The stretch from the Boulevard Bridge to just upriver from the Mayo Bridge — an area popular with paddlers, waders and swimmers — was listed as polluted with mercury and the long-banned pesticides DDT and chlordane.
That stretch already was known to be polluted by fecal bacteria, primarily from the waste of wildlife and upriver cattle, among other sources.
DEQ spokesman Bill Hayden said the additional pollutants don’t pose a threat to people in the river. They primarily mean that eating fish from that stretch could be unsafe.
Gerel said, “More than likely all this has been there forever, and we just haven’t caught it” until now.