One Sustainable Water Solution Water Wastewater - Groundwater DAVIS-WOODLAND WATER SUPPLY PROJECT

Transcription

1 One Sustainable Water Solution Water Wastewater - Groundwater DAVIS-WOODLAND WATER SUPPLY PROJECT

2 Overview Project Drivers Partnerships Implementation Water Supply Management

3 Tale of Two Cities City of Davis City of Woodland Population: 66,000 University (UCD) / Emerging Tech / Residential 100% Groundwater Population: 56,000 Residential / County Seat (Gov.) Agriculture 100% Groundwater

4 Regional Groundwater Issues Studied Surface Water Project Evolved Project Gained and Lost Momentum

5 Overview Project Drivers Partnerships Implementation Water Supply Management

6 Drinking Water Issues 100% Dependent on groundwater Aging water infrastructure Degrading groundwater water quality Increasingly stringent drinking water regulations Customer dissatisfaction

7 Well Shutdowns 15s 22g Woodland EM3 21 EM Davis Well shut downs Active wells

8 Woodland Aging Well System years is the typical lifespan of a well Age (years) s g

9 City of Davis Well Nitrate Levels Concentration (mg/l) Drinking Water Limit = 45 mg/l Historic Projected

10 Compliance with Hexavalent Woodland 17 of 19 active wells are non-compliant Davis 11 of 19 active wells are non-compliant Chromium Standard

11 Wastewater Discharge Compliance Issues Increasingly restrictive wastewater discharge regulations Constituents: Selenium Salinity Boron

12 Major Wastewater Concerns Constituent Anticipated Future Discharge Limit Woodland 2011 Discharges Davis 2011 Discharges Salinity, EC, µmhos/cm ~1,560 ~1,900 Selenium, ppb 3.2 (Woodland monthly avg.) 4.4 (Davis monthly avg.) < Boron, ppb 700 ~2,550 ~1,800 12

13 In 2009: The Scales Tipped and Urgency was Injected into the Project Wastewater Regulations (Salinity/Selenium) Threat of Lost Opportunity Opportunity to Purchase Additional Water Rights Obstacles Objections

14 Overview Project Drivers Partnerships Implementation Water Supply Management

15 Project Partners Intake Reclamation District 2035 Davis-Woodland Water Supply Project City of Davis City of Woodland University of California, Davis

16 FORMED September 15, 2009 JPA Funded Davis and Woodland UC Davis, a Contracting Agency Governing Board: - 2 council members from each city - Non-voting representatives from UC Davis & Yolo County User fees in each city; cost sharing based on capacity allocation

17 Public Participation WDCWA Website and Newsletters Davis Water Advisory Committee Woodland Water Rate Advisory Committee Two Davis Public Votes: 1. Proceeding with project 2. Water rates Photo: Davis Enterprise Project sizing/optimization

18 Overview Project Drivers Partnerships Implementation Water Supply Management

19 Project Goals and Objectives Quantity & Quality Regulations Environmental Diversify Sustainable GW Conservation Improve water supply quantity and quality Comply with drinking water & wastewater discharge regulatory requirements Provide environmental benefits and minimize impacts Diversify supply portfolio to improve supply reliability Allow sustainable groundwater pumping integrated with ASR wells Integrate water conservation elements

20 Project Alternatives Analysis Alternative Alternative Alternative Alternative Alternative Alternative Alternative Alternative Alternative Alternative Alternative Alternative Alternative Alternative Alternative Alternative Alternative Alternative Over two dozen alternatives considered Only groundwater treatment and surface water meet objectives Surface Water Most feasible, lowest cost and least environmental impact Groundwater Treatment Over twice as costly, creates major environmental concerns

21 Water Quality Constituent Groundwater Sacramento River Salinity (EC, µohms/cm) 460 2, Boron, ppb 470 2,300 <100 Selenium, ppb 0-45 <0.1 Nitrates, ppm 1-40 <1 Chromium VI, ppb 1-38 <0.25 Iron, ppb Manganese, ppb <15 Sources: Woodland & Davis Annual Water Quality Reports for groundwater; 2009 treated water quality reports for West Sacramento water treatment plant for Sacramento River

22 Projected Wastewater Discharges Constituent Anticipated Future Discharge Limit Projected WDCWA Salinity (EC, uohms/cm) Selenium, ppb < (Woodland monthly avg.) 4.4 (Davis monthly avg.) < 0.1 Boron, ppb 700 <100

23 Davis-Woodland Water Supply Project Intake Treatment Plant Transmission Mains New 400 cfs maximum combined diversion New 30 mgd Water Treatment Plant 9.9 miles of new inch diameter water transmission mains 4.5 miles of raw water transmission mains

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25 Project Delivery Evaluation Risk allocation Lack of trained operations staff Implementation schedule Rate impacts

26 Delivery Alternatives Design-Bid-Build Single contract Multiple for pipelines Alternative Delivery Design-Build Design-Build-Operate

27 Design-Build-Operate Initial DWWSP Concerns Is this private ownership? Are we stuck with private operations forever? Who controls water rates?

