GD incident on 2022-10-31 — NV

Operator
Southwest Gas Corp
Cause
Pipe, Weld, Or Joint Failure
Commodity
Natural Gas
Program
GD
Damage and Injuries
0 fatalities 0 injuries
Property damage (nominal)
$180,432
Incident datetime
2022-10-31 19:52
Report number
Location
NV, CLARK
Narrative
At 17:35 on october 31, 2022, southwest gas received a call about an odor/hissing on a dirt lot near the intersection of la cienega street and pyle avenue in las vegas, nevada. Crews arrived onsite at 18:23 and began investigation. At 19:52, southwest gas identified a leak on its facilities and made the area secure. The leak was isolated and gas supply was shut off to the affected pipe segment by 21:24 on october 31, 2022. This segment of the main will not be returned to service. Southwest gas evacuated a total of six persons from three nearby homes. After gas was shut off, crews began aerating the surrounding soil to remove residual gas in the ground. Although residual gas reads were dropping, southwest gas remained onsite continuously monitoring the residual reads and aerating the soils. On november 30, 2022 southwest gas determined that the accumulated emergency response costs exceeded $129,300. The incident costs were mostly attributed to employee labor utilized to continuously aerate and remediate the residual gas in the soil. Southwest discontinued its emergency response and decommissioned the incident command structure on december 8, 2022 after the residual gas reads were remediated to safe non-hazardous conditions. Laboratory analysis completed in january 2023 concluded: fractographic and analytical examination indicated that the throughwall axial fracture responsible for the leak path occurred due to internal thermal-oxidative degradation. The fracture progressed through the wall of the pipe from the inside diameter to the outside diameter by way of hoop stress and brittle fracture due to degradation and low slow crack growth resistance of the pipe material. This supplemental report updates the cause of the leak in part g based on the laboratory analysis to be a crack caused by degradation. It also updates part j and the costs associated with the incident in part d.
Detailed record list
Occurred At
2022-10-31 19:52:00
Year
2022
Report Received Date
2022-12-21 00:00:00
Iyear
2022.0
Report Number
20220079.0
Supplemental Number
37670.0
Report Type
Supplemental Final
Operator Id
Name
Southwest Gas Corp
Operator Street Address
8360 S. Durango Drive
Operator City Name
Las Vegas
Operator State Abbreviation
NV
Operator Postal Code
89113
Local Datetime
2022-11-30 17:00:00
Time Zone
Pacific
Daylight Savings Ind
No
Location Street Address
La Cienega Street And Pyle Ave
Location City Name
Las Vegas
Location County Name
Clark
Location State Abbreviation
NV
Location Postal Code
89183
Location Latitude
Location Longitude
Flow Cont Squeeze Off Ind
Yes
Nrc Rpt Datetime
2022-11-30 17:44:00
Nrc Rpt Num
Additional Nrc Report Numbers
1354008
Commodity Released Type
Natural Gas
Unintentional Release
500.0
Intentional Release
0.0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Ignite Ind
No
Num Pub Evacuated
6.0
Incident Identified Datetime
2022-10-31 19:52:00
Communication State Fed Ind
Yes
Party Initiated Communication
Operator
Initial Responder Com Datetime
2022-10-31 23:01:00
On Site Datetime
2022-10-31 18:23:00
Federal
No
Location Type
Public Property
Incident Area Type
Underground
Incident Area Subtype
Under Pavement
Depth Of Cover
48.0
Other Underground Facilities
No
Crossing
No
Pipe Facility Type
Investor Owned
System Part Involved
Main
Installation Year
1999.0
Manufactured Year
