1. Presented by Doug Gapp Pipeline Safety Planning Dept Southwest Gas Corporation August 19, 2014 Western Region Gas Conference

2.  San Bruno Incident, September 9, 2010  Pipeline Hazardous Materials Safety Administration (PHMSA) Advisory Bulletin ADB 11-01, Jan 10, 2011  Evaluate risk – physical and operational characteristics  California Independent Review Panel San Bruno (Recommendation 5.6.4.2), June 24, 2011  Program to collect…construction and operating data  PHMSA 2011 Advanced Notice of Proposed Rulemaking (Section D), August 25, 2011  Requirements for collecting, validating, integrating and reporting pipeline data

3.  National Transportation Safety Board (NTSB), August 30, 2011  San Bruno 29 Recommendations  Recommendations specific to Integrity Management Program (IMP)  Completeness/Accuracy Integrity Management Program Data  Federal legislation, January 3, 2012  Confirm material strength  Pipelines operating in high-consequence areas (HCAs)  Greater than 30 % specified minimum yield strength (SMYS)  California Public Utilities Commission 17 Hazards Report (Item 4), March 14, 2012  Verifiable and traceable records

4.  PHMSA  Integrity Verification Process  Likely will require action on transmission pipe operating in HCAs and Class 3 and 4 locations

5.  Focus of NTSB, federal legislators, regulatory agencies  Transmission pipelines  HCAs  Data – Know your pipelines so you can properly evaluate risk

6.  1979 Acquired gas system from Tucson Gas and Electric  1984 Acquired gas system from Arizona Public Service

7.  November 2012 proposed field data collection initiative-wall thickness pilot  Goal: improve knowledge and records of company pipeline characteristics  Specifically:  Collect wall thickness data where not documented  Accurately classify pipeline  Appropriate integrity management application  Transmission Integrity Management Program (TRIMP)  Distribution Integrity Management Program (DIMP)  pipe that meets transmission classification by actual properties, not lack of records

8.  Conventional In-line Inspection (ILI)  Other ILI tools  Pipetel Explorer – Southern Nevada Division (SND)  Dig and inspects (D&Is)  Southern Arizona Division (SAD)

9. Available for pipe sizes 6” to 36” Either live or de-gassed pipeline Wireless/battery operated ~ 3300 foot range Camera (front and back) Remote Field Eddy Current Sensor (RFEC) Magnetic Flux Leakage (MFL) Maneuver through standard fittings

10. Explorer Project Las Vegas

11.  Successful launch and recover robotic tool (tetherless)  Into a non-live natural gas pipeline  Obtain wall thickness (WT) data  Identify potential metal loss  First SWG commercial application

12.  Crossing that prohibited conventional inline inspection tools from passing  Pipeline diameter – 6-inch  Maximum operating pressure (MOP) – 125 psig  5522 feet unconfirmed wall thickness (WT)  Conservative assumption of 0.083 inches WT  21 feet 0.156 inches WT  Specified Minimum Yield Strength (SMYS) unknown  Conservative assumption of 24,000 psi  20.78% SMYS at MOP  Vintages  1964, 1968, and 1972

13. Originally planned for 3 bellholes, ended up with 4 Tool run twice for each distance Wall thickness data Metal loss data

14.  Urban location traffic & noise  Night work  Crossing over storm drain  Question: What if it gets stuck?  Answer: Put a leash on the pig

18. Manual Tether

19.  Pre excavate pits, larger than standard bell- holes  Horizontal launch  Opted for out of service  Night work due to heat of summer  Reduce project complexity  Heat impacted equipment (no flow to cool)  Improvised air conditioning pipeline

20. PATENT PENDING

21.  Anomalies  No Immediate or Scheduled repair required  No metal loss locations  7 suspected dents  3 suspected dents or material deposits  Wall Thickness data  Majority of pipe is 0.156 inches (11.1% SMYS)  some 0.188 inches WT (9.2% SMYS)  Not the 0.083 inches WT

22.  Validate data – field work  Two locations for inspection  Dent  Lowest WT reading  Updated WT attribute data  Final follow-up with vendor

23.  Experience with Explorer tool  Once confirmatory digs completed able to correctly classify pipe  Avoided replacement  Explorer cost between $200K-$300K per mile  Compared to $2+ million/mile to replace

24.  Questions on Explorer project?

25. Dig and Inspect (D&I) Project Yuma

26.  Pipeline Diameter – 6-inch  Maximum Operating pressure – 150 psig  1.3 miles Unconfirmed wall thickness (WT)  Conservative assumption of 0.083 inches  1.2 miles confirmed WT upstream classified as transmission  Specified Minimum Yield Strength (SMYS) unknown  Conservative assumption of 24,000 psi  24.9% SMYS  7 HCAs  Vintages  1954, 1955

27. 35 D&I Bellholes Wall thickness data

29.  1954 vintage changed to 0.250 wall – 8.3% SMYS  1955 vintage changed to 0.188 wall – 11.0% SMYS  Cost Comparison  Actual cost was approximately $50K  Allowed reclassification 2.5 miles of pipe to high- pressure distribution  Lowered comparative risk

30.  Southern Arizona Division D&I:  Yuma-Wellton  Approximately 93,000 feet of 4-inch pipe unknown WT  2 HCAs  Central Arizona Division Explorer ILI:  Litchfield Ave  Approximately 2500 feet of 6-inch pipe unknown WT  Almost entirely in an HCA

31.  Pipe with:  Unknown wall thickness?  Operating at high % SMYS?  Actual wall thickness likely higher?  Unpiggable?  Determining actual wall thickness:  Lowers relative risk in HCAs  Accurately classify pipe  Appropriate integrity management application

32.  Questions??? Thank You