Andrew J Long
Biography
Andy Long has more than 20 years experience assessing groundwater flow and transport through numerical modeling, analyzing ambient tracers, and geophysical methods.
Education
Ph.D., Geological Engineering (hydrology), 2000, South Dakota School of Mines and Technology (SDSMT)
M.S., Geological Engineering (hydrology), 1995, SDSMT
B.S., Geological Engineering, 1993, SDSMT
Selected Appointments
- 2015-present: Hydrologist and Groundwater Specialist, USGS Washington Water Science Center. In addition to continuing my research activities, I advise the Science Center on technical issues, including interpretive studies, data collection, and archival. I assist the Center in building and guiding the overall groundwater studies and data program.
- 2014-2017: National Research Council committee to evaluate the implementation of the Edwards Aquifer Habitat Conservation Plan (http://www.eahcp.org/).
- 2009-2015: Research Hydrologist, USGS South Dakota Water Science Center. Primary activities included the development of innovative methods to better understand, quantify, and test hypotheses related to groundwater flow and transport in karst aquifers. Groundwater age dating, lumped-parameter models, aquifer classification, hydrochemical evaluation, heat transport, and groundwater recharge were some areas of my research.
- 2005-present: Adjunct Assistant Professor, South Dakota School of Mines and Technology. I served on the graduate advisory committees for five M.S. students and three Ph.D. students. Seven of these students were employed by the USGS and did their research primarily under my direction as part of their USGS work. I gave numerous guest lectures at SDSMT.
- 1999-2009: Hydrologist, U.S. Geological Survey (USGS), South Dakota Water Science Center. I Conducted numerical modeling of groundwater flow and solute transport, dye tracing experiments in karst aquifers, development of new research models.
Full list of publications is at ORCID.
Selected publications are below.
Science and Products
Williston and Powder River Basins Groundwater Availability Study
The development of two nationally important energy-producing areas, the Williston structural basin (containing the Bakken Formation) and Powder River structural basin, provide a critical opportunity to study the water-energy nexus within a groundwater context. Large volumes of water are needed for energy development in these basins. The hydraulically connected aquifers in the...
Keyport Groundwater Model
The Issue: Chlorinated volatile organic compounds have impacted groundwater beneath a former 9-acre landfill at OU 1 of the Naval Base Kitsap Keyport, Washington. The landfill is adjacent to tidal flats that are an extension of Liberty and Dogfish Bays and was the primary disposal area for domestic and industrial waste generated by NBK Keyport from the 1930s through 1973....
Yakima River Basin
The Yakima River flows 215 miles from the outlet of Keechelus Lake in the central Washington Cascades southeasterly to the Columbia River, draining an area of 6,155 square miles. The Yakima River Basin is one of the most intensively irrigated areas in the United States. Population in the Yakima River Basin was about 238,000 in 1990.
Increasing demands for water for municipal, fisheries...
Williston Basin groundwater availability, United States and Canada
The Williston Basin contains important oil and gas resources for the Nation. Freshwater supplies are limited in this semiarid area, and oil and gas development can require large volumes of freshwater. Groundwater is the primary source of water for many water users in the Williston Basin, so to better understand these resources, the U.S. Geological...
Thamke, Joanna N.; Long, Andrew J.; Davis, Kyle W.
Groundwater availability of the Williston Basin, United States and Canada
Executive SummaryThe Williston Basin of the Northern Great Plains is a sedimentary basin—a geologic bowl-like structure filled with layered sedimentary rocks dating as far back as the Paleozoic age. The basin, which is nationally important for the production of energy resources, spans Montana, North Dakota, and South Dakota in the United States,...
Long, Andrew J.; Thamke, Joanna N.; Davis, Kyle W.; Bartos, Timothy T.
Construction and calibration of a groundwater-flow model to assess groundwater availability in the uppermost principal aquifer systems of the Williston Basin, United States and Canada
The U.S. Geological Survey developed a groundwater-flow model for the uppermost principal aquifer systems in the Williston Basin in parts of Montana, North Dakota, and South Dakota in the United States and parts of Manitoba and Saskatchewan in Canada as part of a detailed assessment of the groundwater availability in the area. The assessment was...
Davis, Kyle W.; Long, Andrew J.