1998.0
Pipe Diameter
2.0
Pipe Specification
Astm D-2513
Pipe Manufacturer
Phillips
Material Involved
Plastic
Plastic Type
Polyethylene (Pe)
Plastic Sdr
11
Material Pe Pipe Code
3408
Release Type
Leak
Leak Type
Crack
Class Location Type
Class 3 Location
Est Cost Oper Paid
0.0
Est Cost Prop Damage
180432.0
Est Cost Emergency
12285.0
Est Cost Other
0.0
Gas Cost In Mcf
5.4087
Est Cost Unintentional Release
2704.0
Est Cost Intentional Release
0.0
Prpty
195421.0
Commercial Affected
0.0
Industrial Affected
0.0
Residences Affected
0.0
Num Persons Hosp Not Ovnght
0.0
Num Injured Treated By Emt
0.0
Num Resident Building Affctd
3.0
Num Business Building Affctd
0.0
Accident Psig
48.0
Normal Psig
55.0
Mop Psig
60.0
Mop Cfr Section
192.619(A)(2)
Maop Established Date
1999-01-20 00:00:00
Accident Pressure
Pressure Did Not Exceed Maop
Gas Odorized System Type
Injection Pump
Gas Odorized Level
8
Scada In Place Ind
No
Accident Identifier
Notification From Public
Investigation Status
No, the facility was not monitored by a controller(s) at the time of the incident
Employee Drug Test Ind
No
Contractor Drug Test Ind
No
Cause
Pipe, Weld, Or Joint Failure
Cause Details
Body Of Pipe
Pwjf Failure Type
Body Of Pipe
Pipe Body Subtype
Crack
Additional Crack Ind
Yes
Result Material Ind
Yes
Result Material Subtype
Other
Result Material Details
Material Degradation
Hydrotest Conducted Ind
No
Pwf Manufacturing Ind
Yes
Preparer Name
M****** R***
Preparer Title
Supervisor Of Engineering
Preparer Email
M***********@s****.com
Preparer Telephone
7023652361
Authorizer Name
A****** H****
Authorizer Title
Director Of Gas Operations
Authorizer Telephone
7023652049
Authorizer Email
A************@s****.com
Narrative
At 17:35 on october 31, 2022, southwest gas received a call about an odor/hissing on a dirt lot near the intersection of la cienega street and pyle avenue in las vegas, nevada. Crews arrived onsite at 18:23 and began investigation. At 19:52, southwest gas identified a leak on its facilities and made the area secure. The leak was isolated and gas supply was shut off to the affected pipe segment by 21:24 on october 31, 2022. This segment of the main will not be returned to service. Southwest gas evacuated a total of six persons from three nearby homes. After gas was shut off, crews began aerating the surrounding soil to remove residual gas in the ground. Although residual gas reads were dropping, southwest gas remained onsite continuously monitoring the residual reads and aerating the soils. On november 30, 2022 southwest gas determined that the accumulated emergency response costs exceeded $129,300. The incident costs were mostly attributed to employee labor utilized to continuously aerate and remediate the residual gas in the soil. Southwest discontinued its emergency response and decommissioned the incident command structure on december 8, 2022 after the residual gas reads were remediated to safe non-hazardous conditions. Laboratory analysis completed in january 2023 concluded: fractographic and analytical examination indicated that the throughwall axial fracture responsible for the leak path occurred due to internal thermal-oxidative degradation. The fracture progressed through the wall of the pipe from the inside diameter to the outside diameter by way of hoop stress and brittle fracture due to degradation and low slow crack growth resistance of the pipe material. This supplemental report updates the cause of the leak in part g based on the laboratory analysis to be a crack caused by degradation. It also updates part j and the costs associated with the incident in part d.
