Occurrence and Fate of Pharmaceuticals during Bank Filtration – Preliminary Results from Investigations in Germany and the United States

The growing need for clean drinking water worldwide has increased the interest in natural surface-water treatment techniques such as bank filtration. Bank filtration has been used for more than a century in drinking water production. Historically, it was recognized as an efficient natural attenuation process ensuring sustainability of drinking-water supply. If bank-filtration facilities are designed and constructed properly, the ground water used for drinking-water supply can be protected efficiently from contamination with microbial organisms and inorganic or organic pollutants. Recently, however, several new types of organic contaminants, such as pharmaceuticals, have been found in the aquatic environment. Some of the polar pharmaceuticals also have been detected in ground water and drinking-water samples, especially when water from induced recharge is used for drinking-water production. In 2001, two projects were initiated at bank-filtration sites in Berlin, Germany, and in Nebraska, U.S.A., to investigate the natural attenuation of pharmaceutical residues and several other environmentally relevant contaminants systematically under natural conditions. Preliminary results of the studies in Germany and the United States revealed that several polar organic compounds, especially several pharmaceutically active compounds (PHACs), are relevant to drinking-water production at bank-filtration sites.