Surface Water Conversion - City of Sugar Land

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SuEllen Staggs, City of Sugar Land

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Surface Water Conversion - City of Sugar Land

  1. 1. Surface Water Conversion and CMARSuEllen Staggs - Director of Utilities
  2. 2. Presentation OutlineBackgroundSurface Water Treatment PlantWater Quality Process DecisionsProject Delivery – CMARNext Steps
  3. 3. Project BackgroundFort Bend Subsidence District Regulationin 2002- 30% conversion by 2013 (Phase I)- 60% conversion by 2025 (Phase II)Road Map - GRP approved 200718 Participants
  4. 4. GRP Implementation Strategy4 Strategies 1. Surface Water Conversion 2. Conservation 3. Water Reuse • Obtained TCEQ 210 for reuse at the 3 Wastewater plants in 2008 4. Non–potable surface water use • GRP assumes 2 MGD • 4 projects complete – 500,000 gpd • 3.0 billion gallons banked by 2013 over a year of conversion
  5. 5. Surface WaterTreatment Plant
  6. 6. SWTP Implementation StrategySurface Water Plant Size 9 MGD operational in 2013 Expand to 22 MGD in 2025 MF/UF Membrane Filtration (RO provision 2025)Build base load plant - 9 mgd 365 days yearOver convert dense areas – minimizetransmission linesSurface water delivered to groundwaterplants for distribution and blending tominimize changes in tastePeak water demands met from groundwater
  7. 7. Surface Water PlantSurface Water Plant
  8. 8. Full-scale Plant Location Gannoway Lake Bu rn d ey oa Ro ad s sR Vo
  9. 9. Membrane Treatment Plant
  10. 10. TransmissionLines Take points are City’s water plants Phase I – 2013 Solid Lines Phase II - 2025 Dashed Lines
  11. 11. SWTP - Complex ProjectIntegration of Ground and Surface WaterSupplies - QualityBalance Water Demands to Meet MinimumConversion Requirements - QuantityWinter water demand is only 9 mgd • How to exercise all GW plants and turn water over in tanksComplex Instrumentation and SCADASystems Needed to Achieve Objectives
  12. 12. Water QualityProcess Decisions
  13. 13. Dynamic Source Water Quality High customer expectations Taste test completed in 2009 Goal - customers cannot tell the difference The new SWTP will treat raw water from Oyster Creek that receives water from the Brazos RiverGroundwater Oyster Creek Water
  14. 14. Water Quality GoalsMeet and exceed all regulatoryrequirements Bromate < 5 µg/L THMs/HAAs < 64/48 µg/L for LRAAs Cryptosporidium 4-log removalAesthetic quality goals MIB/geosmin < 5 ng/L (most); < 10 ng/L (peak) Chloride < 180 mg/L (most); < 250 mg/L (peak)
  15. 15. Finished Water Quality Goals Water Quality Parameter Regulation GoalsTurbidity < 0.3 NTU in 95% of time <= 0.05 NTU in 95% of timeGiardia 2 log removal 4 log removalCryptosporidium Based -Raw Water Quality 4 log removalViruses Inactivation > 1 ratio >1 ratioChloramine Residual 0.5 mg/L - 4.0 mg/L 2.5 mg/L - 4.0 mg/LTOC Removal 25% - 45% > 45%Total (TTHM) < 80 mg/L < 64 mg/LTotal (HAA5) < 60 mg/L < 48 mg/LColor (color units) < 15 color units < 5 true color unitsTaste and Odor < 3 TON < 3 TON Geosmin/MIB < 10 ng/L 7.0 - 7.9 as dictated by thepH > 7.0 corrosion control strategyFluoride < 4 mg/L 0.8 mg/LChloride <300 mg/L < 200 mg/LManganese < 0.05 mg/L < 0.015 mg/L
  16. 16. Process Selection Accounted for Source Water Challenges Oyster Creek Treatment Plant Customer Tap Dynamics of source water, treatment, distribution system, and future regulations were considered in process selection
  17. 17. Microbial QualityMicrobial risk factors of source water Wastewater effluents Agricultural runoff Livestock influence Storm water discharges Parameter Units Average Maximum Heterotrophic MPN/ mL 670 740 Plate Counts Total Coliforms MPN/100 mL 2,420 2,420 Microbial Quality - Coliforms, Fecal Coliforms MPN/100 mL 180 689 Pathogens Giardia cysts/L 0.15 0.35* Cryptosporidium oocysts/L 0.27 0.4* *Data from the monitoring location ten miles upstream of Sugar Land Intake Location
  18. 18. Aesthetic Quality 300 30 MIB Geosmin Geosmin (ng/L) 250MIB (ng/L) 200 20 Aesthetic Quality 150 - Taste and Odor Compounds 100 10 50 0 0 800 5/15/07 6/14/07 7/14/07 8/13/07 9/12/07 10/12/07 11/11/07 12/11/07 1/10/08 2/9/08 3/10/08 700 Brazosport Water Authority 600 Brazos River Authority-US290 @ Hempstead Gulf Coast Water Authority 500 Chloride (mg/L) Upstream Location 400 Aesthetic Quality State SMCL 300 - Chloride, TDS 200 100 0 Aug-89 Aug-90 Jan-03 Jan-04 Jun-93 Jun-94 May-95 May-96 Mar-99 Mar-00 Feb-01 Feb-02 Nov-06 Nov-07 Sep-87 Sep-88 Jul-91 Jul-92 Apr-97 Apr-98 Dec-04 Dec-05
