Optimal Exploration and Delineation for Drinking Water Well Protection under Transient Flow Conditions

In order to protect the quality of fresh water aquifers in the vicinity of drinking water wells, the conventional approach is to establish wellhead protection areas (WHPAs). Its delineation often follows a combination between travel time and flow distances based on advective flow analysis. Uncertainties in predicting groundwater flow due to unknown geological properties of the aquifer have recently lead to probabilistic approaches for well vulnerability analysis and WHPA delineation. While this has been a major advance towards realism and more robust risk control, all existing approaches still neglect temporal variations in flow conditions.

This project will extend the probabilistic well vulnerability analysis to include the additional uncertainties through transient effects in flow and transport towards wells. Statistical analysis tools applied to computer simulations will reveal if the newly considered uncertainty is small, comparable or even dominant against the previously considered geological uncertainty. Based on these developments, we will derive a methodology for optimal exploration of well catchments under combined geological and transient uncertainty.

�The results will reveal the optimal spatial locations for aquifer testing in order to reduce the involved uncertainties to acceptable levels at minimal costs for field investigations.