305-310 - A29

The Commission of the European Communities (CEC) is just working out a new directive in order to regulate the agricultural reuse of sewage sludge. This new regulation will also effect a “special case” – sludge usage in a mountainous environment – which will be discussed in this paper. Three reuse sites at small wastewater treatment plants of mountain refuges at altitudes more than 2,000 m a.s.l. are investigated. Applied sludge, soil and drainage flow from lysimeters are analysed. Concerning heavy metal concentrations domestic sewage sludge from these sites differs significantly from municipal sludge. A comparison with background concentrations reveals that no relevant accumulative pollution of the soil is possible. An increase of coliform bacteria of maximum two orders of magnitude is preserved during the long winter period and indicates a limited hygienic risk.