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particularly DeWitt wellfield expansion, more detailed analysis will be required to <br /> estimate yields. <br /> 4. ALTERNATIVES ANALYSIS <br /> Based on our updated analysis of the potential of various water supply options, we will <br /> develop conceptual projects for further analysis. Each conceptual project will include <br /> basic design parameters, construction and operating costs, life-cycle costs per acre-foot <br /> or million gallons, and identification of non-economic risks and benefits, with a level of <br /> detail like that provided for the 2019 study. We will review and update previously <br /> developed conceptual projects and will develop new projects for new or significantly <br /> updated supplies, including for example, a pipeline route and sizing from the Harristown <br /> Pit to the SWTP raw water intake building. We will review the triple bottom line (TBL) <br /> criteria developed for the 2019 report with City staff and will revise and refine the criteria <br /> as needed. Individual projects will be evaluated and ranked based on the TBL criteria. <br /> Conceptual projects will be combined into portfolios that address the projected demand <br /> thresholds developed in Tasks 1 and 2. Portfolios will be evaluated to identify those that <br /> are optimal for each of the demand thresholds. We will identify those projects that are <br /> complementary to each other and those that are beneficial under multiple demand <br /> thresholds. <br /> 5. DROUGHT OPERATIONS <br /> Western Hydrologics(WH), nationally recognized experts in drought management,will be <br /> contracted to update the drought operational rules and action triggers. WH recently <br /> completed a drought emergency table-top exercise. That exercise provided a new <br /> understanding of risk tolerance. For this project, a contrast will be made between the <br /> decisions made during the exercise on topics like lake storage and the invocation of <br /> triggers versus current drought action rules and triggers. The timing and extent of <br /> corrective action will be used to guide development of a drought action plan capturing <br /> new triggers and associated actions. <br /> 6. COORDINATION WITH RELATED PROJECTS <br /> We anticipate communicating with Decatur's engineering consultant selected for <br /> developing the City's 2026 SWTP Water System Expansion Plan as the portfolio of <br /> alternatives is developed. Regular meetings with Illinois State Water Survey (ISWS) <br /> groundwater modelers will be necessary to clearly establish objectives and assess <br /> outcomes from selected operational scenarios of the DeWitt County wellfield including <br /> potential wellfield expansion. <br /> 3 <br /> Last Revised:2/03/2022 <br />