A thorough introduction to the techniques of
Table of Contents
Preface xv
About the Companion Website xvii
1 Introduction to Groundwater 1
1.1 Why Study Groundwater? 1
1.2 Brief History of Groundwater 4
1.2.1 On Books 4
1.2.2 On the Early Evolution of Hydrogeological Knowledge 5
1.2.3 1960–2005 Computers and Contaminants 6
1.2.4 2005 and Onward: Research Diversified 8
References 9
2 Hydrologic Processes at the Earth’s Surface 12
2.1 Basin-Scale Hydrologic Cycle 12
2.2 Precipitation 15
2.2.1 Snowpack Distributions 20
2.3 Evaporation, Evapotranspiration, and Potential Evapotranspiration 20
2.4 Infiltration, Overland Flow, and Interflow 23
2.5 Simple Approaches to Runoff Estimation 25
2.6 Stream Flow and the Basin Hydrologic Cycle 30
2.6.1 Measuring Stream Discharge 30
2.6.2 Hydrograph Shape 32
2.6.3 Estimation of Baseflow 35
2.7 Flood Predictions 37
Exercises 38
References 40
3 Basic Principles of Groundwater Flow 42
3.1 Porosity of a Soil or Rock 42
3.2 Occurrence and Flow of Groundwater 45
3.3 Darcy’s Experimental Law 46
3.3.1 Darcy Column Experiments 47
3.3.2 Linear Groundwater Velocity or Pore Velocity 48
3.3.3 Hydraulic Head 49
3.3.4 Components of Hydraulic Head 50
3.4 Hydraulic Conductivity and Intrinsic Permeability 51
3.4.1 Intrinsic Permeability 52
3.4.2 Hydraulic Conductivity Estimated from Association with Rock Type 53
3.4.3 Empirical Approaches for Estimation 53
3.4.4 Laboratory Measurement of Hydraulic Conductivity 55
3.5 Darcy’s Equation for Anisotropic Material 56
3.6 Hydraulic Conductivity in Heterogeneous Media 57
3.7 Investigating Groundwater Flow 61
3.7.1 Water Wells, Piezometers, and Water Table Observation Wells 61
3.7.2 Potentiometric Surface Maps 62
3.7.3 Water-Level Hydrograph 63
3.7.4 Hydrogeological Cross Sections 65
References 67
4 Aquifers 69
4.1 Aquifers and Confining Beds 69
4.2 Transmissive and Storage Properties of Aquifers 70
4.2.1 Transmissivity 70
4.2.2 Storativity (or Coefficient of Storage) and Specific Storage 72
4.2.3 Storage in Confined Aquifers 73
4.2.4 Storage in Unconfined Aquifers 74
4.2.5 Specific Yield and Specific Retention 74
4.3 Principal Types of Aquifers 75
4.4 Aquifers in Unconsolidated Sediments 75
4.4.1 Alluvial Fans and Basin Fill Aquifers 75
4.4.2 Fluvial Aquifers 79
4.5 Examples Alluvial Aquifer Systems 80
4.5.1 Central Valley Alluvial Aquifer System 80
4.5.2 High Plains Aquifer System 81
4.5.3 Indo-Gangetic Basin Alluvial Aquifer System 82
4.5.4 Mississippi River Valley Alluvial Aquifer 83
4.5.5 Aquifers Associated with Glacial Meltwater 85
4.6 Aquifers in Semiconsolidated Sediments 87
4.7 Sandstone Aquifers 88
4.7.1 Dakota Sandstone 88
4.8 Carbonate-Rock Aquifers 89
4.8.1 Enhancement of Permeability and Porosity by Dissolution 90
4.8.2 Karst Landscapes 91
4.8.3 Floridan Aquifer System 93
4.8.4 Edwards-Trinity Aquifer System 94
4.8.5 Basin and Range Carbonate Aquifer 96
4.9 Basaltic and Other Volcanic-Rock Aquifers 97
4.10 Hydraulic Properties of Granular and Crystalline Media 99
4.10.1 Pore Structure and Permeability Development 99
4.11 Hydraulic Properties of Fractured Media 100
4.11.1 Factors Controlling Fracture Development 101
References 102
5 Theory of Groundwater Flow 106
5.1 Differential Equations of Groundwater Flow in Saturated Zones 106
