Metro Vancouver I&I Reduction Measures

Transcription

1 ,000 DETERMINATION OF RELATIONSHIP BETWEEN I&I RATE AND SANITARY SEWER AGE 5 to 100 Year Age-of-Sewer 5-Year 24-Hour I&I Rate,000,000 y = e x,000,000,000,000,000 y = x ,000, Metro Vancouver I&I Reduction Measures metro vancouver Aby Sharma, P.Eng. Andrew Boyland, P.Eng. 1

2 Outline Aby History of project: Role of Metro Vancouver Description of Problem (SSOs) LWMP progress Andrew I&I reduction: Municipal (ToL, CoL, CoS, CoC) work Literature Review I&I Management Approaches 2

3 Objectives 1 Identify I&I reduction measures taken by 4 Metro Vancouver municipalities tributary to two chronic sanitary sewer overflows 2 Evaluate effectiveness of I&I reduction measures across North America 3 Identify further steps needed by Metro Vancouver municipalities to control I&I within manageable levels. 3

4 Metro Vancouver - Background Population +/- two million, approx 280,000 ha Partnership of 21 municipalities and one electoral area

5 Role of Metro Vancouver Delivery of utility services most effectively provided on a regional basis Protection and enhancement of quality of life in the region 5

6 SSO Locations Coquitlam Surrey City of Langley Langley Township 6

7 ILWRMP (Integrated( Liquid Waste and Resource Management Plan) LWMP process Last LWMP approved 2002 New ILWRMP pending Metro Vancouver Board and Ministry approval Relevance of this project findings have been used in the development of the new ILWRMP 7

8 GVRD 2002 LWMP - Commitments P8 average daily infiltration and inflow will not exceed 11,200 l/ha/day (five year return period storm) C19 - municipalities will determine the condition of the entire system over a 20 year time cycle

9 GVRD LWMP - Commitments C23 Biennial Progress Report Map of current system evaluation Results of flow monitoring Summary of expenditures on evaluation, repair and replacement Extent of sewer repair, replacement, installation over 2 year period Location and frequency of overflows

10 Metro Vancouver ILWRMP Currently, targets I&I to 11,200 L/ha/d (region-wide) Attempts to prevent sanitary overflows from storms < 5yr, 24hr New Plan being reviewed by Board Develop a template for an I&I management plan Develop inspection/certification program for private laterals as a component of real estate sale Develop target allowances for 1:5 yr I&I within each municipality 10

11 Metro Vancouver ILWRMP Additional I&I actions: Review I&I progress every 4 years Enhance enforcement of unauthorized storm discharge into sanitary system Watershed based research Identify on-site rain management opportunities Decrease liquid waste volumes through water consumption initiatives 11

12 Part 1 Local Municipal Efforts 12

13 SSO Locations Coquitlam Surrey City of Langley Langley Township 13

14 Cloverdale Pump Station Problem: Chronic SSOs upstream of PS Discharge to local field Solution: Storage Tank 14

15 Maillardville Trunk Problem: Chronic SSOs at several manholes Discharge in urban environment Solution: Trunk capacity upgrade (Twinning) pre-build for future growth 15

16 I&I Reduction Efforts Biennial Reports All municipalities (except one) are using CCTV 16

17 I&I Reduction Efforts 50%+ conducting flow monitoring for I&I measurement 17

18 I&I Reduction Efforts 50%+ conducting smoke and dye testing to identify storm drainage cross connections 18

19 I&I Reduction Efforts 33% have adopted the GVRD Sewer Condition Reporting Template to estimate I&I rates and perform sewer condition assessments 19

20 I&I Reduction Efforts Only 3 municipalities have experimented with private service lateral improvements Pipe Bursting Service Laterals 20

21 Surrey: Specific Actions by Four Municipalities Pilot programs examining rehab effectiveness Grouting (mainline + service lateral interface) resulted in: No I&I reduction! 21

22 Surrey I&I Reduction Legislation Authority for Private Services Bylaw 2240 No person shall connect any roof drains, tile or conduit collecting surface drainage or rainwater runoff in any way to the sanitary sewer, or drain or permit to be drained into the sanitary sewer any storm water or surface water. 22

23 Langley Township I&I Reduction Trenchless repair of trunk sewer adjacent to Bertrand Creek Raising M/Hs, replacing missing IC caps 23

24 Langley Township I&I Reduction CCTV entire system in 3 years Elimination of storm water cross connections 15-36% decrease in I&I rates 8,000 32,000 L/ha/d 24

25 City of Langley I&I Reduction Flow Monitoring 7 catchments 4,000 17,000 L/ha/d Ongoing structural repair 25

26 Coquitlam I&I Reduction $900,000 spent on sewer repair and replacement over 4 years I&I study concludes I&I < 11,200 L/ha/d 26

