Some effects of pulp and paper wastewater on microbiological water quality of a river

A study was conducted to detect the source of fecal indicator bacteria and measure the resulting impairment of water quality of the Sturgeon River at Sturgeon Falls, Ontario, Canada. The bacteriological water quality of the river above the dam at Sturgeon Falls was fairly good, while below the dam the water quality was degraded. The principal input of fecal indicator bacteria was traced to the paper mill at Sturgeon Falls. The impairment of water quality was detected all the way to recreational areas near the mouth of the river. The impaired stretch of the river had diminished aesthetic appeal. Other sources of indicator bacteria could be masked by the large numbers of similar bacteria discharged from the paper mill. The principal fecal coliform was Klebsiella pneumoniae. In pulp mill wastes the fecal origin of this bacterium can be disputed, and so its presence in large numbers interfered with the interpretation of fecal coliform results. K. pneumoniae is also an opportunistic pathogen which causes infections in humans. Thermotolerant oxidase positive bacteria which were isolated from the paper mill wastes, register as false positives in the fecal coliform test causing problems in interpretation. Pseudomonas aeruginosa was detected in the pulp mill wastewater, and at a level of 82 PA 100 ml⁻¹ in recreational areas of the river. This was considered to be of some hazard to users of the water. In addition, Escherichia coli was detected in the mill wastewater, at about 200 EC 100 ml⁻¹, and this probably indicated some measure of fecal pollution though likely of animal origin. Finally the nutrient rich wastewater led to an approx. 50-fold increase in density of aerobic heterotrophic bacteria in the river water, as well as the production of a slimy filamentous growth on surfaces, stones and wooden pilings, in the river. The principal organism in this slime was the fungus Leptomitus.