Hundertwasser and Bernd Lötsch visit scientist Käthe Seidel at a demonstration plant
ca. 1985
Bernd Lötsch
Hundertwasser Archive
Friedensreich Hundertwasser
Käthe Seidel

Seidel , Waste water , Wastewater treatment , Plant purification plant

Käthe Seidel made pioneering work in biological wastewater treatment