PROJECT OVERVIEW Liquids Stream Solids Stream Potential Area for Solids Stream Improvements Liquids just upgraded, but solids stream untouched as part of project. Because of aging, the incinerators need to be replaced. City taking the opportunity to look at replacement options beyond “in kind” and ones that offer resource recovery opportunity, which is in keeping with City environmental ethic. <UPDATE SCHEDULE TO SHOW 2018-2020: Permitting and Design 2021-2023: Construction> Brown and Caldwell

Existing Solids Stream Process Centrifuge to dewater solids Ash to landfill disposal Aging incinerator Brown and Caldwell

Resources Biogas as fuel for cogeneration Biosolids – Manufactured Topsoil Biogas - Vehicle Fueling Station Brown and Caldwell 3

Land Application (e.g., “loop”) ALTERNATIVES Boiler Land Application (e.g., “loop”) Anaerobic Digester Brown and Caldwell

High Level Screening Alternatives and Results Solids Stabilization Anaerobic digestion Aerobic digestion Lagoons Alkaline stabilization Composting Incineration Gasification Pyrolysis Hydrothermal Liquefaction Supercritical water oxidation Primary End Use Land application (e.g., loop) Soil Amendment (e.g., composting, TAGRO) Dried fertilizer product (e.g., SoundGRO) Dried fuel product Landfill Liquid fertilizer Bioplastic production Alternative fuel products Primary Biogas Use Cogeneration Power Process and Building Heating Gas Upgrading Vehicle fuel Pipeline injection Boiler Flare Brown and Caldwell

TBL+ Criteria Environmental Financial Social Technical (Healthy Environment) E1 – Minimize Carbon Footprint E2 – Protect Air Quality E3 – Maximize Resource Recovery E4 – Minimize Energy Usage E5 – Protect Local Habitat Financial (Quality, Responsive Services, Vibrant Sustainable Economy) F1 – Optimize System Value F2 – Maintain Affordability F3 – Minimize Market Sensitivity Social (Sense of place, Safe and Prepared Community) S1 – Minimize Noise S2 – Minimize Odor S3 – Minimize Truck Traffic S4 – Minimize Visual Impacts S5 – Minimize Toxin Exposure Technical (Quality, Responsive City Services) T1 – Proven Reliability T2 – Minimize Post Point Impacts T3 – Maintain Flexibility T4 – Minimize Complexity