Hedeff I Essaid, Ph.D.

My research has involved the analysis of field data and simulation of realistically-framed groundwater systems and watersheds to characterize water and chemical mass balances and to study the relative importance of different hydrologic processes and flow pathways.  The results of these studies provide an opportunity to compare and contrast groundwater transport, surface water-groundwater interactions and chemical fate in different hydrologic/environmental settings. This work has improved our understanding and quantification of processes and factors that control the magnitude and timing of environmental responses to contaminant loading and changing hydrology. I have used this approach to study: saltwater intrusion in layered coastal aquifer systems; the impact of heterogeneity and hysteresis on the distribution of crude oil at a spill site; the role of dissolution and biodegradation on the fate of hydrocarbon components in the subsurface; the impact of surface water-ground water interactions on stream flow, temperature, and water quality; the hydrology of natural and incised mountain meadows; and nitrogen fate in diverse agricultural watersheds.

EDUCATION:            Stanford University, Ph.D., 1987, Hydrogeology

                                Stanford University, M.S., 1984, Hydrogeology

                                University of Baghdad, Iraq, B.S., 1978, Geology-Geophysics

PROFESSIONAL EXPERIENCE:

1988 to present:           Research Hydrologist, USGS, Water Resources Division, Menlo Park, CA

9/2003 – 12/2003:       Instructor, Dept. of Geological and Environmental Sciences, Stanford University, Physical Hydrogeology course

4/1990 – 6/1990:         Instructor, Civil Engineering Department, Stanford University, Soil Moisture and Groundwater course

1983 – 1988:               Student Appointment, USGS, Water Resources Division, Menlo Park, CA

9/1986 – 12/1986:       Instructor, Earth Sciences Department, University of California, Santa Cruz, Hydrogeology course

1978 – 1982:               Teaching Assistant, University of Baghdad, Iraq

PROFESSIONAL SERVICE:

Advisory Committees:

2008 – 2012:   Member of the NAWQA Cycle 3 Planning Team

2004 – 2005:   Member of the organics subgroup of the Subsurface Reactive Transport Modeling Working Group part of the Federal Interagency Steering Committee on Multimedia Environmental Models.

2001 – 2003    Member of the NAWQA Hydrologic Systems Team (HST), a group of scientists addressing the development and application of hydrologic models for Cycle 2 NAWQA studies. 

2002:               Member of the ground water modeling strategy advisory group for the NAWQA Ground Water Trends Modeling Group.

2001:               Member of the NRP NAWQA committee, a team of scientists that addressed NRP participation in Cycle 2 of NAWQA.

1995 – 1998:   NRP coordinator for the Bemidji, Minn., Toxic Substances Hydrology Program research site.

1994 – 1995:   Member of the WRD Science Advisory Committee of the Chief Hydrologist.

1993:               Technical auditor for the audit of the Yucca Mountain Project study 'Development of conceptual and numerical models of fluid flow in unsaturated, fractured rock' that was headed by F. Bodvarsson of the Lawrence Berkeley Labs.

1992:               Member of the Santa Clara Valley Water District Consultant Review Board for the Maple/San Pedro Injection Well Feasibility Study.

1990:               Member of EPA committee to review proposals for the Exploratory Research in the Chemistry and Physics of Water Program.

Journal Editorial Boards:

1992 – 1994:   Member of the Editorial Board, Ground Water.

1994:               Associate Editor, Water Resources Research.

Graduate Student Committees:

M.S. thesis committee member for "Fluid flow within the barbados ridge complex" by Elizabeth Screaton, University of California, Santa Cruz, 1988

M.S. thesis advisor for "Simulation of Groundwater flow at the Bemidji, Minnesota, crude-oil spill site, and implications for advective transport of dissolved contaminants", by Robert Coontz, Stanford University, 1990.

M.S. thesis advisor for "Multiphase flow modeling of a crude-oil spill site using geostatistical simulation of soil hydraulic properties", by Leslie A. Dillard, Stanford University, 1993.

Member of Ph.D. committee for "Simulating subsurface fluid flow and hydrocarbon migration in three dimensions using synthetic stratigraphic models" by Johannes Wendebourg, Stanford University, 1993.

Member of Ph.D. committee for “Investigating the physics of dissolution of nonaqueous phase liquids: Simulation from pore network to field scale” by Leslie Dillard, Stanford University, 1998.