5.1.1 Useful Knowledge About Differential Equations 107
5.1.2 More About Dimensionality 109
5.1.3 Deriving Groundwater Flow Equations 109
5.2 Boundary Conditions 113
5.3 Initial Conditions for Groundwater Problems 114
5.4 Flow-net Analysis 115
5.4.1 Flow Nets in Isotropic and Homogeneous Media 115
5.4.2 Flow Nets in Heterogeneous Media 118
5.4.3 Flow Nets in Anisotropic Media 119
5.5 Mathematical Analysis of Some Simple Flow Problems 120
5.5.1 Groundwater Flow in a Confined Aquifer 120
5.5.2 Groundwater Flow in an Unconfined Aquifer 121
5.5.3 Groundwater Flow in an Unconfined Aquifer with Recharge 123
References 125
6 Theory of Groundwater Flow in Unsaturated Zones and Fractured Media 126
6.1 Basic Concepts of Flow in Unsaturated Zones 126
6.1.1 Changes in Moisture Content During Infiltration 128
6.2 Characteristic Curves 128
6.2.1 Water Retention or θ(ψ) Curves 128
6.2.2 K(ψ) Curves 130
6.2.3 Moisture Capacity or C(ψ) Curves 132
6.3 Flow Equation in the Unsaturated Zone 133
6.4 Infiltration and Evapotranspiration 134
6.5 Examples of Unsaturated Flow 136
6.5.1 Infiltration and Drainage in a Large Caisson 136
6.5.2 Unsaturated Leakage from a Ditch 137
6.6 Groundwater Flow in Fractured Media 137
6.6.1 Cubic Law 137
6.6.2 Flow in a Set of Parallel Fractures 139
6.6.3 Equivalent-Continuum Approach 141
References 142
7 Geologic and Hydrogeologic Investigations 144
7.1 Key Drilling and Push Technologies 144
7.1.1 Auger Drilling 144
7.1.2 Mud/Air Rotary Drilling 145
7.1.3 Direct-Push Rigs 146
7.2 Piezometers and Water-Table Observation Wells 150
7.2.1 Basic Designs for Piezometers and Water-Table Observation Wells 150
7.3 Installing Piezometers and Water-Table Wells 152
7.3.1 Shallow Piezometer in Non-Caving Materials 152
7.3.2 Shallow Piezometer in Caving Materials 152
7.3.3 Deep Piezometers 153
7.4 Making Water-Level Measurements 154
7.5 Geophysics Applied to Site Investigations 155
7.5.1 Electric Resistivity Method 155
7.5.2 Capacitively Coupled Resistivity Profiling 158
7.5.3 Electromagnetic Methods 159
7.5.4 Large-Scale, Airborne Electromagnetic Surveys 160
7.5.5 Borehole Geophysical and Flow Meter Logging 162
7.5.6 Flowmeter Logging 164
7.6 Groundwater Investigations 166
7.6.1 Investigative Methods 167
References 168
8 Regional Groundwater Flow 170
8.1 Groundwater Basins 170
8.2 Mathematical Analysis of Regional Flow 171
8.2.1 Water-Table Controls on Regional Groundwater Flow 171
8.2.2 Effects of Basin Geology on Groundwater Flow 175
8.3 Recharge 179
8.3.1 Desert Environments 179
8.3.2 Semi-Arid Climate and Hummocky Terrain 180
8.3.3 Recharge in Structurally Controlled Settings 181
8.3.4 Distributed Recharge in Moist Climates 181
8.3.5 Approaches for Estimating Recharge 181
8.4 Discharge 183
8.4.1 Inflow to Wetlands, Lakes, and Rivers 183
8.4.2 Springs and Seeps 183
8.4.3 Evapotranspiration 185
8.5 Groundwater Surface-Water Interactions 186
8.6 Freshwater/Saltwater Interactions 189
8.6.1 Locating the Interface 190
8.6.2 Upconing of the Interface Caused by Pumping Wells 192
References 193
9 Response of Confined Aquifers to Pumping 195
9.1 Aquifers and Aquifer Tests 195
9.1.1 Units 196
9.2 Thiem’s Method for Steady-State Flow in a Confined Aquifer 197
9.2.1 Interpreting Aquifer Test Data 198
