Ścieki źródłem metali ciężkich w wodzie zasilającej stawy karpiowe

The investigations were carried out in autumn 1982. They concerned river Skorynia, the indirect source of water for carp ponds in Wierzchowice Fishing Farm. The effect of wewage from Twardogóra town on quality of river water and the course of self-purification processes in the river were investigated. Four groups of compounds and agents eliminated in various degrees from water along a 3 km segment of the river were separated. The fourth group of compounds which undergo elimination in as little as 0% - 7% proved particularly dangerous to pond habitat. The group consists, among others, of heavy metals which can reach in this way the ponds situated even very far from polluting sources.