Member of Ph.D. committee for “Implications of urban development patterns for subsurface moisture flow paths in tropical sandy coastal areas” by Michele Muinihane, Stanford University, 2008.

Member of Ph.D. oral examination committee for “Modeling the hydrologic interactions between an aging reservoir and the surrounding groundwater “ by Mai Chu, Stanford University, 2009.

Technical Training Provided:

“Saltwater intrusion modeling”, Techniques of Hydrologic Investigations for International Participants, July, 1991 and 1992.

“Multiphase flow ground-water problems: Saltwater intrusion and ground-water contamination by immiscible organic fluids”, New Techniques in Water Resources Science, College faculty enhancement workshop, July 25, 1991.

“Unit 1: General Soil Properties, Unit 2: Hydrostatics, Potentials, Hydrodynamics, and Unit 3: Infiltration, Drainage, and Redistribution”, Unsaturated-Zone Hydrology Correspondence Course, July-Oct 1993, March-May, 1995 .

Teaching of U.S.G.S. workshops on modeling of saltwater intrusion problems and use of the SHARP model: Reston, Virginia (May 1989, half day lecture); NE Region Ground-water modeling workshop, Trenton, New Jersey (Nov. 1990, one day lecture); and Western Region Ground-water modeling workshop, Honolulu, Hawaii (April 1990, two day lecture).

“Coupled microbial growth and transport models”, Microbiology workshop, USGS Advanced Ground Water Seminar, Denver, CO, Oct. 1994 .

 AWARDS:

 1998:               Superior Service Award,

2006:               AGU  editors’ citation for excellence in refereeing, Water Resources Research.

2013:               ASABE Superior Paper Award.

Publications

Essaid, H. I., Baker, N. T. Baker, and K. A. McCarthy, 2016, Contrasting nitrogen fate in watersheds using agricultural and water quality information, Journal of Environmental Quality, doi: 10.2134/jeq2016.02.0071

Essaid, H. I., Bekins, B.A., and Cozzarelli, I.M., 2015, Organic contaminant transport and fate in the subsurface: Evolution of knowledge and understanding, Water Resour. Res., 51, 4861–4902, doi:10.1002/2015WR017121.

Rahimi, M., H. I. Essaid, and J. T. Wilson, 2015, The role of dynamic surface water-groundwater exchange on streambed denitrification in a first-order, low-relief agricultural watershed, Water Resour. Res., 51, 9514–9538, doi:10.1002/2014WR016739.

Essaid, H.I. and Hill, B. R., 2014, Watershed-scale modeling of streamflow change in incised montane meadows, Water Resour. Res., 50, 2657–2678, doi:10.1002/2013WR014420.

Rowe, G.L., Jr., Belitz, K., Demas, C.R., Essaid, H.I., Gilliom, R.J., Hamilton, P.A., Hoos, A.B., Lee, C.J., Munn, M.D., and Wolock, D.W., 2013, Design of Cycle 3 of the National Water-Quality Assessment Program, 2013–23: Part 2: Science plan for improved water-quality information and management: U.S. Geological Survey Open-File Report 2012–1160, 110 p., http://pubs.usgs.gov/of/2013/1160/

Constantz, J., C. A. Eddy-Miller, J. D. Wheeler, and H. I. Essaid, 2013, Streambed exchanges along tributary streams in humid watersheds, Water Resour. Res., 49, doi:10.1002/wrcr.20194.

Healy, R.W., and Essaid, H.I., 2012, VS2DI: Model use, Calibration, and Validation: Transactions of the American Society of Agricultural and Biological Engineers, vol. 55(3), 1249-1260.

Essaid, H.I., Bekins, B.A., Herkelrath, W.N., and Delin, G.N., 2011, Crude Oil at the Bemidji Site: 25 Years of Monitoring, Modeling and Understanding: Ground Water, v. 49, no. 5, p. 706-726. [Link]

Rowe, Gary L., Jr.; Belitz, Kenneth; Essaid, Hedeff I.; Gilliom, Robert J.; Hamilton, Pixie A.; Hoos, Anne B.; Lynch, Dennis D.; Munn, Mark D.; Wolock, David W., 2010. Design of Cycle 3 of the National Water-Quality Assessment Program, 2013-2022: Part 1: Framework of Water-Quality Issues and Potential Approaches . U.S. Geological Survey Open-File Report 2009-1296, v, 54 p. [Link]