9.3 Theis Solution for Transient Flow in a Fully Penetrating, Confined Aquifer 199
9.4 Prediction of Drawdown and Pumping Rate Using the Theis Solution 201
9.5 Theis Type-Curve Method 201
9.6 Cooper–Jacob Straight-Line Method 204
9.7 Distance-Drawdown Method 206
9.8 Estimating T and S Using Recovery Data 208
References 214
10 Leaky Confined Aquifers and Partially-Penetrating Wells 216
10.1 Transient Solution for Flow Without Storage in the Confining Bed 216
10.1.1 Interpreting Aquifer-Test Data 218
10.2 Steady-State Solution 221
10.3 Transient Solutions for Flow with Storage in Confining Beds 223
10.4 Effects of Partially Penetrating Wells 229
References 235
11 Response of an Unconfined Aquifer to Pumping 236
11.1 Calculation of Drawdowns by Correcting Estimates for a Confined Aquifer 236
11.2 Determination of Hydraulic Parameters Using Distance/Drawdown Data 238
11.3 A General Solution for Drawdown 239
11.4 Type-Curve Method 241
11.5 Straight-Line Method 245
11.6 Aquifer Testing with a Partially-Penetrating Well 247
References 250
12 Slug, Step, and Intermittent Tests 251
12.1 Hvorslev Slug Test 251
12.2 Cooper–Bredehoeft–Papadopulos Test 255
12.3 Bower and Rice Slug Test 257
12.4 Step and Intermittent Drawdown Tests 259
12.4.1 Determination of Transmissivity and Storativity 260
12.4.2 Estimating Well Efficiency 263
References 268
13 Calculations and Interpretation of Hydraulic Head in Complex Settings 269
13.1 Multiple Wells and Superposition 269
13.2 Drawdown Superimposed on a Uniform Flow Field 271
13.3 Replacing a Geologic Boundary with an Image Well 272
13.3.1 Impermeable Boundary 272
13.3.2 Recharge Boundary 277
13.4 Multiple Boundaries 278
13.5 Calculation and Interpretation of Hydraulic Problems Using Computers 279
13.5.1 Numerical Models for Groundwater Simulations 279
13.5.2 Interpreting Aquifer Tests 281
References 282
14 Depletion of Groundwater Resources 283
14.1 Water-Level Declines from Overpumping 283
14.1.1 Challenges in the Investigation of Water-level Changes 285
14.2 Land Subsidence 285
14.2.1 Conceptual Model 286
14.2.2 Terzaghi Principle of Effective Stress 288
14.2.3 Subsidence in the San Joaquin Valley of California 289
14.2.4 Challenges in the Investigation of Subsidence 293
14.3 Connected Groundwaters and Surface Waters 294
14.3.1 Declines in Streamflow 294
14.3.2 Induced Infiltration of Streamflow 295
14.3.3 Capture Zone for a Well 298
14.3.4 Pumping of the High Plains Aquifer System and Streamflow Reduction 298
14.3.5 Streamflow Declines in Beaver-North Canadian River Basin 300
14.3.6 Challenges in the Investigation of Streamflow Loss 301
14.4 Destruction of Riparian Zones 301
14.5 Seawater Intrusion 303
14.5.1 Salinas River Groundwater Basin 304
14.6 Introduction to Groundwater Modeling 306
14.6.1 Conceptual Model 306
14.6.2 Model Design 308
14.6.3 Model Calibration and Verification 308
14.6.4 Predictions in Modeling 309
14.7 Application of Groundwater Modeling 309
References 312
15 Groundwater Management 315
15.1 The Case for Groundwater Sustainability 315
15.2 Groundwater Sustainability Defined 317
15.2.1 Sustainability Initiatives 317
15.2.2 Sustainability Indicators for the Sierra Vista Subwatershed in Arizona 318
15.2.3 Socioeconomic Policies and Instruments 320
15.3 Overview of Approaches for Sustainable Management 321
