LAUSR

The number of non-regulated issues for drinking water will continue to rise due to (1) a further increase in the input of anthropogenic trace substances and (2) drastical improvements of methods. In fact, for the majority of the newly identified substances, there are no or only insufficient toxicological data. As a consequence, a comprehensive toxicological assessment is not possible. Nevertheless, in the context of drinking water provision, assessment of the potential health risks of such water-bound substances is indispensable. In response to this requirement, the German Environment Agency (UBA) published the recommendation “Bewertung der Anwesenheit teiloder nicht bewertbarer Stoffe im Trinkwasser aus gesundheitlicher Sicht” (“Assessment of substances contained in drinking water resources that cannot (yet) or only partially be evaluated from a health-related point of view”) already in 2003 after consulting the German Drinking Water Commission (UBA 2003). This recommendation is commonly known as “Health-Related Indicator Value concept” (“Health-Related Indicator Value (HRIV) concept”; “GOW-Konzept ,” “Konzept des gesundhei t l ichen Orientierungswertes”), which has proven to be a valuable tool and has been accepted by various stakeholder groups including public health authorities, water suppliers, and consumer organizations. The HRIV concept provides an instrument to estimate event-related immediate potential risks within a narrow time frame. The resulting management options ensure the security of drinking water supplies. At the same time, the harmonized approach within the administrative sphere provides legal certainty.