Fred D Tillman, Jr., Ph.D.
Fred Tillman joined the USGS Arizona Water Science Center in Tucson, AZ in 2006 after two-plus years as a National Research Council (NRC) fellow with the USEPA Office of Research and Development (ORD) in Athens, Georgia.
Fred's current projects include investigating potential changes in groundwater recharge under projected climate change in the Colorado River basin and understanding the potential for uranium mining effects on regional water resources in the Grand Canyon area.
Prior to joining the USGS, Fred was a post-doctoral researcher with the Ecosystems Research Division of USEPA’s ORD from 2004 through mid-2006, working with Dr. James W. Weaver on issues related to soil vapor intrusion, particularly from leaking underground storage tanks. Fred joined EPA after completion of his doctoral degree in Environmental Engineering at the University of Virginia in 2003, where he worked with Dr. James A. Smith on the response of volatile organic compound (VOC) vapors in the unsaturated zone to natural barometric pressure fluctuations (barometric pumping).
Education and Certifications
Ph.D. 2003, Environmental Engineering, University of Virginia, Charlottesville, VA
M.S. 1998, Environmental Engineering, University of Virginia, Charlottesville, VA
B.S. 1990, Electrical Engineering, Florida State University, Tallahassee, FL
Science and Products
Regional scale estimates of baseflow and factors influencing baseflow in the Upper Colorado River Basin
Geospatial datasets for assessing the effects of rangeland conditions on dissolved-solids yields in the Upper Colorado River Basin
Water-chemistry data collected in and near Kaloko-Honokohau National Historical Park, Hawaii, 2012–2014
Updated estimates of long-term average dissolved-solids loading in streams and rivers of the Upper Colorado River Basin
Investigation of geochemical indicators to evaluate the connection between inland and coastal groundwater systems near Kaloko-Honokōhau National Historical Park, Hawai‘i
A data reconnaissance on the effect of suspended-sediment concentrations on dissolved-solids concentrations in rivers and tributaries in the Upper Colorado River Basin
Preliminary groundwater flow model of the basin-fill aquifers in Detrital, Hualapai, and Sacramento Valleys, Mohave County, northwestern Arizona
Human effects on the hydrologic system of the Verde Valley, central Arizona, 1910–2005 and 2005–2110, using a regional groundwater flow model
A simple method for estimating basin-scale groundwater discharge by vegetation in the basin and range province of Arizona using remote sensing information and geographic information systems
Water availability and use pilot: Methods development for a regional assessment of groundwater availability, southwest alluvial basins, Arizona
Breccia-pipe uranium mining in northern Arizona: Estimate of resources and assessment of historical effects
Trends in groundwater levels in wells in the active management areas of Arizona, USA
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
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Regional scale estimates of baseflow and factors influencing baseflow in the Upper Colorado River Basin
Study region The study region encompasses the Upper Colorado River Basin (UCRB), which provides water for 40 million people and is a vital part of the water supply in the western U.S. Study focus Groundwater and surface water can be considered a single water resource and thus it is important to understand groundwater contributions to streamflow, or baseflow, within a region. Previously, quantificAuthorsChristine Rumsey, Matthew P. Miller, David D. Susong, Fred D. Tillman, David W. AnningGeospatial datasets for assessing the effects of rangeland conditions on dissolved-solids yields in the Upper Colorado River Basin
In 2009, the U.S. Geological Survey (USGS) developed a Spatially Referenced Regressions on Watershed Attributes (SPARROW) surface-water quality model for the Upper Colorado River Basin (UCRB) relating dissolved-solids sources and transport in the 1991 water year to upstream catchment characteristics. The SPARROW model focused on geologic and agricultural sources of dissolved solids in the UCRB andAuthorsFred D. Tillman, Marilyn E. Flynn, David W. AnningWater-chemistry data collected in and near Kaloko-Honokohau National Historical Park, Hawaii, 2012–2014
Kaloko-Honokōhau National Historical Park (KAHO) on western Hawaiʻi was established in 1978 to preserve, interpret, and perpetuate traditional Native Hawaiian culture and activities, including the preservation of a variety of culturally and ecologically significant water resources that are vital to this mission. KAHO water bodies provide habitat for 1 threatened, 11 endangered, and 3 candidate thrAuthorsFred D. Tillman, Delwyn S. Oki, Adam G. JohnsonUpdated estimates of long-term average dissolved-solids loading in streams and rivers of the Upper Colorado River Basin
