Solids Master Plan Briefing June 22, 2017

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1 Solids Master Plan Briefing June 22, 2017

2 Meeting Agenda Review of Master Plan Process Status Update Technology Selection Budget & Next Steps Discussion

3 Review of Master Plan Process

4 Master Plan Process - Where Are We Now? Ongoing outreach to stakeholders COMPLETED! COMPLETED! COMPLETED! Fall 2015 Prioritize needs Narrow down choices Set and Rank Criteria Condition Assessment Winter 2016 Look at Immediate needs Spring/Summer 2016 Develop Alternatives Final Report Fall Winter 2017 WE ARE HERE Ongoing peer review

5 Solids Master Plan: Evaluation Process Universe of Technologies Screened Technologies and Process Analysis Top 4 Selected Alternatives Ranking and Final Evaluation Workshop 1 - Kickoff and Project Objectives Defined Workshop 2 - Define Screening and Evaluation Criteria Workshop 3 - Technology Identification and Screening Workshop 4 - Process Specific Analysis Workshop 5 Alternative Train Development and Preliminary Findings : Selection of top 4 alternatives Workshop 6 Weighted Criteria Ranking of Alternatives Workshop 7 Final Plan Recommendations Recommended Plan

6 Status Update

7 We ve Been Busy! Fall 2016 Initiated Virginia Tech lab-scale digestion pilot Toured UOSA (Centreville) to learn more about their Solids Handling process Winter 2017 Updated DES leadership on the Solids Master Plan process Met with WSSC (Prince Georges and Montgomery Counties) to learn more about their Master Planning process Held meetings with WPCP staff on the Solids Master Plan status, and solicited feedback on alternatives

8 We ve Been Busy! Spring 2017 Met with County Manager, Mark Schwartz, on Solids Master Plan Presented the Solids Master Plan process to industry leaders Presented to Arlington County community members CivFed, ACE, E2C2, FAAC, NCAC, AHCA Optional Meeting with Stakeholders to discuss emissions, regional solutions, and financing

9 Virginia Tech Study Arlington County partnered with Virginia Tech to research which anaerobic digester operating conditions and dewatering methods resulted in optimized gas production and reduced odors.

10 Virginia Tech Study The results found that Arlington s raw sludge are within the expected range for gas production and methane content. Variables such as dewatering method, polymer dose, and storage time all impacted odor production. The results showed that Arlington s digestion process would be more stable than industry standards.

11 Technology Selection

12 Top Four Alternatives Name Lime Stabilization rehab-only Anaerobic Digestion (AD) Thermal Hydrolysis (THP) + Anaerobic Digestion Biosolids quality Class B Class B Class A Major features What we have now; highest amount of biosolids and trucks; no gas production; odorous Biosolids volume lower; gas production; fewer odors Biosolids volume reduced further; more gas production; fewer odors Anaerobic Digestion + Heat Drying Class A Least amount of biosolids; no net gas production; fewer odors 12

13 Weighted Criteria Ranking Summary ECONOMIC OPERATIONAL ENVIRONMENTAL SOCIAL THP + AD highest on social and environmental Lime AD THP+AD AD+DRY Scores are very close; do not provide clear direction on path forward AD HAS HIGHEST OVERALL SCORE THP+AD IS SECOND OVERALL 13

14 Benefits of THP/MAD Compared MAD Pathogen Reductions: Meets Class A (higher quality) standards Fewer, smaller digesters: Thermal hydrolysis greatly reduces the volume of the digester tanks from 32 Higher rate of methane production: More energy generation Increased dewaterability: THP biosolids are easier to dewater and require less polymer Reduced trucking: THP reduces the quantity of biosolids

15 Alt 3: Recommendation to County Manager Primary Sludge Steam Generator Biogas to Utilization Screening and Pre-Dewatering Anaerobic Digestion Dewatering Holding/ Blending/ Tank(s) Secondary Sludge Centrate To Headworks THP Reactors Cake Hopper Holding Tank CentrateTo Headworks Cake Storage Land Application or Distribution and Marketing (Class A)

16 Benefits of Class A Biosolids Greater public acceptance More outlets for distribution: land application, soil amendment, revenue stream Less land application restrictions than Class B biosolids Pathogen reduction over 90% lower than Class B requirements Rigorous testing to ensure compliance Reduced hauling costs

17 DC Metro Region Biosolids Trends 80% 70% 60% 50% 40% 30% 20% 10% 0% Percentage of Class A and Class B Biosolids over time in Mid-Atlantic Region 76.10% 12.10% 43% 39.80% Class B Class A

18 County Opportunities BIOSOLIDS IN OUR COMMUNITY Class A option can be used as an organic soil amendment soil blends created now like Milorganite (Milwaukee) or Bloom (DC) High nutrient content of biosolids means little or no use of chemical fertilizers ENERGY RECOVERY POSSIBILITIES Energy Recovery On-Site Combined Heat and Power (CHP) Energy Recovery using biogas derived fuels is of interest to County Transit Bureau - ART Bus Fleet runs on compressed natural gas (CNG) New ART fueling station being constructed across the street from the Plant Looking at digesting other organic wastes in future would result in greater gas production

19 Budget and Next Steps

20 Utilities Fund is an Enterprise Fund Enterprise Funds are self-sufficient. Water-sewer rate set at level which, along with other revenues including excess fund balance, will fully fund activities. Ensuring that the rate stays at an affordable level is a key goal of managing this fund. Utilities Fund must balance the needs on the water and wastewater sides Capital Improvement Plan (CIP) process for FY will start in the fall and be adopted in July 2018.

21 45,000,000 40,000,000 35,000,000 Projected Utility Fund Annual Debt Service w/o Water Project FY17-26 CIP Water & Sewer Infrastructure Debt Service 30,000,000 25,000,000 20,000,000 15,000,000 Existing VRA Debt Plant Debt Service (includes Solids Master Plan THP/AD) 10,000,000 5,000,000 Existing GO Debt - FY16 FY17 FY18 FY19 FY20 FY21 FY22 FY23 FY24 FY25 FY26 FY27 FY28 FY29 FY30

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23 Next Steps Short Term (Next Two Years) Finalize Master Plan Report Air Quality Study Emissions from sources associated with CNG and CHP options Further Exploration of Regional Solutions Meetings with DC Water Determine proposed end use for biogas (CNG or CHP) Continue Phase 1 SMP Design Finalize timing of Phases 2 and 3 (depending on Washington Aqueduct decisions) Hold periodic update meetings with stakeholders

24 Next Steps Longer Term (Next 3-5 Years) Review Solids Master Plan Report Conduct negotiations with outside entities: DC Water, Washington Gas, and/or ART/WMATA bus facilities Hire a Design Engineer Begin Design of Phase 2 and Phase 3 Projects Hire a Construction Manager Prepare drawings and specifications for construction Hold periodic update meetings with stakeholders

25 DISCUSSION