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HomeMy WebLinkAbout07. Authorize addition of final design services to agreement for Solids Handling Facility Improvements, DP 7348 Page 1 of 30 Item 7. CENTRAL SAN BOARD OF DIRECTORS ' POSITION PAPER MEETING DATE: APRIL 26, 2018 SUBJECT: AUTHORIZE THE GENERAL MANAGER TO INCLUDE FINAL DESIGN SERVICES TO THE PROFESSIONAL ENGINEERING SERVICES AGREEMENT WITH BLACK & VEATCH CORPORATION FOR THE SOLIDS HANDLING FACILITY IMPROVEMENTS, DISTRICT PROJECT7348ATA COST NOTTO EXCEED $5.9 MILLION SUBMITTED BY: INITIATING DEPARTMENT: NATHAN HODGES, ASSOCIATE ENGINEER ENGINEERING AND TECHNICAL SERVICES- CAPITAL PROJECTS REVIEWED BY: CRAIG MIZUTANI, SENIOR ENGINEER EDGAR J. LOPEZ, CAPITAL PROJECTS DIVISION MANAGER JEAN-MARC PETIT, DIRECTOR OF ENGINEERING AND TECHNICAL SERVICES Roger S. Bailey General Manager ISSUE Board of Directors' (Board) authorization is required for the General Manager to execute an amendment to a professional engineering services agreement for amounts greater than 15-percent of the original agreement amount. BACKGROUND On December 1, 2016, the Board authorized the General Manager to execute an agreement with Black & Veatch Corporation (B&V)for the predesign of the Solids Handling Facility Improvements, District Project 7348 (Solids Project) at a cost of$2.0 million. At that time, there were six individual solids projects in the Capital Improvement Budget (CIB). Due to the inter-dependency of each project element, it became apparent that these April 26, 2018 Special Board Meeting Agenda Packet- Page 68 of 177 Page 2 of 30 efforts should be combined into a single project. Decisions made regarding one process would affect the other processes. Therefore, these projects were combined to create the Solids Project. Additionally, the Comprehensive Wastewater Master Plan (CWMP) identified several needs, such as piloting wet scrubber and air pollution control equipment, aging infrastructure, and future regulatory requirements. Following a competitive selection process, B&V was hired to complete an extensive evaluation of Central San's solids handling facilities and develop a recommended design approach for the Solids Project to address capacity, reliability, and future regulatory requirements related to each system for the next 20 plus years. The Solids Project predesign consisted of numerous field investigations, workshops, meetings (with Operations, Maintenance, Planning, and Capital Projects staff), facility tours, piloting, testing, 3-D scanning, and other important efforts to comprehensively evaluate and recommend improvements. Seven (7)technical memorandas (TM)were produced that recommend improvements; TM 1: Sludge Blending, TM 2: Sludge Dewatering, TM 3: Multiple Hearth Furnaces (MHF), TM 4: Seismic Improvements, TM 5: Air Pollution Control, and TM 6: Ash Handling and Emergency Sludge Loadout Improvements. Aseventh technical memorandum (Executive Summary)was produced to summarize all the recommendations and address global issues, such as impact on the Federal Requirement Plan for Sewage Sludge Incinerators - Maximum Achievable Control Technology (SSI MACT) 50-percent Cost Threshold, project delivery options, and construction sequencing. Electrical, instrumentation and controls requirements associated with all the improvements were also included as part of the TMs. These technical memorandas form the basis for the Solids Project final design scope of work. The following is a summary of the predesign work and the recommended improvements for final design. 1. Sludge Blending and Storage The existing sludge blending and storage system includes the Sludge Blending Tank (SBT), Emergency Sludge Storage Tank (ESST), and a combination of pumped and mechanical mixing that uses two 75 horsepower(HP) pumps for mixing. The SBT (a repurposed anaerobic digester tank)was built in 1967 and structurally reinforced in 2015 after experiencing structural failures. The ESST was originally constructed as a digester but later converted to its current usage as a sludge storage tank. The SBT and ESST are oversized for day-to-day needs and the mixing system are inadequate and inefficient. These inadequacies result in reduced dewaterability under average and peak loading conditions. Sludge blending and storage will be improved by installing new, appropriately sized blending tanks in place of the existing ESST (existing ESST to be demolished)to meet the normal daily operational needs. Additionally, the existing SBT will be converted to be used as the new ESST during MHF service rotations. The new blending systems will use smaller 7.5 HP pumps for the new SBT and 50 HP pumps for the new ESST, which will result in significant energy savings. 2. Sludge Dewatering The sludge dewatering consists of four (4) centrifuges each paired to four(4) cake pumps that have been in operation since 1988 for the centrifuges and 1991 for the cake pumps. This equipment is at the end of its useful life with increasing maintenance costs, as demonstrated by the high number of corrective work orders being generated by our Computerized Maintenance Management System (CMMS). Certain centrifuge parts are obsolete and cannot be obtained from the manufacturer or distributors. New dewatering equipment, combined with improved sludge blending, will provide a consistent dewatered sludge feed to the MHFs. Modern centrifuges are significantly more energy efficient compared to the existing units and can produce a higher cake with less chemical addition, less energy and a better quality centrate. Energy savings is also anticipated from reduced auxiliary fuel usage in the MHFs due to the higher solids content in the sludge. 