Agenda Item 5 - SFPUC AWSS Presentation
Transcription
Agenda Item 5 - SFPUC AWSS Presentation
AWSS 2010 ESER Bond Services of the San Francisco Public Utilities Commission Capital Planning Committee Meeting December 17, 2012 San Francisco Water Power Sewer AECOM-AGS, a joint venture AECOM/AGS 1 Agenda • Reliability Modeling and Selection of LOS • Development of Projects and Program Alternatives • Criteria and Selection of Preferred Alternative AECOM/AGS CS-199 AWSS Facilities Preliminary Options Study 2 Planning Study Objectives • Planning Study for the Auxiliary Water Supply System (AWSS) pipelines, controls, seawater intake tunnels and cisterns. • Critical Goal: To maximize the likelihood that AWSS will effectively provide required firefighting capabilities after a major seismic event • Assessing existing system capabilities • Preparing alternatives to increase AWSS Reliability AECOM/AGS CS-199 AWSS Facilities Preliminary Options Study 3 Existing AWSS AECOM/AGS CS-199 AWSS Facilities Preliminary Options Study 4 Fire Response Areas (FRA) • Based on SFFD engine response areas • Modified in the downtown area to capture density of AWSS • 46 FRAs in total AECOM/AGS CS-199 AWSS Facilities Preliminary Options Study 5 Fire Demand Assumptions • Based on median ground motions from a M7.8 Earthquake on the San Andreas Fault • Applied probabilistic “fire demands” to AWSS system (Scawthorn Monte Carlo analysis) • 60 minute demands were chosen based on SFFD and CDD response times, they provide a “hard test” and reflect the aftermath of a major earthquake event AECOM/AGS CS-199 AWSS Facilities Preliminary Options Study 6 Reliability Scoring Serviceability: Percentage of demand met by the supply • Each FRA’s reliability is its serviceability (i.e., sum of water supplies in the FRA divided by the demand in the FRA) • The citywide reliability score is the average of the FRA serviceabilities AECOM/AGS CS-199 AWSS Facilities Preliminary Options Study 7 Reliability Modeling Assumptions • Assumes no MWSS hydrant use during the first 60 minutes following the earthquake • Applies reliability factor to all facilities (pump stations, tanks, pipelines) • Assumes existing facilities and pipelines maintained and perform as intended • PWSS use is tracked AECOM/AGS CS-199 AWSS Facilities Preliminary Options Study 8 Observations on Existing AWSS • Pipe condition not well known • Hydraulics and supply limited to meet demands • Twin Peaks Zone has insufficient pressure due to high elevation • Islais Creek and Avenue areas are only fed by one line • Dead ends in some zones limit delivery • Three infirm zones are not isolated by seismic valves and loss due to pipe leaks and breaks after the earthquake is significant. High number of leaks makes lower zone ineffective. • 9 of 46 FRAs not currently connected to HPS • 10 of the FRAs have reliability <15% • Maintenance, planning and emergency response issues have been brought to SFPUC’s attention AECOM/AGS CS-199 AWSS Facilities Preliminary Options Study 9 Existing Condition (HPS, Cistern, Suction Connections and Alt. Sources Citywide Reliability Score is 47% AECOM/AGS CS-199 AWSS Facilities Preliminary Options Study 10 Previous Direction from Steering Committee • More important to bring low reliability FRAs up than seek a high citywide score (i.e. equity important) • Use WSIP strengthened facilities as much as possible Different projects were developed and then packaged into 3 alternative programs that each meet a minimum of 50% reliability per FRA AECOM/AGS CS-199 AWSS Facilities Preliminary Options Study 11 LOS Objectives Recommended Objectives: • • AWSS will be 75% reliable in supplying probable demands Citywide by 20XX Each fire response area will be 50% reliable in supplying probable demands by 20XX. Current Condition • • 47% reliability score citywide and 7 fire response areas are less than 10% reliable AECOM/AGS CS-199 AWSS Facilities Preliminary Options Study 12 Alternative Programs Future Bonds 2010 Bond Project # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Project Name Motorization and Addition of Seismic Switches on Gate Valves 4th Street Hose PS1 Tunnel Upgrade Twin Peaks Outlet Connection Jones St Tank Bypass Valves Repair Suction Connections SCADA Improvements Fireboat Manifold Rehabilitation & Replacement Pipeline Investigation and Repairs Sutro Connection and PS Reliability Upgrades at Facilities Cistern Expansion Phase 1-3 (90+/-) Cistern Expansion Phase 4-6 (350+/-) South Side Supply Alternative 1 South Extension Pipeline Southeast Extension Pipeline 1 Southeast