28 Faster Delivery Cost Savings Design-Build-Operate Early Price Certainty Encourages Innovation Benefits Collaborative Selection and Negotiation Process Singular Responsibility Appropriate Allocation of Risk Long-Term Operations

29 Delivery Methods Selected Design-Build-Operate Treatment Plant & Transmission Pipelines Design-Bid-Build: Intake City distribution pipelines

30 Owner/Owner s Rep Quality Assurance/ Contract Compliance Design Construction Quality Control Design-Build- Operate Firm Testing & Startup Schedule Operation & Maintenance Submittal & RFI Response Construction

31 DBO Service Agreement Guaranteed Price for performance Compliance with drinking water standards Treated water delivery to meet demands Timely project completion Pre-approval of subcontractors and key personnel Uncontrollable circumstances Local employment and contracting Incentive for energy efficiency

32 Advantages of Including Operations in Contract Qualified operations staff End of term guarantees Facilities repair and replacement program Guaranteed maximum energy use

33 Joint Intake Under Construction Existing RD 2035 Intake

34 Benefits of a Joint Intake Avoids construction of two intakes Decreases the cost to both entities Replaces largest unscreened intake on the Sacramento River Provides RD 2035 with financial backing if grant funds are delayed

35 Water Treatment Plant Photo by Multivista

36 Treatment Process Ability to meet highly fluctuating turbidity levels Intermediate ozone disinfection Meets existing Drinking Water Standards Anticipates future Drinking Water Standards (PCP, Contaminants of Emerging Concern, etc.)

37 Project Costs Regional Construction Costs Project Component Cost UCD DBO Contract $ WOODLAND DAVIS Agency Quality Assurance & Contract Compliance $7.79 Joint Intake $16.52 TOTAL $ Total Capital Costs: $279.2

38 Project Funding Intake Federal/State Grants Local WDCWA Share Project State Revolving Fund Loans (SRF) Safe Drinking Water SRF Clean Water SRF SRF saves customers over $130 million in loan interest payments

39 Project Implementation Schedule Financing 2011 Permitting Land Acquisition Pre-Design Water Right Permits DBO Procurement Financing 2010 Permitting Pre-Design 2012 Design/Permitting Land Acquisition DBO Procurement 2014 Regional/Local Facilities Design & Construction Intake Construction Financing 2013 DBO Contract Negotiation Permitting Land Acquisition Project Optimization Local Facilities Design Financing 2015 Intake/Pipelines/Water Treatment Facility/Local Facilities Construction 2016 Completion of Construction System Testing Start-up and Operation D E S I G N C O N S T R U C T I O N O P E R A T I O N

40 Overview Project Drivers Partnerships Implementation Water Supply Management

41 Balancing Supply and Demand Demands/Plant Sizing Supply Yield Analysis Supplemental Supply Sources Treated Surface Water

42 Surface Water Supply WDCWA Water Right Permit 1994: Initial application filed 2011: SWRCB Adopted Decision ,000 af / 80 cfs Subject to Term 91 curtailments Water Right Purchase/ Contract Assignment 10,000 acre-feet/yr Available April - October Subject to Shasta Critical Year reductions

43 Supply Source Issues Surface Water 0 to 7 (Average 3) Month Term 91 Curtailment Up to 25% Reduction - Shasta Critical Year Ground Water Drinking Water Standards/Discharge Regs Customer Satisfaction Aquifer Storage & Recovery ASR Injection and extraction capacity Storage capacity and extraction efficiency

44 Water Supplies ASR/ Supplemental Supplies (primarily Woodland) Municipal Groundwater (Davis: Deep aquifer wells; Woodland: Emergency GW use only) Purchased Water (available Apr Oct; subject to Shasta critical years) Agency Water Right (subject to Term 91 curtailments)

45 ASR Program ASR Supply/Demand Analysis Aquifer Characterization Geochemical Evaluations Injection/Extraction Testing Groundwater Flow Modeling Water Right Modifications/Permitting

46 Distribution of Water Supplies and ASR Potential, Year 2025, Typical Year Conditions

47 Integrated Water Supply Solution Surface Water Supply Climate Change Term 91 Curtailments Settlement Contract Reductions Woodland & Davis Groundwater Woodland ASR Additional Supplemental Supply Needs

48 More Information Lindsay Smith, PE West Yost Associates