3. Multiple Hearth Furnaces As determined by field investigation and condition assessment conducted during the CWMP, the existing MHFs are in overall good condition. Central San only operate one MHF at a time, which allows maintenance staff the ability to routinely inspect and perform repairs as needed on an annual basis which has extended their useful April 26, 2018 Special Board Meeting Agenda Packet- Page 69 of 177 Page 3 of 30 life. Central San's past and current maintenance practices are a key reason why the MHFs continue to perform reliably and are expected to continue their service life for the next 20 or more years. One of the most significant findings under the Solids Project predesign was the confirmation that the MHFs were not capacity constrained, and that the MHFs have sufficient capacity up to and beyond the 20-year planning period. This conclusion was achieved by actual field-testing performed by staff and verified by B&V. The CWMP indicated that the MHFs may not have enough capacity for the 20-year planning period. This resulted in the CWMP recommendation to include the addition of two Anaerobic Digesters within the next decade to address the lack of solids capacity and for energy resource recovery to be located upstream of the MHF. Due to work under the Solids Project predesign, the addition of Anaerobic Digesters has been moved to the end of the 20-year planning period under certain conditions. Two major MHF improvements are recommended as follows: • Burner Upgrades - The existing afterburners are significantly oversized and, therefore, are rarely used. Installation of appropriately sized afterburners will permit their use for air pollution control and improve regulatory compliance, especially related to reducing oxides of nitrogen (NOx). Replacement of hearth burners will also improve MHF control. Both after- and hearth-burners replacement will include new controls, flame supervision, and associated safety improvements. Energy savings are anticipated by using less natural gas fuel. • Center Shaft Drives - With the recent failure of the hydraulic drive on MHF 1, staff installed an electric drive with variable frequency drives (VFD)for that furnace. Some critical parts from the hydraulic drive are no longer available. A new electric drive will be installed on MHF 2 under this project. The new center shaft drive systems will provide reliable control of shaft speed. This upgrade was also noted on staff's tour of other facilities with similar MHF and pollution control equipment. Other utilities using MHFs of our vintage have converted to electric drives after experiencing failure of hydraulic drive systems. They noted improved control and lower maintenance costs. 4. Seismic Improvements In 2009, a seismic evaluation was performed on the Solids Conditioning Building (SCB). Soon after, the SCB seismic improvements were prioritized behind the Headquarters Office Building (HOB) and the Pump and Blower Building (PBB) seismic improvements. Seismic improvements to HOB and PBB have now been completed. The current SCB seismic evaluation is based on the same criteria as the recent HOB and PBB Seismic Upgrade projects. To achieve the same design level, the SCB seismic upgrade includes column and beam strengthening, infill of an open bay, and installation of a combination of steel braces and concrete shear walls. The SCB not only houses Central San solids, energy and steam production equipment critical to our operation, but is also staffed 24/7 year-round with personnel located on the top floor in the Control Room. Staff is recommending the seismic improvements in coordination with the Solids Project since this work will impact many of the systems discussed by coordinating equipment placement, electrical, wall penetrations, clearances, and overall construction sequencing. The MHFs are especially vulnerable to a seismic event. The MHFs are comprised of a thin, outer steel shell, supporting brick walls (unreinforced masonry refractory), and cast-iron center shaft. Extensive analysis was conducted during the predesign and determined that base isolators were the best retrofit (technically and economically) approach for Central San. These base isolators have been and are used frequently in seismic retrofits and for design of new structures, bridges, and critical equipment in the building industry. These improvements will isolate the MHFs from the solids building structure allowing the MHFs to move independent of the building. 5. Wet Scrubber and Air Pollution Control April 26, 2018 Special Board Meeting Agenda Packet- Page 70 of 177 Page 4 of 30 The regulatory issues facing the existing wet scrubber equipment include the inability to treat bypass emissions, difficulties handling a wide range of operational conditions, consistent compliance with the Clean Air Act Section 129 (Section 129) hydrogen chloride (HCI) emissions limit, the proposed amendments to Bay Area Air Quality Management District (BAAQMD) Rule 6-1 for more stringent particulate matter limits, and BAAQMD Rule 11-18 for reduction of risk from air toxic emissions. Staff and B&V recently completed an extensive pilot test of air pollution control equipment (Envirocare Wet Scrubber) to accurately estimate performance against current and potential future air emission limits. The pilot testing also allowed for measurement of the liquid waste stream to determine if additional treatment would be required. The results of pilot testing will be used to select the appropriate equipment design criteria and estimate