Urban Evolution and Aging Infrastructure (IMAGE) University of Maryland Caption Eroding stream banks and aging sewer lines contribute to evolving water pollution problems in cities. In this photo from Baltimore, Maryland, a sewage pipe that was originally placed in a stream bed developed leaks, and is now surrounded by a concrete casing. Credit Tamara Newcomer Johnson, University of Maryland Usage Restrictions None 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.