“Silver Lake” was the colloquial term for a lake that formed in a former open pit mine south of the East German city of Wolfen. After strip mining ceased, the remaining pit was used as a dump for photo-chemical waste from the nearby Agfa (later: ORWO) film factory, and for toxic sludge from a factory that produced synthetic fiber. The chemical waste not only gave the lake a silverish tint but also resulted in a growing accumulation of sludge containing hydrogen sulfide, which emitted a noxious odor. Since the environmental degradation was not addressed, nearby residents suffered not only from the horrific stench but also from health problems, including respiratory tract irritation. After 1992, the discharge of chemical waste was halted, and the cleanup of the lake began.