GD incident on 2010-07-11 — NV

Operator
Southwest Gas Corp
Cause
Excavation Issue
Commodity
Natural Gas
Program
GD
Damage and Injuries
0 fatalities 0 injuries
Property damage (nominal)
$0
Incident datetime
2010-07-11 06:40
Report number
Location
NV, CLARK
Narrative
Southwest gas emergency dispatch was notified of an explosion and possible gas leak in the area of first street and coolidge avenue by a representative of the city of las vegas fire department at 0640 on the morning of july 11, 2010. Multiple company emergency personnel responded to the scene and discovered a gas main leak on a two inch pvc main in the right of way for the public street on first street behind 921 south main street. Responding personnel had the gas main leak under control by 0929. January 2012 supplement: based upon the results of a third party analysis of the failed segment of pipe, the cause of the two-inch pvc main pipe leak discovered on first street on july 11, 2010 was a previous third party's failure to employ proper excavation practices. Specifically, it is likely that the pipe had been uncovered during a previous excavation and that the backfill was unlawfully and inproperly dumped back in the hole without compaction. This left the pipe without lateral support from the downward loading caused by the weight of the non-compacted backfill, and from other possible loadings. This led to excessive long-term deformation of the pipe, causing premature failure.
Detailed record list
Occurred At
2010-07-11 06:40:00
Year
2010
Report Received Date
2010-08-16 00:00:00
Iyear
2010.0
Report Number
20110038.0
Supplemental Number
15378.0
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
2010-07-11 06:40:00
Location Street Address
First Street And Coolidge Avenue
Location City Name
Las Vegas
Location County Name
Clark
Location State Abbreviation
NV
Location Postal Code
89101
Location Latitude
Location Longitude
Nrc Rpt Datetime
2010-07-11 11:37:00
Nrc Rpt Num
Commodity Released Type
Natural Gas
Unintentional Release
215.0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Ignite Ind
No
Explode Ind
No
Num Pub Evacuated
0.0
Incident Identified Datetime
2010-07-11 06:40:00
On Site Datetime
2010-07-11 07:14:00
Federal
No
Location Type
Public Property
Incident Area Type
Underground
Incident Area Subtype
Under Pavement
Depth Of Cover
36.0
Crossing
No
Pipe Facility Type
Privately Owned
System Part Involved
Main
Installation Year
1964.0
Pipe Diameter
2.0
Pipe Specification
Pvc 2110
Pipe Manufacturer
Kraloy
Material Involved
Plastic
Plastic Type
Polyvinyl Cloride (Pvc)
Wt Plastic
0.1
Release Type
Leak
Leak Type
Crack
Class Location Type
Class 4 Location
Est Cost Oper Paid
0.0
Est Cost Prop Damage
0.0
Est Cost Emergency
8009.0
Est Cost Other
0.0
Est Cost Unintentional Release
945.0
Prpty
8954.0
Commercial Affected
2.0
Industrial Affected
0.0
Residences Affected
0.0
Accident Psig
39.0
Normal Psig
39.0
Mop Psig
43.0
Accident Pressure
Pressure Did Not Exceed Maop
Scada In Place Ind
No
Accident Identifier
Notification From Emergency Responder
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
Excavation Damage
Cause Details
Previous Damage Due To Excavation Activity
Ex Party Type
Previous Damage Due To Excavation Activity
Ex Hydrotest Leak Survey Date
2010-07-02 00:00:00
Ex Hydrotest Conducted Ind
No
Notify Cga Dirt
No
Public Row Ind
Yes
Public Subtype
City Street
Excavator Type
Unknown/other
Excavator Equipment
Unknown/other
Work Performed
Unknown/other
One Call Notified Ind
No
Locator Type
Unknown/other
Visible Marks
Unknown/other
Service Interruption
Unknown/other
Root Cause Category
Excavation Issue
Root Cause Type
Excavator Failed To Protect/shore/support Facilities
Preparer Name
K**** E******
Preparer Title
Administrator-Compliance
Preparer Email
K************@s****.com
Preparer Telephone
(702) 365-2324
Preparer Fax
(702) 221-4116
Authorizer Name
P*** A*****
Authorizer Title
Director-Gas Operations
Authorizer Telephone
(702) 365-2207
Authorizer Email
P**********@s****.com
Narrative
Southwest gas emergency dispatch was notified of an explosion and possible gas leak in the area of first street and coolidge avenue by a representative of the city of las vegas fire department at 0640 on the morning of july 11, 2010. Multiple company emergency personnel responded to the scene and discovered a gas main leak on a two inch pvc main in the right of way for the public street on first street behind 921 south main street. Responding personnel had the gas main leak under control by 0929. January 2012 supplement: based upon the results of a third party analysis of the failed segment of pipe, the cause of the two-inch pvc main pipe leak discovered on first street on july 11, 2010 was a previous third party's failure to employ proper excavation practices. Specifically, it is likely that the pipe had been uncovered during a previous excavation and that the backfill was unlawfully and inproperly dumped back in the hole without compaction. This left the pipe without lateral support from the downward loading caused by the weight of the non-compacted backfill, and from other possible loadings. This led to excessive long-term deformation of the pipe, causing premature failure.