Extension Pipeline 2 Lake Merced Pump Station West Extension Pipeline West Extension Rezoning Pipeline Northwest Extension Pipeline Southeast Supply Southwest Supply New Bay Suction Connections Pipeline Replacement Program Phase 1 Pipeline Replacement Program Phase 2 AECOM/AGS CS-199 AWSS Facilities Preliminary Options Study Priority Alt A √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ Priority Priority Alt B Alt C √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ 13 Citywide AWSS Reliable Water Supply (in gpm) by Source Alternative A Alternative B Alternative C Source Existing High pressure System 17,870 57,940 63,187 23,566 Cisterns Suction Connections Alternative Water 16,870 30,020 28,695 49,835 423 1,044 1,044 1,256 1,530 1,530 1,530 1,530 Total Citywide Serviceability 1 Citywide Reliability 2 36,693 90,534 94,456 76,186 41% 101% 106% 85% 47 91 92 80 1. Uncapped total supply divided by total demand 2. Average of FRA serviceability (capped at 100%) High Pressure System provides a minimum of 20 PSI pressure vs. atmospheric pressure for other sources AECOM/AGS CS-199 AWSS Facilities Preliminary Options Study 14 Modeling Results % Reliability Contributions by Source 65% 67% 31% 70% 60% 50% 40% 30% 20% 10% 0% 2% 30% 64% 1% 33% 1% 2% 2% 2% AECOM/AGS CS-199 AWSS Facilities Preliminary Options Study 15 Existing Condition (HPS, Cistern, Suction Connections and Alt. Sources Citywide Reliability Score is 47% AECOM/AGS CS-199 AWSS Facilities Preliminary Options Study 16 Delivery Reliability (Preliminary) for 2010 Bond including Sutro Connection Citywide Reliability Score is 67% AECOM/AGS CS-199 AWSS Facilities Preliminary Options Study 17 Total Delivery Reliability – Alternative A Citywide Reliability Score is 91% AECOM/AGS CS-199 AWSS Facilities Preliminary Options Study 18 Total Delivery Reliability –Alternative B Citywide Reliability Score is 92% AECOM/AGS CS-199 AWSS Facilities Preliminary Options Study 19 Total Delivery Reliability –Alternative C Citywide Reliability Score is 80% AECOM/AGS CS-199 AWSS Facilities Preliminary Options Study 20 Approximated Citywide Reliability Potential Bond Tier Citywide Performance Levels 100 90 80 70 60 Alternative A Alternative B Alternative C 50 40 30 20 10 0 $0 $200 $400 $600 $800 $1,000 Costs, millions (includes1.5 miles/yr pipe replacement costs) AECOM/AGS CS-199 AWSS Facilities Preliminary Options Study 21 Task 9 Alternatives Analysis – Criteria (Analysis per PD 2.02) • • • • • • • Water Supply Reliability Score Capital Cost/Life Cycle Costs Operation and Maintenance Schedule Fire Fighting Resources and Deployment Time Insurance Premiums Benefits Environmental/Community Impacts AECOM/AGS 22 2012 Dollars Midpoint of Constr. Capital Cost/Life Cycle Costs Alternative A Alternative B Alternative C Soft Cost $127,907,659 $123,988,909 $160,142,373 Construction Cost $665,119,827 $644,742,327 $832,740,337 Program Capital Cost $793,027,486 $768,731,236 $992,882,710 Annual Operations and Maintenance Cost (New Assets) $284,586 $293,209 $361,266 Net Present Value (New Assets) $657,736,004 $647,166,696 $733,721,014 Assumptions added in NPV Calculation: NPV Discount rate = 4.0% Construction Escalation = 3% Soft Cost Escalation = 3% Pipeline Maintenance cost = 0.5% per annum of Mechanical/Electrical estimate Pump Station Maintenance Cost = 1.5% per annum of Mechanical/Electrical estimate AECOM/AGS CS-199 AWSS Facilities Preliminary Options Study 23 Program Schedules •Alternative A and B each completed by 2034 •Alternative C completed by 2046 AECOM/AGS CS-199 AWSS Facilities Preliminary Options Study 24 Next Steps for Planning Study • Incorporating comments on Draft Report and TMs • Supplemental Geotechnical and Materials Testing underway • February 2013 Final Report Completion date 25 Physical Plant (Core Facilities) • • • • Twin Peaks Reservoir: Replace fence and valves Ashbury Tank: Install new tank Jones Street Tank: Reinforce tank foundation General: Modify pipe at each site as needed • Pumping Station 1 • Pumping Station 2 26 Cisterns – Repair 27 Cisterns – New Construction start Contract A ~ 7/1/2013 Contract B ~ 9/1/2013 Contract C ~ 12/1/2013 28 AWSS Schedule Project Jones Street Tank Ashbury Heights Tank Twin Peaks Reservoir Pumping Station 1 Pumping Station 2 Cisterns Pipelines and Tunnels Planning Study Start April April April April April April April April Finish 2011 October 2015 2011 October 2015 2011 October 2015 2011 April 2015 2011 September 2016 2011 April 2017 2011 September 2018 2011 November 2013 29
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