Hydrogeology of the Lower Mississippi Valley as related to the work of Harold N. Fisk

Principally concerned with the evolution of the Lower Mississippi Valley (LMV), the Fisk (1944) investigation provided one of the first descriptions of the stratigraphic and structural framework of the region. The study provided new data for hydrogeological studies by state and federal agencies. The Fisk report was the basic reference for one of the earliest studies of a complex regional aquifer system — the Mississippi embayment project. Begun by the US Geological Survey (USGS) in 1957, the study covered the Lower Mississippi Region north of the 32nd parallel. A study of ground water in the alluvium in the upper and central part of the region was completed by the US Army Corps of Engineers in 1964 (Krinitzsky and Wire, 1964). A study, completed in 1970 by the USGS for the Mississippi River Commission (MRC) as part of a plan to export water to west Texas and New Mexico, assessed the availability of fresh ground water in the entire Lower Mississippi Region (Boswell, 1970). Some results of this study were included in Appendix C of the Lower Mississippi Region Comprehensive Study Coordinating Committee (1974). During the last 20 years, hundreds of hydrogeological studies have been made in the region, and several computer models of aquifer systems have evolved. The USGS Regional Aquifer System Analysis (RASA) Program included the region in two models: the Mississippi embayment aquifer system and the Gulf Coast regional aquifer system. RASA models establish a geological, hydrological, and geochemical database for use in regional and local development and in the management of ground-water resources. The Mississippi embayment study unit of the National Water Quality Assessment Program is currently underway. Continuing hydrogeological studies are needed to assess in more detail the hydrogeology of all aquifers in the region. The vast alluvial aquifer system is of special importance because it is the largest ground-water reservoir in the region, and it is the most susceptible to contamination and the effects of mismanagement.