AWWA WQTC69339

This powerpoint presentation begins by providing a brief overview of solving water quality problems in Texas, tracking fecal pollution, total maximum daily loads (TMDLs) and bacterial source tracking (BST), and targeting E. coli. Specific study objectives include: determine human and animal sources of E. coli fecal pollution of watersheds; develop publicly available BST libraries; evaluate method precision and accuracy; compare BST methods; and, provide a foundation for future BST studies. The experimental approach included the following: E. coli isolation from samples using the same media for compliance water monitoring; U.S. Environmental Protection Agency (USEPA) Method 1603 - modified mTEC medium; confirmation of ß-D-glucuronidase activity of isolates using NA-MUG; and, no broth enrichment or clinical media, avoid selecting different populations of E. coli. Presentation conclusions indicate the following: four-method composite data set had the highest accuracy; two-method composites better than any single method - ERIC-RP or ERIC-ARA; moderate accuracy and confidence in results - need to improve; and, Lake Waco and Belton Lake, wildlife leading pollution source (~40%), while cattle were ~20%. Includes tables, figures.