2016 NGWA Groundwater Summit

Quantifying Potential for Spills at Unconventional Gas Well Sites to Impact the South Platte Aquifer

Tuesday, April 26, 2016
Confluence Ballroom Foyer (The Westin Denver Downtown)
Cynthia Kanno , Colorado School of Mines, Golden, CO
Molly McLaughlin , Colorado State University, Fort Collins, CO
Jens Blotevogel , Department of Civil and Environmental Engineering, Colorado State University, Fort Collins, CO
John E. McCray, PhD , Civil and Environmental Engineering, Colorado School of Mines, Golden, CO

With the rise in unconventional oil and gas development over the past decade, the public is concerned about how these stimulation, extraction, and production activities may impact groundwater resources. Although there are many possible ways for accidental leakage to occur and different fluids that could be released, the most probable contamination pathway is through surface spills of produced and hydraulic fracturing fluids. These fluids could potentially infiltrate through the vadose zone, reach the groundwater table, and be transported. The purpose of this study is to conduct fate and transport simulations of surface spills of chemical contaminants, such as biocides, friction reducers, surfactants, and hydrocarbons, typically found in hydraulic fracturing fluid and produced water. Accounting for degradation, sorption processes, co-contaminant interactions, and spill statistics, we seek to understand the hydrologic and site conditions under which a surface spill would pose risk to groundwater quality. This study focuses on the South Platte Alluvial Aquifer, which overlaps a zone of high-density oil and gas development in the greater Denver metro area. We propose a coupled analytical-numerical approach that could be reproduced by environmental consultants. Preliminary results suggest that risk of groundwater pollution, based on predicted concentration at the groundwater table, is low in most areas of the South Platte system for the contaminants investigated. However, substantial risk may exist in certain areas where the groundwater table is shallow. In addition, transport of certain contaminants is influenced by interactions with other constituents in produced or stimulation fluids. By helping to identify locations in the Front Range of Colorado that are at risk for groundwater contamination due to a surface spill, it is our hope that this work will aid in improving best management practices so that decision-makers can be better prepared to address accidental releases in Colorado.

Cynthia Kanno, Colorado School of Mines, Golden, CO

Molly McLaughlin, Colorado State University, Fort Collins, CO
PhD student at Colorado State University; Research interests include understanding the degradation pathways of the chemicals used in hydraulic fracturing fluids.

Jens Blotevogel, Department of Civil and Environmental Engineering, Colorado State University, Fort Collins, CO
Dr. Jens Blotevogel is a Research Assistant Professor in the Department of Civil & Environmental Engineering at Colorado State University (CSU). He holds a PhD in Environmental Chemistry from CSU and a Diploma in Environmental Engineering from the Technical University Berlin, and has several years of professional experience as project engineer for groundwater remediation. Dr. Blotevogel’s research interests revolve around the fate of emerging contaminants, conducting laboratory- and field-scale experiments to elucidate degradation in both natural and engineered systems. He has developed innovative water treatment technologies, theoretical models for contaminant degradation pathways and kinetics, as well as various analytical techniques with focus on high-resolution mass spectrometry. He is currently working on solutions for managing 1,4-dioxane, perfluorinated compounds, pesticides, heavy hydrocarbons, and hydraulic fracturing fluid additives.

John E. McCray, PhD, Civil and Environmental Engineering, Colorado School of Mines, Golden, CO
John McCray is the Head of the Civil and Environmental Engineering Department, and the former Founding Director of the Hydrologic Science and Engineering Graduate Program at Colorado School of Mines. He has served as Associate Editor on many hydrologic journals, including Groundwater, Water Resources Research, Journal of Contaminant Hydrology, Vadose Zone Journal, and JAWRA. His current research interests include carbon geosequestration, groundwater remediation, urban hydrology, and wastewater reclamation using the vadose zone and other natural systems.