HYDROGEOLOGY DIVISION: A FIFTY YEAR RETROSPECTIVE

Association with G.B. Maxey, a Division founder, began at U. of Conn. (1952-56) and with others at U. of IL and IL Geol. Survey (1956-61). We were encouraged to meet Survey visitors, attend field trips and GSA. The Division grew out of lively debate three years. Think of it, a half-day session for hydrogeology and aqueous geochemistry. We were involved in science, worthy of division status. Advances in well hydraulics were made for idealized aquifers and confining beds, liberated by the power of electric analogues. Aquifers and confining beds were analyzed as complex bodies if characterized. Numerical models were introduced limited only by the quality of field data, conceptual-models and computational power. Complex flow and reactive transport models followed. Principles of aqueous geochemistry were advanced.

Environmental geology began in 1961. Pollutant plumes were analyzed and cleanup efforts driven by state and federal environmental regulations. Geophysical tools were improved, remote sensing, new borehole equipment, testing methods and GIS introduced. Environmental job opportunities fulfilled expectations. Plowshare activities predated efforts to isolate TRU wastes, select sites and open a mined geological repository for spent nuclear fuel. Comprehensive investigations were undertaken in bedded and domal salt, granite, flood basalt, tuff and shale. Methods were developed to quantify hydraulic properties spanning 15 to 18 orders of magnitude. Some rocks had negative pore pressures. Dating methods were advanced. The credibility of numerical flow, transport and TSPA 10,000-year forecasts questioned. Geological analogues added credibility.

Surface water-groundwater interactions were studied for ecosystem protection. Groundwater influenced the genesis of ore bodies, fractures, tectonic details, migration and emplacement of petroleum and evolution of earth’s crust. Global systems analyses required coupling of complexly interrelated physical, chemical and biological phenomena to address climate change, human health and related concerns. Explosion of theme, concurrent sessions, the percentage of hydrologic/geochemical abstracts of the total submitted and job opportunities attest to the vitality, maturity and exciting future of the Division. Founders are deserving of our recognition.