TO REPLACE? TO REHAB? TO UPSIZE? THAT IS THE QUESTION.

Transcription

1 TO REPLACE? TO REHAB? TO UPSIZE? THAT IS THE QUESTION. CITY OF IRVING WASTEWATER SYSTEM MASTER PLAN Jessica Brown, P.E. Thomas Haster, P.E. Freese and Nichols, Inc. April 16, 2009

2 ACKNOWLEDGEMENTS City of Irving Todd Reck, P.E. Steve Pettit, P.E. David Canady Freese and Nichols Nick Dons, P.E. Corrie Bondar Nelson Esquivel Charles Wilmut, GSWW 2

3 BACKGROUND & TRENDS IN IRVING 2008 Population 214,073 Wholesale Customer of TRA 3.8 Million Linear Feet of Sewer Pipe up to 54 in size Aging Infrastructure in Southern Portion of the City Major Redevelopment Major Highway & Transit Expansions Texas Stadium 3

4 PROJECT DRIVERS Compliance with the TCEQ Sanitary Sewer Overflow Initiative (SSOI) Agreement Upcoming Growth and Redevelopment Desire to Prioritize System Renewal Need to Plan Utility Relocations into CIP Process 4

5 WASTEWATER SYSTEM MASTER PLANNING PROCESS GIS Update for Larger WW Infrastructure gories Hydraulic Capacity Analysis Wastewater Model Development Flow Monitoring & Model Calibration ng Cate Screeni Condition Analysis TxDOT/ Development Conflict Analysis RISK BASED PRIORITIZED CAPITAL IMPROVEMENT PLAN Wastewater Flow Projections & TRA Coordination 5

6 CRITICALITY OF THE WASTEWATER ASSETS What is the Consequence of a Sewer Line or Lift Station Failing? Criticality parameters to consider: Number of Upstream Wastewater Connections Line Size and Access Issues Proximity to: - Environmentally Sensitive Areas - Schools / Hospitals - Major Road Crossings - High Density Commercial Developments 6

7 CRITICALITY OF THE WASTEWATER ASSETS Develop a grading system that scores each asset by the impact of a failure on the sewer system ASSET CRITICALITY SCORING LEGEND FOR IRVING Score Asset Criticality Scoring Definition Low Lines serving < 1000 connections. Medium Lines serving 1000 connections but < 3000 connections.. High Lines serving 3000 connections and within 1000 ft of a waterway; or within 200 feet of a major road. Very High Lines serving 3000 connections and in close proximity to high density commercial developments. 7

8 CONDITION O OF THE WASTEWATER ASSETS S What is the Likelihood of an Asset Failing? Develop a grading system that scores each asset by its condition. Condition parameters to consider: Pipe Diameter SSO, sewer stop & work order history Material CCTV condition assessment Age data Level of infiltration/inflow Pipeline corrosion Soil conditions What parameters have data available and are applicable and how should they be weighted? Irving Total Condition Assessment Score (100 pts maximum) = (Material) + (Age) + (I/I) + (SSO & Sewer Stop History) + (Pipeline Corrosion) 8

9 CONDITION SCORING & PARAMETER WEIGHTING WASTEWATER CONDTION PARAMETERS & WEIGHTING SYSTEM FOR IRVING Pipe Material (max = 25 pts) RCP = 25 points VCP = 21 points UNKNOWN = 19 points CI = 19 points DI = 13 points PVC/HDPE = 3 points FIBERGLASS/CIPP = 2 points Pipe Age (max = 25 pts) Before 1960 = 25 points 1960 to 1970 = 20 points 1970 to 1980 = 15 points 1980 to 1990 = 10 points 1990 to 2000 = 5 points After 2000 = 2 points SSOs & Stoppages (max = 20 pts) Infiltration/Inflow ti fl (max = 15 pts) (over the last 3 years) One or more SSOs = 20 points Wet Weather Peaking Factor 4.0 = 15 points Three or more Sewer Stoppages = 18 points Wet Weather Peaking Factor 3.0 = 11 points Two Sewer Stoppages = 12 points WtW Wet Weather Peaking Factor = 6 points One Sewer Stoppage = 6 points Wet Weather Peaking Factor < 2.5 = 0 points No SSOs or Sewer Stoppages = 0 points Pipeline Corrosion (max = 15 pts) Moderate to Heavy Corrosion = 15 points Light to Moderate Corrosion = 7 points No Corrosion = 0 points 9

