Hedeff I Essaid, Ph.D.
Hedeff Essaid is a Research Hydrologist with the USGS Water Resources Mission Area.
My research has involved the analysis of field data and simulation of 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 nutrient fate in diverse watersheds.
EDUCATION:
- Stanford University, Ph.D., 1987, Hydrogeology
- Stanford University, M.S., 1984, Hydrogeology
- University of Baghdad, Iraq, B.S., 1978, Geology-Geophysics
Science and Products
Filter Total Items: 35
Design of Cycle 3 of the National Water-Quality Assessment Program, 2013-2022: Part 1: Framework of Water-Quality Issues and Potential Approaches
In 1991, the U.S. Congress established the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Program to develop long-term, nationally consistent information on the quality of the Nation's streams and groundwater. Congress recognized the critical need for this information to support scientifically sound management, regulatory, and policy decisions concerning the increasingly
Authors
Gary L. Rowe, Kenneth Belitz, Hedeff I. Essaid, Robert J. Gilliom, Pixie A. Hamilton, Anne B. Hoos, Dennis D. Lynch, Mark D. Munn, David W. Wolock
In situ measurements of volatile aromatic hydrocarbon biodegradation rates in groundwater
Benzene and alkylbenzene biodegradation rates and patterns were measured using an in situ microcosm in a crude-oil contaminated aquifer near Bemidji, Minnesota. Benzene-D6, toluene, ethylbenzene, o-, m- and p-xylenes and four pairs of C3- and C4-benzenes were added to an in situ microcosm and studied over a 3-year period. The microcosm allowed for a mass-balance approach and quantification of hydr
Authors
I.M. Cozzarelli, B.A. Bekins, R.P. Eganhouse, E. Warren, H.I. Essaid
Characterization of Interactions between Surface Water and Near-Stream Groundwater along Fish Creek, Teton County, Wyoming, by Using Heat as a Tracer
Fish Creek, a tributary of the Snake River, is about 25 river kilometers long and is located in Teton County in western Wyoming near the town of Wilson. Local residents began observing an increase in the growth of algae and aquatic plants in the stream during the last decade. Due to the known importance of groundwater to surface water in the area, the U.S. Geological Survey (USGS), in cooperation
Authors
Cheryl A. Eddy-Miller, Jerrod D. Wheeler, Hedeff I. Essaid
Benthic nutrient sources to hypereutrophic Upper Klamath Lake, Oregon, USA
Three collecting trips were coordinated in April, May, and August 2006 to sample the water column and benthos of hypereutrophic Upper Klamath Lake (OR, USA) through the annual cyanophyte bloom of Aphanizomenon flos‐aquae. A pore‐water profiler was designed and fabricated to obtain the first high‐resolution (centimeter‐scale) estimates of the vertical concentration gradients of macro‐ and micronutr
Authors
J.S. Kuwabara, B.R. Topping, D. D. Lynch, J.L. Carter, H.I. Essaid
Using heat to characterize streambed water flux variability in four stream reaches
Estimates of streambed water flux are needed for the interpretation of streambed chemistry and reactions. Continuous temperature and head monitoring in stream reaches within four agricultural watersheds (Leary Weber Ditch, IN; Maple Creek, NE; DR2 Drain, WA; and Merced River, CA) allowed heat to be used as a tracer to study the temporal and spatial variability of fluxes through the streambed. Syno
Authors
H.I. Essaid, C.M. Zamora, K. A. McCarthy, J. R. Vogel, J.T. Wilson
Transport and fate of nitrate at the ground-water/surface-water interface
Although numerous studies of hyporheic exchange and denitrification have been conducted in pristine, high-gradient streams, few studies of this type have been conducted in nutrient-rich, low-gradient streams. This is a particularly important subject given the interest in nitrogen (N) inputs to the Gulf of Mexico and other eutrophic aquatic systems. A combination of hydrologic, mineralogical, chemi
Authors
L.J. Puckett, C. Zamora, H. Essaid, J.T. Wilson, H.M. Johnson, M.J. Brayton, J. R. Vogel
Influence of groundwater pumping on streamflow restoration following upstream dam removal
We compared streamflow in basins under the combined impacts of an upland dam and groundwater pumping withdrawals, by examining streamflow in the presence and absence of each impact. As a qualitative analysis, inter-watershed streamflow comparisons were performed for several rivers flowing into the east side of the Central Valley, CA. Results suggest that, in the absence of upland dams supporting l
Authors
James E. Constantz, Hedeff I. Essaid
Progression of methanogenic degradation of crude oil in the subsurface
