Definition
A hydrogeological assessment is a study of how groundwater moves, how much water is available, and how groundwater interacts with the surrounding environment and surface water. It typically evaluates subsurface geology (soil and rock layers), groundwater levels, flow directions, recharge sources (where water enters the aquifer), and water quality.
What it covers
Depending on the project, an assessment may include: (1) reviewing existing maps, borehole logs, and monitoring data; (2) field investigations such as drilling, installing monitoring wells, pumping tests, and measuring groundwater levels; (3) groundwater modeling to estimate flow and potential impacts; (4) water quality sampling (e.g., salinity, nutrients, metals, contaminants); and (5) risk evaluation for nearby receptors like wells, springs, rivers, wetlands, or foundations.
Why it’s done
Hydrogeological assessments are commonly used for land development, water supply planning, dewatering for construction, waste disposal or remediation, and evaluating potential impacts from industrial activities. They help determine whether groundwater can be safely abstracted or protected, and they support permitting and environmental compliance. If the assessment relates to drinking water or health-related exposure, consult qualified professionals and follow local public health guidance; do not rely on preliminary results for medical or safety decisions.