Todd UmstotTodd Umstot

Principal Hydrogeologist

Albuquerque, New Mexico

Email

(505) 822-9400

Mr. Todd Umstot is a Principal Hydrogeologist at DBS&A.

He specializes in the quantitative analysis of recharge, soil-gas flow, non-aqueous phase liquid (NAPL) migration, groundwater flow, and contaminant fate and transport. He has more than 24 years of experience in New Mexico, Nevada, California, New Jersey, New York, Arizona, Texas, Florida, and Puerto Rico. His experience includes watershed modeling to determine the quantity of recharge and runoff in water rights cases, groundwater flow modeling to evaluate the potential impacts of groundwater pumping on existing water rights, contaminant fate and transport modeling to evaluate the sources and timing of contamination, NAPL modeling to distinguish operational releases versus spills in insurance allocations, and evaluation of environmental investigations and remedial corrective actions at a large scale refinery. He is frequently called upon to evaluate and dissect groundwater and contaminant transport models developed by opposing experts. In addition, Mr. Umstot has developed a watershed model that has been successfully used in water rights hearings to estimate the quantity of recharge available for groundwater appropriation. His model has been applied to numerous basins in New Mexico, Nevada, and California.

Mr. Umstot contributes technical expertise in support of attorneys during trial testimony and depositions of opposing expert witnesses. He has provided expert witness testimony at State water rights hearings and in State court.

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  • Education

    M.S., Hydrogeology, University of Nevada, Reno

    B.S., Geology, University of Massachusetts, Amherst

    B.S., Environmental Science, University of Massachusetts, Amherst

  • Specializations

    Hydrogeology

    Watershed modeling for water rights

    Contaminant fate and transport modeling

Select Publications and Presentations

Hendrickx, J.M.H., R.G. Allen, A. Brower, A.R. Byrd, S. Hong, F.L. Ogden, N.R. Pradhan, C.W. Robison, D. Toll, R. Trezza, T.G. Umstot, and J.L. Wilson. 2016. Benchmarketing optical/thermal satellite imagery for estimating evapotranspiration and soil moisture in decision support tools. Journal of the American Water Resources Association 52(1):89-119.

Umstot, T., Schnaar, G., Blandford T.N., Cullen, S., Kaiser, P., Ayarbe, J., 2015. Recharge estimates from a soil water-balance model improve groundwater model calibration. Presentation at the MODFLOW and More 2015: Modeling a Complex World conference. May 31 – June 3, 2015. Golden, Colorado.

Stephens, D.B., J. Cherney, J. Kay, T. Umstot, and B. Casadevall. 2014. High Recharge at a Semi-Arid Site Explains Wide-Spread Perchlorate in Groundwater with a Deep Water Table. Presentation at the National Ground Water Association Ground Water Summit. May 7, 2014. Denver, Colorado.

Blandford, T.N., Umstot, T., Wolf, C., Marley, R., and Bushner, G.L., 2013. Exploration and characterisation of deep fractured rock aquifers for new groundwater development, an example from New Mexico, USA.

Stephens, D. B., Miller, M., Moore, S. J., Umstot, T. and Salvato, D. J. (2012), Decentralized Groundwater Recharge Systems Using Roofwater and Stormwater Runoff. JAWRA Journal of the American Water Resources Association, 48: 134–144. doi: 10.1111/j.1752-1688.2011.00600.x

Stephens, D.B., J. Cherney, J. Kay, T. Umstot, P. Kaiser, and B. Casadevall. 2013. Unexpectedly rapid migration of perchlorate through a thick vadose zone under low rainfall conditions. Invited speaker at the National Ground Water Association Pillars of Groundwater Innovation Conference. November 7-8, Phoenix, Arizona.

Umstot, T. 2012. Recharge in the Tule Desert and Clover Valley Hydrographic Basins of Southern Nevada. Hydrology Seminar Series. New Mexico Tech, Socorro, NM. November 5.

Kaiser, Phil, T. Umstot, G. Schnaar, Stephen J. Cullen, 2012.  The Distributed Parameter Watershed Model for Predicting Recharge in Southern California. California Groundwater Association, 21st Annual Meeting and Conference, “California Groundwater: Data, Planning and Opportunities” October 4-5, 2012, Rohnert Park, California.

