Processing water samples (IMAGE) Penn State Caption Lab technician Bill Clees filters a wastewater effluent sample in the Natural Resources Engineering laboratory to prepare it for pharmaceutical analysis. Credit Heather Preisendanz, Penn State Usage Restrictions Educational use only License Original 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.