A systematic study was made of one of Ohio's principal aquifers, a sand and gravel outwash in the Scioto River Valley, to determine the feasibility of developing a ground-water supply of 20 million gallons per day at a site near Piketon. The first part of the study was spent in determining the thickness and physical properties of the sand and gravel aquifer and in drilling test wells to determine the best site for the supply wells.
The second part of the investigation was an aquifer infiltration test to determine the hydraulic properties of the aquifer and the conditions of stream recharge. A well 83 feet deep was drilled on the flood plain and was pumped for 9 days at the rate of 1,000 gallons per minute. Tile effect on the hydrologic system during and after the pumping was determined by measuring the water levels in an array of deep and shallow observation wells and in 8 drive-point wells installed in the bed of the river. Seldom have more comprehensive data been collected showing the effects of pumping on a natural, unconfined, hydrologic system. From these data were calculated the coefficient of transmissibility (215,000 gallons per day per foot) and the rate of streambed infiltration (0.235 million gallons per day per acre per foot).
The aquifer was tested near the end of a long drought; so the ground-water levels and the river stage were very nearly following a level trend. Because the ground-water levels were essentially unaffected by extraneous influences, the test data are probably as precise and uncomplicated as is practical to obtain in the field. These data proved to be valid for use as design criteria for the location, spacing, and construction of four supply wells.
The third part of the investigation was the testing and quantitative evaluation of the four supply wells before they were put into service. The wells were found to perform about as predicted, indicating that the hydraulic properties of the aquifer, as determined by standard methods, are fairly representative.
