· No
environmentally significant trends in water quality were detected
through visual assessment of the data.
· Fecal coliforms at
times exceeded the site-specific objective designed to permit
drinking water use after partial treatment and disinfection. It
appears that complete water treatment and disinfection are needed,
and that consumption during spring freshet should be
avoided.
· Periphyton
chlorophyll-a (a measure of attached algal growth)
consistently exceeded the site-specific objective to protect
recreation and aquatic life. Dissolved phosphorus levels were
elevated, indicating an ample supply to support algal
growth.
· Non-filterable
residue (suspended solids) and turbidity were often elevated during
spring freshet, and site-specific objectives were regularly not
met. Turbidity removal (complete water treatment) and disinfection
or remediation are needed before drinking water use.
· The pH was
slightly high for drinking water, possibly affecting chlorination
effectiveness and causing encrustation and scaling.
· The river was well
buffered against acid and metal inputs.
· Hardness levels
during the winter were poor for drinking water aesthetics, but
still tolerable.
· The variables that
exceeded criteria during spring freshet were: aluminum, chromium,
copper, iron, manganese, titanium and zinc. These metals were
largely associated with high levels of turbidity and suspended
sediments, suggesting that they were in particulate form, probably
not biologically available, and would be removed by the drinking
water treatment needed to remove turbidity.