Bacteriological Assessment of the Lower San Antonio River

Citizens in the lower portion of the San Antonio River Watershed have expressed concerns about bacteria levels in the San Antonio River and asked that the San Antonio River Authority address their concerns. Many felt that the City of San Antonio was the principle source of the bacterial concerns on the lower San Antonio River (Segment 1901). However, since water quality data showed that the stream standard for contact recreation was generally being met at sites on the San Antonio River from I-37 in Bexar County to FM 791 in Karnes County , it was likely that the concerns identified in the lower portion of the River had other sources. Therefore, this study was designed to concentrate its limited resources on Segment 1901. Segment 1901 encompasses the area from the confluence with the Guadalupe River in Refugio and Victoria Counties to a point approximately 600 meters downstream of the FM 791 bridge near Falls City , Texas in Karnes County . Limited fecal coliform bacteria data has identified several areas where the State stream standard for contact recreation has occasionally not been met in this segment, and the segment has been placed on the Texas 2002 Clean Water Act Section 303(d) List of impaired water bodies. This study was designed to collect and analyze surface water samples from the lower San Antonio River in order to identify reaches that may, or may not, be meeting the State stream standard for contact recreation, and attempt to identify the source(s) of bacterial contamination.