Incident details
Operator, cause, commodity and consequences with raw source fields.
GD incident on 2016-07-26 — NV
Operator
Southwest Gas Corp
Cause
Locating Issue
Commodity
Natural Gas
Program
GD
Damage and Injuries
0 fatalities
0 injuries
Property damage (nominal)
$82,668
Incident datetime
2016-07-26 11:30
Report number
Location
NV, CLARK COUNTY
Narrative
Southwest gas (company) construction crews were performing maintenance to replace a 4-inch pe valve, that had a previously discovered non-hazardous grade 2 leak, and hit a 4-inch pe gas line with a backhoe during excavation. Part a, 16: fire department conducted a precautionary evacuation of 30 occupants as a result of the fire. Part c, 5: the damage to the 4-inch pe main was extensive as a result of the ignition and subsequent fire; therefore, the size of the puncture could not be determined. The estimated volume of gas released was calculated assuming a full 4-inch circumfrential break. Part g3, 11: several non-gas utilitiy line markings were visible in the area the company delineated for excavation, including water, power and street lighting. Company personnel did not sufficiently locate and mark all of the gas facilities within the delineated area in accordance with its line locating procedures. As a result of the company's investigation to date, the company believes that if its line locating procedures were followed a discrepancy in the alignment of the facility would have been identified between the map, asbuilt and the actual field facility location. Part g3, 14: in addition to the primary cause of insufficient locating practices the company identified an additional contributing cause. The excavation damage occurred at or near an unmapped and non-located 4-inch 45 degree elbow that did not appear on as-built documentation. The excavation damage is believed to have occurred on a portion of the pipe that changed direction because the 4" pe main and valve were exposed and being spotted by company employees while the backhoe operator was removing dirt adjacent to the pipeline facility.
Detailed record list
Occurred At
2016-07-26 11:30:00
Year
2016
Report Received Date
2016-08-24 00:00:00
Iyear
2016.0
Report Number
20160075.0
Supplemental Number
16368.0
Report Type
Original Final
Operator Id
18536
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
2016-07-26 11:30:00
Location Street Address
On Acacia Tree Dr., 150-Feet West Of Anasazi Drive
Location City Name
Las Vegas
Location County Name
Clark County
Location State Abbreviation
NV
Location Postal Code
89144
Location Latitude
36.18097
Location Longitude
-115.328
Nrc Rpt Datetime
2016-07-26 13:28:00
Nrc Rpt Num
1154508
Commodity Released Type
Natural Gas
Unintentional Release
1425.0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Ignite Ind
Yes
Explode Ind
No
Num Pub Evacuated
30.0
Incident Identified Datetime
2016-07-26 11:30:00
On Site Datetime
2016-07-26 11:30:00
Federal
No
Location Type
Public Property
Incident Area Type
Underground
Incident Area Subtype
Exposed Due To Excavation
Depth Of Cover
48.0
Crossing
No
Pipe Facility Type
Investor Owned
System Part Involved
Main
Installation Year
1996.0
Pipe Diameter
4.0
Pipe Specification
Astm D2513
Pipe Manufacturer
Phillips
Material Involved
Plastic
Plastic Type
Polyethylene (Pe)
Plastic Sdr
11
Material Pe Pipe Code
3408
Release Type
Other
Release Type Details
Mechanical Puncture - For Explanation Refer To Narrative Part C, 5
Class Location Type
Class 3 Location
Est Cost Oper Paid
25499.0
Est Cost Prop Damage
82668.0
Est Cost Emergency
221494.0
Est Cost Other
1624.0
Est Cost Other Details
Plumber Fees And Vehicle Towing.
Est Cost Unintentional Release
2903.0
Prpty
334188.0
Commercial Affected
44.0
Industrial Affected
0.0
Residences Affected
3476.0
Accident Psig
55.0
Normal Psig
55.0
Mop Psig
60.0
Accident Pressure
Pressure Did Not Exceed Maop
Scada In Place Ind
Yes
Scada Operating Ind
Yes
Scada Functional Ind
Yes
Scada Detection Ind
No
Scada Conf Ind
No
Accident Identifier
Local Operating Personnel, Including Contractors
Operator Type
Operator Employee
Investigation Status
No, the operator did not find that an investigation of the controller(s) actions or control room issues was necessary due to: (provide an explanation for why the operator did not investigate)
Investigation Status Details
The line was damaged during excavation activity.
