Book excerpt: This updated and expanded edition provides a thorough understanding of the measurable properties of groundwater systems and the knowledge to apply hydrochemical, geological, isotopic, and dating approaches to their work. This volume includes question and answer discussions for key concepts presented in the text and the basic hydrological, geological, and physical parameters to be observed and measured. Chemical and Isotopic Groundwater Hydrology, Third Edition covers the chemical tools of groundwater hydrology, the isotopic composition of water and groundwater dating by tritum, carbon-14, Cl-36, and He-4, as well as the application of fossil groundwater as a paleoclimatic indicator.