THE FUTURE OF HYDROGEOLOGY LIES IN SOMETHING OLD SOMETHING NEW SOMETHING BORROWED AND SOMETHING ELSE

A wonderful benefit of working in hydrogeology is that it borrows from many disciplines of science. As advances are made in biology, chemistry, physics, mathematics and engineering, applications to the study of groundwater systems naturally follow. Indeed, the study of aquifers can lead to improved methods and theoretical developments, as well as to new, purely hydrogeological contributions. Examples of both of these cases are mentioned below. Hydrogeology may advance in new directions or by revisiting old research questions. For example, between 1920 and today, views have alternated concerning the relative importance of biotic and abiotic processes in determining groundwater geochemistry. Hypotheses changed as new tools (physical and theoretical) became available and deepened our understanding of the subsurface. Presently, there is a prevailing view that subsurface microbes largely govern aquifer geochemistry, including organic pollutant degradation by natural attenuation. However, a recent remediation technology, granular iron reactive barriers, relies on abiotic processes. Laboratory investigations are yielding insights into the kinetics of reactions with iron that may be applicable to general aquifer and aquitard settings. Important abiotic contributions to natural attenuation may yet be documented. Another topic that has seen considerable evolution over the years is dispersion. Considered a weak process 50 years ago, it was later considered important for pollutant attenuation but is now considered weak again. It is known to be affected by aquifer heterogeneity, which is an increasingly important aspect of aquifers needing characterization for contaminant transport and water resource investigations. A new point-scale velocity probe addresses an old question – what is the nature of groundwater flow in aquifers?. In addition to the old, new and borrowed, hydrogeology needs something else for its future. It needs a stream of qualified, inquisitive and enthusiastic people, excited by the breadth and challenges of the discipline and by the positive contributions they can make to society by studying it. If this need is fulfilled, the research will naturally follow and the future of hydrogeology will be assured.