Temporal variation of ethylene dibromide (EDB) in an unconfined aquifer, Whatcom County, Washington, USA: a twenty-seven month study

Results are presented from a long-term study on the concentrations of the agricultural pesticide ethylene dibromide (EDB) in an unconfined aquifer in Whatcom County, Wash., to investigate how the concentrations of a groundwater contaminant might vary from month to month and whether these variations could be correlated with soil temperature or precipitation. Statistical analysis of the data suggested that a precipitation event could create a pulse of rapid infiltration into the aquifer, so diluting EDB in the groundwater, but this would be followed by slow infiltration of EDB from overlying soils over a period of 1-3 months, to re-establish previous levels.