Evaluation of slug tests in a bounded, phreatic, sand and gravel aquifer

The purpose of this research was to compare hydraulic conductivity estimates in a bounded phreatic aquifer derived from slug tests to those calculated from more accurate and costly tracer tests. A slug test is a simple method to estimate the hydraulic conductivity of near well material by recording the water level in the well after the instantaneous removal of a known volume of water. The pneumatic method was modified so that it could be used to initiate the slug tests in water table wells. The slug tests were conducted according to new guidelines proposed by the Kansas Geologic Survey (KGS) and analyzed with a new semi-analytical solution (the KGS model) which eliminates many of the simplifying assumptions in the widely accepted models. The slug test estimates were found to underestimate the tracer results by up to a factor of 5