The Colorado River and its tributaries supply water to more than 35 million people in the United States and 3 million people in Mexico, irrigating over 4.5 million acres of farmland, and annually generating about 12 billion kilowatt hours of hydroelectric power. The Upper Colorado River Basin, part of the Colorado River Basin, encompasses more than 110,000 mi2 and is the source of much of more thaAuthorsFred D. Tillman, David W. AnningInvestigation of geochemical indicators to evaluate the connection between inland and coastal groundwater systems near Kaloko-Honokōhau National Historical Park, Hawai‘i
Kaloko-Honokōhau National Historical Park (KAHO) is a coastal sanctuary on the western side of the Island of Hawai‘i that was established in 1978 to preserve, interpret, and perpetuate traditional Native Hawaiian culture and activities. KAHO contains a variety of culturally and ecologically significant water resources and water-related habitat for species that have been declared as threatened or eAuthorsFred D. Tillman, Delwyn S. Oki, Adam G. Johnson, Larry B. Barber, Kimberly R. BeisnerA data reconnaissance on the effect of suspended-sediment concentrations on dissolved-solids concentrations in rivers and tributaries in the Upper Colorado River Basin
The Colorado River is one of the most important sources of water in the western United States, supplying water to over 35 million people in the U.S. and 3 million people in Mexico. High dissolved-solids loading to the River and tributaries are derived primarily from geologic material deposited in inland seas in the mid-to-late Cretaceous Period, but this loading may be increased by human activitieAuthorsFred D. Tillman, David W. AnningPreliminary groundwater flow model of the basin-fill aquifers in Detrital, Hualapai, and Sacramento Valleys, Mohave County, northwestern Arizona
Preliminary numerical models were developed to simulate groundwater flow in the basin-fill alluvium in Detrital, Hualapai, and Sacramento Valleys in northwestern Arizona. The purpose of this exercise was to gather and evaluate available information and data, to test natural‑recharge concepts, and to indicate directions for improving future regional groundwater models of the study area. Both steadyAuthorsFred D. Tillman, Bradley D. Garner, Margot TruiniHuman effects on the hydrologic system of the Verde Valley, central Arizona, 1910–2005 and 2005–2110, using a regional groundwater flow model
Water budgets were developed for the Verde Valley of central Arizona in order to evaluate the degree to which human stresses have affected the hydrologic system and might affect it in the future. The Verde Valley is a portion of central Arizona wherein concerns have been raised about water availability, particularly perennial base flow of the Verde River. The Northern Arizona Regional GroundwaterAuthorsBradley D. Garner, D. R. Pool, Fred D. Tillman, Brandon T. ForbesA simple method for estimating basin-scale groundwater discharge by vegetation in the basin and range province of Arizona using remote sensing information and geographic information systems
Groundwater is a vital water resource in the arid to semi-arid southwestern United States. Accurate accounting of inflows to and outflows from the groundwater system is necessary to effectively manage this shared resource, including the important outflow component of groundwater discharge by vegetation. A simple method for estimating basin-scale groundwater discharge by vegetation is presented thaAuthorsF.D. Tillman, J.B. Callegary, P.L. Nagler, E.P. GlennWater availability and use pilot: Methods development for a regional assessment of groundwater availability, southwest alluvial basins, Arizona
Executive Summary: Arizona is located in an arid to semiarid region in the southwestern United States and is one of the fastest growing States in the country. Population in Arizona surpassed 6.5 million people in 2008, an increase of 140 percent since 1980, when the last regional U.S. Geological Survey (USGS) groundwater study was done as part of the Regional Aquifer System Analysis (RASA) progrAuthorsFred D. Tillman, Jeffrey T. Cordova, Stanley A. Leake, Blakemore E. Thomas, James B. CallegaryBreccia-pipe uranium mining in northern Arizona: Estimate of resources and assessment of historical effects