10 CONDITION OF THE WASTEWATER ASSETS Determine the total condition score for each asset and group total asset scores into five general categories: CITY OF IRVING CONDITION ASSESSMENT SCORING LEGEND Score Condition Assessment Scoring Definition Very Good Sound physical condition. Total Score < 25 Good Fair Poor Acceptable physical condition. 25 Total Score < 40 Significant deterioration evident. 40 Total Score < 55 Failure likely in short to medium term. 55 Total Score < 70 Very Poor Failed or near failure. Total Score > 70 Major work or replacement required urgently. 10

11 CONDITION OF THE WASTEWATER ASSETS 11

12 CAPACITY OF THE WASTEWATER ASSETS Use the existing system wastewater model to predict areas of system deficiency for future defined planning period CAPACITY ASSESSMENT SCORING LEGEND Score Capacity Assessment Scoring Definition Very High Model predicted overflows during the design storm (Overflowing) High Medium Model predicted surcharge, ratio of flow to pipe capacity, q/q > 2.0 but HGL within 1 feet of rim elevation (Extensive surcharging) g) Model predicted surcharge, ratio of flow depth to pipe diameter, 1.0 d/d 2.0 (Surcharging) Low Model predicted no surcharge (Pipe has excess capacity) 12

13 CAPACITY OF THE WASTEWATER ASSETS 13

14 CAPACITY SCREENING PROCESS Risk Rating = Capacity x Consequence Score Facility Capacity Score Low Medium High Very High Conse equence of Failure Sc core Low Impact Medium Impact High Impact (12) 882 Segments 57.6 Miles 136 Segments 9.0 Miles (10) 245 Segments 10.3 Miles (7) 5 Segments 0.4 Miles (3) 41 Segments 3.9 Miles (11) (8) (5) (2) 39 Segments 2 Segments 2.3 Miles 0.0 Miles 383 Segments 22.2 Miles 34 Segments 3.2 Miles (5) (6) (4) (1) 211 Segments 5 Segments 16.9 Miles 0.3 Miles 14 Segments 1.3 Miles SHORT TERM CRITICAL NEEDS 14

15 CAPACITY SCREENING PRIORITIES Projects from Categories 1, 2, & 3 (Red Matrix Boxes) Identified for CIP Project Project Cost Total Cost 1 42-inch and 48-inch Delaware Creek Interceptor Capacity Improvements Priority Capacity Rank (1) Percent of Maximum Flow (2) $5,250, % 2 15-inch Interceptor along Carl Rd. South of Highway 183 in Southeast Irving. $1,047, % 3 18-inch Interceptor North of Grauwyler Rd. along Story Rd. in the Delaware Creek Basin $726, % 4 36-inch Interceptor from Grauwyler Rd. Northeast to Rochelle St. in South Irving. $3,171, % 5 21-inch Interceptor North of Highway 183 along Rochelle St. in Central Irving. $1,451, % 6 15-inch, 18-inch, & 21-inch Interceptor along Mac Arthur Blvd in South Irving. $2,122, % 36-inch & 42-inch Interceptor Line North of 7 Grauwyler Rd in Central Irving $ % Project Driver: Over flowing manholes = TCEQ regulatory violation Over flowing manholes = TCEQ regulatory violation Over flowing manholes = TCEQ regulatory violation Over flowing manholes = TCEQ regulatory violation Over flowing manholes = TCEQ regulatory violation Over flowing manholes = TCEQ regulatory violation High flows and some surcharging contributes to upstream manholes overflowing 7 Grauwyler Rd. in Central Irving. $2,255, % contributes to upstream manholes inch Interceptor North of Shady Grove Rd. along Bowman St. in Southwest Irving. $977, % 9 15-inch Interceptor Crossing Rochell Rd. in Northeast Delaware Creek Sewer Basin $556, % Total $17,557,900 Over flowing manholes = TCEQ regulatory violation Over flowing manholes = TCEQ regulatory violation Notes: (1) Represents prioritized capacity rank. Lower number indicates higher risk (2) Represents the maximum modeled flow in the pipe as % of pipe capacity 15

16 CONDITION SCREENING PROCESS Risk Rating = Condition x Consequence Score Facility Condition Score Very Good Good Fair Poor Very Poor Consequ uence of Fa ailure Score Low Impact Medium Impact High Impact (15) 490 Segments 26.6 Miles (14) 89 Segments 4.9 Miles (12) 184 Segments 10.1 Miles (13) 395 Segments 26.2 Miles (11) 29 Segments 2.0 Miles (5) 143 Segments 11.3 Miles (10) 195 Segments 11.7 Miles (8) 57 Segments 4.3 Miles (6) 182 Segments 12.3 Miles (7) 104 Segments 6.4 Miles (5) 8 Segments 0.6 Miles (3) 16 Segments 1.5 Miles (4) 9 Segments 0.8 Miles (2) 25 Segments 2.3 Miles (1) 0 Segments 0.0 Miles SHORT TERM CRITICAL NEEDS 16

