2.2 Slug Tests

A slug test is performed by rapidly displacing water in the well and observing the recovery of the water level over time (Figure 1b). The water can be displaced by insetting or removing an object or, in a low hydraulic conductivity material, by pumping water from the well, as long as the pumping is brief relative to the recovery. Different analytical methods are available for analyzing the test data depending on the well design and water‑bearing unit types (e.g., confined, or unconfined). Slug tests can be performed on small‑diameter wells in which pump installation is problematic. Slug tests may also be chosen to evaluate low‑ and high‑yielding groundwater units and at locations with contaminated groundwater, where pumping tests are impractical because discharge cannot be disposed of economically.