However, where it is demonstrated that recreational use is highly unlikely due to shallow depths or other factors that make a stream physically impossible to swim in, and, no public water supply exists on the stream within a distance of concern, sewage treatment plants may obtain an exemption from disinfection. No bacteria standard applies in these receiving streams. The rule expressly protects all recreational waters and tributaries that may threaten these waters. Effluents to these waters must be disinfected and then dechlorinated. A site-specific review process is applied to all dischargers seeking disinfection exemptions to ensure that potential or existing recreation is protected.
Animal waste is everywhere.
These fecal coliforms and potential tagalong organisms enter streams and lakes by a route known as non-point source pollution. Rainfall washes feces into the water where the bacteria persist for a time. This prospect isn't a new problem. Imagine what happened when a thunderstorm hit after a herd of bison finished grazing next to a stream in pre-settlement Illinois. You get the picture.