Potential application of radiogenic isotopes and geophysical methods to understand the hydrothermal dystem of the Upper Geyser Basin, Yellowstone National Park
Numerous geochemical and geophysical studies have been conducted at Yellowstone National Park to better understand the hydrogeologic processes supporting the thermal features of the Park. This report provides the first 87Sr/86Sr and 234U/238U data for thermal water from the Upper Geyser Basin (UGB) intended to evaluate whether heavy radiogenic...
Paces, James B.; Long, Andrew J.; Koth, Karl R. RRAWFLOW: Rainfall-Response Aquifer and Watershed Flow Model (v1.15)
The Rainfall-Response Aquifer and Watershed Flow Model (RRAWFLOW) is a lumped-parameter model that simulates streamflow, spring flow, groundwater level, or solute transport for a measurement point in response to a system input of precipitation, recharge, or solute injection. I introduce the first version of RRAWFLOW available for download and...
Long, Andrew J.
Historical and projected climate (1901–2050) and hydrologic response of karst aquifers, and species vulnerability in south-central Texas and western South Dakota
Two karst aquifers, the Edwards aquifer in the Balcones Escarpment region of south-central Texas and the Madison aquifer in the Black Hills of western South Dakota, were evaluated for hydrologic response to projected climate change through 2050. Edwards aquifer sites include Barton Springs, the Bexar County Index Well, and Comal Springs. Madison...
Stamm, John F.; Poteet, Mary F.; Symstad, Amy J.; Musgrove, MaryLynn; Long, Andrew J.; Mahler, Barbara J.; Norton, Parker A.
Conceptual model of the uppermost principal aquifer systems in the Williston and Powder River structural basins, United States and Canada
The three uppermost principal aquifer systems of the Northern Great Plains—the glacial, lower Tertiary, and Upper Cretaceous aquifer systems—are described in this report and provide water for irrigation, mining, public and domestic supply, livestock, and industrial uses. These aquifer systems primarily are present in two nationally important...
Long, Andrew J.; Aurand, Katherine R.; Bednar, Jennifer M.; Davis, Kyle W.; McKaskey, Jonathan D.R.G.; Thamke, Joanna N.
Hydrogeologic framework of the uppermost principal aquifer systems in the Williston and Powder River structural basins, United States and Canada
The glacial, lower Tertiary, and Upper Cretaceous aquifer systems in the Williston and Powder River structural basins within the United States and Canada are the uppermost principal aquifer systems and most accessible sources of groundwater for these energy-producing basins. The glacial aquifer system covers the northeastern part of the Williston...
Thamke, Joanna N.; LeCain, Gary D.; Ryter, Derek W.; Sando, Roy; Long, Andrew J.
A framework for assessing water and proppant use and flowback water extraction associated with development of continuous petroleum resources
The U.S. Geological Survey is developing approaches for the quantitative assessment of water and proppant involved with possible future production of continuous petroleum deposits. The assessment approach is an extension of existing U.S. Geological Survey petroleum-assessment methods, and it aims to provide objective information that helps...
Haines, Seth S.; Cook, Troy; Thamke, Joanna N.; Davis, Kyle W.; Long, Andrew J.; Healy, Richard W.; Hawkins, Sarah J.; Engle, Mark A. Two approaches for incorporating climate change into natural resource management planning at Wind Cave National Park
Wind Cave National Park (WICA) protects one of the world’s longest caves, has large amounts of high quality, native vegetation, and hosts a genetically important bison herd. The park’s relatively small size and unique purpose within its landscape requires hands-on management of these and other natural resources, all of which are interconnected....
Symstad, Amy J.; Long, Andrew J.; Stamm, John; King, David A.; Bachelet, Dominque M.; Norton, Parker A. Comparison of a karst groundwater model with and without discrete conduit flow
Karst aquifers exhibit a dual flow system characterized by interacting conduit and matrix domains. This study evaluated the coupled continuum pipe-flow framework for modeling karst groundwater flow in the Madison aquifer of western South Dakota (USA). Coupled conduit and matrix flow was simulated within a regional finite-difference model over a 10...
Saller, Stephen P.; Ronayne, Michael J.; Long, Andrew J. Prediction, time variance, and classification of hydraulic response to recharge in two karst aquifers
Many karst aquifers are rapidly filled and depleted and therefore are likely to be susceptible to changes in short-term climate variability. Here we explore methods that could be applied to model site-specific hydraulic responses, with the intent of simulating these responses to different climate scenarios from high-resolution climate models. We...
Long, Andrew J.; Mahler, Barbara J.