27.03.2026, Germany, Berlin - View of an aeration tank at the Ruhleben sewage treatment plant. These tanks belong to the biological treatment stage of the wastewater treatment. 00R260327D129CAROEX.JPG [MODEL RELEASE: NOT APPLICABLE, PROPERTY RELEASE: NO (c) caro images / Ruffer, http://www.caro-images.com, [email protected] - In case of using the picture for any purpose, please contact the agency - the picture is subject to royalty!]