  19. 19. Alternatives for T&O RemovalAlternative 1 – Two-stage GAC Lead/lag GACAlternative 2 – Ozone followed by GACAlternative 3 – Single-stage GAC • PAC was considered and eliminated during process short listing phase
  20. 20. T&O Process Selection Life Cycle Assessment
  21. 21. Single-stage GAC Benefits and Drawbacks Benefits DrawbacksSimple to operate Increased GACSmaller footprint replacement frequencyLow operations/maintenanceMultiple barriers withineach contactor(biological + adsorption)Removes EDCs/PPCPs
  22. 22. Single-stage GAC Biological Contactor • Single Stage of GAC is Bio/Filtered Adsorption operated year-round Water Contactor • GAC replacement is staggered Adsorption Contactor To Disinfection Chamber
  23. 23. Key Conclusions
  24. 24. SWTP - Key Design Elements Chloramines Fluoride Chlorine dioxide PACl Caustic Chlorine dioxide Corrosion InhibitorFromOyster ToCreek Distribution PRE - RAPID PLATE MF/UF DISINFECT - CLEAR System SEDIMENTA - GAC ION BASIN TION BASIN MIX CLARI- MEMBRANE -WELL CONTACTORS FIER FILTRATION RO PUMP STATION INDEX Brine Liquid Streams Disposal Solid Streams Backwash Future Option Clarifier • Source Water -Brazos River GRAVITY THICKNER through Oyster Creek • Capacity: Initial - 9 MGD Centrifuge • Ultimate - 22 MGD To Off-site Solids Disposal
  25. 25. Project DeliveryConstruction Manager at Risk
  26. 26. CMAR Project DeliveryTraditional Method: > Design-Bid-Build (DBB)Alternative Method: > Construction Manager At Risk (CMAR)Primary Reasons for Choosing CMAR Benefits of early contractor involvement Project has a high level of technical complexity Project is governed by schedule constraints Preconstruction Service – Constructability Value Engineering Occurs Through Design Process Not After
  27. 27. Why CMAR?Define Goals & Desires: Well functioned, long lasting, & lowest lifecycle cost plant Value engineering during design constructability Operable facility tested Selected a builder during design Open book accounting Owner can provide input in vendor & subcontractor selection Select subs and vendors based on bids and City approval
  28. 28. CMAR SelectionOne Step Selection Process Highlights: - Included 1st year contract operation - Include CMAR Agreement in RFP - Structured the design contract to allow for the CMAR process
  29. 29. Sugar Land’s CMAR ContractThree distinct phases that are authorized separately CMAR Contract 3/10 – 3/14 1. Pre Construction services - VE 2. Construction Phase Services • CMAR becomes general contractor 3. First Year Operations
  30. 30. SWTP ConstructionCMAR GMP Process Two GMPS •Site work - March 2011 •The rest of plant – April 2011 Prequalify venders & subcontractors •Pre-bid meeting on 1/26/11 Obtain bids from pre-qualified vendors andsubs based on 100% design •Anticipate ~20 bid packages Merge and QC bids, obtain City approval Develop construction schedule & cash flow Develop CMAR Agreement Amendments
  31. 31. SWTP Contract OperationScope of Work• One year 24 hours per day full O&M services• Update O&M manual• Manage equipment & construction warranties• Develop O&M costs• Operation optimizationCity staff will operate after the first year
  32. 32. Is It Working?25 VE & Operational Cost Saving Ideas$20 Million in Capital Savings withoutModifying the Original Treatment ProcessCollaborative Owner-Designer-CMARRelationshipDesign Engineer Working HarderCMAR Detailed Budget TrackingAbility to Obtain Competitive Quotes forMultiple, Smaller PackagesLeveraging Current Market Conditions toObtain Most Competitive Pricing
  33. 33. Surface Water Capital Improvement ProjectsSurface Water Plant $69,000,000Transmission Lines $19,700,000Groundwater plant upgrades $8,800,000CIP Construction Estimate $97,500,000 Challenging site constraints Expandability - Some components sized for 2025 expansion or ease of expansion
  34. 34. Raw Water Intake DesignDam Safety
  35. 35. Financial CapacityCity determined that Certificates ofObligation with pledge of GRP fees morecost effective than revenue bonds Lower cost of borrowing No bond coverage required No debt service reserve requirementAnticipated GRP rate in 2013 ~$1.50 per 1,000 gallons of water produced
  36. 36. SWTP - Project MilestonesProcess Pilot Study: November 2008Preliminary Engineering: June 2009Final Design: February 2011CMAR: March 2010 - March 2014 GMP Package #1: March 2011 GMP Package #2 : April 2011Construction: March 2011 – March 2013Plant Operational: March 2013CMAR firm to operate plant first yearCity Staff operations beginning 2014
  37. 37. Plan for Sugar Lands FutureWater Today

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