Employee Drug Test Ind
Yes
Num Employees Tested
8
Num Employees Failed
0
Contractor Drug Test Ind
Yes
Num Contractors Tested
3
Num Contractors Failed
0
Cause
Excavation Damage
Cause Details
Excavation Damage By Operator (First Party)
Ex Party Type
Excavation Damage By Operator (First Party)
Notify Cga Dirt
No
Public Row Ind
Yes
Public Subtype
City Street
Excavator Type
Utility
Excavator Equipment
Backhoe/trackhoe
Work Performed
Natural Gas
One Call Notified Ind
Yes
One Call Ticket Num
620800166
Locator Type
Utility Owner
Visible Marks
No
Service Interruption
Yes
Service Interruption Hours
27.0
Root Cause Category
Locating Issue
Root Cause Type
Facility Not Marked Due To Incomplete Marks At Damage Location
Preparer Name
R**** C********
Preparer Title
Compliance Specialist
Preparer Email
R**************@s****.com
Preparer Telephone
702-365-2080
Preparer Fax
702-369-0542
Authorizer Name
T***** C*****
Authorizer Title
Director Of Gas Operations
Authorizer Telephone
702-365-2028
Authorizer Email
T************@s****.com
Narrative
Southwest gas (company) construction crews were performing maintenance to replace a 4-inch pe valve, that had a previously discovered non-hazardous grade 2 leak, and hit a 4-inch pe gas line with a backhoe during excavation. Part a, 16: fire department conducted a precautionary evacuation of 30 occupants as a result of the fire. Part c, 5: the damage to the 4-inch pe main was extensive as a result of the ignition and subsequent fire; therefore, the size of the puncture could not be determined. The estimated volume of gas released was calculated assuming a full 4-inch circumfrential break. Part g3, 11: several non-gas utilitiy line markings were visible in the area the company delineated for excavation, including water, power and street lighting. Company personnel did not sufficiently locate and mark all of the gas facilities within the delineated area in accordance with its line locating procedures. As a result of the company's investigation to date, the company believes that if its line locating procedures were followed a discrepancy in the alignment of the facility would have been identified between the map, asbuilt and the actual field facility location. Part g3, 14: in addition to the primary cause of insufficient locating practices the company identified an additional contributing cause. The excavation damage occurred at or near an unmapped and non-located 4-inch 45 degree elbow that did not appear on as-built documentation. The excavation damage is believed to have occurred on a portion of the pipe that changed direction because the 4" pe main and valve were exposed and being spotted by company employees while the backhoe operator was removing dirt adjacent to the pipeline facility.
| Occurred At | 2016-07-26 11:30:00 |
|---|---|
| Year | 2016 |
| Report Received Date | 2016-08-24 00:00:00 |
| Iyear | 2016.0 |
| Report Number | 20160075.0 |
| Supplemental Number | 16368.0 |
| Report Type | Original 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 | 2016-07-26 11:30:00 |
| Location Street Address | On Acacia Tree Dr., 150-Feet West Of Anasazi Drive |
| Location City Name | Las Vegas |
| Location County Name | Clark County |
| Location State Abbreviation | NV |
| Location Postal Code | 89144 |
| Location Latitude | 36.18097 Google Maps OpenStreetMap |
| Location Longitude | -115.328 Google Maps OpenStreetMap |
| Nrc Rpt Datetime | 2016-07-26 13:28:00 |
| Nrc Rpt Num | 1154508 NRC Report How to search |
| Commodity Released Type | Natural Gas |
| Unintentional Release | 1425.0 |
| Fatality Ind | No |
| Fatal | 0 |
| Injury Ind | No |
| Injure | 0 |
| Ignite Ind | Yes |
| Explode Ind | No |
| Num Pub Evacuated | 30.0 |
| Incident Identified Datetime | 2016-07-26 11:30:00 |
| On Site Datetime | 2016-07-26 11:30:00 |
| Federal | No |
| Location Type | Public Property |
| Incident Area Type | Underground |
| Incident Area Subtype | Exposed Due To Excavation |
| Depth Of Cover | 48.0 |
| Crossing | No |
| Pipe Facility Type | Investor Owned |
| System Part Involved | Main |
| Installation Year | 1996.0 |
| Pipe Diameter | 4.0 |
| Pipe Specification | Astm D2513 |
| Pipe Manufacturer | Phillips |
| Material Involved | Plastic |
| Plastic Type | Polyethylene (Pe) |
