Occurrence of arsenic and selenium in aquifers used to produce drinking water near Orleans, France: indices of active biogeochemical processes

Abstract : Survey of 26 drinking water wells selected in the whole region Arsenic and selenium are both toxic elements whose concentration should not exceed 10 µg/L in drinking water. Their mobility and toxicity, depending on their speciation, is often driven by microbial reactions. In an area of approximately 5000 km 2 around Orleans (Val de Loire, France), occurrence of arsenic and/or selenium above the drinking water standards imposes application of treatment strategies in several localities.