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• Ion Exchange (IX) Treatment o Primarily removes PFAS by exchanging it for a benign ion as water is passed through a resin media. o In general, requires less media and thus vessels on a per unittreatment basis when compared to GAC treatment. However, the unitcostof media is more expensive than thatused in GAC. o Once the resin media can no longer sufficiently remove PFAS, the media and PFAS are typically incinerated and destroyed. 3. A oreliminary life-cvcle cost was performed with the followina results: Treatment Goal Cost IX GAC High Capital (millions) $5.0 $5.7 Annual O&M (millions) $0.15 $0.12 Net Present Value (millions) $7.8 $7.9 Medium Capital (millions) $11.7 $12.7 Annual O&M (millions) $0.35 $0.32 Net Present Value (millions) $18 $19 Low Capital (millions) $11.7 $12.7 Annual O&M (millions) $0.60 $1.5 Net Present Value (millions) $23 $41 4. Key cost assumptions forthe above life -cycle costs include: • Dedicated treatment is assumed at Well 5/6 site and Well 8 site. • The High Treatment Goal requires PFAS treatment at Well 8 only. • Vessels are outdoors (i.e. no building). • Other required Well 5/6 and Well 8 repair and replacement improvements (not related to PFAS treatment) are not included. • Net present value (NPV) is the estimated dollarvalue of a project based on initial costs (i.e. capital) and future costs (i.e. annual O&M) that are discounted to the present. It provides a method forfinancial evaluation and comparison of capital projects with cash flows spread overtime. The net present values shown in the estimates above are based on 30 years. 5. Key findings from the evaluation include: • Construction costs of PFAS treatment facilities at Well 5/6 and Well 8 are not significantly impacted by treatment goal selection. The exception is with the High Treatment Goal where treatment at Well 5/6 may not be required due to current detection levels. O&M costs do vary based on treatment goal selection, primarily due to differences in frequency of media replacement. Page 5 of 9