About 1 million acres of Federal land in the Grand Canyon region of Arizona were temporarily withdrawn from new mining claims in July 2009 by the Secretary of the Interior because of concern that increased uranium mining could have negative impacts on the land, water, people, and wildlife. During a 2-year interval, a Federal team led by the Bureau of Land Management is evaluating the effects of wiAuthorsDonald J. Bills, Kristin M. Brown, Andrea E. Alpine, James K. Otton, Bradley S. Van Gosen, Jo Ellen Hinck, Fred D. TillmanTrends in groundwater levels in wells in the active management areas of Arizona, USA
In 1980, the Arizona legislature passed the Groundwater Management Act (GMA), creating the active management areas (AMAs) to protect shared groundwater resources and to control severe overdrafts occurring in many parts of the state. With the 30-year anniversary of the GMA approaching, this article addresses the question: Have there been notable changes in the trends in observed groundwater levelsAuthorsFred D. Tillman, Stanley A. LeakeNon-USGS Publications**
Tillman, F.D and Weaver, J.W., 2007, Parameter sets for upper and lower bounds on soil-to-indoor-air contaminant attenuation predicted by the Johnson and Ettinger vapor intrusion model. Atmospheric Environment, 41, no. 27, p. 5797–5806.Tillman, F.D and Weaver, J.W., 2007, Temporal moisture content variability beneath and external to a building and the potential effects on vapor intrusion risk assessment. Science of the Total Environment, 379, no. 1, p. 1-15.Tillman, F.D and Weaver, J.W., 2006, Uncertainty from synergistic effects of multiple parameters in the Johnson and Ettinger (1991) vapor intrusion model. Atmospheric Environment, 40, no. 22, p. 4098–4112.Tillman, F.D and Weaver, J.W., 2005, Review of recent research on vapor intrusion. U.S. Environmental Protection Agency Publication No. EPA/600/R-05/106, 40 p.Weaver, J.W. and Tillman, F.D, 2005, Uncertainty and the Johnson-Ettinger model for vapor intrusion calculations. U.S. Environmental Protection Agency Publication No. EPA/600/R-05/110, 43 p.Tillman, F.D and Smith, J.A., 2005, Vapor transport in the unsaturated zone, in Lehr, J.H., and Keely, J., eds., Water Encyclopedia: Ground Water. New Jersey, John Wiley & Sons, p. 543–548Tillman, F.D and Smith, J.A., 2005, Site characteristics controlling airflow in the shallow unsaturated zone at Picatinny Arsenal, NJ. Environmental Engineering Science, 22, no. 1, p. 25–37.Tillman, F.D, Bartelt-Hunt, S.L., Craver, V.A, Smith, J.A., and Alther, G.R., 2005, Relative metal ion sorption on natural and engineered sorbents: Batch and column studies. Environmental Engineering Science, 22. no. 3, p. 400–410.Alther, G.R., Tillman, F.D, and Smith, J.A., 2005, Evaluation of Two Organoclays, Clinoptilolite, and Hydroxy-Apatite as Sorbents for Heavy Metal Removal from Water, in Calabrese E.J., Kostecki P.T., Dragun J. (eds) Contaminated Soils, Sediments and Water. Springer, Boston, MA, p. 457–468.Tillman, F.D, Bartelt-Hunt, S.L., Smith, J.A., and Alther, G.R., 2004, Evaluation of an organoclay, an organoclay-anthracite blend, clinoptilolite, and hydroxy-apatite as sorbents for heavy metal removal from water. Bulletin of Environmental Contamination and Toxicology, 72, no. 6, p. 1134–1141.Tillman, F.D and Smith, J.A., 2004, Design and laboratory testing of a chamber device to measure total flux of volatile organic compounds from the unsaturated zone under natural conditions. Journal of Contaminant Hydrology, 75, no. 1-2, p. 71–94.Tillman, F.D, Choi, J.-W., and Smith, J.A., 2003, A comparison of direct measurement and model simulation of total flux of volatile organic compounds from the subsurface to the atmosphere under natural field conditions. Water Resources Research, 39, no. 10, p. 1284–1294.Choi, J.-W., Tillman, F.D, and Smith, J.A, 2002, Relative Importance of Gas-Phase Diffusive and Advective Trichloroethene (TCE) Fluxes in the Unsaturated Zone under Natural Conditions. Environmental Science and Technology, 36, no. 14, p. 3157–3164.Olson, M.S., Tillman, F.D, Choi, J.-W., and Smith, J.A., 2001, Comparison of three techniques to measure unsaturated-zone air permeability at Picatinny Arsenal, New Jersey. Journal of Contaminant Hydrology, 53, no. 1-2, p. 1–19.Tillman, F.D, Choi, J.-W., Katchmark, W., Smith, J. A., and Wood, H.G.III, 2001, Unsaturated-zone airflow: Implications for natural remediation of ground water by contaminant transport through the subsurface, in Smith, J.A., and Burns, S.E., eds., Physicochemical Groundwater Remediation. New York, Kluwer Academic/Plenum Publishing, ISBN 978-0-306-46928-2, p. 307–340.**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
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