the project costs associated with air pollution control during final design. The piloting confirmed that installation of a multi-Venturi wet scrubber technology would be sufficient to comply with Section 129 limits for existing MHFs, Title V permit, and proposed limit for particulate matter (Rule 6-1). Compliance was demonstrated during the pilot for both normal operation and bypass conditions. Our current system does not allow for air pollution control of bypass conditions resulting in reportable incidents. Pilot testing also demonstrated that additional or future air pollution control equipment such as a Wet Electrostatic Precipitator or mercury modules are not expected to be required at this time. The results of the pilot work are estimated to save $14 million in equipment/infrastructure improvements, and almost $100,000 annual savings in operations and maintenance (O&M) costs for systems that may have been recommended without the pilot. The installation of a new wet scrubber is expected to ensure compliance with existing Section 129 and Title V emission limits for existing MHFs. Compliance is also expected with respect to particulate matter and health risk threshold limits (along with furnace burner improvements). Particulate matter limits have been proposed by BAAQMD and new wet scrubbers are expected to comply with those limits based on the pilot test results. Health risk assessment limits are still under development, and staff continues to monitor anticipated regulations and assess impacts for compliance. The new wet scrubber will also be designed to treat bypass emissions, which will reduce the frequency of reportable compliance activity (RCA) related to bypass events. Several RCAs have been reported, some resulting in violations, since the reporting of bypass events was initiated in April 2016. Additional air pollution control technology modules were evaluated against existing MHF emission limits, new MHF emission limits, and the more stringent emission limits associated with new fluidized bed incinerators (FBI). Equipment was recommended in the event Central San must comply with enhanced air emission limits. Building floor space will be reserved for any future pollution control equipment that may be required, but not installed at this time. B&V and staffs understanding of current and near-term future regulations is that the installation of a new multi-Venturi wet scrubber and furnace improvements is recommended for reliability and regulatory compliance. 6. Ash Handling Facility The existing ash system, while well maintained, has many components nearing the end of its useful life and will need major renovation within the next five years. This system has experienced difficulties in containing ash within the SCB and outside the building. There are also new air emission regulatory drivers such as Section 129 to control visible fugitive ash emissions. A new wet ash system is recommended to replace the existing dry ash system. Wet ash systems require less equipment, have lower overall O&M costs, and significantly reduce ash dust in and out the SCB.Awet ash system will require a filter system to dewater the ash. Awet ash pilot is recommended to confirm it will function appropriately and will be compatible with our current ash disposal requirements prior to final design, including repurposing the Emergency Sludge Loadout Facility to load wet ash on trucks. 7. Emergency Sludge Loadout Facility April 26, 2018 Special Board Meeting Agenda Packet- Page 71 of 177 Page 5 of 30 The Emergency Sludge Loadout Facility has deficiencies that prevent it from meeting its performance objectives. All three silos are connected to the cross conveyor and gates are only located beneath the conveyor at each of the three discharge chutes. The existing discharge slide gates are also difficult to control. Improvements include adding silo isolation gates, improving the discharge gates for better modulation of sludge flow, and improving drainage. Odor control improvements may also be recommended, after field verification and testing by staff prior to start of final design. 8. Other Project Considerations Several project considerations were evaluated by B&V due to their impact to the Solids Project as follows: Electrical, Instrumentation and Controls Coordination and Replacement- The existing electrical, instrumentation and controls systems associated with the Solids Project have been in service for over 40 years. Replacement of these systems will be required when new equipment and systems are installed. The existing control and electrical room equipment should be replaced to meet current electrical code and to allow installation of the new equipment while keeping existing facilities operational and online. B&V will integrate the location of the new electrical and control facilities with the mechanical, structural, and seismic work in the SCB. • SSI MACT 50-Percent Cost Threshold - One critical consideration was the evaluation of SSI MACT 50-percent Cost Threshold. Section 129 mandates that should improvements to an existing incinerator exceed 50-percent of the original cost of installation (adjusted to present dollars)the incinerator would be subject to enhanced emission limits. If the cost threshold were exceeded, the MHFs would likely need additional enhanced air pollution control equipment to be installed in order to comply with enhanced emission limits. B&V updated the MHF original installation cost to 2017 dollars.After deducting previous non-exempt modifications (those modifications that are counted towards the 50-percent improvements), there is $34.6 