E. coli bacterial concentrations did not approach hazardous levels in the most recent water quality assessments performed by the Bandera County River Authority & Groundwater District, but that should not suggest that the Medina and Sabinal rivers are safe for swimmers to get in again, the authority’s general manager said last week.
BCRAGD General Manager David Mauk said despite the E. coli readings from water quality tests on Aug. 22, hot, dry conditions still make swimming and other recreational contact with the rivers hazardous.
Searing heat, which has pushed temperatures in the rivers into the high 80s, and little or no rainfall to get water flowing in both rivers continue to create unhealthy conditions and have convinced officials to keep the warnings advising visitors not to swim in the rivers in place, Mauk said.
Those warnings were first issues on Aug. 15.
“There could be a lot more stuff out there than E. coli,” he said. “Until we get meaningful rain, I would not get back into parts of the river that are not flowing.”
The Texas Commission on Environmental Quality has set a standard saying E. coli readings in excess of 399 most probable number – or MPN – per 100 milliliters of water are the point at which swimming and other “primary contact recreation” should cease in waterways where those readings were recorded.
The E. coli readings near the Highway 173 bridge on the Medina River in city park exceeded that level twice in June before falling to safer levels and got close to the hazard level at the city park intersection with First Street in Bandera in June and July before falling.
In the most recent measurements on Aug. 22, the highest E. coli readings among 11 sited tested were in city park at the Highway 173 bridge and at First Street, but the counts did not exceed 150 MPN at either spot.