Linear regression and related statistical techniques are used to analyze hydraulic conductivity and test termination criteria are suggested. These criteria include that the slope of k versus pore volumes does not differ significantly from zero and that a minimum number of permeant pore volumes pass through the clay to provide saturation. To simplify the presentation, specific characteristics of the clay/chemical combination, such as cation exchange capacity, are not a focus of this presentation. The use of clay liners at hazardous waste disposal sites has prompted an interest in the k of clays exposed to chemicals. k is commonly determined in the laboratory using fixed or flexible wall permeameters and consolidometers, but past and current procedures reflect a lack of consistency in termination criteria for such tests. Fixed wall permeameters are used to study the effects of calcium sulfate and two simulated waste chemicals on three field clays. Results indicate the usefulness of the analysis in defining equilibrium conditions in laboratory testing. (Copyright (c) Journal of Technological Engineering 1986.)