Cozzarelli, I.M., Bekins, B.A., Eganhouse, R.P., Warren, E., and Essaid, H.I., 2010, In situ measurements of volatile aromatic hydrocarbon biodegradation rates in groundwater: Journal of Contaminant Hydrology, vol. 111, p. 48–64, doi:10.1016/j.jconhyd.2009.12.001. [Link]

Risley, J.C., Constantz, J., Essaid, H., and Rounds, S., 2010, Effects of upstream dams versus groundwater pumping on stream temperature under varying climate conditions: : Water Resources Research, v. 46, W06517, doi:10.1029/2009WR008587 [Link]

Eddy-Miller, Cheryl A.; Wheeler, Jerrod D.; Essaid, Hedeff I., 2009. Characterization of Interactions between Surface Water and Near-Stream Groundwater along Fish Creek, Teton County, Wyoming, by Using Heat as a Tracer. U.S. Geological Survey Scientific Investigations Report 2009-5160, vi, 54 p. [Link]

Kuwabara, J.S., Topping, B.R., Lynch, D.D., Carter, J.L., and Essaid, H.I., 2009, Benthic nutrient sources to hypereutrophic Upper Klamath Lake, Oregon: Environmental Toxicology and Chemistry, v. 28, p. 516-524. [Link]

Essaid, H.I., Zamora, C., McCarthy, K., Vogel, J., and Wilson, J.T., 2008, Using heat to characterize streambed water flux variability in four stream reaches: Journal of Environmental Quality, v. 37, p. 1010-1023. [Link]

Puckett, L.J., Zamora, C., Essaid, H.I., Wilson, J.T., Johnson, H.M., Brayton, M.J., and Vogel, J.R., 2008, Transport and fate of nitrate at the ground water-surface water interface: Journal of Environmental Quality, v. 37, p. 1034-1050. [Link]

Constantz, J. and Essaid, H., 2007, Influence of groundwater pumping on streamflow restoration following upstream dam removal: Hydrological Processes, v. 21, no. 21, p. 2823-2834. [Link]

Essaid, H.I., Wilson, J.T., and Baker, N.T., 2006, Spatial and temporal variability in streambed fluxes, Leary Weber Ditch, IN: Conference Proceedings of the 3rd Federal Interagency Hydrologic Modeling Conference, April, 2006, Reno, Nevada, 8 p

Bekins, B.A., Hostettler, F.D., Herkelrath, W.N., Delin, G.N., Warren, E., and Essaid, H.I., 2005, Progression of methanogenic degradation of crude oil in the subsurface: Environmental Geosciences, v. 12, p. 139-152. [Link]

Essaid, H.I., Cozzarelli, I. M., Eganhouse, R.P., Herkelrath, W.N., Bekins, B.A., and Delin, G.N., 2003, Inverse modeling of BTEX dissolution and biodegradation at the Bemidji, MN crude-oil spill site, Journal of Contaminant Hydrology, v. 67, p.269-299.

Dillard, L.A., Essaid, H.I., and Blunt, M.J., 2001, A functional relation for field-scale nonaqueous phase liquid dissolution developed using a pore network model: Journal of Contaminant Hydrology, 48, 89-119.

Bekins, B.A., Cozzarelli, I.M., Godsy, E.M., Warren, E., Essaid, H.I., and Tuccillo, M.E., 2001, Progression of natural attenuation processes at a crude oil spill site: II. Controls on spatial distribution of microbial populations: Journal of Contaminant Hydrology, v. 53, p. 387-406, 2001.

Essaid, H.I., 1999, USGS SHARP Model, in Bear, J., Cheng, A.H.-D., Sorek, S., Ouazar, D., and Herrera I., eds, Seawater Intrusion in Coastal Aquifers – Concepts, Methods and Practices, Kluwer Academic Publishers, The Netherlands, p. 213-247.

Bekins, B.A., Baehr, A.L., Cozzarelli, I.M., Essaid, H.I., Haack, S.K., Harvey, R.W., Shapiro, A.M., Smith, J.A., and Smith. R.L., 1999, Capabilities and challenges of natural attenuation in the subsurface: Lessons from the U.S. Geological Survey Toxics Substances Hydrology Program, in Morganwalp, D.W. and Buxton, H.T., eds, U.S. Geological Survey Toxic Substances Hydrologiy Program, Proceedings of the Technical Meeting, Charleston, South Carolina, March 8-12, 1999: U.S. Geological Survey Water-Resources Investigations Report 99-4018C, v. 3, p. 37-56.

