Solids Master Plan Briefing June 22, 2017
Meeting Agenda Review of Master Plan Process Status Update Technology Selection Budget & Next Steps Discussion
Review of Master Plan Process
Master Plan Process - Where Are We Now? Ongoing outreach to stakeholders COMPLETED! COMPLETED! COMPLETED! Condition Final Report Assessment • Fall 2015 • Spring/Summer 2016 • Prioritize needs • Winter 2016 • Fall 2016- • Narrow down Winter 2017 • Look at choices Immediate needs Set and Rank Develop Criteria Alternatives WE ARE HERE Ongoing peer review
Solids Master Plan: Evaluation Process Universe of Technologies Workshop 1 - Kickoff and Project Objectives Defined Workshop 2 - Define Screening and Screened Evaluation Criteria Technologies and Process Analysis Workshop 3 - Technology Identification and Screening Workshop 4 - Process Specific Analysis Top 4 Selected Alternatives Workshop 5 – Alternative Train Development and Preliminary Findings : Selection of top 4 alternatives Workshop 6 – Weighted Criteria Ranking of Alternatives Ranking and Final Evaluation Workshop 7 – Final Plan Recommendations Recommended Plan
Status Update
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
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
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.
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.
Technology Selection
Top Four Alternatives Name Biosolids Major features quality Lime Stabilization Class B What we have now; highest rehab-only amount of biosolids and trucks; no gas production; odorous Anaerobic Digestion Class B Biosolids volume lower; gas (AD) production; fewer odors Thermal Hydrolysis Class A Biosolids volume reduced further; (THP) + Anaerobic more gas production; fewer odors Digestion Anaerobic Digestion + Class A Least amount of biosolids; no net Heat Drying gas production; fewer odors 12
Weighted Criteria Ranking Summary ECONOMIC OPERATIONAL ENVIRONMENTAL SOCIAL 40 THP + AD highest on social and environmental 35 4.77 5.56 30 3.04 5.43 9.09 25 7.78 10.14 8.76 20 15 14.07 14.70 Scores are very 11.79 12.07 10 close; do not provide clear 5 8.06 6.71 6.12 5.85 direction on path 0 forward Lime AD THP+AD AD+DRY AD HAS THP+AD IS HIGHEST SECOND 13 OVERALL OVERALL SCORE
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 3 2 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
Alt 3: Recommendation to County Manager Steam Biogas to Generator Primary Utilization Sludge Screening and Pre-Dewatering Dewatering Anaerobic Digestion THP Reactors Land Cake Storage Cake Holding Application or Holding/ Hopper Tank Distribution Blending/ and Marketing Tank(s) Secondary (Class A) Centrate To CentrateTo Sludge Headworks Headworks
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
Percentage of Class A and Class B DC Metro Region Biosolids Trends Biosolids over time in Mid-Atlantic Region 76.10% 80% 70% 60% 43% 50% 40% 39.80% 30% 20% 10% 12.10% 0% 2010 2016 Class B Class A
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
Budget and Next Steps
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 FY2019-28 will start in the fall and be adopted in July 2018.
Projected Utility Fund Annual Debt Service 45,000,000 FY17-26 CIP w/o Water Project Water & Sewer 40,000,000 Infrastructure Debt Service 35,000,000 30,000,000 Plant Debt Service 25,000,000 (includes Existing VRA Debt Solids Master 20,000,000 Plan THP/AD) 15,000,000 10,000,000 Existing GO Debt 5,000,000 - FY16 FY17 FY18 FY19 FY20 FY21 FY22 FY23 FY24 FY25 FY26 FY27 FY28 FY29 FY30
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
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
DISCUSSION
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