The feasibility of using biological monitoring of industrial point sources as a tool for river management has been demonstrated by a number of laboratory simulations. However, it is another task entirely to move these techniques to an industrial setting. The necessary modifications of a computerized biological monitoring system to install it in the Celanese Corporation Plant on the New River in Virginia are described. The system employs the respiration rates of bluegills (Lepomis macrochirus) as an indicator of abnormal variations in the effluent.