Using Periodic Pumping to Characterize Aquifers: Field and Modeling Advantages

Pumping tests and slug tests are commonly implemented as reliable methods for estimating field-scale aquifer parameters (transmissivity or hydraulic conductivity), and when resources are available for multiple such tests, they provide a method for interrogating aquifer heterogeneity. A less-commonly used strategy is the implementation of periodic pumping tests, in which the head or flow rate in a well is oscillated at a set period. In this presentation, we discuss 3 aspects of oscillatory tests relevant to field practitioners: 1) Reliable and low-cost methods for implementing periodic pumping tests in the field; 2) Strategies and guidelines for the analysis of obtained pressure data, which consists of sinusoidal pressure changes with obtained amplitude and phases; and 3) Methods for recognizing and interpreting the effects of aquifer heterogeneity on oscillatory pumping tests, which can be especially apparent during multi-frequency testing. Results of robust analyses will be demonstrated from field applications in noisy, non-ideal environments.