Our results show that subsurface crude-oil degradation rates at a long-term research site were strongly influenced by small-scale variations in hydrologic conditions. The site is a shallow glacial outwash aquifer located near Bemidji in northern Minnesota that became contaminated when oil spilled from a broken pipeline in August 1979. In the study area, separate-phase oil forms a subsurface oil bo
Authors
B.A. Bekins, F. D. Hostettler, W.N. Herkelrath, G. N. Delin, E. Warren, H.I. Essaid
Inverse modeling of BTEX dissolution and biodegradation at the Bemidji, MN crude-oil spill site
The U.S. Geological Survey (USGS) solute transport and biodegradation code BIOMOC was used in conjunction with the USGS universal inverse modeling code UCODE to quantify field-scale hydrocarbon dissolution and biodegradation at the USGS Toxic Substances Hydrology Program crude-oil spill research site located near Bemidji, MN. This inverse modeling effort used the extensive historical data compiled
Authors
H.I. Essaid, I.M. Cozzarelli, R.P. Eganhouse, W.N. Herkelrath, B.A. Bekins, G. N. Delin
Progression of natural attenuation processes at a crude oil spill site: II. Controls on spatial distribution of microbial populations
A multidisciplinary study of a crude-oil contaminated aquifer shows that the distribution of microbial physiologic types is strongly controlled by the aquifer properties and crude oil location. The microbial populations of four physiologic types were analyzed together with permeability, pore-water chemistry, nonaqueous oil content, and extractable sediment iron. Microbial data from three vertical
Authors
B.A. Bekins, I.M. Cozzarelli, E.M. Godsy, E. Warren, H.I. Essaid, M.E. Tuccillo
A functional relation for field-scale nonaqueous phase liquid dissolution developed using a pore network model
A pore network model with cubic chambers and rectangular tubes was used to estimate the nonaqueous phase liquid (NAPL) dissolution rate coefficient, Kdissai, and NAPL/water total specific interfacial area, ai. Kdissai was computed as a function of modified Peclet number(Pe′) for various NAPL saturations (SN) and ai during drainage and imbibition and during dissolution without displacement. The lar
Authors
L.A. Dillard, H.I. Essaid, M.J. Blunt
Ground water contamination by crude oil near Bemidji, Minnesota
Ground-water contamination by crude oil, and other petroleum-based liquids, is a widespread problem. An average of 83 crude-oil spills occurred per year during 1994-96 in the United States, each spilling about 50,000 barrels of crude oil (U.S. Office of Pipeline Safety, electronic commun., 1997). An understanding of the fate of organic contaminants (such as oil and gasoline) in the subsurface is n
Authors
G. N. Delin, H.I. Essaid, I.M. Cozzarelli, M.H. Lahvis, B.A. Bekins
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Filter Total Items: 35
Design of Cycle 3 of the National Water-Quality Assessment Program, 2013-2022: Part 1: Framework of Water-Quality Issues and Potential Approaches
In 1991, the U.S. Congress established the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Program to develop long-term, nationally consistent information on the quality of the Nation's streams and groundwater. Congress recognized the critical need for this information to support scientifically sound management, regulatory, and policy decisions concerning the increasinglyAuthorsGary L. Rowe, Kenneth Belitz, Hedeff I. Essaid, Robert J. Gilliom, Pixie A. Hamilton, Anne B. Hoos, Dennis D. Lynch, Mark D. Munn, David W. WolockIn situ measurements of volatile aromatic hydrocarbon biodegradation rates in groundwater
Benzene and alkylbenzene biodegradation rates and patterns were measured using an in situ microcosm in a crude-oil contaminated aquifer near Bemidji, Minnesota. Benzene-D6, toluene, ethylbenzene, o-, m- and p-xylenes and four pairs of C3- and C4-benzenes were added to an in situ microcosm and studied over a 3-year period. The microcosm allowed for a mass-balance approach and quantification of hydrAuthorsI.M. Cozzarelli, B.A. Bekins, R.P. Eganhouse, E. Warren, H.I. EssaidCharacterization of Interactions between Surface Water and Near-Stream Groundwater along Fish Creek, Teton County, Wyoming, by Using Heat as a Tracer
Fish Creek, a tributary of the Snake River, is about 25 river kilometers long and is located in Teton County in western Wyoming near the town of Wilson. Local residents began observing an increase in the growth of algae and aquatic plants in the stream during the last decade. Due to the known importance of groundwater to surface water in the area, the U.S. Geological Survey (USGS), in cooperationAuthorsCheryl A. Eddy-Miller, Jerrod D. Wheeler, Hedeff I. EssaidBenthic nutrient sources to hypereutrophic Upper Klamath Lake, Oregon, USA
