City of Nampa Wastewater Program Nampa WWTP Phase II/III Preliminary Design: Design Review Committee #3 November 15, 2018 Agenda 1. Introductions 2. Industrial Capacity Review 3. Energy Recovery/Production Opportunities and Economics 4. Capital Costs Comparison 5. Secondary Treatment Technology Evaluation 6. Tertiary Treatment Technology Evaluation 7. Project Delivery and Package Options 8. Parallel Path Update 9. Next Steps Design Review Committee #3 2 Design Review Committee #2 Meeting Summary • Permitting and Regulatory Requirements • Current & Future Flow and Loadings • Cost of Service Review • Overview of Resource Recovery Options Design Review Committee #3 3 Industrial Capacity Review Design Review Committee Briefing #6 Sources of Current Flow and Loadings • Domestic Contributions - Domestic flows and loads are generated by the general public (residential and commercial), • Industrial Contributions – The Nampa WWTP receives wastewater from several industrial customers categorized as Significant Industrial Users (SIUs). For the purposes of this analysis, it is assumed that all industrial dischargers use their full flow and capacity allotment established by the City’s Industrial Waste Acceptance (IWA) permits as a conservative approach. • Infiltration and Inflow – Infiltration and inflow flows are a combination of those influenced by irrigation and those influenced by storm events (i.e. non-irrigation). • Future Domestic Contributions – The City has made future capacity commitments to developers through the platting and building permit processes. Until these structures are occupied, this capacity is not realized as influent to the Nampa WWTP but must be accounted for within the allocated flow and loadings. • Vacancy Allowance – The City’s policy has been to assume that an additional 5 percent of the current domestic flow and loadings are allocated to vacant properties. Design Review Committee #2 5 Current Nampa WWTP Flow and Loadings 100% 16% 18% 90% 23% 29% 80% 39% 70% 60% 50% 40% 30% 20% 10% 0% Flow BOD TSS TKN TP Domestic Industrial Infiltration and Inflow Future Domestic Contributions Design Review CommitteeVacancy #2 Allowance Unallocated Maximum Month 6 Allocated Capacity & Planning Process WWTP Capacity = Domestic + Allocated Industrial Population and water Based on IWA Permit terms usage dependent • All industrial dischargers are assumed to use their full capacity allocations at all times during the year • Actual used industrial capacity often is below the allocated portion (recently, 30 – 40% of allocated capacity is actually used) Design Review Committee #3 7 Allocated vs. Used Capacity Design Review Committee #3 8 Allocated vs. Used Capacity Design Review Committee #3 9 Allocated vs. Used Capacity Design Review Committee #3 10 Allocated vs. Used Capacity Design Review Committee #3 11 Table 1. Comparison of Allocated and Utility Industrial Capacity Maximum 30-Day Rolling Permitted Maximum Month Percent Utilization of Permitted Year Average Capacity Maximum Month Capacity 2016 2.38 2.82 84% Flow 2017 0.82 2.82 29% (mgd) 2018 0.87 2.82 31% 2016 7,015 20,554 34% BOD 2017 7,531 20,554 37% (ppd) 2018 8,868 20,554 43% 2016 4,192 10,661 39% TSS 2017 3,258 10,661 31% (ppd) 2018 4,278 10,661 40% 2016 1,040 1,940 54% TKN 2017 593 1,940 31% (ppd) 2018 884 1,940 46% 2016 50 350 14% TP 2017 22 350 6% (ppd) 2018 67 350 19% Design Review Committee #3 12 Factors Leading to Capacity Differential • Allocated capacity assumes all industrial dischargers are sending full allocation, at the same time • Industrial discharges are often seasonal, below their full allocation, and are not in alignment between industries • Balance between providing certainty (and value) to purchased capacity versus unused capacity • Simplot retains unused capacity within the system • The Capacity Optimization Fee (COFee) helped optimize industrial capacity use and allocations • Some industries opted to retain capacity for future growth (and pay the COFee) Design Review Committee #3 13 Factors Leading to Capacity Discrepancy What if Simplot’s capacity were given back to the City? Impacts to Capacity Utilization Percent Utilization of Permitted Percent Utilization of Permitted Year Maximum Month Capacity Maximum Month Capacity (including Simplot) (Simplot removed) 2016 84% 109% Flow 2017 29% 37% (mgd) 2018 31% 40% 2016 34% 53% BOD 2017 37% 57% (ppd) 2018 43% 67% 2016 39% 86% TSS 2017 31% 67% (ppd) 2018 40% 88% 2016 54% 79% TKN 2017 31% 45% (ppd) 2018 46% 67% 2016 14% 45% TP 2017 6% 20% (ppd) 2018 19% 61% Design Review Committee #3 14 Design Review Committee Considerations The Preliminary Design Technical Team will continue to progress with the preliminary design based on the flow and loading projections from the Facility Plan until otherwise