be responsible for deterioration of water quality in the surrounding area, including the aquifer. Previous studies conducted in the region have addressed water supply issues and simulated contaminant transport from the reclaimed mine. The limited scope of these models did not extend to natural hydrogeological boundaries. This study extended the model boundaries to natural boundaries including the Saline River to the south, the Wabash and Ohio Rivers to the east, and the bedrock high pinch-out and fining valley textures to the west. The flow model uses parameters from each study as a base then calibrated to 18 discrete head measurements. Initial contaminant transport runs using values from previous studies show successful mine reclamation except for surface discharge to a nearby ditch from well pumping. An analysis was performed that varied parameters to determine if any likely scenarios may cause the plume to travel farther than anticipated. These scenarios include things such as cessation of surface discharge, increasing contaminant source load, and altering recharge and hydraulic conductivity. In all cases sulfate concentrations in the SVCD production wells modeled up to 155mg/L which is under the EPA drinking water guideline for sulfate. Three wells in particular, SVCD-1, SVCD- i 4, and SVCD-7 never model higher than 7mg/L indicating that several wells lie outside the influence of the sulfate plume. Based on the results of the scenario analysis, the mine can shut off remediation pumping without overly contaminating the SVCD water supply. ii DEDICATION I dedicate this thesis to my loving parents, Gary and Peggy Cox, for all their support and encouragement throughout my life and time in school. iii ACKNOWLEDGMENTS I wish to express my gratitude and appreciation to my committee chair Dr. Steven Esling for having much patience with me and for all his help and hard work to put together this thesis. Without his guidance this thesis would never have been possible. Furthermore, I would also like to thank my committee members, Dr. Ken Anderson and Dr. Liliana Lefticariu who taught me the importance of organizing my thoughts into something more coherent. In addition, a thank you goes to Richard Winston from the USGS who went above and beyond the call of duty by helping with any implementation and technical issues with ModelMuse. And last but not least, I would also like to thank my beautiful wife Kelsey Cox who had the strength and patience of a saint for the last two years. She encouraged me to keep pressing on even when I didn’t think I had the perseverance to continue. iv TABLE OF CONTENTS CHAPTER PAGE ABSTRACT ..................................................................................................................................... i DEDICATION ............................................................................................................................... iii ACKNOWLEDGMENTS ............................................................................................................. iv LIST OF TABLES ....................................................................................................................... viii LIST OF FIGURES ....................................................................................................................... ix CHAPTERS CHAPTER 1 – Introduction.................................................................................................1 Introduction .....................................................................................................................1 Background .....................................................................................................................1 Location ..........................................................................................................................4 Previous Work ................................................................................................................4 Purpose ..........................................................................................................................10 CHAPTER 2 – Geological setting .....................................................................................11 Geography .....................................................................................................................11 Geology .........................................................................................................................11 Quaternary Geology .................................................................................................11 Bedrock Geology .....................................................................................................14 Hydrology .....................................................................................................................14 Water Supply ................................................................................................................17 CHAPTER 3 – Methods ....................................................................................................19 Model Protocol..............................................................................................................19 v Mathematical Foundations and Code Selection ............................................................21 Darcy’s Law .............................................................................................................21 Average Linear Velocity and the Fickian Model of Hydrodynamic Dispersion .....22 MODFLOW .............................................................................................................23 MT3DMS .................................................................................................................26 ModelMuse ...................................................................................................................28 Calibration/Sensitivity Analysis ...................................................................................29 CHAPTER 4 – Conceptual Model .....................................................................................31 Hydrostratigraphy .........................................................................................................31 Model Boundaries .........................................................................................................31 Internal Sources and Sinks ............................................................................................33 Hydrologic Budget ........................................................................................................33 Model Parameters .........................................................................................................34 Wells ........................................................................................................................36 Recharge ..................................................................................................................38 Hydraulic Conductivity ............................................................................................39 Dispersivity ..............................................................................................................40 Bedrock Elevation ....................................................................................................44 Porosity ....................................................................................................................44