Three collecting trips were coordinated in April, May, and August 2006 to sample the water column and benthos of hypereutrophic Upper Klamath Lake (OR, USA) through the annual cyanophyte bloom of Aphanizomenon flos‐aquae. A pore‐water profiler was designed and fabricated to obtain the first high‐resolution (centimeter‐scale) estimates of the vertical concentration gradients of macro‐ and micronutrAuthorsJ.S. Kuwabara, B.R. Topping, D. D. Lynch, J.L. Carter, H.I. EssaidUsing heat to characterize streambed water flux variability in four stream reaches
Estimates of streambed water flux are needed for the interpretation of streambed chemistry and reactions. Continuous temperature and head monitoring in stream reaches within four agricultural watersheds (Leary Weber Ditch, IN; Maple Creek, NE; DR2 Drain, WA; and Merced River, CA) allowed heat to be used as a tracer to study the temporal and spatial variability of fluxes through the streambed. SynoAuthorsH.I. Essaid, C.M. Zamora, K. A. McCarthy, J. R. Vogel, J.T. WilsonTransport and fate of nitrate at the ground-water/surface-water interface
Although numerous studies of hyporheic exchange and denitrification have been conducted in pristine, high-gradient streams, few studies of this type have been conducted in nutrient-rich, low-gradient streams. This is a particularly important subject given the interest in nitrogen (N) inputs to the Gulf of Mexico and other eutrophic aquatic systems. A combination of hydrologic, mineralogical, chemiAuthorsL.J. Puckett, C. Zamora, H. Essaid, J.T. Wilson, H.M. Johnson, M.J. Brayton, J. R. VogelInfluence of groundwater pumping on streamflow restoration following upstream dam removal
We compared streamflow in basins under the combined impacts of an upland dam and groundwater pumping withdrawals, by examining streamflow in the presence and absence of each impact. As a qualitative analysis, inter-watershed streamflow comparisons were performed for several rivers flowing into the east side of the Central Valley, CA. Results suggest that, in the absence of upland dams supporting lAuthorsJames E. Constantz, Hedeff I. EssaidProgression of methanogenic degradation of crude oil in the subsurface
Our results show that subsurface crude-oil degradation rates at a long-term research site were strongly influenced by small-scale variations in hydrologic conditions. The site is a shallow glacial outwash aquifer located near Bemidji in northern Minnesota that became contaminated when oil spilled from a broken pipeline in August 1979. In the study area, separate-phase oil forms a subsurface oil boAuthorsB.A. Bekins, F. D. Hostettler, W.N. Herkelrath, G. N. Delin, E. Warren, H.I. EssaidInverse modeling of BTEX dissolution and biodegradation at the Bemidji, MN crude-oil spill site
The U.S. Geological Survey (USGS) solute transport and biodegradation code BIOMOC was used in conjunction with the USGS universal inverse modeling code UCODE to quantify field-scale hydrocarbon dissolution and biodegradation at the USGS Toxic Substances Hydrology Program crude-oil spill research site located near Bemidji, MN. This inverse modeling effort used the extensive historical data compiledAuthorsH.I. Essaid, I.M. Cozzarelli, R.P. Eganhouse, W.N. Herkelrath, B.A. Bekins, G. N. DelinProgression of natural attenuation processes at a crude oil spill site: II. Controls on spatial distribution of microbial populations
A multidisciplinary study of a crude-oil contaminated aquifer shows that the distribution of microbial physiologic types is strongly controlled by the aquifer properties and crude oil location. The microbial populations of four physiologic types were analyzed together with permeability, pore-water chemistry, nonaqueous oil content, and extractable sediment iron. Microbial data from three verticalAuthorsB.A. Bekins, I.M. Cozzarelli, E.M. Godsy, E. Warren, H.I. Essaid, M.E. TuccilloA functional relation for field-scale nonaqueous phase liquid dissolution developed using a pore network model
A pore network model with cubic chambers and rectangular tubes was used to estimate the nonaqueous phase liquid (NAPL) dissolution rate coefficient, Kdissai, and NAPL/water total specific interfacial area, ai. Kdissai was computed as a function of modified Peclet number(Pe′) for various NAPL saturations (SN) and ai during drainage and imbibition and during dissolution without displacement. The larAuthorsL.A. Dillard, H.I. Essaid, M.J. BluntGround water contamination by crude oil near Bemidji, Minnesota
Ground-water contamination by crude oil, and other petroleum-based liquids, is a widespread problem. An average of 83 crude-oil spills occurred per year during 1994-96 in the United States, each spilling about 50,000 barrels of crude oil (U.S. Office of Pipeline Safety, electronic commun., 1997). An understanding of the fate of organic contaminants (such as oil and gasoline) in the subsurface is nAuthorsG. N. Delin, H.I. Essaid, I.M. Cozzarelli, M.H. Lahvis, B.A. Bekins