Butte County Public Health (BCPH) announced Friday that water and sediment samples collected May 4 from several locations along Big Chico Creek did not detect E. coli O157 following laboratory testing by the State Water Board's laboratory. The testing was conducted as part of BCPH's ongoing investigation into an outbreak of E. coli O157 illness linked to recreational water exposure in the creek during summer 2025. Officials say they will continue consulting with the State Water Board in the coming weeks to determine whether additional sampling and testing for E. coli O157 will be conducted.