Hydraulics of wells : design, construction, testing, and maintenance of water well systems

523 Pages·2014·7.511 MB·English

by  Task Committee on Hydraulics of Wells, Nazeer Ahmed, Stewart W. Taylor, Zhuping Sheng

ASCE Manuals and Reports on Engineering Practice No. 127
Hydraulics of Wells
Design, Construction,
Testing, and Maintenance
of Water Well Systems
Prepared by
the Task Committee on Hydraulics of Wells of the
Groundwater Hydrology Technical Committee of the
Groundwater Council and Watershed Council of
the Environmental and Water Resources Institute of the
American Society of Civil Engineers
Edited by
Nazeer Ahmed , Ph.D., P.E.;
Stewart W. Taylor , Ph.D., P.E.; and
Zhuping Sheng , Ph.D., P.E.
Library of Congress Cataloging-in-Publication Data
Hydraulics of wells : design, construction, testing, and maintenance of water well
systems / prepared by the Task Committee on Hydraulics of Wells of the Groundwater
Hydrology Technical Committee of the Groundwater Council and Watershed Council of
the Environmental and Water Resources Institute of the American Society of Civil
Engineers ; edited by Nazeer Ahmed, P.E., Stewart W. Taylor, Ph.D., P.E., and Zhuping
Sheng, Ph.D., P.E.
pages cm – (ASCE manuals and reports on engineering practice; No. 127)
Includes bibliographical references and index.
ISBN 978-0-7844-1273-2 (print : alk. paper) – ISBN 978-0-7844-7826-4
(ebook) 1. Wells. 2. Hydrogeology. 3. Hydrology. I. Ahmed,
Nazeer. II. Environmental and Water Resources Institute (U.S.). Task Committee on
Hydraulics of Wells.
TD405.H93 2014
628.1’14–dc23
2013047661
Published by American Society of Civil Engineers
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MANUALS AND REPORTS ON
ENGINEERING PRACTICE
(As developed by the ASCE Technical Procedures Committee, July 1930,
and revised March 1935, February 1962, and April 1982)
A manual or report in this series consists of an orderly presentation of
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CONTENTS
CONTRIBUTORS ...................................................................................... xi
PREFACE ..................................................................................................... xvii
INTRODUCTION ...................................................................................... xix
1. FUNDAMENTAL CONCEPTS OF GROUNDWATER
FLOW ....................................................................................................... 1
Bruce L. Jacobs
1.1 General ............................................................................................ 1
1.2 Hydrologic Cycle .......................................................................... 2
1.3 Porous Media ................................................................................. 3
1.4 Aquifer Systems ............................................................................ 5
1.5 Aquifer Storage ............................................................................. 11
1.6 Darcy Equation .............................................................................. 15
1.7 Basic Equations of Groundwater Flow ..................................... 24
1.8 Aquifer Flow .................................................................................. 26
1.9 Summary ........................................................................................ 29
1.10 Solved Design Example 1 ............................................................ 30
1.11 Solved Design Example 2 ............................................................ 31
1.12 References ....................................................................................... 34
2. HEAD LOSSES, TOTAL DRAWDOWN, TOTAL DYNAMIC
HEAD, AND EFFICIENCY OF WATER-WELL SYSTEMS .......... 37
Nazeer Ahmed and James A. Cardle
2.1 General ............................................................................................ 37
2.2 Head Loss in the Suction Pipe .................................................... 55
2.3 Head Loss in the Delivery Pipe .................................................. 56
2.4 Total Dynamic Head ..................................................................... 58
2.5 Effi ciency of Water-Well Systems ............................................... 65
2.6 Solved Design Example 1 ............................................................ 72
v
vi CONTENTS
2.7 Solved Design Example 2 ............................................................ 76
2.8 Solved Design Example 3 ............................................................ 79
2.9 References ....................................................................................... 81
3. DESIGN OF WATER WELLS ............................................................. 83
Otto Helweg, Zohrab Samani, Jorge Garcia, Rao Govindaraju,
Dinesh R. Katti, and Clinton Willson
3.1 General ............................................................................................ 83
3.2 Design of Borehole, Casing, and Screen ................................... 85
3.3 Design of Filter Pack .................................................................... 91
3.4 Design of Well Screen ................................................................... 101
3.5 Economic Considerations in Design .......................................... 105
3.6 Summary ........................................................................................ 120
3.7 References ....................................................................................... 120
4. CONSTRUCTION, DEVELOPMENT, AND TESTING
OF WATER WELLS .............................................................................. 123
Dennis E. Williams
4.1 General ............................................................................................ 123
4.2 Site Assessment for Potential Municipal Water Well
Sites ................................................................................................. 125
4.3 Drilling, Installation, and Cementing of Conductor
Casing ............................................................................................. 133
4.4 Drilling the Borehole .................................................................... 134
4.5 Geophysical Borehole Logging ................................................... 164
4.6 Isolated Aquifer Zone Testing .................................................... 170
4.7 Water Quality and Yield .............................................................. 171
4.8 Well Destruction Methods ........................................................... 172
4.9 Mechanical Grading Analyses .................................................... 195
4.10 Lithologic Descriptions of Formation Materials Using
Unifi ed Soil Classifi cation System ............................................. 196
4.11 Preparation for Well Completion ............................................... 196
4.12 Installation of Casing, Screen, and Filter Pack......................... 201
4.13 Interaquifer Seals .......................................................................... 205
4.14 Principles of Well Development ................................................. 205
4.15 Final Development with Deep Well Turbine Pump
(Vertical Line Shaft) ...................................................................... 211
4.16 Pumping Tests ............................................................................... 213
4.17 Flowmeter (Spinner) Survey ....................................................... 229
4.18 Collecting Water Quality Samples at the End of the
Constant-Rate Test ........................................................................ 230
4.19 Miscellaneous Final Tasks ........................................................... 230
4.20 Final Report including Analysis ................................................. 234
