This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
THIS SECONDARY SEWAGE TREATMENT PLANT CAN REMOVE UP TO PER CENT OF IMPURITIES BUT SCIENTISTS AIM FOR MORE. FROM... NARA .tif Scope and content General notes Local identifier DA Environmental Protection Agency NARAAuthor Sennett Tomas Photographer File THISSECONDARYSEWAGETREATMENTPLANTCANREMOVEUPTOPERCENTOFIMPURITIES BUTSCIENTISTSAIMFORMORE