Economic and Biologic Benefits of Cooling Tower Retrofits

One possible outcome of the ongoing 316(b) regulatory process could be a requirement to install cooling towers at all existing Phase II facilities nationwide. Such a regulatory requirement would substantially reduce current levels of entrainment and impingement but would do so as at considerable costs and potentially produce other environmental impacts.  As part of a large project to evaluate the environmental and economic trade-offs resulting from such a regulatory outcome, we estimated the benefits of cooling tower retrofits resulting from expected reductions in entrainment and impingement.  These benefits were defined in both biologic (fishery yield and biomass production) and economic terms.  This estimation process began with determining benefits of cooling tower installation at 50 representative facilities nationwide.  These benefits were estimated based on recent entrainment and impingement monitoring data using standard population modeling and resource economics techniques. In addition to the most probable estimates, both sensitivity and Monte Carlo techniques were used to evaluate the uncertainty in these results. The results from this estimation process were combined with estimates of biologic and economic benefits developed for other facilities to project the biologic and economic benefits on a national basis.  The results of this effort will provide a sound basis for comparing the costs to the benefits of national cooling tower retrofits on both an environmental and an economic basis.  This paper will provide an overview of the process used as well as examples of results and a discussion on the factors contributing to the wide range in benefits projected to occur across the individual facilities.