4.21 Acknowledgments ........................................................................ 235
4.22 References ....................................................................................... 235
CONTENTS vii
5. CORROSION OF WATER WELLS ................................................... 239
Robert G. McLaughlan
5.1 General ............................................................................................ 239
5.2 Theory of Corrosion ..................................................................... 239
5.3 Types of Corrosion ........................................................................ 242
5.4 Corrosive Properties of Water ..................................................... 246
5.5 Corrosion of Water-Well Systems ............................................... 248
5.6 Prediction of Corrosion ................................................................ 251
5.7 Evaluation of Corrosion Rate Data ............................................ 257
5.8 Protective Measures for Corrosion............................................. 259
5.9 Troubleshooting for Well Corrosion .......................................... 263
5.10 Solved Design Example 1 ............................................................ 264
5.11 References ....................................................................................... 282
6. INCRUSTATION OF WATER WELLS ............................................. 285
John H. Schneiders
6.1 General ............................................................................................ 285
6.2 Theory of Incrustation .................................................................. 285
6.3 Analysis of Groundwater ............................................................ 286
6.4 Forms of Incrustation ................................................................... 290
6.5 Causes of Incrustation .................................................................. 290
6.6 Effects of Velocity, Pressure, and Temperature Changes ........ 291
6.7 Chemical Incrustation .................................................................. 292
6.8 Physical Incrustation .................................................................... 293
6.9 Biological Incrustation ................................................................. 294
6.10 Character of Iron Deposits .......................................................... 297
6.11 Field Testing of Incrustation ....................................................... 298
6.12 Timely Maintenance ..................................................................... 299
6.13 Acid Treatment .............................................................................. 301
6.14 Chlorine Treatment ....................................................................... 305
6.15 Polyphosphate Treatment ............................................................ 308
6.16 Design Considerations to Prevent Well Fouling ...................... 309
6.17 References ....................................................................................... 312
6.18 Recommended Reading ............................................................... 312
7. WELLHEAD PROTECTION FOR WATER WELLS ...................... 315
Zohrab Samani and Jorge Garcia
7.1 General ............................................................................................ 315
7.2 Wellhead Protection and Wellhead Protection Area ............... 316
7.3 Fundamentals of Groundwater Flow and Contaminant
Transport ........................................................................................ 318
7.4 Delineation Methods for the Wellhead Protection Area ........ 322
7.5 A Case Study ................................................................................. 329
7.6 Summary ........................................................................................ 335
7.7 References ....................................................................................... 336
viii CONTENTS
8. MAINTENANCE OF WATER WELLS ............................................. 337
Stuart A. Smith
8.1 General ............................................................................................ 337
8.2 Causes of Well Performance: Problems and Failures ............. 337
8.3 Preventive Material, Design, and Treatment Choices
to Avoid Well Performance Decline and Failure ..................... 340
8.4 Preventive Maintenance, Monitoring Methods, and
Records ........................................................................................... 351
8.5 Schedule of Well Maintenance Activities .................................. 356
8.6 Economics of Well Maintenance ................................................. 356
8.7 The Future: Field and Laboratory Research on Well
Maintenance ................................................................................... 360
8.8 Solved Design Example 1 ............................................................ 360
8.9 Solved Design Example 2 ............................................................ 367
8.10 References ....................................................................................... 370
APPENDIX A. EXAMPLE OF A WATER-WELL SYSTEM
DESIGN .................................................................................................. 373
Dennis E. Williams
A.1 General .......................................................................................... 373
A.2 Hydrogeology ............................................................................... 375
A.3 Groundwater ................................................................................ 377
A.4 Well Site Characteristics .............................................................. 380
A.5 Technical Aspects of Water Wells .............................................. 383
A.6 Geophysical Logging and Aquifer Zone Testing.................... 384
A.7 Design Aspects of Water Wells .................................................. 387
A.8 Pumping Tests .............................................................................. 392
A.9 Video Survey, Plumbness, and Alignment .............................. 399
A.10 Well Equipping, Operation, and Maintenance ....................... 399
A.11 Acknowledgments ....................................................................... 401
APPENDIX B. TECHNICAL SPECIFICATIONS FOR
DRILLING, CONSTRUCTING, AND TESTING
OF WATER WELLS .............................................................................. 405
Dennis E. Williams
B.1 General .......................................................................................... 405
B.2 Drilling Method and Equipment .............................................. 417
B.3 Well Construction Sequence ...................................................... 423
B.4 Testing For Yield and Drawdown ............................................. 441
B.5 Video Survey ................................................................................ 445
B.6 Well Disinfection .......................................................................... 445
B.7 Figures ........................................................................................... 447
B.8 Attachments .................................................................................. 448
APPENDIX C. GLOSSARY ..................................................................... 455
CONTENTS ix
APPENDIX D. NOTATION .................................................................... 471
APPENDIX E. SI UNIT PREFIXES ....................................................... 483
APPENDIX F. CONVERSION TABLE AND USEFUL
CONSTANTS ......................................................................................... 485
INDEX .......................................................................................................... 491