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 2 ka. 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 of 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 aquifers; redox processes; cation exchange and salinity origins).