Occurred At 2022-10-31 19:52:00
Year 2022
Report Received Date 2022-12-21 00:00:00
Iyear 2022.0
Report Number 20220079.0
Supplemental Number 37670.0
Report Type Supplemental Final
Operator Id 18536 PHMSA Enforcement
Name Southwest Gas Corp
Operator Street Address 8360 S. Durango Drive
Operator City Name Las Vegas
Operator State Abbreviation NV
Operator Postal Code 89113
Local Datetime 2022-11-30 17:00:00
Time Zone Pacific
Daylight Savings Ind No
Location Street Address La Cienega Street And Pyle Ave
Location City Name Las Vegas
Location County Name Clark
Location State Abbreviation NV
Location Postal Code 89183
Location Latitude 36.0055 Google Maps OpenStreetMap
Location Longitude -115.16137 Google Maps OpenStreetMap
Flow Cont Squeeze Off Ind Yes
Nrc Rpt Datetime 2022-11-30 17:44:00
Nrc Rpt Num 1353841 NRC Report How to search
Additional Nrc Report Numbers 1354008
Commodity Released Type Natural Gas
Unintentional Release 500.0
Intentional Release 0.0
Fatality Ind No
Fatal 0
Injury Ind No
Injure 0
Ignite Ind No
Num Pub Evacuated 6.0
Incident Identified Datetime 2022-10-31 19:52:00
Communication State Fed Ind Yes
Party Initiated Communication Operator
Initial Responder Com Datetime 2022-10-31 23:01:00
On Site Datetime 2022-10-31 18:23:00
Federal No
Location Type Public Property
Incident Area Type Underground
Incident Area Subtype Under Pavement
Depth Of Cover 48.0
Other Underground Facilities No
Crossing No
Pipe Facility Type Investor Owned
System Part Involved Main
Installation Year 1999.0
Manufactured Year 1998.0
Pipe Diameter 2.0
Pipe Specification Astm D-2513
Pipe Manufacturer Phillips
Material Involved Plastic
Plastic Type Polyethylene (Pe)
Plastic Sdr 11
Material Pe Pipe Code 3408
Release Type Leak
Leak Type Crack
Class Location Type Class 3 Location
Est Cost Oper Paid 0.0
Est Cost Prop Damage 180432.0
Est Cost Emergency 12285.0
Est Cost Other 0.0
Gas Cost In Mcf 5.4087
Est Cost Unintentional Release 2704.0
Est Cost Intentional Release 0.0
Prpty 195421.0
Commercial Affected 0.0
Industrial Affected 0.0
Residences Affected 0.0
Num Persons Hosp Not Ovnght 0.0
Num Injured Treated By Emt 0.0
Num Resident Building Affctd 3.0
Num Business Building Affctd 0.0
Accident Psig 48.0
Normal Psig 55.0
Mop Psig 60.0
Mop Cfr Section 192.619(A)(2) View CFR 49 §192
Maop Established Date 1999-01-20 00:00:00
Accident Pressure Pressure Did Not Exceed Maop
Gas Odorized System Type Injection Pump
Gas Odorized Level 8
Scada In Place Ind No
Accident Identifier Notification From Public
Investigation Status No, the facility was not monitored by a controller(s) at the time of the incident
Employee Drug Test Ind No
Contractor Drug Test Ind No
Cause Pipe, Weld, Or Joint Failure
Cause Details Body Of Pipe
Pwjf Failure Type Body Of Pipe
Pipe Body Subtype Crack
Additional Crack Ind Yes
Result Material Ind Yes
Result Material Subtype Other
Result Material Details Material Degradation
Hydrotest Conducted Ind No
Pwf Manufacturing Ind Yes
Preparer Name M****** R***
Preparer Title Supervisor Of Engineering
Preparer Email M***********@s****.com
Preparer Telephone 7023652361
Authorizer Name A****** H****
Authorizer Title Director Of Gas Operations
Authorizer Telephone 7023652049
Authorizer Email A************@s****.com
Narrative At 17:35 on october 31, 2022, southwest gas received a call about an odor/hissing on a dirt lot near the intersection of la cienega street and pyle avenue in las vegas, nevada. Crews arrived onsite at 18:23 and began investigation. At 19:52, southwest gas identified a leak on its facilities and made the area secure. The leak was isolated and gas supply was shut off to the affected pipe segment by 21:24 on october 31, 2022. This segment of the main will not be returned to service. Southwest gas evacuated a total of six persons from three nearby homes. After gas was shut off, crews began aerating the surrounding soil to remove residual gas in the ground. Although residual gas reads were dropping, southwest gas remained onsite continuously monitoring the residual reads and aerating the soils. On november 30, 2022 southwest gas determined that the accumulated emergency response costs exceeded $129,300. The incident costs were mostly attributed to employee labor utilized to continuously aerate and remediate the residual gas in the soil. Southwest discontinued its emergency response and decommissioned the incident command structure on december 8, 2022 after the residual gas reads were remediated to safe non-hazardous conditions. Laboratory analysis completed in january 2023 concluded: fractographic and analytical examination indicated that the throughwall axial fracture responsible for the leak path occurred due to internal thermal-oxidative degradation. The fracture progressed through the wall of the pipe from the inside diameter to the outside diameter by way of hoop stress and brittle fracture due to degradation and low slow crack growth resistance of the pipe material. This supplemental report updates the cause of the leak in part g based on the laboratory analysis to be a crack caused by degradation. It also updates part j and the costs associated with the incident in part d.

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