Modeling of transient groundwater flow, pollutant transport, and biodegradation in an aquifer with large hydraulic head variations

摘要: Industrially sourced dense non-aqueous phase liquids (DNAPLs) contaminated an alluvial aquifer in France decades ago. The location(s) and nature of the pollution source zone(s) were unknown, dissolved concentrations volatile organic compounds monitoring wells varied greatly with time. was hydraulic equilibrium artificial canal whose water level highly variable (up to 5 m). These variations propagated into aquifer, causing changes groundwater flow direction; a transient numerical model solute transport showed that they correlate concentration because direction resulted contaminant plume shifting. hydrogeological built, taking account solvent biodegradation first-order chain, since has significant influence on pollutant evolution. parameterization confirms position zones among potential troughs bedrock where DNAPLs could have accumulated. successfully calibrated reproduce observed over several years allowed rapid validation hypotheses functioning polluted system.