Micropollutants: challenges in hydrogeology

Abstract

In the 1990s, clofibric acid, a metabolite of lipid regulators, was found in the drinking water of Berlin, Germany (Heberer and Stan 1997). This drug made its way from households via wastewater treatment plants to surface waters and further into the waterworks’ wells by artificial groundwater enrichment and bank filtration. All over the world, hundreds of pharmaceuticals, hormones, additives of personal care products and detergents (collectively referred to as PPCP) have been found in wastewater, surface water and groundwater. Schwarzenbach et al. (2006) pointed to the contamination of water systems with these industrial and chemical compounds as “one of the key environmental problems facing humanity”. Most of them are present only at low concentrations in a range of pg l to ng l and therefore are termed micropollutants. In contrast, concentrations of macropollutants such as inorganic nitrogen, phosphate or BTEX (benzene, toluene, ethylbenzene and xylenes) are orders of magnitude higher (Schirmer and Schirmer 2008). The latter are relatively well knownwith respect to source, spatial extent, behaviour and remediation. Micropollutants, on the other hand, are ubiquitously present in complex mixtures and therefore much more difficult to assess (Schwarzenbach et al. 2006).