15.3.1 Indicator Tracking 321
15.3.2 Water Balance Analyses 322
15.3.3 Model-Based Analyses of Sustainability 326
15.4 Strategies for Groundwater Sustainability 327
15.4.1 Increasing Inflows 327
15.4.1.1 Managed Aquifer Recharge (MAR) 327
15.4.1.2 Traditional MAR Approaches 329
15.4.1.3 “Sponge City” and Opportunities for Unmanaged Aquifer Recharge 330
15.4.2 Reducing Outflows 331
15.4.2.1 Replacing Groundwater with Surface Water 331
15.4.2.2 Reduction in Water Used for Irrigation 331
15.4.3 Scaling Issues with Sustainability 331
15.5 Global Warming Vulnerabilities 332
15.6 Chemical Impacts to Sustainability 334
15.6.1 Salinization 334
15.6.2 Geogenic and Aenthropogenic Contamination 335
15.6.3 Salinity and Contamination—Indo-Gangetic Basin (IGB) Alluvial Aquifer 336
15.6.4 Seawater Intrusion 339
References 342
16 Water Quality Assessment 345
16.1 Dissolved Constituents in Groundwater 346
16.1.1 Concentration Scales 346
16.2 Constituents of Interest in Groundwater 348
16.2.1 Gases and Particles 348
16.2.2 Routine Water Analyses 350
16.2.3 Contamination: Expanding the Scope of Chemical Characterization 351
16.2.3.1 Contaminated Sites 351
16.2.4 Comprehensive Surveys of Water Quality 352
16.3 Water Quality Standards 353
16.3.1 Health-Based Screening Levels—USGS 353
16.3.2 Secondary Standards for Drinking Water 354
16.3.3 Standards for Irrigation Water 355
16.4 Working with Chemical Data 356
16.4.1 Relative Concentration and Health-Based Screening 356
16.4.2 Scatter Diagrams and Contour Maps 358
16.4.3 Contour Maps 359
16.4.4 Piper Diagrams 360
16.5 Groundwater Sampling 362
16.5.1 Selecting Water Supply Wells for Sampling 362
16.6 Procedures for Water Sampling 363
16.6.1 Well Inspection and Measurements 363
16.6.2 Well Purging 363
16.6.3 Sample Collection, Filtration, and Preservation 364
References 364
17 Key Chemical Processes 366
17.1 Overview of Equilibrium and Kinetic Reactions 366
17.1.1 Law of Mass Action and Chemical Equilibrium 367
17.1.2 Complexities of Actual Groundwater 368
17.1.3 Deviations from Equilibrium 369
17.1.4 Kinetic Reactions 371
17.2 Acid–Base Reactions 372
17.3 Mineral Dissolution/Precipitation 374
17.3.1 Organic Compounds in Water 375
17.4 Surface Reactions 375
17.4.1 Sorption Isotherms 376
17.4.2 Sorption of Organic Compounds 377
17.4.3 Ion Exchange 379
17.4.4 Clay Minerals in Geologic Materials 380
17.4.5 Sorption to Oxide and Oxyhydroxide Surfaces 381
17.5 Oxidation–Reduction Reactions 382
17.5.1 Kinetics and Dominant Couples 384
17.5.2 Biotransformation of Organic Compounds 385
17.5.3 pe-pH and E H -pH Diagrams 385
17.5.4 Quantifying Redox Conditions in Field Settings 386
17.5.5 Redox Zonation 388
17.6 Microorganisms in Groundwater 389
17.6.1 Quantifying Microbial Abundances 390
17.6.2 Microbial Ecology of the Subsurface 390
References 392
18 Isotopes and Applications 395
18.1 Stable and Radiogenic Isotopes 395
18.2 18 O and Deuterium in the Hydrologic Cycle 397
18.2.1 Behavior of D and 18 O in Rain 400
18.3 Variability in 18 O and Deuterium in Groundwater 401
18.3.1 Spatial and/or Temporal Variability of δ 18 O and δD Compositions in Aquifers 401
18.3.2 Connate Water in Units with Low Hydraulic Conductivity 402
18.4 Evaporation and the Meteoric Water Line 403
