Customizing Climate Change Adaptation at Drinking Water Treatment Plants

Abstract

Climate change may adversely affect source water quality and therefore impact the design and operation of drinking water treatment plants. Many water utilities are concerned about the effect of climate change on the operation and sustainability of their drinking water treatment infrastructure. The USEPA Water Resources Adaptation Program (WRAP) has studied this effect through a water treatment plant simulation model (WTP model) and demonstrated that the risk of violating total organic carbon (TOC) guidelines in finished water under potential future scenarios at the Richard Miller water treatment plant in Cincinnati could be managed by modifying the operation of the existing granular activated carbon (GAC) unit. In this initial work, TOC removal at the GAC unit was controlled by adjusting the GAC reactivation period. In reality, however, TOC removal can be also affected by site-specific factors such as contact time, type of GAC, and structure of contactors. As a follow-up investigation, this paper demonstrates how site-specific treatment studies can be used to customize simulation algorithms for GAC units at municipal water treatment utilities. Results from simulation of the Richard Miller treatment plant demonstrate that customized models offer a measurable improvement over the general statistical approach used in the existing WTP model. These findings can help utilities define practical plans to control TOC removal at GAC units and adapt to changes in source water quality.