17 IS THERE A ONE SIZE FITS ALL ANSWER? REPLACEMENTVERSUSREHABILITATION DECISIONMATRIX Condition Risk Low Medium High Low 1239 Segments 74.7 Miles 339 Segments 20.2 Miles 68 Segments 4.2 Miles Capacity Risk Medium 104 Segments 6.3 Miles 118 Segments 10.6 Miles 39 Segments 2.9 Miles High 5 Segments 0.2 Miles 74 Segments 4.5 Miles 14 Segments 0.9 Miles No 17

18 CONDITION SCREENING PRIORITIES Projects from Categories 1, 2, & 3 (Red Matrix Boxes) Identified for CIP Large Diameter Sewer Interceptor Replacements Project Project Cost Total Cost Priority Condition Rank Max Condition Score 1 18-inch Interceptor from Sixth to Eighth Street along Wanda Drive $758, inch Interceptor from SH 183 to Grauwyler Rd. along Betsy $999, inch Interceptor from Grauwyler to Delaware Creek along Betsy Lane $1,303, inch Interceptor from Nursery Rd. to Singleton Rd. along Oakdale Dr. $4,831,200, Total $7,891,800 Small Diameter Sewer Interceptor Rehabilitation Project Sub-Basin SSES Cost ($) 1 Cost ($) Total Cost ($) Rehabilitation 1 IRV-15 (Upper Delaware Creek Basin) - $1,600,000 $1,600,000 2 IRV-25 (Lower Southwest Irving Basin) $227,652 $1,421,274 $1,648,926 Total $227,652 $3,021, $3,248,926 18

19 Priority Meter Basins for SSES Program SSES Wet Weather Peaking Factor by Rain Event Priority Ranking Discrete Flow Meter Basins 10/15/07 10/22/07 12/15/07 5/15/08 Maximum Peaking Factor By Basin 1 IRV-15* IRV IRV 19-B TRA 8.0E IRV IRV IRV IRV IRV-25A IRV-21A TRA 1.1E IRV IRV IRV19A+IRV20A

20

21 PRIORITIES FROM TXDOT / DEVELOPMENT CONFLICT SCREENING Project Project Cost Total Cost Project Driver New 36-inch Interceptor South of Meadow Creek Rd. Eiti it t bi dd 1 along Highway 144 in East Irving. Existing interceptor being relocated due to $4,244,600 TxDOT expansion of Spur New 42-inch Interceptor North of Highway 114 from Las Colinas St. to Love St. in East Irving. $3,870,500 New 48-inch Interceptor North of Highway 114 along Riverside Dr. in East Irving. $6,930,200 Existing interceptor being relocated due to TxDOT expansion of Spur 348 Existing interceptor being relocated due to TxDOT expansion of Spur 348 Total $15,045,300 21

22 CIP PROJECT COST SUMMARY Project Category Short Term Longer Term Capacity $17,557, $40,102, Condition $10,913,074 $10,676,680 TxDOT/ Development Conflicts $15,045,300 - Total $43,515,874 $50,778,780 System Renewal represented ~25% of the CIP. 22

23 CAPITAL IMPROVEMENT 5-YEAR PHASING PLAN Capacity Improvement Phasing Number Project Estimated Costs FY 2009 FY 2010 FY 2011 FY 2012 FY 2013 FY 2014 FY 2015 Total $5,250, inch and 48-inch Delaware Creek Interceptor 1 Engineering $ - Capacity Improvements Construction $5,250,100 $2,625,050 $2,625, inch Interceptor along Carl Rd. South of Highway 183 in Southeast Irving. 18-inch Interceptor North of Grauwyler Rd. along Story Rd. in the Delaware Creek Basin 36-inch Interceptor from Grauwyler Rd. Northeast to Rochelle St. in South Irving. 21-inch Interceptor North of Highway 183 along Rochelle St. in Central Irving. 15-inch, 18-inch, & 21-inch Interceptor along Mac Arthur Blvd in South Irving. 36-inch & 42-inch Interceptor Line North of Grauwyler Rd. in Central Irving. 18- inch Interceptor North of Shady Grove Rd. along Bowman St. in Southwest Irving. 15-inch Interceptor Crossing Rochell Rd. in Northeast Delaware Creek Sewer Basin Total $1,047,300 Engineering $96,370 $96,370 Construction $950,930 $190,186 $760,744 Total $726,900 Engineering $64,460 $64,460 Construction $662,440 $662,440 Total $3,171,100 Engineering $313,980 $313,980 Construction $2,857,120 $1,428,560 $1,428,560 Total $1,451, Engineering $131,300 $131,300 Construction $1,319,800 $1,319,800 Total $2,122,000 Engineering $192,710 $192,710 Construction $1,929,290 $964,645 $964,645 Total $2,255, Engineering $223,240 $223,240 Construction $2,031,960 $1,015,980 $1,015,980 Total $977,800 Engineering $86,510 $86,510 Construction $891,290 $891,290 Total $556,000 Engineering $46,950 $46,950 Construction $509,050 $ 509,050 Total Capacity Project Cost $17,557,500 $3,290,046 $5,800,804 $3,936,245 $1,980,625 $1,015,980 $133,460 $1,400,340 23

