What does a "slug test" help to assess in groundwater monitoring?

A slug test is a field procedure used primarily to measure the hydraulic properties of groundwater, specifically the hydraulic conductivity of an aquifer. This test involves quickly adding or removing a volume of water (the "slug") from a well and observing how the water level in the well recovers over time. The rate at which the water level returns to equilibrium provides valuable information about the ability of the aquifer materials to transmit water, which is quantified as hydraulic conductivity.

This measurement is crucial in hydrogeology and groundwater management because hydraulic conductivity affects how easily water can flow through soils and rocks, influencing aquifer recharge, contamination spread, and water supply yield. Understanding hydraulic conductivity is essential for designing effective groundwater management strategies and for the proper assessment of wells used for irrigation, drinking water, or environmental monitoring.