Occurred At 2010-07-11 06:40:00
Year 2010
Report Received Date 2010-08-16 00:00:00
Iyear 2010.0
Report Number 20110038.0
Supplemental Number 15378.0
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 2010-07-11 06:40:00
Location Street Address First Street And Coolidge Avenue
Location City Name Las Vegas
Location County Name Clark
Location State Abbreviation NV
Location Postal Code 89101
Location Latitude 36.16131 Google Maps OpenStreetMap
Location Longitude -115.15177 Google Maps OpenStreetMap
Nrc Rpt Datetime 2010-07-11 11:37:00
Nrc Rpt Num 947326 NRC Report How to search
Commodity Released Type Natural Gas
Unintentional Release 215.0
Fatality Ind No
Fatal 0
Injury Ind No
Injure 0
Ignite Ind No
Explode Ind No
Num Pub Evacuated 0.0
Incident Identified Datetime 2010-07-11 06:40:00
On Site Datetime 2010-07-11 07:14:00
Federal No
Location Type Public Property
Incident Area Type Underground
Incident Area Subtype Under Pavement
Depth Of Cover 36.0
Crossing No
Pipe Facility Type Privately Owned
System Part Involved Main
Installation Year 1964.0
Pipe Diameter 2.0
Pipe Specification Pvc 2110
Pipe Manufacturer Kraloy
Material Involved Plastic
Plastic Type Polyvinyl Cloride (Pvc)
Wt Plastic 0.1
Release Type Leak
Leak Type Crack
Class Location Type Class 4 Location
Est Cost Oper Paid 0.0
Est Cost Prop Damage 0.0
Est Cost Emergency 8009.0
Est Cost Other 0.0
Est Cost Unintentional Release 945.0
Prpty 8954.0
Commercial Affected 2.0
Industrial Affected 0.0
Residences Affected 0.0
Accident Psig 39.0
Normal Psig 39.0
Mop Psig 43.0
Accident Pressure Pressure Did Not Exceed Maop
Scada In Place Ind No
Accident Identifier Notification From Emergency Responder
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 Excavation Damage
Cause Details Previous Damage Due To Excavation Activity
Ex Party Type Previous Damage Due To Excavation Activity
Ex Hydrotest Leak Survey Date 2010-07-02 00:00:00
Ex Hydrotest Conducted Ind No
Notify Cga Dirt No
Public Row Ind Yes
Public Subtype City Street
Excavator Type Unknown/other
Excavator Equipment Unknown/other
Work Performed Unknown/other
One Call Notified Ind No
Locator Type Unknown/other
Visible Marks Unknown/other
Service Interruption Unknown/other
Root Cause Category Excavation Issue
Root Cause Type Excavator Failed To Protect/shore/support Facilities
Preparer Name K**** E******
Preparer Title Administrator-Compliance
Preparer Email K************@s****.com
Preparer Telephone (702) 365-2324
Preparer Fax (702) 221-4116
Authorizer Name P*** A*****
Authorizer Title Director-Gas Operations
Authorizer Telephone (702) 365-2207
Authorizer Email P**********@s****.com
Narrative Southwest gas emergency dispatch was notified of an explosion and possible gas leak in the area of first street and coolidge avenue by a representative of the city of las vegas fire department at 0640 on the morning of july 11, 2010. Multiple company emergency personnel responded to the scene and discovered a gas main leak on a two inch pvc main in the right of way for the public street on first street behind 921 south main street. Responding personnel had the gas main leak under control by 0929. January 2012 supplement: based upon the results of a third party analysis of the failed segment of pipe, the cause of the two-inch pvc main pipe leak discovered on first street on july 11, 2010 was a previous third party's failure to employ proper excavation practices. Specifically, it is likely that the pipe had been uncovered during a previous excavation and that the backfill was unlawfully and inproperly dumped back in the hole without compaction. This left the pipe without lateral support from the downward loading caused by the weight of the non-compacted backfill, and from other possible loadings. This led to excessive long-term deformation of the pipe, causing premature failure.

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