『Abstract
　As part of the events celebrating 40 a of IAGC, it is fitting to trace the modern evolution and development of hydrogeochemistry. However, fascination with water quality can be traced back more than 2ka. In the post-war years, hydrogeochemistry was influenced heavily by the advances in other disciplines including physical chemistry, metallurgy and oceanography. Hydrological applications of isotope science also developed rapidly at this time, and important advances in analytical chemistry allowed multi-element and trace element applications to be made. Experimental studies on equilibrium processes and reaction kinetics allowed bench-scale insight into water-rock interaction. Consolidation of knowledge on processes in groundwaters and the current awareness of hydrogeochemistry by water professionals owe much to the work Robert Garrels, John Hem, and co-workers in the early 1960s. Studies of down-gradient evolution enabled a field-scale understanding of groundwater quality and geochemical processes as a function of residence time (dissolution and precipitation processes in carbonate and non-carbonate aquifer; redox processes; cation exchange and salinity origins).
　Emerging water resource and water quality issues in the 1960s and 70s permitted the application of hydrogeochemistry to contaminant and related problems and this trend continues. The impacts of diffuse pollution from intensive agriculture, waste disposal and point source pollution from urban and industrial sources relied on geochemistry to solve questions of origin and attenuation. In semi-arid regions facing water scarcity, geochemical approaches have been vital in the assessment of renewability and characterising palaeowaters. The protection and new incoming regulation of water resources will rely increasingly on a sound geochemical basis for management.』

1. Introduction
2. Historical perspectives
　2.1. Early stirrings
　2.2. Towards an understanding of water quality - the age of enlightenment
　2.3. The post-war era
　2.4. Evolution of analytical and investigative tools
　　2.4.1. Nineteenth century
　　2.4.2. Modern conventions, modern analysis
　　2.4.3. Isotope analysis
3. Consolidation of knowledge on processes in aquifer systems
　3.1. Carbonate systems
　3.2. Non-carbonate systems
　3.3. Classic studies of groundwater flow systems
　3.4. Development of geochemical modelling
4. Water resources - towards problem-orientated geochemistry
　4.1. More food, more water, less quality
　4.2. From pristine waters to human impacts
　4.3. Natural remediation
　4.4. Acid rain impacts
5. Water scarcity - water quantity vs. water quality
　5.1. Groundwater renewability
　5.2. Non-renewable water
　5.3. Salinity issues
6. Water policy and regulation
　6.1. The European Water Framework Directive
　6.2. Natural baseline water quality
　6.3. Reversing pollution trends
　6.4. Groundwater-surface water interactions
7. Future challenges
Acknowledgments
References