| Plastic Sdr | 11 |
| Material Pe Pipe Code | 3408 |
| Release Type | Other |
| Release Type Details | Mechanical Puncture - For Explanation Refer To Narrative Part C, 5 |
| Class Location Type | Class 3 Location |
| Est Cost Oper Paid | 25499.0 |
| Est Cost Prop Damage | 82668.0 |
| Est Cost Emergency | 221494.0 |
| Est Cost Other | 1624.0 |
| Est Cost Other Details | Plumber Fees And Vehicle Towing. |
| Est Cost Unintentional Release | 2903.0 |
| Prpty | 334188.0 |
| Commercial Affected | 44.0 |
| Industrial Affected | 0.0 |
| Residences Affected | 3476.0 |
| Accident Psig | 55.0 |
| Normal Psig | 55.0 |
| Mop Psig | 60.0 |
| Accident Pressure | Pressure Did Not Exceed Maop |
| Scada In Place Ind | Yes |
| Scada Operating Ind | Yes |
| Scada Functional Ind | Yes |
| Scada Detection Ind | No |
| Scada Conf Ind | No |
| Accident Identifier | Local Operating Personnel, Including Contractors |
| Operator Type | Operator Employee |
| Investigation Status | No, the operator did not find that an investigation of the controller(s) actions or control room issues was necessary due to: (provide an explanation for why the operator did not investigate) |
| Investigation Status Details | The line was damaged during excavation activity. |
| Employee Drug Test Ind | Yes |
| Num Employees Tested | 8 |
| Num Employees Failed | 0 |
| Contractor Drug Test Ind | Yes |
| Num Contractors Tested | 3 |
| Num Contractors Failed | 0 |
| Cause | Excavation Damage |
| Cause Details | Excavation Damage By Operator (First Party) |
| Ex Party Type | Excavation Damage By Operator (First Party) |
| Notify Cga Dirt | No |
| Public Row Ind | Yes |
| Public Subtype | City Street |
| Excavator Type | Utility |
| Excavator Equipment | Backhoe/trackhoe |
| Work Performed | Natural Gas |
| One Call Notified Ind | Yes |
| One Call Ticket Num | 620800166 |
| Locator Type | Utility Owner |
| Visible Marks | No |
| Service Interruption | Yes |
| Service Interruption Hours | 27.0 |
| Root Cause Category | Locating Issue |
| Root Cause Type | Facility Not Marked Due To Incomplete Marks At Damage Location |
| Preparer Name | R**** C******** |
| Preparer Title | Compliance Specialist |
| Preparer Email | R**************@s****.com |
| Preparer Telephone | 702-365-2080 |
| Preparer Fax | 702-369-0542 |
| Authorizer Name | T***** C***** |
| Authorizer Title | Director Of Gas Operations |
| Authorizer Telephone | 702-365-2028 |
| Authorizer Email | T************@s****.com |
| Narrative | Southwest gas (company) construction crews were performing maintenance to replace a 4-inch pe valve, that had a previously discovered non-hazardous grade 2 leak, and hit a 4-inch pe gas line with a backhoe during excavation. Part a, 16: fire department conducted a precautionary evacuation of 30 occupants as a result of the fire. Part c, 5: the damage to the 4-inch pe main was extensive as a result of the ignition and subsequent fire; therefore, the size of the puncture could not be determined. The estimated volume of gas released was calculated assuming a full 4-inch circumfrential break. Part g3, 11: several non-gas utilitiy line markings were visible in the area the company delineated for excavation, including water, power and street lighting. Company personnel did not sufficiently locate and mark all of the gas facilities within the delineated area in accordance with its line locating procedures. As a result of the company's investigation to date, the company believes that if its line locating procedures were followed a discrepancy in the alignment of the facility would have been identified between the map, asbuilt and the actual field facility location. Part g3, 14: in addition to the primary cause of insufficient locating practices the company identified an additional contributing cause. The excavation damage occurred at or near an unmapped and non-located 4-inch 45 degree elbow that did not appear on as-built documentation. The excavation damage is believed to have occurred on a portion of the pipe that changed direction because the 4" pe main and valve were exposed and being spotted by company employees while the backhoe operator was removing dirt adjacent to the pipeline facility. |
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