Cows Observe Researchers (IMAGE) Drexel University Caption The impact of agricultural best management practices and urban stormwater control measures is mostly perceived; data is undocumented -- or simply missing. Credit The Academy of Natural Sciences of Drexel University Usage Restrictions per this release 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.