Sewage treatment (IMAGE) Cell Press Caption This photo shows part of a sewage treatment plant (Hyderabad, India), which relies on biological processes as a key part of the sanitation process. Credit Simon Wilcock Usage Restrictions Credit required. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.