Dispersion of chlorine at seven southern California coastal generating stations

The objectives of this study were to (1) determine chlorine concentrations and exposure time gradients of chlorine through seven coastal generating stations and (2) assess the dispersion characteristics of chlorine in the receiving waters. Remarkable variability in chlorine injection concentrations, condenser outlet concentrations, outfall concentrations, and dissipation rates between generating stations and, to a lesser extent, between surveys at the same generating station was found in this chlorine monitoring study. Other than quite consistent low injection and correspondingly low outfall concentrations at San Onofre (a generating station that had one of the more rigorous chlorine control and minimization programs in effect at the time), no recognizable patterns of chlorination could be discerned in the data. Over half of the outfall chlorine surveys had chlorine concentrations below 0.08 mg/L, which is the accepted level of detection for the titrator being used in the surveys. The post-outfall dilution calculations further showed that the chlorine that does enter the receiving water is initially diluted with entrained ambient water at a ratio of 5.2:19.0