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1 Achieving the City of Davis WWTP Sustainability Goals Using Envision Kathryn Gies, PE, ENV SP, LEED AP BD+C APWA Sustainability in Public Works San Diego, CA May 15, :00 a.m. Presentation Outline Existing WWTP WWTP Secondary and Tertiary Improvements Project Envision WWTP Improvements Project Sustainability Elements Envision and the Design Build Process 1

2 Presentation Outline Existing WWTP WWTP Secondary and Tertiary Improvements Project Envision WWTP Improvements Project Sustainability Elements Envision and the Design Build Process Where is Davis? 2

3 Existing WWTP Processes Treatment Ponds Overland Flow System 001 Willow Slough Bypass Primary Treatment, Disinfection, and Anaerobic Solids Digestion A Blending of Conventional and Natural Treatment Processes to Achieve High Water Quality Standards Restoration Wetlands 002 Conventional Treatment: Primary Clarification 3

4 Digester Gas Utilization/ Cogeneration for Building Heat Natural Treatment: Ponds 4

5 Natural Treatment: Overland Flow Plant Effluent Stormwater Natural Treatment: Restoration Wetlands Optional Effluent/ Stormwater Connection Wetland Effluent Pump Station Wastewater Ponds Stormwater Ponds Stormwater Ponds 002 5

6 Presentation Outline Existing WWTP WWTP Secondary and Tertiary Improvements Project Envision WWTP Improvements Project Sustainability Elements Envision and the Design Build Process New Effluent Limitations Cannot Be Met with Existing Treatment Facilities Title 22 Tertiary Filtration and Disinfection Ammonia/ Nitrate Metals and Selenium 6

7 Title 22 Filtration and Disinfection Ensures Downstream Water Bodies are Protected for Recreational Uses Ammonia and Nitrate Removal Requires Conventional Activated Sludge Processes 7

8 Metals and Other Priority Pollutants Impacted By Natural Systems Existing natural systems are very effective at reducing selenium concentrations and are likely to perform better than conventional processes Natural systems contribute iron and aluminum (from soil) and can increase salinity Presentation Outline Existing WWTP WWTP Secondary and Tertiary Improvements Project Envision WWTP Improvements Project Sustainability Elements Envision and the Design Build Process 8

9 Envision s Sustainability Categories Quality of Life Leadership Resource Allocation Natural World Climate and Risk Purpose, Community, Wellbeing Collaboration, Management, Planning Materials, Energy, Water Siting, Land & Water, Biodiversity Emissions, Resilience 17 Envision s Award Levels Recognition Level Minimum Applicable Points Points (Based on 708 Total) Bronze 20% 142 Silver Award 30% 212 Gold Award 40% 283 Platinum Award 50% 354 No minimum category percentage required 18 9

10 Presentation Outline Existing WWTP WWTP Secondary and Tertiary Improvements Project Envision WWTP Improvements Project Sustainability Elements Envision and the Design Build Process Quality of Life Comprehensive planning process to maximize available resources Creates local jobs Improved access to public areas (i.e. restoration wetlands) Identify and implement meaningful enhancements to the Restoration Wetlands 20 10

11 Comprehensive Planning Evaluation Found the Most Sustainable Approach (2005) Master Plan (2008) Preliminary Design $200 Million! (2009) Comprehensive Reuse Evaluation (2010) UC Davis Alumni Complete Charrette Report - cuts project costs in half (2011) Design-Build to be used to maximize project efficiencies Quality of Life Local Jobs Are Created as a Direct Result of the Upgrade Project Two key planning team members are headquartered in Davis DB teams will be required to maintain a local hiring program Quality of Life 11

12 The Davis Restoration Wetlands Will Continue Provide a Valuable Community Asset 220 Acres of Permanent Wetlands 44 Acres of Seasonal Wetlands 26 Acres of Riparian Woodlands 108 Acres of Upland Habitat Seeded With All Native Species Quality of Life Leadership A Sustainability Management Plan will be developed that will be followed by the entire project team Significant City-wide commitments to sustainability Regular stakeholder communications Considered other related community infrastructure elements 24 12

13 City-Wide Sustainability Leadership City Leadership Actions: Sustainability Program Manager Comprehensive Bicycles Program Cities for Climate Protection (CCP)/ Climate Change Resolutions Zero Waste Resolution Community Input: Climate Action Team Natural Resources Commission Leadership Infrastructure Synergies: Davis-Woodland Water Supply Project City of Woodland Treatment Facility New Drinking Water Intake On Sacramento River City of Davis Davis WWTP Leadership 13

14 Water Supply/Wastewater Linkages Current/ Water Supply Water Quality Future Discharge Current Current Projected Parmeter Limits Woodland Davis WDCWA Salinity 700-1,000 (EC), 1,660 1,700 <700 (future) uohms/cm Boron, ppb 700 (future) ~2,550 ~1,800 <100 Selenium, ppb 4.4 (Davis) 3.2 (Woodland) < < 0.1 Leadership Leadership (cont.) Comprehensive Maintenance and Monitoring Plan Resolution to conflicting regulations is sought Directed extensions in the design, addressing flexibility, durability and resilience 28 14

