State Water Resources Control Board Beach Water Quality Workgroup - - PowerPoint PPT Presentation

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State Water Resources Control Board Beach Water Quality Workgroup - - PowerPoint PPT Presentation

Jun 12, 2023 27 likes •817 views

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

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SANITARY SEWER INVESTIGATION RESULTS

Baby Beach

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

Presentation Prepared for

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Presented By

Mark Buccola, Underground Service Company, Inc. Charles Busslinger, PE Orange County Environmental Engineering Section Mark Grabowski, Electro Scan, Inc.

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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”

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  • 1. Acknowledgements

2.Executive Summary 3.Introduction 4.Project Study Area and Physical Setting 5.Testing Procedure 6.Results and Recommendations 7.Conclusions

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1.South Coast Water District

  • John Langill & Staff

2.The Ocean Institute

  • Randy Teague & Staff

3.Orange County Parks

  • Steve Bonhall & Staff

Acknowledgements

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  • 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.

Executive Summary

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  • 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

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  • 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

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  • 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.

Introduction - Baby Beach

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Project Area

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  • Study area included all active and accessible sewer lines from

the Ocean Institute eastward to Ensenada Place

  • Pipe material included:
  • VCP
  • CIP
  • PVC
  • Truss PVC

9 | P a g e

Pipe Diameters included:

  • 4”
  • 6”
  • 8”

Project Area

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Pictures from site

Project Area – Laterals (Public and Private)

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  • 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

Testing Procedures

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Areas Where Private Mains and Laterals Were Hydrostatically Tested

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Electro Scan Investigation Area

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Flow Testing / Dye Testing

  • Verifies Connectivity
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CCTV – Push Camera or Crawler

  • Visual Observation
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Electromagnetic Locating

  • Verifies Location of Pipe- either

by pipe structure or with locating sonde

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Hydrostatic Pressure Testing

  • Verifies (with pass / fail results)

water tightness of pipe.

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Low Pressure Air Testing

  • Verifies (with pass / fail results)

water tightness of pipe.

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Electro Scan

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10 20 30 100 150 200 250 300

DISTANCE ELECTRIC CURRENT

50

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10 20 30 100 150 200 250 300

DISTANCE ELECTRIC CURRENT

50

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10 20 30 100 150 200 250 300

DISTANCE ELECTRIC CURRENT

50

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10 20 30 100 150 200 250 300

DISTANCE ELECTRIC CURRENT

50

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10 20 30 100 150 200 250 300

DISTANCE ELECTRIC CURRENT

50

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10 20 30 100 150 200 250 300

DISTANCE ELECTRIC CURRENT

50

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10 20 30 100 150 200 250 300

DISTANCE ELECTRIC CURRENT

50

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  • 5. Perform follow-up hydrostatic testing of “inconclusive” segments
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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

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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)
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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

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“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

Methods

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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

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Lateral Pressure Test Result Examples

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Baby Beach Restroom and Lateral

  • 60 GPH loss between FFE and 24” Below FFE
  • Pipe below 24” passed test
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Mainline Electro Scan Test Result Examples

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D758 End of Scan (Downstream)

D757 to D758

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D757 Start of Scan (Upstream)

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D757 to D758

4

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D757 to D758

Total Defect Flow (GPM): 25.10

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D757 to D758 Scan Graph – 0 to 120 Ft.

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  

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D757 to D758 Scan Graph – 120 to 243 Ft.

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D757 to D758 Defect Chart

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Estimated Infiltratio n Flow: 5.12 GPM 5.3’ (CCTV) 5’ (ES) Estimated Infiltratio n Flow: 6.54 GPM 5.8’ (CCTV) 6’ (ES)

Sample CCTV Snapshots Overlaid with Electro Scan Readings

CCTV Callout: Tap Factory Active - OK CCTV Callout: NONE

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 

Lateral Connection Lateral Connection Wye Fitting

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Estimated Infiltratio n Flow: 0.00 GPM 116.7’ (CCTV) 117’ (ES) Estimated Infiltratio n Flow: 2.23 GPM 128.9’ (CCTV) 128’ (ES)

