projects described by these authors have not yet been completed, so convincing evidence of success must await studies of the actual impacts of those designs. Nevertheless, the designs appear to satisfy the particular ecological constraints that served as design criteria.
Strang and Sage (this volume) describe a similar collaboration, but one with a 30-year track record. Since 1965, Eastman Chemical Company (and its predecessors) has worked closely with aquatic scientists from the Academy of Natural Sciences in Philadelphia to improve the environmental performance of the Tennessee Eastman Division, a facility that releases effluents to the South Fork Holston River. Staff members of the Academy of Natural Sciences periodically assess the condition of the river. Eastman personnel then use the assessment results to help determine what specific objectives are appropriate for efforts to improve environmental performance. As Eastman modifies facilities and practices to improve performance, subsequent studies by the Academy of Natural Sciences document resulting changes in the river's condition. This procedure, which depends on a strong collaboration between corporate managers and aquatic ecologists, has led to a long record of continual improvement in both environmental performance and ecosystem condition. Eastman used what it learned from the Tennessee Eastman Division to design facilities on the White River in Arkansas. Studies of that river by the Academy of Natural Sciences have shown no differences between the ecosystem conditions upstream and downstream from the Eastman plant.
The close relationship between the properties of liquid effluents and the condition of receiving waters undoubtedly facilitated the success of the collaboration between Eastman Chemical Company and the Academy of Natural Sciences. Many other situations involve a less direct connection between environmental performance and ecosystem condition. Nevertheless, Strang and Sage's account confirms the potential for progress in environmental performance and ecosystem condition when corporate managers and environmental scientists collaborate closely.
This volume is intended to facilitate that progress by reporting on a variety of important metrics that have been developed to assess environmental performance and the condition of ecosystems. Our hope is that the discussion of these various indicators in one volume will foster not only further refinement of the particular measurement techniques but also more communication between users of the two sets of measures so that examples such as the one described by Strang and Sage will accumulate rapidly. The remainder of this chapter provides a brief summary of some of the important metrics that are used to assess environmental performance and ecosystem condition.
Measurement methods are being developed for a variety of purposes, from tracking the impact of a soda can to gauging the performance of national economies.