24 CAPITAL IMPROVEMENT 5-YEAR PHASING PLAN Large Diameter Condition Replacement Project Phasing Number Project Estimated Costs FY 2009 FY 2010 FY 2011 FY 2012 FY 2013 FY 2014 FY inch Interceptor from Sixth to Eighth Street along Wanda Drive Total $ 758,000 Engineering $ 67,250 $67,250 Construction $ 690,750 $690, inch Interceptor from SH 183 to Grauwyler Rd. along Betsy 18-inch Interceptor from Grauwyler to Delaware Creek along Betsy Lane 48-inch Interceptor from Nursery Rd. to Singleton Rd. along Oakdale Dr. Total $ 999,100 Engineering $ 89,860 $89,860 Construction $ 909,240 $909,240 Total $ 1,303,500 Engineering $ 117, $117, Construction $ 1,186,390 $ 1,186,390 Total $ 4,831,200 Engineering $ 485,930 $485,930 Construction $ 4,345,270 $2,172,635 $2,172,635 Total Large Diameter Condition Cost $7,891,800 $0 $157,110 $1,717,100 $1,186,390 $485,930 $2,172,635 $2,172,635 Small Diameter Condition Rehabilitation Project Phasing Number Project Estimated Costs FY 2009 FY 2010 FY 2011 FY 2012 FY 2013 FY 2014 FY IRV-15 (Upper Delaware Creek Basin) Total $ 1,600, SSES - Rehabilitation $ 1,600,000 $800,000 $800,000 2 IRV-25 (Lower Southwest Irving Basin) Total $ 4,737,580 SSES $ 227,652 $227,652 Rehabilitation $ 4,737,580 $710,637 $710,637 Total Small Diameter Condition Cost $6,337,580 $0 $800, $800, $227,652 $710,637 $710,637 $0 24

25 CAPITAL IMPROVEMENT 5-YEAR PHASING PLAN TxDOT / Development Conflict Project Phasing Number Project Estimated Costs FY 2009 FY 2010 FY 2011 FY 2012 FY 2013 FY 2014 FY New 36-inch Interceptor South of Meadow Creek Rd. along Highway 144 in East Irving. Total $ 4,244,600 Engineering $ 432,240 $432,240 Construction $ 3,812,360 $1,906,180 $1,906, New 42-inch Interceptor North of Highway 114 from Las Colinas St. to Love St. in East Irving. New 48-inch Interceptor North of Highway 114 along Riverside Dr. in East Irving. Total $ 3,870,500 Engineering $ 390,530 $390,530 Construction $ 3,479,970 $1,739,985 $1,739,985 Total $ 6,930,200 Engineering $ 712,030 $712,030 Construction $ 6,218,170, $3,109,085, $3,109,085, Total Large Diameter Condition Cost $7,891,800 $ - $ - $ 822,770 $ 3,646,165 $ 4,358,195 $ 3,109,085 $ 3,109,085 Total Short Term Yearly Wastewater Capital Improvement Cost Total FY 2009 FY 2010 FY 2011 FY 2012 FY 2013 FY 2014 FY 2015 $43,515,874 $3,290,046 $6,757,914 $7,025,785 $6,149,625 $6,044,494 $7,720,412 $6,755,250 Integrates Highest Risk Based Capacity & Condition Needs of the City 25

26 26

27 NEXT STEPS Evaluate extended impact on wastewater rates Before implementation of each Condition Project, assess latest field data to determine if rehabilitation is an option vs. replacement Longer term: Populate attribute data for smaller lines Develop continuous process to capture field data into CIP prioritization iti 27

28 QUESTIONS?