Natural Attenuation of Emerging Pharmaceuticals by Bank Filtration in Addressing Regional Groundwater Management Issues - Dimkic et al. page 05

Arsenic concentrations recorded at a number of sites, including aquifer age, are presented in Table 1, which shows that high arsenic concentrations generally correspond to lower (Pliocene) aquifers, compared to Eopleistocene (BWC) and Holocene (mostly alluvial) aquifers. Figure 6 shows indicative levels of groundwater KMnO4 consumption, in parallel with groundwater age and piezometric isolines. Most of the data relate to Pliocene and Eopleistocene groundwaters.