Sample CCTV Snapshots Overlaid with Electro Scan Readings

CCTV Callout: PVC Repair

CCTV Callout: Tap Break-In Active – Heavy Roots

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Fernco-type Fitting, NOT Leaking Roots in Lateral

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D758 End of Scan (Downstream)

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D757 Start of Scan (Upstream)

D757 to D758 Scan Graph Map Overlay for Major Defects

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D757 to D758 Summary

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D760 End of Scan (Downstream)

D758 to D760

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D758 Start of Scan (Upstream) 5

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D758 to D760

5

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D758 to D760

Total Defect Flow (GPM): 7.05

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D758 to D760 Scan Graph – 0 to 120 Ft.

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 

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D758 to D760 Scan Graph – 120 to 241 Ft.

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 

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D758 to D760 Defect Chart

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Estimated Infiltratio n Flow: 0.28 GPM 22’ (CCTV) 21’ (ES) Estimated Infiltratio n Flow: 0.27 GPM 117’ (CCTV) 116’ (ES)

Sample CCTV Snapshots Overlaid with Electro Scan Readings

CCTV Callout: NONE CCTV Callout: NONE

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 

Typical Low- Level Leakage Joint Typical Low- Level Leakage Joint

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Estimated Infiltratio n Flow: 0.30 GPM 186’ (CCTV) 186’ (ES) Estimated Infiltratio n Flow: 0.41 GPM 241’ (CCTV) 241’ (ES)

Sample CCTV Snapshots Overlaid with Electro Scan Readings

CCTV Callout: NONE CCTV Callout: NONE

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Typical Low- Level Leakage Joint Typical Low- Level Leakage Joint

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D758 to D760 Summary

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D763 End of Scan (Downstream)

D761 to D763

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D761 Start of Scan (Upstream)

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D761 to D763

8

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D761 to D763

Total Defect Flow (GPM): 28.69

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D761 to D763 Scan Graph – 0 to 170 Ft.

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  

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D761 to D763 Scan Graph – 170 to 341 Ft.

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D761 to D763 Defect Chart

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Estimated Infiltratio n Flow: 8.20 GPM 38.6’ (CCTV) 36’ (ES) Estimated Infiltratio n Flow: 1.55 GPM 40’ (CCTV) 40’ (ES)

Sample CCTV Snapshots Overlaid with Electro Scan Readings

CCTV Callout: NONE

CCTV Callout: Repair Localized Liner Defective

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Failed Repair w/ Active Infiltration Failed Repair w/ Active Infiltration

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Estimated Infiltratio n Flow: 4.1 GPM (total) 41.1’ (CCTV) 41’ (ES) Estimated Infiltratio n Flow: 0.25 GPM 188.3’ (CCTV) 188’ (ES)

Sample CCTV Snapshots Overlaid with Electro Scan Readings

CCTV Callout: NONE CCTV Callout: NONE

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Failed Repair w/ Active Infiltration Typical Low- Level Leakage Joint

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D763 End of Scan (Downstream)

D761 to D763 Scan Graph Map Overlay for Major Defects

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D761 Start of Scan (Upstream) 8

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  • USCO tested the active sanitary sewer system through

the area of concern using a combination of flow testing, CCTV and electromagnetic survey test methods.

  • In order to ascertain whether the sewer system is water

tight, USCO used hydrostatic, low pressure air, and Electro Scan testing.

  • Results indicated that nine (9) of the fifteen (15) tested

segments are not water-tight.

Conclusions

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  • Test methods in the present study simulated a fully-

impacted pipeline, but under normal operating conditions, sewage is conveyed in the lower third to half of the pipeline. Thus, tests covered areas of the pipeline that may not normally experience flow.

  • Many low-level faults were observed within the test

segments, and several more significant faults were identified which require follow-up repair.

  • Achievement of 100% certainty that no leaks occur in the

system would require replacement or slip-lining of the failed test segments.

Conclusions

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Site Pictures

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Site Pictures

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