Agenda - 02-16-2021; 4-b - OWASA Annual Update Presentation

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Information on OWASA's Long-Range Water Supply Plan 16 January 29,2021 Page 10 o Recommendation: Eliminate from further evaluation since it is not legal • Alternative 9: Direct Potable Reuse—Under this alternative, additional treatment would be constructed at the Mason Farm WWTP and treated water would then be pumped directly to our distribution system. Two methods of treating the reclaimed water were identified: (1)use of carbon(generally preferred since typically lower capital and operating/maintenance costs) and(2)reverse osmosis—may be required to removed total dissolved solids. o Recommendation: Eliminate from further evaluation since it is not legal OWASA considered four main demand management alternatives based on research and stakeholder engagement with the Towns and UNC Chapel Hill. Three of these alternatives involve the use of reclaimed water and one is a series of programmatic demand management strategies that collectively had the potential to reduce water demand to a degree that could delay the need for additional supply. • Alternative 10: Reclaimed Water to UNC Cogeneration Facility—This alternative involves the installation, operation and maintenance of new infrastructure that would enable UNC to use RCW instead of drinking water at its Cogeneration Facility. o Recommendation: Eliminate from further evaluation due to very high capital cost per gallon of water saved and UNC concerns about quality requirements • Alternative 11: Expanded Reclaimed Water Use at UNC Main Campus —This alternative involves expanding the use of reclaimed water on UNC's campus to meet certain non-drinking water demands in new buildings envisioned in the University's recently updated Master Plan. o Recommendation: Eliminate from further evaluation due to high life cycle cost per gallon of water saved • Alternative 12: Onsite Wastewater Treatment and Reuse—This alternative evaluated the use of reclaimed water systems to meet non-drinking water needs at the building or major development scale. o Recommendation: Eliminated from evaluation due to high capital and life cycle costs per gallon of water saved • Alternative 13: Programmatic Demand Management Strategies—Four alternatives were evaluated: o Alternative 13a: Unit Submetering and WaterSense Installation—Multi- family development is projected to be a significant area of water use growth in our service area. Sub-metering will help to ensure that the users of water within those developments are aware of the amount of water they use. This strategy was coupled with a requirement for developers to use high efficiency WaterSense fixtures. The impact was assumed to be relatively minor because most new developments are installing submeters without a requirement. o Recommendation: Eliminate from including as long-range water supply option because of minor impact on water use; consider as part of Water Conservation Plan