million remaining before the 50-percent threshold is exceeded. The recommended improvements that would apply against the 50-percent threshold are the cake pumps, furnace improvements (burner replacement, combustion air blower, and burner controls), and ash handling. Air emission control, wet scrubbers, and centrifuges are specifically exempt from the 50-percent threshold. After applying the estimated cost of the non-exempt improvements, Central San would have approximately$10.2 million remaining in modifications before exceeding the 50-percent threshold. Because of the comprehensive approach of this project, with the intent to provide reliable solids handling for the next 20 years, there are no additional major furnace modifications planned once this project is completed. Potential future work that may count against the available modification dollar threshold are hearth replacements, and these costs are well within the $10.2 million range. The most likely future furnace related improvements would be installation of additional air emissions control equipment. However, this equipment is specifically exempt from the 50-percent cost threshold and would not be counted against the SSI MACT 50-percent cost threshold. • Operating Department Impacts - There are several cost savings components to this project, including energy savings from new centrifuges and sludge mixing systems, reduced chemical usage, and optimized furnace and other controls for reduction of natural gas that will have a significant, positive (reduction in cost) impact to the Operations budget. Maintenance staff will be able to focus on preventative maintenance rather than ongoing costly and time-consuming reactive repairs.Although the predesign has estimated a potential cost savings of up to $1.2 million dollars a year, there would be some offsetting maintenance costs for upgraded equipment; however, a significant savings is expected. Project Delivery- Delivery options were evaluated. A traditional design-bid-build approach was selected as the most favorable project delivery method with the pre-selection of key equipment. April 26, 2018 Special Board Meeting Agenda Packet- Page 72 of 177 Page 6 of 30 Pre-selection of the centrifuges, cake pumps, and wet scrubbers was evaluated and recommended for the Solids Project. There are substantial differences in design and configuration between potential suppliers of this equipment that selecting the equipment manufacturer during design would greatly simplify the required work and reduce potential construction complications. This will have design savings and reduce the risk of construction change orders and other contractual issues that may arise. Staff and B&V have already started the pre-selection process. Equipment suppliers are being contacted to obtain product and performance data. Staff, B&V, and Central San's legal counsel have also started to develop the documents for equipment qualifications, selection process, and terms and conditions. The total estimated cost of this equipment is $5.1 million. • Project Sequencing-A project of this magnitude will greatly impact plant operations. B&V has considered the time required to construct the various project elements. With one MHF off-line at a time, equipment can be installed, and improvements made near the off-line MHF, with minor risk to solids treatment. Certainly, not all risk will be eliminated. B&V and staff will develop sequence specifications that will help minimize operational risk while producing a project that can be constructed effectively. B&V will undergo a constructability review of the Solids Project and staff will also seek input from a third-party PEER review during the final design process. • Health Risk Assessment - BAAQMD issued a draft air toxics regulation, Regulation 11, Rule 18 (Rule 11-18) in late 2016. This rule will require facilities found to pose a significant health risk to reduce the impacts and control toxic air emissions. B&V's predesign scope of work included support for Central San's internal assessment of what impacts compliance with Rule 11-18 would have on treatment processes. A preliminary health risk assessment completed by B&V showed Central San will be required to mitigate health risks from toxic air contaminants in order to comply with Rule 11-18. In late 2017, Rule 18 was adopted. B&V is currently updating the baseline health risk assessment using recently completed air emissions testing data that will show more accurately which processes contribute to the risk. Included in B&V's final design scope of work is assessment on risk reduction strategies. Risk reduction measures may range from wet scrubber replacement to minor modifications, such as operational changes and stack modifications. These mitigation measures will be confirmed with B&V's health risk model in order to assess any impact to plant processes and, specifically, to solids process equipment. Consultant Selection On October 20, 2017, staff issued a Request for Proposal (RFP)for final design services to the engineering consulting community via PlanetBids and Central San's website. B&V was the only consultant to respond to the RFP. Staff reviewed the proposal and considers B&V capable of meeting Central San's needs to complete the final design. California Environmental Quality Act (CEQA): At its December 1, 2016 meeting, the Board independently found that the agreement with this vendor was exempt from CEQA under Central San's CEQA Guidelines Section 15262, since it allowed for further planning and feasibility studies for possible future actions which Central San has not approved, adopted, or