Infrastructure Integrity and Climate Change: Metro Vancouver Case Study

1. Infrastructure Integrity and Climate Change: Metro Vancouver Case Study Brent Burton, M.A.Sc., P.Eng. Utility Analysis and Environmental Management Division Policy and Planning Department Metro Vancouver APEGGA Professional Development Sessions Infrastructure Integrity – Climate Change Impacts and Adaptation Shaw Conference Centre, Edmonton, Alberta April 18, 2008 ????????

2. Outline • Background on Metro Vancouver • Existing role in water supply and wastewater • Adaptation and Metro Vancouver • Metro Vancouver sewerage case study • Next Steps

3. Metro Vancouver • Common name of several legal entities including Greater Vancouver Water District and Greater Vancouver Sewerage and Drainage District • Partnership of 21 municipalities and one electoral area • Board comprises elected officials from member municipalities • Services a population exceeding two million (projected 2.7 million by 2027) and a land area of approx 280,000 ha

4. Role of Metro Vancouver • Delivery of utility services most effectively and efficiently provided on a regional basis • Protection and enhancement of quality of life in the region

5. Role in water supply • Supply water to most of region from three mountain reservoirs • Reservoirs are typically spilling about 9 months a year • High demand in summer (outdoor water use) • Largely supplied by gravity during winter

6. Role in wastewater • Maintain and operate major interceptor sewers • Maintain and operate 5 treatment plants AAD (MLD) = 98 AAD (MLD) = 603 AAD (MLD) = 11 AAD (MLD) = 78 AAD (MLD) = 510

7. Liquid waste planning • Policies and commitments identified in Liquid Waste Management Plan (approved by Province in 2002) • Climate change not specifically identified in LWMP • Currently undergoing regularly-scheduled 5-year review and update

8. Metro’s role and climate change adaptation • Mitigation activities (GHG reduction) already well established by late 90s via air quality role, but… • Awareness of need for adaptation still developing • Adaptation issues first formally reviewed in an overview in 2000: • Adaptation Strategies for Utility Planning (Environment Canada) • Identifies climate projections and briefly outlines potential impacts (rising sea levels, spring flooding, summer drought, etc.)

9. Metro’s role and climate change adaptation for wastewater infrastructure • Focus on precipitation analysis for wastewater systems in 2002 • Development of GVRD Precipitation Scenarios (KWL Consulting) • Comprehensive analysis of historical precipitation and future projections, • Identifies patterns of increased rainfall • But likely yet “…no urgent need to upgrade the capacity of combined sewers, storm sewers and drainage systems.” • But situation needs to be monitored and periodically re-assessed…

10. 2004: Increasing recognition of need for adaptation in engineering practice

11. 2005: Drinking Water Management Plan • A number of recent studies used to identify climate change impacts / adaptations • Some impacts / adaptations related to ensuring sufficient water stored for summer months and increased efforts at DSM • Climate change may move forward the date when storage increase required (i.e. dam raising, lower intakes and alpine lakes) by approximately 10 years.

12. And then there was 2007… • IPCC report released early in the year • GVRD Historical and Future Rainfall Analysis Update (Pacific Climate Impacts Consortium) • Generally affirms KWL conclusions • Identifies more evidence of statistically-significant trends of increased rainfall (especially short duration storms in spring) • Political Board requests update on adaptation activities

13. Engineers Canada and vulnerability assessments • Staff membership on Water Resources Expert Working Group and Stormwater / Wastewater Expert Working Group • Staff determined that wastewater vulnerability assessment needed most urgently • At staff request, Board approves partnership with Engineers Canada in study of wastewater infrastructure vulnerability

14. Initiating vulnerability assessment • Agreement developed between Metro Vancouver and Engineers Canada • Working with Engineers Canada, staff issued Request for Proposal focussing on Vancouver Sewerage Area • KWL Consulting awarded contract • Lead: Andrew Boyland, P.Eng. • Associated Engineering • Treatment Sub-Consultant • Dean Shiskowski, Ph.D, P.Eng.

15. Local Geography of VSA North Shore Mountains Burrard Inlet Iona Island WWTP Fraser River Strait of Georgia

16. Quick Facts:Vancouver Sewerage Area • Service Population: 600,000 • Service Area: 13,000 ha • Predominantly serviced by combined sewers • Combined sewer overflows during wet weather • Approximately 40% serviced by separated sanitary sewers • Wastewater drains to Iona Island Wastewater Treatment Plant • As well as City of Vancouver, VSA includes all of UBC and part of the cities of Burnaby and Richmond

17. Regional collection system

18. Climate Quick Facts:Vancouver Sewerage Area • Located in a west-coast marine climate zone • Regional climate highly influenced by El Nino Southern Oscillation and Pacific Decadal Oscillation (additive or mitigating) • Generally subject to west to east weather patterns • Winter climate dominated by repeated cyclonic storms (long duration precipitation of moderate intensity) • Rainfall • Annual rainfall is typically about 1,800 mm • One day maximum rainfall about 73.1 mm • Typically highly variable through region due to geography • Temperatures • January temperatures average about -0.6 to 5 deg C. • August temperatures average about 11 to 23 deg C.

