Regional Issue Identification and Assessment Program (RIIA). Issue Paper 4. A Methodology for Analyzing the Water Quality Impacts of Cooling-Tower Blowdown

摘要

In a manner similar to that of a boiling teapot, the concentration of substances discharged by a power plant cooling tower (i.e., blowdown) may increase above permissable levels, despite the fact that no additions be made to intake waters. This phenomenon is captured in the design concept referred to as the cooling tower concentration factor, and raises several interesting legal questions. An approximation is presented for the water quality in cooling tower blowdown based upon the concentration factor and a mixing zone comprised of some fraction of the total river flow. The method avoids problems associated with the use of average loading rates. Several examples are given based upon existing and proposed power plant sites. Regulatory ramifications of the concentration phenomenon are discussed in terms of energy facility siting options. (ERA citation 06:010860)