Evaluation of Climate Change Impact on Drinking Water Treatment Plant Operation

This paper describes a technique for evaluating the impact of climate change on drinking water treatment operations and for applying engineering principles to minimize those impacts. The U.S. Environmental Protection Agency (USEPA) Water Treatment Plant model was modified, validated, and applied to a case study based on the Greater Cincinnati Water Works' Richard Miller treatment plant to provide quantitative measures of these impacts. Multivariate Monte Carlo experiments were executed to simulate and track performance of the Miller plant subject to nine jointly distributed source water quality parameters under both current and potential future hydrologic conditions. Results from the case study indicate a risk that finished water may exceed critical total organic carbon (TOC) levels, leading to potential violations of disinfection by-product regulations under plausible future scenarios. The future risk, however, can be managed with operational adjustments at the water treatment plant, such as increasing the frequency of granular activated carbon reactivation. Utility costs associated with the operation adjustments were expressed as cost curves. The approach presented in this paper can be useful for evaluating climate change impacts and for planning infrastructure and operational adaptation. (C) 2014 American Society of Civil Engineers.