directed. This DRC briefing is intended to be informational to the committee as the preliminary design process advances. Design Review Committee #3 15 Energy Recovery/Production Opportunities and Economics Design Review Committee Briefing #7 Energy Recovery Opportunities Generating Value from Biogas • Two primary means for generating value from biogas • Sale of renewable natural gas (to pipeline) • Sale of Renewable Identification Numbers (RINs) • Value does not come without consequences • Capital and operating costs to make biogas “pipeline quality” • Purchase of natural gas to offset loss in biogas use for in-plant demands • Early analysis has shown relatively short (~12 year) payback periods for these investments Design Review Committee #3 18 Value of RINs • RINs sales account for approximately 8X the value of RNG sales • Preferred approach is sensitive to value of RINS • Current value is approximately $2.50 per Gallon Ethanol Equivalent (GEE) Design Review Committee #3 19 Recommendation This briefing is intended to provide an overview of the general economics associated with biogas recovery. If this is a topic that the DRC is interested in pursuing further, the Preliminary Design Technical Team recommends developing an evaluation of potential biogas recovery opportunities and selecting the opportunity that is most favorable economically for the City. These opportunities could include cogeneration, biogas recovery for vehicle fueling, and biogas recovery for pipeline injection. Each of these opportunities would require additional capital costs. The DRC could then elect in the future to recommend pursuing the preferred approach to biogas recovery by increasing the overall Program budget or through cost savings realized on other parts of the project. Design Review Committee #3 20 Capital Cost Comparison Design Review Committee Briefing #8 Design Review Committee #3 21 Capital Cost Approach • Developed during the facility planning process • Equipment manufacturers • Local commodity (e.g. chemical) pricing • Local labor prices • Markups capture the fully-loaded cost of a project • Markups nearly double raw costs based on level of estimate Design Review Committee #3 22 Cost Estimate Limitations Cost Estimate Classification System Class 4 Class 3 Level of Project Definition 1% to 15% complete 10% to 40% End Usage Concept Study or Feasibility Budget, Authorization, or Control Accuracy Range Low: - 30% Low: - 10% High: + 50% High: + 30% As applied in Engineering, Procurement, and Construction for Process Industries; adapted from American Advancement of Cost Engineering (AACE) International Design Review Committee #3 23 Potential Consequences: Cost Estimating Contingency • Used to account for undefined scope of work, unforeseen conditions, and changing More Contingency Less Contingency economic factors • These unknown variables cannot be Planning Stage Construction captured in each of the markups (labor, Stage contractor overhead & profit, etc.) • AACE International specifies 30% as the appropriate level of contingency – this was Contingency reduces with level used in the Facility Plan of Project Definition Design Review Committee #3 24 Programmatic Contingency • Contingency Goals: • Provide adequate funding to complete planned work • Account for programmatic risks • Contingency funds are only used when needed and approved by City leadership • Current Program Contingency = $19,285,511 (future $) • Developed using a risk register – considers Process, Regulatory, Repair and Replacement, Construction and Policy risks Design Review Committee #3 25 Programmatic Contingency Known Costs (Capital Costs) + Known Unknowns (Cost Estimating Contingency) Unknown Unknown Costs (Programmatic Contingency) Total Program Costs Programmatic contingency represents funds that can be used to address potential risks for capital program during design and construction Design Review Committee #3 26 Impacts of Inflation • Inflation impacts the overall project cost over time 2017 Program-Level Future Program-Level Estimated Cost: Estimated Cost: $150.1 M $213.1 M Inflation Cost Impact = $59.4 M 44% Increase in Program-Level Cost Design Review Committee #3 27 Secondary Treatment Process Evaluation Overview of Options for Secondary Treatment Secondary Treatment Alternatives • BCE Alternatives: • Alternative 1: Base Case (Expand Existing) • Alternative 2: Secondary Nitrification and Denitrification • Alternative 3: Membrane Bioreactor (MBR) • Alternative 4: BioMag • Alternative 5: Design Review Committee #3 29 Alternative 1: Expand Existing Process Alternative 1: Expand Existing Process 4th Aeration Basin Alternative 2: Alternate process configuration SND Alternative 2: Alternate process configuration SND Update diffusers and mixing in all 4th Aeration