Bekins, B.A., Cozzarelli, I.M., Godsy, E.M., Warren, E., Tuccillo, M.E., Essaid, H.I., and Paganelli, V.V., 1999, Chemical and physical controls on microbial populations in the Bemidji Toxics Site crude-oil plume, in Morganwalp, D.W. and Buxton, H.T., eds, U.S. Geological Survey Toxic Substances Hydrologiy Program, Proceedings of the Technical Meeting, Charleston, South Carolina, March 8-12, 1999: U.S. Geological Survey Water-Resources Investigations Report 99-4018C, v. 3, p. 133-142.

Delin, G. N.; Essaid, H. I.; Cozzarelli, I. M.; Lahvis, M. H.; Bekins, B. A. , 1998. Ground Water Contamination by Crude Oil near Bemidji, Minnesota. U.S. Geological Survey Fact Sheet 084-98, 4 p.

Essaid, Hedeff I.; Bekins, Barbara A., 1998. Modeling solute-transport and biodegradation with BIOMOC. U.S. Dept. of the Interior, U.S. Geological Survey ; Branch of Information Services [distributor], Fact Sheet 095-98, 1 folded sheet ([4]) : ill. ; 28 cm. ill. [Link]

Essaid, Hedeff I.; Bekins, Barbara A., 1997. BIOMOC, a multispecies solute-transport model with biodegradation. U.S. Dept. of the Interior, U.S. Geological Survey ; Information Services [distributor], Water-Resources Investigations Report 97-4022, viii, 68 p. :ill. ;28 cm.

Dillard, L.A., Essaid, H.I., and Herkelrath, W.N., 1997, Multiphase flow modeling of a crude-oil spill site using a bimodal permeability distribution: Water Resources Research, v. 33, no. 7, p. 1617-1632.

Essaid, H.I., Baedecker, M.J., and Cozzarelli, I.M., 1996, Use of simulation to study field-scale solute transport and biodegradation at the Bemidji, Minnesota, crude-oil spill site, in Morganwalp, D.W. and D.A. Aronson (editors), U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings of the Technical Meeting, Colorado Springs, Colorado, September 20-24, 1993: U.S. Geological Survey Water-Resources Investigations Report 94- 4015, v. 2, p. 621-630.

Dillard, L.A., Essaid, H.I., and Herkelrath, W.N., 1996, Multiphase flow modelling at the Bemidji, Minnesota, crude-oil spill site using geostatistical simulation of soil hydraulic properties, in Morganwalp, D.W. and D.A. Aronson (editors), U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings of the Technical Meeting, Colorado Springs, Colorado, September 20-24, 1993: U.S. Geological Survey Water-Resources Investigations Report 94-4015, v. 2, p. 679- 687.

Essaid, H.I., Bekins, B.A., Godsy, E.M., Warren, E., Baedecker, M.J., and Cozzarelli, I.M., 1995, Simulation of aerobic and anaerobic biodegradation processes at a crude-oil spill site: Water Resources Research, v. 31, no. 12, p. 3309-3327.

Essaid, H.I., 1995, Using Numerical Simulation to Study Field-Scale Flow, Transport, and Biodegradation Processes at the Bemidji, Minnesota, Crude-Oil Spill Site, in K.L. Sublette (editor), Environmental Issues and Solutions in Petroleum Exploration, Production, and Refining, Proceedings of the Second International Petroleum Environmental Conference, Sept. 25 - 27, 1995, New Orleans, LA: National Technical Information Service, U.S. Department of Commerce, Springfield, VA, p. 347-366.

Essaid, H.I., Herkelrath, W.N., and Dillard, L.A., 1994, Field and modeling studies of multiphase fluid flow at the Bemidji, Minnesota crude-oil spill site, in Dutton, Alan R. (editor), Toxic Substances and the Hydrologic Sciences: American Institute of Hydrology, Minneapolis, MN, p. 52-68.