19. Quick Facts on Liquid Waste Management Plan • Sewer separation is major long-term strategy outlined to address CSOs • Commitment to eliminate CSOs by 2050 with interim rates of sewer separation • Most regional sewers, once fully separated, would be transferred to City ownership • Iona upgrade to secondary by 2020 • Iona to maintain 17 m3/s peak flow capacity

20. Infrastructure components considered upstream of treatment plant • Wastewater Infrastructure and Collection System • Combined Sewer Trunks • Pump Stations & Wet Wells • Force Mains • Siphons • Outfalls • Manholes • Flow & Level Monitors • Grit Chambers • Flow Control Structures • Control Valves • Air Valves

21. Iona Island Wastewater Treatment Plant • Began operating in 1963 • Primary treatment • Current plan is to upgrade to secondary by 2020 • Discharges through a 7 km deep sea outfall to Strait of Georgia (90 m below sea level) • 2007 AAD = 603 MLD

22. Infrastructure components considered at treatment plant • Process, hydraulic and supporting infrastructure • Screening • Influent pumping • Grit removal • Primary clarification • Sludge thickening • Sludge digestion • Sludge lagoons • Treatment liquid stream • Effluent disposal • On-site pipelines • Buildings, tankage and housed process equipment • Standby generators

23. Timelines and general climate factors • Focus on 2020 and 2050 (i.e. no 2080 scenario) • Climate modelling by OURANOS suggested that by 2020 and, to a greater extent by 2050, we can expect: • Increased rainfall, including more frequent and more intense rainfall events • Rises in the sea level • Increases in storm surge, floods and extreme gusts

24. Detail climate factors • 2050 Horizon • *Intense Rain – (24 hr – 73mm) ➚17% increase • *Annual Rain – (1881mm) ➚ 14%increase • *Sea Level – 0.3 – 1.6m (2080 Horizon) increase • *Storm Surge – N/A, expected increase • Temperature – 1.4 – 2.8c increase • Drought – no change (20 days) • Wind – N/A, expected increase

25. Climate factors • Snowfall – decrease • Frost, Ice, Freeze Thaw – decrease • Other Effects: • Flooding – Fraser River - decrease (?) • Ground Subsidence – 2mm/yr • Data Gaps: • Rainfall IDF curves, shorter durations • Wind, Storm Surge

26. Key Vulnerabilities • Key Vulnerabilities • Combined Sewer Overflows (CSO) • Intense rain, annual rain • WWTP Flooding • Combined effects of storm surge, sea level rise and subsidence • Effluent Disposal – outfall/jetty structure • Storm surge, wind/wave effects Photo: Corporation of Delta

27. Detail vulnerabilities

28. Policy Recommendations • Important to use this information in: • Review and update of the Liquid Waste Management Plan (i.e. regional design standards / commitments related to climate change, reaffirming commitments to green infrastructure?) • Next phase of treatment upgrading (i.e. designing secondary treatment to accommodate sea level rise and storm surge) • Reaffirming timelines and commitments to sewer separation

29. Technical recommendations • Further study suggested to determine increase in sewer flows • Further study suggested to determine if additional sewer separation effort required to eliminate CSOs by 2050 • Identify stand-by power requirements • Assess potential for WWTP flooding

30. Cross-cutting issues (?) for other communities • Combined Sewers may have ‘built-in’ adaptive capacity. • Designed to overflow in controlled manner • Many built when sizing was empirical. (i.e. big enough for a person to walk through) • Mitigation of CSOs and reduction of risk consistent with sewer separation and can be consistent with adaptation (if new climate data considered) • Climate data uncertainty • Regional models unable to account for local effects (wind speed & direction, storm surge, extremely variable geography) • Expense/practicality limited the model runs to two initial conditions (same GHG scenario)

31. Cross-cutting issues (?) • Infrastructure vulnerability issues more cross-cutting than climate change factors? • i.e. climate change factors possibly only relevant to Vancouver (mild coastal effects), but the “infrastructure deficit” is more cross-cutting • Process highlights ongoing management actions • i.e. complete emergency response plan, review standby power availability • Design assumptions for very old infrastructure often not readily available • i.e. to determine basis of capacity

32. Next steps for Metro Staff • Report to Regional Engineers Advisory Committee • Consists of most senior engineer from each member municipality • Discuss and finalize technical recommendations • Report to Waste Management Committee and Board • With recommendation for further actions and studies for this and other aspects of our utilities • Major policy decisions ($$$) need Board approval

33. Questions? Metro Vancouver Sewerage Area Case Study