Surface Water Staff from the Bandera County River Authority and Groundwater District collected water samples from sites along the Medina River, Medina Lake, Sabinal River and their tributaries to assess levels of E. coli bacteria on Dec. 20.E. coli is a bacteria found in the gut of warm-blooded animals and is known to potentially cause illness in humans if ingested. No primary contact recreation should take place if the number of E. coli exceeds 399 most probable number per 100 mL of water.This standard is set by the Texas Commission on Environmental Quality in the Texas Administrative Code (30 TAC §307.7).Meaning, no one ...