Technical Bulletin No. 0414: Effects Of Biologically Stabilized Bleached Kraft Effluent On Warm Water Stream Productivity In Experimental Streams – Third Progress Report

In 1974 the National Council initiated the second in a series of aquatic biology field investigative efforts. The objective was to provide a basis for estimating the concentration of kraft mill effluents that would not be expected to directly or indirectly decrease the production of fish. During the seven year period covered by the material in this technical bulletin, the amount of biologically treated bleached kraft mill effluent was increased incrementally on an annual basis, starting with 0.4 ppm BOD added to the experimental streams and finally reaching the level of 2.5 ppm BOD added, or about 15 percent by volume.

The macroinvertebrate biomass and numbers were equally as good or better in streams receiving effluent than the control streams. The total production and biomass of the three test species of fish, golden shiners, bluegill sunfish and bass, was equally as good and frequently better in streams receiving effluent than controls. At effluent concentrations of 1.7 ppm BOD added (9 percent by volume) and greater, the seasonal productivity during spring and early summer, of control streams for bass was slightly greater than those receiving effluent. The spawning success of all three species was not impaired at the levels of effluent thus far tested.