27 Part 2 North American Survey 27

28 Pilot Studies North America I&I Reduction Targeted Programs Full Basin Programs Unit Cost 28

29 Mainline Grouting Only 29

30 Public Lateral Rehab 30

31 Private Lateral Rehab 31

32 Possible Rehab Target Level 40,000 L/ha/d 20-Yr Peak Hour ~22,000 L/ha/d 5-Yr 24 Hour 32

33 I&I Increases over time Pipe deterioration Abandoned sewer laterals Illegal storm connections 33

34 PVC AC VIT Extreme I&I RATE (L/ha/d) 36 Basins in CRD & Metro Vancouver Relationship for all pipes Upper Envelope Relationship for < 40 year-old pipes AVERAGE CATCHMENT AGE (YEARS) 34

35 Effects of Climate Change Metro Vancouver VSA + FSA Study Rainfall: +7% 24-hour max by 2020 s +17% 24-hour max by 2050 s +9% total annual by 2020 s +14% total annual by 2050 s 35

36 Part 3 Proposed Controls 36

37 So many connections, so few buildings 37

38 Private Laterals Tuesday 1:50pm David Dunkley (Metro Vancouver) Addressing Private Sector Laterals Is it Time? Approaches and Legal Authority of Metro Vancouver Municipalities. Replace after 50 yr, Inspect after 10 yr upon property sale 38

39 Three Approaches to I&I and Rehab Cycles Year Replacement 2. Targeted 25-Year Rehabilitation 3. Meet regional L/ha/d target 39

40 100-Year Replacement Cycle 5-Year, 24-Hour I&I After rehabilitation, Pipe segment returns to lower I&I values Based on a 100-year replacement cycle (1% funding), a pipe Segment is rehabilitated Every 100 years. 0 Average Pipe Age 100 (years) 40

41 Extreme I&I RATE (L/ha/d) Relationship for all pipes Upper Envelope Relationship for < 40 year-old pipes AVERAGE CATCHMENT AGE (YEARS) 41

42 Long-Term Extreme I&I Rate Management 1%/Year Replacement to 11,200 L/ha/day 53,000 Extreme Envelope Starting at 34,000 L/ha/day i.e. when system is 50 years old 1%/Year Replacement to 6,800 L/ha/day 2%/Year Replacement to 11,200 L/ha/day 2%/Year Replacement to 6,800 L/ha/day 39,000 27,000 17,000 *Assumes the < 40 year linear I&I-age relationship 42

43 100-Year Replacement Replace or repair 1% per year Replace public portions of system at unit cost of ~$1,000/m Annual investment rate $10/m Post-repair I&I rate 6,800 L/ha/d End up at ~39,000 L/ha/d Pay for higher conveyance costs and upsize trunk facilities & WWTPs 43

44 Targeted 25-Year Rehab Monitored Results I&I-Age Curve 250,000 I&I RATE (L/ha/d) Total I&I (L/ha/day) 200, , ,000 Likely choices for rehab Bring back to line Typical I&I (CRD + Surrey) 50,000 0 Wait until later Average Catchment Age (Years) 44 AVERAGE CATCHMENT AGE (YEARS)

45 Targeted 25-Year Rehabilitation Apply to 4% of system per year Unit cost $ /m Annual investment rate $8-12/m Estimated post-rehab rate at 22,000 L/ha/d Long-term I&I 30,000 L/ha/d 45

46 Meet Target of 11,200 L/ha/d Rehab > 2% per year to brand new condition (6,800 L/ha/d) Full-basin approach $1,500-2,500/m unit cost Annual investment rate $30-50/m Savings on future upsizing & conveyance costs 46

47 How is everyone doing? Metro Vancouver Sewer Renewal Rates by Municipality 2004 and 2006 Biennial Reports $60 $50 $40 Meet LWMP Target of 11,200 L/ha/d $/m $ $20 $ Year Replacement, or 25-Year Targeted Repair $0 Municipalities 47

48 Go-Canucks Canucks-Go GO-CANUCKS-GO 48 Photo: Jeff Vinnick

49 Questions? Aby Sharma, P.Eng. Senior Project Engineer Metro Vancouver, Policy and Planning (604) metro vancouver Andrew Boyland, P.Eng. Infrastructure Planning Engineer Kerr Wood Leidal Associates Ltd. (604)

50 I&I Envelope Method Rainfall Return Period I&I Most Saturated Event (Upper Envelope) SOIL SATURATION Least Saturated Event (Lower Envelope) RAINFALL 50

51 Convert 25 Year 5 Year 51