18.4.1 Other Deviations from GMWL 404
18.4.2 Illustrative Applications with Deuterium and Oxygen- 18 404
18.4.2.1 Role of Wetland in Streamflow 404
18.4.2.2 Integrated Study of Recharge Dynamics in a Desert Setting 405
18.5 Radiogenic Age Dating of Groundwater 406
18.5.1 Exploring Old and New Concepts of Age for Groundwater 408
18.5.2 Carbon- 14 409
18.5.3 Chlorine-36 and Helium-4: Very Old Groundwater 411
18.5.4 Tritium 412
18.5.5 Categorial Assessments Using Tritium Ages 414
18.6 Indirect Approaches to Age Dating 416
18.6.1 Isotopically Light Glacial Recharge 417
18.6.2 Chlorofluorocarbons and Sulfur Hexafluoride 417
References 420
19 Mass Transport: Principles and Examples 423
19.1 Subsurface Pathways 423
19.2 Advection 425
19.3 Dispersion 427
19.3.1 Tracer Tests 427
19.3.2 Dispersion at Small and Large Scales 429
19.4 Processes Creating Dispersion 429
19.5 Statistical Patterns of Mass Spreading 431
19.6 Measuring, Estimating, and Using Dispersivity Values 433
19.6.1 Sources with a Continuous Release 433
19.6.2 Available Dispersivity Values 434
19.7 Dispersion in Fractured Media 435
19.8 Chemical Processes and Their Impact on Water Chemistry 437
19.8.1 Gas Dissolution and Redistribution 437
19.8.2 Mineral Dissolution/Precipitation 438
19.8.3 Cation Exchange Reactions 439
19.8.4 Dissolution/Utilization of Organic Compounds 439
19.8.5 Redox Reactions 439
19.9 Examples of Reactions Affecting Water Chemistry 441
19.9.1 Chemical Evolution of Groundwater in Carbonate Terrains 441
19.9.2 Shallow Brines in Western Oklahoma 441
19.9.3 Chemistry of Groundwater in an Igneous Terrain 442
19.9.4 Evolution of Shallow Groundwater in an Arid Prairie Setting 443
19.10 A Case Study Highlighting Redox Processes 444
19.10.1 Iron and Manganese 444
19.10.2 Arsenic 445
19.10.3 Nitrate 446
19.10.4 Machine Learning for Mapping Redox Conditions 447
References 450
20 Introduction to Contaminant Hydrogeology 452
20.1 Point and Nonpoint Contamination Problems 452
20.2 Families of Contaminants 455
20.2.1 Minor/Trace Elements 455
20.2.2 Nutrients 455
20.2.3 Other Inorganic Species 456
20.2.4 Organic Contaminants 456
20.2.4.1 Petroleum Hydrocarbons 456
20.2.4.2 Halogenated Aliphatic Compounds 457
20.2.4.3 Halogenated Aromatic Compounds 457
20.2.4.4 Polychlorinated Biphenyls 458
20.2.4.5 Health Effects 458
20.2.5 Biological Contaminants 458
20.2.6 Radionuclides 458
20.3 Presence or Absence of Nonaqueous Phase Liquids (NAPLs) 459
20.4 Roles of Source Loading and Dispersion in Shaping Plumes 460
20.4.1 Source Loading 460
20.5 How Chemical Reactions Influence Plumes 461
20.5.1 Biodegradation of Organic Contaminants 462
20.5.2 Degradation of Common Contaminants 462
20.5.3 Reactions Influencing Plume Development 463
20.6 Nonaqueous Phase Liquids in the Subsurface 464
20.6.1 Features of NAPL Spreading 464
20.6.2 Occurrence of DNAPLs in the Saturated Zone 466
20.6.3 Secondary Contamination Due to NAPLs 466
20.7 Approaches for the Investigation of Contaminated Sites 466
20.7.1 Preliminary Studies 467
20.7.2 Reconnaissance Geophysics 467
20.7.3 Soil Gas Characterization 467
20.7.4 Distribution of Dissolved Contaminants 468
20.7.5 Plume Maps 470
20.7.6 Mapping the Distribution of NAPLs 471
20.8 Field Example of an LNAPL Problem 473
References 478
Index 481
