Biosensing for the protection of water quality

This paper reports that Weyerhaeuser's Rothschild sulfite pulp and paper facility produces approximately 150 a.d. tons/day of pulp and 350 tons/day of fine paper. The wastewater receives secondary treatment in an activated sludge system for removing solids and reducing the biochemical oxygen demand (BOD{sub 5}). The BOD{sub 5} is reduced nearly 98% across the secondary system. The final effluent is discharged into the Wisconsin River. After extensive field work, the Wisconsin Dept. of Natural Resources (DNR) developed the Qual III model to represent the assimilative capacity of the Wisconsin River. Using both the Qual III model and guidelines set forth in Section 208 of the Water Pollution Control Act of 1972 (PL 92-500), the agency developed allocations restricting the discharge of BOD{sub 5} wasteload. This paper reports that as a result of the DNR modeling, the Rothschild facility has been under a variable restriction on BOD{sub 5} since 1983. The restrictive period is May through October, with daily BOD{sub 5} discharge limits of between 1360 and 7711 kg/day. Discharge limits change daily based on the receiving water flow, the water temperature, and the allocation period. Industrial companies that discharge effluent to the Wisconsin River system have a serious problem whenmore » the river flow is moderated to low and their final effluent BOD{sub 5} loadings begin to approach the wasteload limits.« less