Reconnaissance of ground-water resources in the Mississippian Plateau region, Kentucky

Abstract

The U.S. Geological Survey, in cooperation with the Kentucky Geological Survey, and previous to 1958 with the Department of Economic Development of Kentucky, presents in this report a reconnaissance study of ground-water occurrence in the Mississippian Plateau region of central Kentucky. Included in the region are three major physiographic units the Mammoth Cave plateau, the Pennyroyal plain, and the Knobs. The region is drained by the Cumberland, Tennessee, and Green Rivers, all of which are tributary to the Ohio River. The mean annual precipitation is about 48 inches; the minimum annual precipitation is about 30 inches, and the maximum annual precipitation about 74 inches. The mean annual temperature is 57 °F. The region is underlain chiefly by limestone, shale, and sandstone ranging in age from Ordovician to Pennsylvanian. Alluvial deposits of sand and gravel of Quaternary age occur along the Ohio River and its tributaries. More than half of the wells in the region yield supplies adequate for modern domestic use, and a few wells yield more than 1,000 gpm (gallons per minute). Many large springs are in the Pennyroyal plain. Some of these springs were measured quarterly to determine the variability of discharge and the quality of water. Measured maximum flows were as high as 150,000 gpm. Many small springs occur in the Mississippian rocks of Chester and Osage ages. Hydrographs in the report show the effects of recharge and discharge of shallow and deep aquifers. Diagrammatic sketches of observation wells and a spring show the conditions, such as lithology of the aquifer, topographic situation, distance from streams and sinkholes, and height of water level above stream level, controlling the occurrence of ground water in the Mississippian Plateau region. The factors controlling occurrence of ground water are correlated with the yield of wells by means of tables and charts. The water from most limestone aquifers in the region is hard, and during periods of heavy rainfall, the water becomes turbid. Charts and tables show the quality of water from aquifers in the region and the relationship of discharge of a few springs to the dissolved constituents and specific conductance.