funded, and the outcome of these tasks will not have a legally binding effect on later activities. Central San will conduct an environmental evaluation of any capital project that is proposed in the future as a result of the tasks authorized herein to determine the need for any additional CEQA documentation. ALTERNATIVES/CONSIDERATIONS An alternative would be to phase or postpone the final design, which is not recommended due to the solids process dependency and design complications previously noted above, and the increase in overall project cost by extending the length of the project implementation. A new wet scrubber and air pollution control improvements would significantly help the current issues being April 26, 2018 Special Board Meeting Agenda Packet- Page 73 of 177 Page 7 of 30 experienced with bypass events and reduce chemical costs in controlling HCI emissions. Although the proposed CIB and current budget have adequate cash funding for the final design, it is anticipated that Central San will most likely request bond financing to construct these improvements. This decision will be presented at a future Board Meeting and no action is required at this time. FINANCIAL IMPACTS The B&V final design services for the Solids Project is estimated at$5.9 million. The total B&V agreement cost ceiling is estimated at$8.13 million ($2.0 million for pre-design and piloting assistance, $230,000 for the design of the urgent water system upgrades, and $5.9 million for final design), which is approximately 10-percent of the $82.1 million total estimated project cost as detailed in Attachment 1. The Solids Project is listed in the Fiscal Year(FY) 2017-18 CIB on page 161 with a budget of$2,625,000 this fiscal year and $8,200,000 for FY 2018-19. The design costs will span two fiscal years with funding as shown in the following table: Financial Impact Table: Amount 0 Funds budgeted this FY 2017-18 for this project $2,625,000 ❑ Funds taken from current FY 2017-18 Cl B contingency $ 0 Funds transferred from current FY 2017-18 projects: ❑ a. Updated forecast; estimated savings from project available $ 0 0 b. Acceleration of funds for project that is budgeted in future year $ 3,275,000 ❑ c. Combined project scope for bidding purposes $ 0 d. Potential future year budget impact ❑ (May be mitigated through (1) savings from close-outs of current $ 0 year projects; (2) reprioritizing future year projects; (3) cost savings on future year projects) Total Current Year Cost $ 5,900,000 COMMITTEE RECOMMENDATION The Engineering and Operations Committee reviewed this agreement amendment at the March 13, 2018 meeting and recommended approval to include final design services for the Solids Project. RECOMMENDED BOARD ACTION Authorize the General Manager to include final design services with Black & Veatch Corporation, Agreement Number 044848, in an amount not to exceed $5.9 million for the Solids Handling Facility Improvements Project, District Project 7348. Strategic Plan re-In GOAL TWO: Strive to Meet Regulatory Requirements Strategy 1 - Strive to Achieve 100% Permit Compliance in Air, Water, Land and Other Regulations GOAL THREE: Be a Fiscally Sound and Effective Water Sector Utility Strategy 1 - Conduct Long-Range Financial Planning GOAL FIVE: Maintain a Reliable Infrastructure Strategy 1 - Manage Assets Optimally Throughout Their Lifecycle, Strategy 3- Protect District Personnel and Assets April 26, 2018 Special Board Meeting Agenda Packet- Page 74 of 177 Page 8 of 30 from Threats and Emergencies GOAL SIX.Embrace Technology, Innovation and Environmental Sustainability Strategy 2- Evaluate Business Processes and Optimize Business Operations, Strategy 3- Encourage the Review and Testing of Promising and Leading Technology ATTACHMENTS: 1. Estimated Capital Costs of Recommended I mprovements 2. Presentation April 26, 2018 Special Board Meeting Agenda Packet- Page 75 of 177 Page 9 of 30 Attachment 1 Solids Handling Facility Improvements District Project 7348 Estimated Capital Costs of Recommended Improvements Item Recommended Improvements Total Construction Cost Total Project Cost 1 Sludge Blending and Storage $2,590,000 $3,700,000 2 Sludge Dewatering $11,780,000 $16,500,000 3 Multiple Hearth Furnaces $8,750,000 $12,300,000 Seismic Improvements 4 Building Seismic Retrofit $11,100,000 $15,600,000 Furnace Seismic Retrofit $3,000,000 $4,200,000 5 Wet Scrubber and Air Pollution Control $10,560,000 $14,800,000 6 Ash Handling Facility $7,430,000 $10,500,000 7 Emergency Sludge Loadout Facility $3,200,000 $4,500,000 Total Capital Costs $58,410,000 $82,100,000 April 26, 2018 Special Board Meeting Agenda Packet- Page 76 of 177 Page 10 of 30 1 SOLIDS HANDLING FACILITY IMPROVEMENTS PROFESSIONAL ENGINEERING SERVICES FOR SOLIDS HANDLING FACILITY IMPROVEMENTS FINAL DESIGN Board Meeting Y _ April 26, 2018 !!� - Jean-Marc Petit,Director of Engineering and Technical Services Edgar Lopez,Capital Projects Division Manager Nathan Hodges,Associate Engineer 1 . BACKGROUND 1 Ii C". 