Hendrickx, J. M., T. Umstot, J. Wilson, D. B. Stephens, 2012. Ground water recharge in semi-arid mountain blocks. Geological Society of America, Rocky Mountain Section, 64th Annual Meeting, May, 9-12, 2012

Schnaar, G., T. Umstot, and S. Cullen, Correction TO: Birkholzer, J.T. et al., 2011. Brine flow up a well caused by pressure perturbation from geologic carbon sequestration: Static and dynamic evaluations. International Journal of Greenhouse Gas Control; Vol. 5: 850–861. Int. J. Greenhouse Gas Control (2013), http://dx.doi.org/10.1016/j.ijggc.2013.05.021

Umstot, T., 2011.  Advanced Topics in Hydrology: Runoff.  New Mexico Institute of Technology, Socorro, NM.  Guest lecturer on simulating runoff in watershed models.

Umstot, T., J. Hendrickx, and J.L. Wilson. 2011. Hydrology of the San Gabriel Mountains: The Source of Mountain Front Recharge to Los Angeles and Antelope Valley. Presentation at 2011 American Water Resources Association Annual Water Resources Conference. Albuquerque, New Mexico, November 10, 2011.

Stephens, D.B., M. Miller, S. Moore, T. Umstot, and D. Salvato. 2011. Decentralized Groundwater Recharge Systems Using Roofwater and Stormwater Runoff. Presented by Daniel B. Stephens on behalf of DBS&A at the 2011 American Water Resources Association Annual Water Resources Conference. Albuquerque, New Mexico, November 7, 2011.

Umstot, T., 2011.  Application of a distributed parameter land surface-atmosphere model to assess the quantity of mountain-block and mountain front recharge.  MODFLOW and More 2011 Conference, Golden, CO, June  8

Cullen, S.J., T.G. Umstot, and D.B. Stephens, 2009. Parameter Estimation or Measurement for Vapor Transport Modeling? Invited presentation to The 19th Annual AEHS Meeting and West Coast Conference on Soils, Sediments, and Water, March 9-12, 2009 Mission Valley Marriott, San Diego, California.

Umstot, T. and D. B. Stephens, 2008. Distributed Parameter Modeling of an Arid Watershed to Assess Net Infiltration. AWRA 2008 Annual Water Resources Conference, New Orleans, LA, November 17.

Stephens, D. B. and Umstot, T., 2008. Recharge Analyses in a Desert Groundwater Basin. AWRA 2008 Annual Water Resources Conference, New Orleans, LA, November 17.

Stephens, D. B. and Umstot, T., 2008. Challenges in Characterizing and Simulating Flow and Transport in Stony Soils.  2008 Joint Meeting of The Geological Society of America, Soil Science Society of America, American Society of Agronomy, Crop Science Society of America, Gulf Coast Association of Geological Societies with the Gulf Coast Section of SEPM, October 9.

Stephens, D. B. and Umstot, T., 2008. Recharge Analyses in a Desert Groundwater Basin. 2008 Joint Meeting of The Geological Society of America, Soil Science Society of America, American Society of Agronomy, Crop Science Society of America, Gulf Coast Association of Geological Societies with the Gulf Coast Section of SEPM, October 8, 2008.

Umstot, T., 2008.  Advanced Topics in Hydrology: Hydrological Modeling.  New Mexico Institute of Technology, Socorro, NM.  Guest lecturer on vadose zone and watershed modeling.

Umstot, T., N. Sweetland, B. Casadevall, D. B. Stephens, M. J. Huggins, and D. E. Potts, 2006. Field Data and Modeling MTBE Remediation by SVE: Case Study in Southern California. Petroleum Hydrocarbons and Organic Chemicals in Ground Water: Prevention, Assessment, and Remediation Conference. National Ground Water Association, Houston, Texas.

Sweetland, N.T., T.G. Umstot, and D.B.Stephens. 2004. Distinguishing Operational Releases Versus Spills for Insurance Allocation. Poster presentation at the Investigation and Remediation of Dry Cleaner Release Sites, April 7, 2004, Sacramento, California

Umstot, T. 2003. Comparison of Analytical and Numerical Models for the Advection-Dispersion Equation: Mass Balance Errors in Analytical Solutions from Incorrect Application of the Retardation Factor. MODFLOW and More 2003 Conference Proceedings, International Ground Water Modeling Center, Colorado School of Mines, Golden, Colorado.

Umstot, T. and L. Shevenell. 2000. Refinement of techniques for the analysis of well hydrographs in a karst aquifer. Geological Society of America Annual Meeting, Reno, Nevada. 2000.

Umstot, T. 1997-1999. Applications in Advanced Hydrogeology, Cook College, Rutgers University, New Brunswick, New Jersey.  Guest lecturer at annual short course on the setup of dataloggers and pressure transducers and computer methods for the manipulation and analysis of pumping test data