Change in Drawdown Caused by Enlarging a Well in a Dolomite Aquifer

Abstract

Step‐drawdown tests of a well in a dolomite aquifer in north‐central Ohio, before and after it was enlarged from 10 to 12 inches (250 to 300 millimetres) in diameter, indicate changes in the well‐loss constant, the exponent for turbulent flow, and the formation loss factor. The calculated difference in drawdown resulting from enlarging the well is of little practical importance at rates of 300 to 500 gallons per minute (19 to 31 litres per second), the range of rates at which the well is expected to be pumped, but for higher rates the decrease in drawdown and consequent reduction in power costs could be significant. For a pumping rate of 1,500 gallons per minute (95 litres per second), the decrease in drawdown would be 20.4 feet (6.2 metres). Copyright © 1976, Wiley Blackwell. All rights reserved