1 April 26, 2018 Special Board Meeting Agenda Packet- Page 77 of 177 Page 11 of 30 OVERALL PROJECT OBJECTIVES Ensure employee safety Ensure reliable capacity and operation of _ the Furnaces and related systems over next 20+ years Ensure reliable air emissions and permit compliance (Current and Future) • Reduce, minimize, and eliminate majority of Reportable Compliance Activity (RCA) • Reduce Operations and Maintenance (O&M)cost(e.g.; reduce chemical and A energy usage and labor cost associated with maintenance and frequent repairs) r . CENTRAL SAN SOLIDS PHASE PROJECT BACKGROUND Project elements were identified over past 12 years in CIBs and reaffirmed as part of CWMP RFP issued for consultant selection for pre-design in 2016 Black & Veatch Corporation (B&V) selected and awarded on December 1, 2016 Completed Preliminary Design over past 16 months RFP issued for final design; B&V selected Recommending to proceed with Final Design 2 April 26, 2018 Special Board Meeting Agenda Packet- Page 78 of 177 Page 12 of 30 SOLIDS HANDLING FACILITY IMPROVEMENT PROJECT SCOPE Furnace Burner Controls Improvements Electrical and Controls Emergency Sludge Upgrade and Replacement and Ash Loadout Improvements Centrifuge and Cake Pumps Replacement Emergency rl V Sludge Storages> Tank New Air Quality Control Equipment New Sludge Blending Tank with Mixing Seismic Design(SCB and MHFs) CENTRALSAN r �r INTEGRATED PILOT TESTING DURING PREDESIGN AIMED AT MINIMIZING FUTURE COSTS AND PLANT OPERATION IMPACTS Sludge Blending Tank Centrate Test 7.enc Centrifuge Furnaces scale ntrifuge �. . Furnaces BEEN MHF er rqe omp a ion Duct Connections .ir Permitting Air Emission Air Emissions Test !Scrubber Effluent Test IL3 April 26, 2018 Special Board Meeting Agenda Packet- Page 79 of 177 Page 13 of 30 SOLIDS FLOW METER TESTING CONFIRMED SUFFICIENT CAPACITY FOR 20+ YEARS Status Completed in 2017 ; Purpose Confirm reliability of the centrifuge sludge feed flow Vs meters data. Findings Flow meters are accurate. The use of historical flow meter data is appropriate. ' • MHFs have sufficient solids capacity(including lime addition)beyond the 2035 planning :f7re p period. z` . Recommendation:There is sufficient solids handling capacity; there is no need to add additional solids treatment capacity at this time. I CENTRALSAN WET SCRUBBER PILOT WAS A SIGNIFICANT UNDERTAKING BUT PRODUCED VALUABLE RESULTS CENTRALSAN 4 April 26, 2018 Special Board Meeting Agenda Packet- Page 80 of 177 • ' A r ■ • Gained engineering, operations, maintenance experience - Confirmed Technology Viability— Pilot met existing Title V and PI"I ``, f Clean Air Act 129 Limits and Proposed BAAQMD Rule 6-1 for normal and bypass conditions Saved $12M — Eliminated Wet Y :I{ Electrostatic Precipitator and } Mercury Sorbent Modules Saved $ 2M — Eliminated . 1 y scrubber water treatment -- CENTRALSTN-- PROJECT AN. . CENTRAL SAN Page 15 of 30 ESTIMATED CAPITAL COSTS OF RECOMMENDED IMPROVEMENTS RECOMMENDED IMPROVEMENTS . PROJECT COS_T- 0Sludge Blending and Storage $2,590,000 $3,700,000 0 Dewatering System $11,780,000 $16,500,000 0 $8,750,000 $12,300,000 Building Seismic Retrofit F' $11,100,000 $15,600,000 0 Furnace Seismic Retrofit $3,000,000 $4,200,000 0Air Pollution Control $10,560,000 $14,800,000 IAsh Handling and Loadout System $7,430,000 $10,500,000 0 1 $3,200,000 $4,500,000 TOTAL • $58,410,000 $82,100,000 0 Note:Electrical and Controls Improvements are included as part of each recommended Improvements Cost CENTRALSAN ANTICIPATED DESIGN AND CONSTRUCTION SCHEDULE Equipment Pre-Selection L__J Q Final Design Bid and Award Phase Construction _1 :quipment Pre-Selection Process:Jan 2018—Sep 2018 1.1 Pre-Selection of Key Equipment for Design:Oct 2018—Dec 2018 Final Design Phase: May 2018—Oct 2019 Bid&Construction Phase: Nov 2019—Dec 2023 Construction will require careful coordination with Operations and Maintenance CENTRALSAN 6 April 26, 2018 Special Board Meeting Agenda Packet- Page 82 of 177 Page 16 of 30 ANTICIPATED CASH FLOW FOR PROJECT FORECASTED OVER NEXT FIVE YEARS $30 M $25 M — — $20 M ■Engineering Preliminary E mIplPiNg Tes5ng -.Central San Manage.M $15M ■CQ­It tD.Igacamv d.Mwusemeirt ■Ceeatnedvn $10 M •Evuw�•M P.oc�r�.n�t $5 M 0 0 o FYXI'1IE ;VWZS&19 FTj(il,2D FY 20711.71 FY]0714] FWMZ,79 CENTRALSAN RECOMMENDED IMPROVEMENTS FROM PRE-DESIGN EFFORT 12 7 4 5 7&8 3 6 = � b V SLUDGE LIME ADDITION CENTRIFUGE MULTIPLE AIR POLLUTION SCB SEISMIC ASH HANDLING EMERGENCY BLENDING/ DEWATERING HEARTH CONTROL RETROFIT AND LOADOUT SLUDGE STORAGE SYSTEM FURNACES LOADOUT 7 April 26, 2018 Special Board Meeting Agenda Packet- Page 83 of 177 Page 17 of 30 ® SLUDGE BLENDING IMPROVEMENTS • New Lime System New right-sized lime silos and metering pumps • Repurposed Sludge Blending Tank Convert current sludge blending tank to emergency sludge storage tank with new il engineered pump mixing system • New Sludge Blending Tanksy New sludge blending tanks sized for i improved mixing of primary sludge and Thickened Waste Activated Sludge(TWAS) with vertical turbine mixing system 7 New sludge blending tanks in place of demolished,existing ESST • Benefits to Central San: Improved dewaterability of sludge Reduction in CM Lower chemical and ` electrical cost I CENTRALSAN © SLUDGE DEWATERING IMPROVEMENTS • New Polymer System New polymer storage tanks,day tank, transfer pumps,blending units,and feed tanks to serve new dewatering centrifuges • New Dewatering Centrifuges ti Four new high efficiency centrifuges to replace centrifuges beyond useful life • New Sludge Cake Pumps Four new cake pumps with flow metering _ to replace pumps beyond useful life • Benefits to Central San: Reduction in o&M:Lower chemical, electrical cost,and maintenance repairs Increase reliability Increased cake solids with less polymer; Decrease in fuel for furnace CENTRAL SAN 8 April 26, 2018 Special Board Meeting Agenda Packet- Page 84 of 177 Page 18 of 30 © FURNACE IMPROVEMENTS • New Burners and Controls New low-NOx afterburners on Hearth 1 for CO/NOx emissions reduction and new JI low-NOx burners on Hearths 2-10;new modern,automated controls on all burners • New Center Shaft Drive System New center shaft drive system with VFD to replace unreliable hydraulic drive system • New