A long, cool drink of water and a quick dip in the local watering hole—that sure is refreshing on a hot summer day in Texas. Thanks to researchers at the Texas Agricultural Experiment Station in El Paso (TAES), it just got easier to ensure water from certain rivers and lakes are drinkable and safe for recreational users.

  Two state agencies tasked the TAES with using lab analysis to pinpoint whether agricultural activities, wildlife, or humans were responsible for particular bacteria found in specific watersheds. Using state-of-the-art DNA fingerprinting—commonly depicted on forensic-crime-scene television dramas—and antibiotic resistance typing methods for E. coli bacteria, researchers identified the sources of bacteria affecting numerous bodies of water in Texas. TAES used its cutting-edge analysis methods on water samples collected from the watersheds of Lake Waco and Belton Lake, the Upper and Lower San Antonio River, Salado Creek, Leon River, and Peach Creek—all classified as “impaired” due to high levels of E. coli bacteria, potential indicators of fecal pollution.

  Results showed that wildlife accounted for the greatest number of E. coli bacteria in the samples, with cattle being the second greatest contributor, and human sewage ranking third. Now, resource managers in those watershed areas can recognize and outline specific pollution control strategies that can reduce fecal pollution, ensure safe sources of drinking water, and give recreational users peace of mind.

  An additional benefit from the project work includes the first step toward developing a statewide genetic library of E. coli bacteria associated with known sources, which could be the first publicly available library of its kind. Sharing the library with researchers across the state—and ultimately nationwide—may save millions of dollars on similar bacteria-tracking projects in the future.