Assessment of the contamination of drinking water supply wells by pesticides from surface water resources using a finite element reactive transport model and global sensitivity analysis techniques

摘要: Summary A reactive transport model is employed to evaluate the potential for contamination of drinking water wells by surface pollution. The considers various geologic settings, includes sorption and degradation processes tested comparison with data from a tracer experiment where fluorescein dye injected in river monitored at nearby wells. Three compounds were considered: an older pesticide MCPP (Mecoprop) which mobile relatively persistent, glyphosate (Roundup), newer biodegradable strongly sorbing pesticide, its product AMPA. Global sensitivity analysis using Morris method identify dominant parameters. Results show that characteristics clay aquitards (degree fracturing thickness), pollutant properties well depths are crucial factors when evaluating risk water. This study suggests it unlikely streams can pose threat wells, while represent risk: concentration be up 7% confined aquifers 10% unconfined aquifers. Thus, presence confining may not prevent persistent consistent on occurrence Denmark pesticides found higher concentrations shallow close streams.