SANITARY SEWER INVESTIGATION RESULTS Baby Beach Presentation Prepared for State Water Resources Control Board Beach Water Quality Workgroup Division of Water Quality 1001 I Street • Sacramento, California 95814 • (916) 341 -5283 Meeting Location: Southern California Coastal Water Research Project 3535 Harbor Boulevard, Suite 110, Costa Mesa, CA 92626-1437
Presented By Mark Buccola , Underground Service Company, Inc. Charles Busslinger, PE Orange County Environmental Engineering Section Mark Grabowski , Electro Scan, Inc.
A Follow-Up Presentation from the August 2014 SWRCB Meeting Presentation by Chuck Hansen: “Introducing a New Standard for Locating and Measuring Leaking Sewers – ASTM 2550- 13”
1. Acknowledgements 2.Executive Summary 3.Introduction 4.Project Study Area and Physical Setting 5.Testing Procedure 6.Results and Recommendations 7.Conclusions
Acknowledgements 1.South Coast Water District • John Langill & Staff 2.The Ocean Institute • Randy Teague & Staff 3.Orange County Parks • Steve Bonhall & Staff
Executive Summary • Nine (9) of the fifteen (15) test segments are not “water tight.” • Identification of failed test segments do not necessarily indicate that exfiltration is occurring, particularly in instances where the identified defect is in the crown of a gravity-flow pipe, which may not experience flow in normal operating conditions.
Introduction - Baby Beach • Small man-made beach in northwest corner of Dana Point Harbor • Owned & Operated by County of Orange, OC Dana Point Harbor, and OC Parks Department
Introduction - Baby Beach • Various closures starting in ‘96 due to FIB (Fecal Indicator Bacteria) Levels • Popular beach for children and paddleboarders due to calm waters
Introduction - Baby Beach • Phased plan implemented to investigate, identify, and remediate potential sources • Previous inspections included CCTV and Dye Testing and were inconclusive • In February 2015, Underground Services Company, Inc. (USCO) was directed to test & inspect the sanitary sewer system thoroughly, including using the Electro Scan technology.
Project Area
Project Area • Study area included all active and accessible sewer lines from the Ocean Institute eastward to Ensenada Place • Pipe material included: Pipe Diameters included: • VCP • 4” • CIP • 6” • PVC • 8” 9 | P a g e • Truss PVC
Project Area – Laterals (Public and Private) Pictures from site
Testing Procedures 1. Profile, Locate and Confirm Connectivity of Laterals • Flow-testing • Dye-testing • CCTV Inspection • Electromagnetic locating 2. Perform Low-Pressure Air Testing / Hydrostatic Testing of Laterals and Associated “Private” Sewer Pipe • Per ASTM F1417-11a, C1091-3, and C1091-03a 3. Perform CCTV inspections of “public” sewer piping to review line conditions and verify no undocumented connections. 4. Perform Electro Scan testing of public and private sewer pipes 5. Perform follow- up hydrostatic testing of “inconclusive” segments
Areas Where Private Mains and Laterals Were Hydrostatically Tested
Electro Scan Investigation Area
Flow Testing / Dye Testing • Verifies Connectivity
CCTV – Push Camera or Crawler • Visual Observation
Electromagnetic Locating • Verifies Location of Pipe- either by pipe structure or with locating sonde
Hydrostatic Pressure Testing • Verifies (with pass / fail results) water tightness of pipe.
Low Pressure Air Testing • Verifies (with pass / fail results) water tightness of pipe.
