| Abstract: | ABSTRACT: Two computer models, the Continuous Stormwater Pollution Simulation System (CSPSS) and the Computer Optimized Storm-water Treatment Program (COST), were developed to aid in performing water quality planning. This paper describes COST and its site specific applications to the Philadelphia urban area, using the results from an updated CSPSS receiving water simulation. COST provides a planning and conceptual design tool to identify the economically optimum combination of wet weather and dry weather pollution abatement alternatives. Economic analysis procedures incorporated are based on production theory and marginal cost analysis. This study demonstrates that by transforming BOD removal to reduction in low DO events, using CSPSS results, the benefits associated with pollutant removal can be accounted for explicitly by COST simulations. This is important because a pound of BOD removed from combined sewer overflow may be of more benefit to the receiving water than a pound of BOD removed from urban stormwater runoff. The selection of a pollution control strategy is often a difficult decision which should consider social, political, financial, and regulatory factors. It is suggested that such a selection can be based on evaluating the tradeoffs between total annual costs and receiving water improvements, as determined using the COST and CSPSS programs. |