Combustion Air Blower System } New combustion air blower to be integrated with new burner control system �f "• I • Benefits to Central San: - Reduction in O&M:Lower fuel(gas), electrical cost,and maintenance repairs Increase reliability(center drive) Increase controls on burners improves air emission(lower NOx)with less fuel CENTRALSAN a SEISMIC IMPROVEMENTS RECOMMENDATIONS • Separate Stairwells and Elevators Seismically separate stairs and elevator core walls from building • Add Shear Walls and Infill Slabs Strategically locate new shear walls and infill slabs to seismically strengthen building • Isolate Furnaces from Building Install new MHF base isolators and flexible duct,piping,and conduit connections to allow for lateral movement of furnaces • Benefits to Central San: Ensures employee safety Increases resiliency CENTRALSAN 9 April 26, 2018 Special Board Meeting Agenda Packet- Page 85 of 177 Page 19 of 30 SEISMIC RETROFIT PROGRAM (10-YEAR PLAN d; t'oncord Fault 4A'i Properly Line to .13 miles or—7p9 R 1 imp&E&a Bldg to F"- lids Bldg to Paull miles nr-d.0�-i H .64nlKesor_,3,354 fi OB to Faul! -SO miles Concord Fault Proximity to Central San Facilities: 0.64 Miles from Solids Handling CENTRALSAN SOLIDS CONDITIONING BUILDING DESCRIPTION • Constructed in mid-1970s with partial seismic upgrade in 1985 • 126 feet by 180 feet—4 levels • Gravity System — Concrete w slab spanning to steel beams s: and columns - • Lateral System — Concrete diaphragm with large openings, o steel moment frame and stair towers Northwest Corner of Solids Conditioning Building CENTRALSAN 10 April 26, 2018 Special Board Meeting Agenda Packet- Page 86 of 177 Page 20 of 30 MULTIPLE HEARTH FURNACE DESCRIPTION • Constructed in 1974 4 • 22 feet in diameter, 60 feet tall ` s` • Constructed of unreinforced brick • Encased in a thin steel plate shell • Rotating cast iron inner shaft CENTRALSAN IMPROVING SAFETY RELIABILITY WITH SEISMIC UPGRADES • Building upper floor (4th) occupied by staff around the clock, year-round • Confirmed Target Seismic Performance y 1■`"+� _--- levels for building and MHFs • Updated building seismic evaluation for the following: • Target Seismic Performance Level J I • ASCE 41-13 Seismic Evaluation and Upgrade Standard Solids Conditioning Building • New short term and long term SCB equipment modifications • Update and further developed base isolation design concepts for MHFs CENTRALSAN 11 April 26, 2018 Special Board Meeting Agenda Packet- Page 87 of 177 Page 21 of 30 SEISMIC ANALYSIS RESULTS 1.SOLIDS CONDITIONING BUILDING SEISMIC DEFICIENCIES • Concrete shear walls at stair towers are overstressed in shear • Columns and beams are overstressed • Diaphragm capacity is inadequate to transfer forces • Moment frames and connections are inadequate • Braces have inadequate connection capacity ^`"'' 2. FURNACE DEFICIENCIES • Cast iron center shaft is brittle and overstressed Wall Shear in flexure Stresses • Brick hearths could collapse in design based earthquake (DBE) • Unreinforced brick along perimeter inadequate in shear and flexure • Steel shell could buckle in DBE CENTRALSAN SEISMIC UPGRADE CONCEPTS Solids Conditioning Building Strengthening Scheme: • Add new concrete shear walls ! - Ti • Strengthen select columns ;.,, and beams • Add horizontal diaphragm ETABS 2015 Model braces a T, • Infill slab on first floor(to be m�- used for new electrical room) — • Strengthen existing brace connections • Isolate stair towers from 1 building CENTRALSAN 12 April 26, 2018 Special Board Meeting Agenda Packet- Page 88 of 177 Page 22 of 30 SEISMIC UPGRADE CONCEPTS Furnace Strengthening Scheme: • Add new base isolators under MODELS each column and center shaft Ua—E. • Add braces at furnace base columns and center shaft • Add seismic joints for all utility connections, stairs and = platforms CENTRALSAN 0 AIR POLLUTION CONTROL IMPROVEMENTS • New Wet Scrubbers New high performance wet scrubbers to replace wet scrubbers beyond useful life 11 • New MHF Emergency Bypass Route dry scrubber/waste heat boiler bypass to new wet scrubbers for treatment • New Ash Slurry Drain System Route wet scrubber drain to new wet ash handling system with potential future treatment to reduce metals • Benefits to Central San: Ensures compliance with existing and expected future regulatory compliance Reduction in O&M:Lower chemical cost, and less maintenance repairs I CENTRAL SAN 13 April 26, 2018 Special Board Meeting Agenda Packet- Page 89 of 177 Page 23 of 30 0 ASH HANDLING AND LOADOUT SYSTEM IMPROVEMENTS • New Wet Ash Loadout System i Replace dry ash loadout system with wet ash loadout system with ash dewatering in truck trailer or loadout container • New Wet Ash Collection System Replace MHF dry ash conveyor with new wet ash receivers and drain from wet scrubbers v " • New Ash Slurry Pump System s "=7-F s Replace dry ash vacuum system with newL E Ex ash slurry pumps and piping • Benefits to Central San: � - _ _ a Increase employee safety(less dust) Reduction in O&M:Lower electrical cost, simpler and fewer equipment and less maintenance repairsCENTRALSAN ` I 0 EMERGENCY SLUDGE LOADOUT IMPROVEMENTS • Include new Ash Loading Feature Evaluate design of a new Wet Ash - Loading as part of this Building Improvements ` • New Sludge Loadout Operation Add sludge discharge gates to allow even filling of trailer without moving truck • New Sludge Loadout Containment - Upsize sludge loadout drainage system and add retractable curtain containment around sludge loadout truck IL ----- • Benefits to Central San: Increase employee safety(exposure to raw sludge) Increase Resiliency Dual purpose use of the