Electro Scan
30 ELECTRIC CURRENT 20 10 0 0 50 100 150 200 250 300 DISTANCE
30 ELECTRIC CURRENT 20 10 0 0 50 100 150 200 250 300 DISTANCE
30 ELECTRIC CURRENT 20 10 0 0 50 100 150 200 250 300 DISTANCE
30 ELECTRIC CURRENT 20 10 0 0 50 100 150 200 250 300 DISTANCE
30 ELECTRIC CURRENT 20 10 0 0 50 100 150 200 250 300 DISTANCE
30 ELECTRIC CURRENT 20 10 0 0 50 100 150 200 250 300 DISTANCE
30 ELECTRIC CURRENT 20 10 0 0 50 100 150 200 250 300 DISTANCE
5. Perform follow- up hydrostatic testing of “inconclusive” segments
Methods How were the respective testing methods chosen? • Operational Requirements, such as Location, Reach, Pipe Diameter, Pipe Material, Access, Etc • Electro Scan was method of choice where feasible due to speed, accuracy, and efficiency • Hydrostatic and low-air pressure worked well for interior and difficult, smaller reach segments
Methods “Six - Pack Restroom” “Pilgrim Lateral” “Baby Beach Restroom” “Rock Restroom” Actions Performed: • CCTV (to look for obvious issues or potential obstacles • Profiled (for As-Built Records • Flow Tested (to verify connection) • Hydrostatic tested (to test water tightness)
Methods Public Mains Actions Performed : • CCTV (to look for obvious issues or potential obstacles • Electro Scan tested (with ES-620) because • Lines did not have to be taken out of service • Results far exceed conventional low-pressure or hydrostatic methods • With various elevations, Electro Scan was able to test both infiltration and exfiltration
Methods “Gift Shop Lateral” Actions Performed: • CCTV (to look for obvious issues or potential obstacles • Revealed multiple changes in direction, difficult to set temporary test bladder • Electro Scan Tested using portable ES-38 Push Rod System
Summary • Six (6) pipes passed • One (1) pipe passed, but required attention at the manhole connection • One (1) Lateral required a small point repair • Seven (7) pipes require major rehabilitation efforts
Lateral Pressure Test Result Examples
Baby Beach Restroom and Lateral • 60 GPH loss between FFE and 24” Below FFE • Pipe below 24” passed test
Mainline Electro Scan Test Result Examples
D757 to D758 D757 Start of Scan (Upstream) D758 End of Scan (Downstream) 45
D757 to D758 4 46
D757 to D758 Total Defect Flow (GPM): 25.10 47
D757 to D758 Scan Graph – 0 to 120 Ft. 48
D757 to D758 Scan Graph – 120 to 243 Ft. 49
D757 to D758 Defect Chart 50
Sample CCTV Snapshots Overlaid with Electro Scan Readings Estimated 5.3’ Infiltratio (CCTV) n Flow: 5’ 5.12 GPM (ES) Lateral Connection CCTV Callout: Tap Factory Active - OK Estimated 5.8’ Infiltratio n (CCTV) Flow: 6.54 GPM 6’ Lateral Connection (ES) Wye Fitting CCTV Callout: NONE 51
Sample CCTV Snapshots Overlaid with Electro Scan Readings Estimated 116.7’ Infiltratio (CCTV) n Flow: 117’ 0.00 GPM (ES) Fernco-type Fitting, NOT Leaking CCTV Callout: PVC Repair Estimated 128.9’ Infiltratio n (CCTV) Flow: 2.23 GPM 128’ (ES) Roots in Lateral CCTV Callout: Tap Break-In Active – Heavy Roots 52
D757 to D758 Scan Graph Map Overlay for Major Defects D757 D758 Start of Scan End of Scan (Upstream) (Downstream) 53
D757 to D758 Summary 54
5 D758 to D760 D760 End of Scan (Downstream) D758 Start of Scan (Upstream) 55
D758 to D760 5 56
D758 to D760 Total Defect Flow (GPM): 7.05 57
D758 to D760 Scan Graph – 0 to 120 Ft. 58
D758 to D760 Scan Graph – 120 to 241 Ft. 59
D758 to D760 Defect Chart 60
Sample CCTV Snapshots Overlaid with Electro Scan Readings Estimated 22’ Infiltratio (CCTV) n Flow: 21’ 0.28 GPM (ES) Typical Low- Level Leakage Joint CCTV Callout: NONE Estimated 117’ Infiltratio n (CCTV) Flow: 0.27 GPM 116’ Typical Low- Level (ES) Leakage Joint CCTV Callout: NONE 61
Sample CCTV Snapshots Overlaid with Electro Scan Readings Estimated 186’ Infiltratio (CCTV) n Flow: 186’ 0.30 GPM (ES) Typical Low- Level Leakage Joint CCTV Callout: NONE Estimated 241’ Infiltratio n (CCTV) Flow: 0.41 GPM 241’ Typical Low- Level (ES) Leakage Joint CCTV Callout: NONE 62
D758 to D760 Summary 63
D761 to D763 D761 Start of Scan (Upstream) D763 End of Scan (Downstream) 64
D761 to D763 8 65
D761 to D763 Total Defect Flow (GPM): 28.69 66
D761 to D763 Scan Graph – 0 to 170 Ft. 67
D761 to D763 Scan Graph – 170 to 341 Ft. 68
D761 to D763 Defect Chart 69
Sample CCTV Snapshots Overlaid with Electro Scan Readings Estimated 38.6’ Infiltratio (CCTV) n Flow: 36’ 8.20 GPM (ES) Failed Repair w/ Active Infiltration CCTV Callout: NONE Estimated 40’ Infiltratio n (CCTV) Flow: 1.55 GPM 40’ Failed Repair (ES) w/ Active Infiltration CCTV Callout: Repair Localized Liner Defective 70
Sample CCTV Snapshots Overlaid with Electro Scan Readings Estimated 41.1’ Infiltratio (CCTV) n Flow: 41’ 4.1 GPM (ES) (total) Failed Repair w/ Active Infiltration CCTV Callout: NONE Estimated 188.3’ Infiltratio n (CCTV) Flow: 0.25 GPM 188’ Typical Low- (ES) Level Leakage Joint CCTV Callout: NONE 71
Recommend
More recommend
