Groundwater Age is the first book of its kind that incorporates and synthesizes the state-of-the-art knowledge about the business of groundwater dating - including historical development, principles, applications, various methods, and likely future progress in the concept. It is a well-organized, advanced, clearly written resource for all the professionals, scientists, graduate students, consultants, and water sector managers who deal with groundwater and who seek a comprehensive treatment of the subject of groundwater age.

JAY H. LEHR is the Senior Scientist on the Technical Advisory Board at Earthwater Global, LLC and a Senior Scientist at the Heartland Institute. He is the author of fourteen books and over 500 articles on environmental science.

PIERRE PERROCHET has twenty years of experience in the field of groundwater flow and transport modeling within various world-renowned research institutions. His scientific interests focus on theoretical and computational developments related to hydro-thermo-chemical phenomena, with numerous applications to environmental and hydrogeological engineering issues. He is presently Professor at the Centre of Hydrogeology, University of Neuchâtel, Switzerland, where he teaches groundwater dynamics, transport processes, and mathematical modeling.

Traditionally concerned with the flow rate calculation, recharge estimation, and renewability of groundwater resources, the application of groundwater age data has now expanded to include such issues as the calibration of groundwater flow and transport models, the management of dry land salinity, and the study of groundwater vulnerability and pollution. In short, thanks to both technical developments in the field and worldwide concerns about water resources, the study of groundwater age has coalesced into a potent and much respected field. In this comprehensive book, the field of groundwater age dating receives the major reference it needs and deserves.

Written by three leading experts in the field, Groundwater Age aggregates, in one volume, state-of-the-art knowledge concerning groundwater dating, including its historical development, principles, applications, various methods, and likely future progress in its concepts.

The book discusses such topics as:

• Essential definitions and the basics of groundwater dating science
• The history of groundwater dating, including pioneers and key contributors to the field
• Applications and uses of age data for consulting companies and resource managers
• Various methods for age dating young, old, and very old groundwaters
• New mathematical approaches
• Modeling of groundwater age and residence time distributions
• Thoughts on and suggestions for current practices and future progress

Presenting modern knowledge and cutting-edge research simply and clearly, Groundwater Age will satisfy and stimulate both seasoned professionals and student novices alike.

Acknowledgments.

Chapter 1. Introduction.

1.1 Age and lifetime.

1.2 Age determination in geology (Geochronology) and in other disciplines.

1.2.1 Absolute age and relative age.

1.2.2 Determination of absolute age of rocks.

1.2.3 Geological time table.

1.3 Groundwater age and groundwater residence time.

1.3.1 Young, old and very old groundwaters.

1.3.2 Dead water and active water.

1.3.3 Age gradient.

1.3.4 Age mass.

1.3.5 Mixing, dispersion and transport of groundwater age, mean age and distribution of ages.

1.3.6 Average residence time of water in various compartments of the hydrologic cycle .

1.3.7 Hydrogeochronolgy, interdisciplinary groundwater age science and hydrologic time concept.

1.3.8 Event markers.

1.4 Life expectancy.

1.5 Isochrone and life expectancy maps.

1.6 Some groundwater age related terms.

1.6.1 Isotopic age, radiometric age and decay age.

1.6.2 Hydraulic age.

1.6.3 Piston-flow age, streamtube age and advective age .

1.6.4 Model age and apparent age.

1.6.5 Storage time, mean transit time, turn over time, flushing time and travel time.

1.6.6 Reservoir theory and its relation with groundwater residence time.

Chapter 2. History of groundwater age dating research.

2.1 Pioneer of Groundwater Age discipline-sequence of the earliest publications.

2.2 Laboratories worldwide for dating groundwater samples.

2.3 Major contributors to Groundwater Age dating discipline.

2.4 Names familiar in the Groundwater Dating business.

2.5 Important publications.

2.5.1 Book chapters.

2.5.2 PhD and MSc theses.

2.5.3 Journals.

2.5.4 Reports (mainly by the USGS) .

2.6 Aquifers subjected to extensive dating studies.

Chapter 3. The applications of groundwater age data.

3.1 Renewability of the groundwater reservoirs.

3.2 An effective communication tool for scientists and managers- and curiosity to laymen as well.

3.3 Age monitoring for the prevention of over exploitation and contamination of aquifers.

3.4 Estimation of the recharge rate.

3.5 Calculation of the groundwater flow velocity.

3.6 Identification of the groundwater flow paths.

3.7 Assessing the rates of groundwater and contaminants transport through aquitards.

3.8 Constraining the parameters of groundwater flow and transports models (estimation of large scale flow and transport properties).

3.9 Identification of the mixing between different end members.

3.10 Study of the pre-Holocene (late Pleistocene) climate.

3.11 Evaluation of the groundwater pollution.

3.12 Calculation of the travel time of the groundwater plume to the points of interest.

3.13 Mapping vulnerability of the shallow aquifers.

3.14 Performance assessments for radioactive waste disposal facilities.

3.15 Site specific applications.

3.15.1 Identification of the seawater level fluctuations.

3.15.2 Calculating the timescale of seawater intrusion.

3.15.3 Disposal of wastes into the deep old saline groundwater systems.

3.15.4 Management of the dryland salinity in Australia.

3.15.5 Hydrograph separation.

Chapter 4. Age-dating young groundwaters.

4.1 Important points.

4.2 Tritium.

4.2.1 Production of tritium.

4.2.2 Sampling, analyzing and reporting the results.

4.2.3 Age dating groundwater by tritium.

4.2.4 Advantages and disadvantages.

4.2.5 Case studies.

4.3 3H/3He.

4.3.1 Sources of 3He.

4.3.2 Sampling, analysis and reporting the results.

4.3.3 Dating groundwater by 3H/3He.

4.3.4 Advantages and disadvantages.

4.3.5 Case studies.

4.4 Helium-4.

4.5 Krypton-85.

4.5.1 Production of 85Kr.

4.5.2 Sampling and analyzing groundwater for 85Kr.

4.5.3 Age dating groundwater with 85Kr.

4.5.4 Advantages and disadvantages.

4.5.5 Case studies.

4.6 CFCs.

4.6.1 Sampling and analyzing groundwater for CFCs.

4.6.2 Dating groundwater by CFCs.

4.6.3 Limitations and possible sources of error in CFCs dating technique.

4....