building(ash and emergency sludge loading) A117 ` CENTRAL SAN 14 April 26, 2018 Special Board Meeting Agenda Packet- Page 90 of 177 Page 24 of 30 0 ELECTRICAL AND CONTROLS IMPROVEMENTS • New PLC Control panels for all new equipment Provide new local control panels with PLC for all new process equipment and connect with SCADA system • New Motor Control Centers =' (MCC)for Equipment in SCB "I . New MCC Room • New Furnace Controls - Replace obsolete hard wire control panel • Benefits to Central San: Increase employee safety(arc flash protection) Increase Resiliency Reduces maintenance of obsolete equipment CENTRALSAN REGULATORY DRIVERS 15 April 26, 2018 Special Board Meeting Agenda Packet- Page 91 of 177 Page 25 of 30 SOLIDS HANDLING PROJECT REGULATORY DRIVERS A new scrubber will help ensure compliance with existing and upcoming incinerator regulations: ✓ Clean Air Act Section 129 ✓ BAAQMD Rule 11-18: Reduction of Risk from Air Toxic Emissions at Existing Facilities ✓ Draft BAAQMD Particulate Matter(PM) Rule 6-1 (BAAQMD=Bay Area Air Quality Management District) CENTRALSAN Jw - CLEAN AIR ACT SECTION 129 • Regulated Use of Emergency Bypass Damper • Following numerous recent RCAs for use of Bypass Damper, BAAQMD issued violations for November, December 2017 and January 2018 bypass events • Expecting additional RCAs as bypass events are not currently avoidable with existing wet scrubber • HCI Emissions Limit • Furnace failed to meet HCl emission limit in April 2017 • Wet Scrubber Effluent pH operating limit • Existing wet scrubber is not designed for long term caustic injection • Caustic injection is causing significant fouling issues • Requires recent furnace burnout and extensive maintenance to remove and clean excess build-up RCA:Reportable Compliance Activity) - h CENTRALSAN 16 April 26, 2018 Special Board Meeting Agenda Packet- Page 92 of 177 Page 26 of 30 BAAQMD ADOPTED FINAL REGULATION 11 , RULE 18 - NOVEMBER 2017 Reduction of Risk from Air Toxic Emissions at Existing Facilities BAAQMD conducts HRA to BAAQMD communicates determine risk action levels required action plan OFFF • Cancer Risk(10/Million) • Risk Reduction Plan (6 months) • Other hazard indexes • Path to compliance(5 years) (Chronic and Acute) • Address sources of risk mitigation I BAAQMD RULE 11 -18 IMPLEMENTATION ESTABLISHES A RAPID SCHEDULE FOR AIR TOXICS MITIGATION 1 2019-20202020-2021 2021-2025 or sooner Exceedance of Capital 5 years to Risk Action Levels Plans Implement Triggers Reduction Risk Reduction Requirements Measures Risk Action Levels: Cancer Risk>10N Non-Cancer Index>1 1 i A— CENTRALSAN 17 April 26, 2018 Special Board Meeting Agenda Packet- Page 93 of 177 Page 27 of 30 BAAQMD DRAFT PM RULE 6-1 Proposed Amendments to BAAQMD PM Rule 6-1 Public adoption hearing — May 2018 Central San will be required to meet more stringent furnace exhaust PM limits by July 1, 2025 Current scrubber will not be able to meet the proposed PM limits Recent scrubber pilot demonstrated a new venturi scrubber will be able to meet the proposed PM limits POTENTIAL TECHNOLOGIES FOR MEETING CURRENT/FUTURE REGULATIONS orTarget' • , �- ! ®® Pollutants Hg,Pb,Cd, New Wet HCI,SO2 V Scrubber Filterable PM, Dioxins/Furans Wet Cd,Pb, Electrostatic Filterable PM Precipitator Mercury Modules Hg,SO2 Low-NOx . / Afterburners NO, v (FBI=Fluidized Bed Incinerator) j C' AM a 18 April 26, 2018 Special Board Meeting Agenda Packet- Page 94 of 177 Page 28 of 30 REGULATORY BENEFITS OF NEW SCRUBBERS • Eliminate use of bypass stack and associated RCA Clean Air ' • Ensures compliance with HCl emissions limit Section • • Ensures compliance with scrubber effluent pH minimum limits • Reduces caustic chemical usage and maintenance AA Rule 11-18 1L • Reduces toxic air contaminants from furnaces Draft B' 'QD • Ensures compliance with PM concentration Rule 6-1 limit CENTRALSANI SUMMARY OF IMPROVEMENTS AND ASSOCIATED BENEFITS FOR CENTRAL SAN • Seismic improvements will provide safety for employees and increase resiliency of structure and critical components in the Solids Conditioning Building: Sludge Handling, Steam Production, Energy Production, and Air Emission Control Equipment • New air emission control equipment validated by extensive pilot testing will insure compliance with current and future BAAQMD and Title V air permit • Increase reliability of key equipment Replacing key equipment will increase process performances and reliability at reduced O&M cost(e.g.; new centrifuges, cake pumps, electrical motor control centers) • Rightsizing of components and equipment will improve performance, reduce energy and chemical cost(e.g.; Sludge blending tanks, lime addition, polymer natural gas and landfill gas) • New electrical, instrumentation, and controls will ensure employee safety, improve reliability, increase process controls tools and performance monitoring while reducing O&M CENTRALSAN 19 April 26, 2018 Special Board Meeting Agenda Packet- Page 95 of 177 Page 29 of 30 RECOMMENDATION 12 7 4 5 7&8 3 6 b SLUDGE LIME ADDITION CENTRIFUGE MULTIPLE AIR POLLUTION SCB SEISMIC ASH HANDLING EMERGENCY BLENDING/ DEWATERING HEARTH CONTROL RETROFIT AND LOADOUT SLUDGE STORAGE SYSTEM FURNACES LOAD T CENTRALSAN STAFF RECOMMENDATIONS • Authorize the General Manager to include final design services with Black & Veatch Corporation, Agreement Number 044848, in an amount not to exceed $5.9 million for the Solids Handing Facility Improvements Project, District Project 7348 20 April 26, 2018 Special Board Meeting Agenda Packet- Page 96 of 177 Page 30 of 30 QUESTIONS? CENTRALSAN21 April 26, 2018 Special Board Meeting Agenda Packet- Page 97 of 177