Herkelrath, W.N., Essaid, H.I., and Dillard, L.A., 1994, Multiphase fluid distributions in a shallow water-table aquifer contaminated by crude oil, in Dracos, TH., and Stauffer, F. (editors), Transport and Reactive Processes in Aquifers, Proceedings of the IAHR/AIRH Symposium, Zurich, Switzerland, April 11-15, 1994: Rotterdam, Netherlands, A.A. Balkema, p. 537-542.

Essaid, H.I., 1994, Simulation of flow and transport processes at the Bemidji, Minnesota, crude- oil spill site: Proceedings of the EPA-USGS sponsored Symposium on Intrinsic Bioremediation of Ground Water, Denver, Colorado, Aug. 30 - Sept. 1, 1994, p. 121-134.

Essaid, H.I., and Hess, K.M., 1993, Monte Carlo simulations of multiphase flow incorporating spatial variability of hydraulic properties: Ground Water, v. 31, no. 1, p. 123-134.

Essaid, H.I., Herkelrath, W.N., Hess, K.M., 1993, Simulation of fluid distributions observed at a crude-oil spill site incorporating hysteresis, oil entrapment, and spatial variability of hydraulic properties: Water Resources Research, v. 29, no. 6, p. 1753-1770.

Scholl, M.A., Ingebritsen, S.E., and Essaid, H.I., 1993, Comment on "Consequences of phase separation on the distribution of hydrothermal fluids at ASHES vent field, Axial Volcano, Juan de Fuca Ridge" by Christopher G. Fox: Journal of Geophysical Research, v. 98, no. B2, p. 1813-1815.

Mallard, G.E., Baedecker, M.J., Essaid, H.I., and Eganhouse, R.P., 1993, Hydrocarbon transport and degradation in ground water: Geotimes, v. 38, no. 12, p. 18-20.

Essaid, H. I., 1992. Simulation of freshwater and saltwater flow in the coastal aquifer system of the Purisima Formation in the Soquel-Aptos Basin, Santa Cruz County, California. U.S. Geological Survey ; Books and Open-File Reports Section [distributor], Water-Resources Investigations Report 91-4148, v, 35 p. :ill. ;28 cm.

Hess, K. M., Herkelrath, W. N., and Essaid, H. I., 1992, Determination of subsurface fluid contents at a crude-oil spill site: Journal of Contaminant Hydrology, v. 10, p.75-96.

Essaid, H.I., 1992, Long term issues in ground water management: Seawater intrusion, in Changing practices in ground water management - the pros and cons of regulations, Eighteenth Biennial Conference on Ground Water, Sacramento, CA, Sept. 16-17, 1991: University of California, Water Resources Center, Report No. 77, p. 75-91.

Herkelrath, W.N., Essaid, H.I., and Hess, K.M., 1991, Field and modeling studies of immiscible fluid flow above a contaminated water-table aquifer: Proceedings of the International Hydrology and Water Resources Symposium 1991, Challenges for Sustainable Development, Perth, Australia, 2-4 Oct. 1991, p. 424-428.

Essaid, H. I., Herkelrath, W. N., and Hess, K. M., 1991, Air, Oil, and Water Distributions at a Crude-Oil Spill Site, Bemidji, Minnesota, in G.E. Mallard and D.A. Aronson (editors), U.S. Geological Survey Toxic Substances Hydrology Program Meeting: U.S. Geological Survey Water- Resources Investigations Report 91-4034, p. 614-620.

Essaid, H. I., 1990. The computer model SHARP, a quasi-three-dimensional finite-difference model to simulate freshwater and saltwater flow in layered coastal aquifer systems. U.S. Geological Survey ; Books and Open-File Reports Section [distributor], Water-Resources Investigations Report 90-4130, xi, 181 p. :ill. ;28 cm.

Essaid, H. I., 1990, A multilayered sharp interface model of coupled freshwater and saltwater flow in coastal systems: Model development and application: Water Resources Research, v. 26, no. 7. p. 1431-1454.

Essaid, H. I., 1986, A comparison of the coupled fresh water-salt water flow and the Ghyben- Herzberg sharp interface approaches to modeling of transient behavior in coastal aquifer systems: Journal of Hydrology, v. 86, p. 169-193.

Al-Ansari, N. A., Essaid, H. I., and Salim, Y. N., 1981, Water resources in Iraq: Journal of the Geological Society of Iraq, v. 14, no. 1, p. 34-42.