15 Conflicting Regulatory Issue #1: Existing Levees Recently Decertified Willow Slough Bypass Existing levees have protected the WWTP site since 1930 The City will eventually fix/replace them Regulatory standards require that WWTPs be protected from flooding adding $4 million in project costs Regional Board is considering relaxing requirements Leadership Conflicting Regulatory Issue #2: No More Wastewater Discharged From the City s Wetlands Wetlands reduce water quality Discharge to water bodies surrounding the wetlands must meet high quality standards Desired strategy would use recycled water instead of valuable groundwater resources Leadership 15

16 Conflicting Regulatory Issue #3: Municipal Drinking Water Designation 001 Willow Slough Bypass Regulatory standards require a higher level of treatment for discharges to Willow Slough Bypass because state law technically designates this water body as a drinking water source (but not the downstream Yolo Bypass) Without regulatory relief, the City will incur an additional $3 million in project costs to construct new outfall pipeline and will put critical habitat at risk 002 Yolo Bypass Leadership Design Will Provide Flexibility For Future Needs Expansion of major treatment facilities by ~25% as a first stage, and by another ~25% in a second stage Advanced nutrient removal Alkalinity adjustment (potential impact from new water supply) Leadership 16

17 Resource Allocation Renewable energy resources used: digester gas and solar panels No net impact on water supply volumes by extensive recycled water use 33 Expanded Energy Generation More than double the biogas generator capacity Expand cogeneration system to heat new building spaces Look to expand solar power system to offset increased energy usage Resource Allocation 17

18 Recycled Water Use Will Minimize Demands on Potable Supplies Only use well water for critical areas and where public safety is a concern Change all existing non-critical well water connections to recycled water All irrigation with recycled water Resource Allocation Natural World At least75% greyfield site and avoids prime habitat Require plant species that are locally appropriate and that minimize need for fertilizers and pesticides. Groundwater protection with ongoing monitoring 36 18

19 Vegetation Management The City currently practices nonchemical vegetation control when possible Replace turf with water-tolerant trees, shrubs, and ground covers that can tolerate irrigation with recycled water and alkaline clay soils Natural World Yolo County Landfill MW-1 MW-2 MW-3 Groundwater Monitoring Wells Groundwater Quality Objectives: EC = 0.9 ds/m NO3-N = 10 mg/l MW-4 MW-6 MW-5 Natural World 19

20 Natural World (cont.) Restore 100% of disturbed solids Ensure existing habitats are not harmed, and compensate for losses. Maintain or enhance at least two ecosystem functions downstream of the discharge point. 39 Biological Resources Near the Project Site Seasonal Wetlands Giant Garter Snakes Burrowing Owls Swainson s Hawk Natural World 20

21 Discharges From the WWTP Create and Maintain Valuable Habitats Natural World Climate and Risk Meet California standards for air quality control Although the project includes many strategies to limit emissions by defining the most sustainable project, documentation and quantification of the impacts of these strategies is not anticipated

22 Presentation Outline Existing WWTP WWTP Secondary and Tertiary Improvements Project Envision WWTP Improvements Project Sustainability Elements Envision and the Design Build Process Design-Build Team Requirements Quality of Life Leadership Resource Allocation Local job creation requirements Conformance with Sustainability Management Plan Develop comprehensive Maintenance and Monitoring Plan Document how required flexibilities are built into the design Use recycled water for all non-critical uses Limit digester gas flaring to less than 10 percent 22

23 Design-Build Team Requirements Natural World Climate and Risk Landscaping requirements Restore 100% of disturbed soils Maintain established separation distances from all identified habitat areas Meet all California Air Quality Standards Estimated Number of Envision Points From on Planning Tasks Only Quality of Life Leadership Resource Allocation Natural World Climate and Risk The City could be awarded estimated 142 Credits Based on Planning Efforts Completed to Date Bronze 46 23

24 Design Build Team Incentives Minimum of 75 points must be achieved through the design and construction process City to define categories where points are allowed to avoid duplication with City efforts Extra credit given if DB team can achieve a minimum of 150 points without significantly increasing project costs Envision Provides Metrics for Assessing DB Team Proposals and Ensures Accountability DB Teams proposals will identify the number of credits that can be achieved for a guaranteed price DB Teams will submit documentation needed to earn credits as the project is designed and constructed Clearly define submission standards ensures the City that sustainability objectives are achieved 24

25 Achieving the City of Davis WWTP Sustainability Goals Using Envision Kathryn Gies, PE, ENV SP, LEED AP BD+C Kathryn Gies West Yost Associates (925) Westyost.com 25