Incident details
Operator, cause, commodity and consequences with raw source fields.
GTG incident on 2023-12-06 — NE
Operator
Northern Natural Gas Co
Cause
Material Failure Of Pipe Or Weld
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities
0 injuries
Property damage (nominal)
$1,990,000
Incident datetime
2023-12-06 00:00 UTC
Report number
Location
NE
Narrative
On november 7, 2023, a technician identified a grade 3 leak while performing a leak survey on a cased crossing. No ppm was measured in the atmosphere, but the technician was able to detect 580 ppm when the cap for the vent on the cased crossing was removed and a probe was inserted in the vent stack. On november 8, 2023, an ethane detector was used to confirm whether the ppm was natural gas or not. Ethane was confirmed and the ppm had increased to 3,037 inside the vent stack and 56 ppm at atmosphere due to an increase in flow from the previous day. A plan to isolate the segment was implemented while the engineering department started to develop a repair plan. On november 9, 2023, the engineering department concluded that repair costs would exceed the reporting threshold and the nrc was notified as soon as possible after that determination. The leak was stopped on november 22, 2023, after a line stop was installed downstream of the leak, to limit the amount of gas released to the environment. The crossing will be replaced with a new hdd and is scheduled to be completed mid-december 2023. Lab report indicates cracklike indications on the original 1948 construction sleeves and welds.
Detailed record list
Report Received Date
2023-12-06 00:00:00
Iyear
2023
Report Number
20230112
Supplemental Number
39279
Report Type
Supplemental Final
Operator Id
13750
Name
Northern Natural Gas Co
Operator Street Address
1111 South 103rd Street
Operator City Name
Omaha
Operator State Abbreviation
NE
Operator Postal Code
68124
Time Zone
Central
Daylight Savings Ind
No
Location Latitude
37.592543
Location Longitude
-99.413753
Nrc Rpt Num
1383910
Additional Nrc Report Numbers
1384001
Commodity Released Type
Natural Gas
Unintentional Release
10.7
Intentional Release
500
Accompanying Liquid
0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Status When Identified
Normal Operation, Includes Pauses During Maintenance
Shutdown Due Accident Ind
Yes
Communication State Fed Ind
No
Ignite Ind
No
Upstream Action Taken
Valve Closure
Downstream Action Taken
Valve Closure
Num Pub Evacuated
0
On Off Shore
Onshore
Onshore State Abbreviation
Ks
Onshore Postal Code
67109
Onshore City Name
Not Within A Municipality
Onshore County Name
Kiowa
Designated Location
Milepost
Designated Name
0.22
Pipe Fac Name
Mullinville To Macksville
Segment Name
M670b
Federal
No
Location Type
Pipeline Right-Of-Way
Incident Area Type
Underground
Incident Area Subtype
Other
Incident Area Details
Casing
Depth Of Cover
240
Other Underground Facilities
No
Crossing
Yes
Railroad Crossing Ind
Yes
Railroad Type
Cased
Pipe Facility Type
Interstate
System Part Involved
Onshore Pipeline, Including Valve Sites
Item Involved
Pipe
Pipe Type
Pipe Body
Pipe Diameter
24
Puddle Weld Ind
No
Pipe Wall Thickness
0.281
Pipe Smys
42000
Pipe Specification
Api 5lx
Pipe Seam Type
Longitudinal Erw - Unknown Frequency
Pipe Manufacturer
Ao Smith
Pipe Coating Type
Coal Tar
Coating Applied Ind
Yes
Installation Year
1948
Manufactured Year
1946
Material Involved
Carbon Steel
Release Type
Leak
Leak Type
Crack
Class Location Type
Class 1 Location
Could Be Hca
No
Pir Radius
466
Heat Damage Ind
No
Non Heat Damage Ind
No
Did Occur In Mca Ind
No
Est Cost Oper Paid
0
Est Cost Unintentional Release
18
Est Cost Intentional Release
852
Est Cost Prop Damage
1990000
Est Cost Emergency
0
Est Cost Other
0
Gas Cost In Mcf
1.704
Prpty
1990870
Num Persons Hosp Not Ovnght
0
Num Injured Treated By Emt
0
Num Resident Building Affctd
0
Num Business Building Affctd
0
Wildlife Impact Ind
No
Accident Psig
620
Gas Flow In Pipe In Mcf
8100
Mop Psig
708
Mop Cfr Section
192.619(A)(1)
Maop Established Date
1948-08-01 00:00:00
Maop Reversal Flow Ind
No
Accident Pressure
Pressure Did Not Exceed Maop
Pressure Restriction Ind
No
Gas Required Odorized Ind
No
Upstream Valve Type Ind
Manual
Downstream Valve Type Ind
Manual
Length Segment Isolated
75404
Internal Inspection Ind
Yes
Operation Complications Ind
No
Pipeline Function
Transmission System
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
Yes, specify investigation result(s): (select all that apply)
Invest No Control Room Ind
Yes
Invest No Controller Ind
Yes
Employee Drug Test Ind
No
Contractor Drug Test Ind
No
Cause
Material Failure Of Pipe Or Weld
Cause Details
Design-, Construction-, Installation-, Or Fabrication-Related
Pwjf Failure Type
Design-, Construction-, Installation-, Or Fabrication-Related
Field Exam Ind
Yes
Metallurgical Ind
Yes
Other Factor
Yes
Other Factor Details
Original Construction, Girth Weld Reinforcement Crack
Additional Crack Ind
Yes
Post Constr Pressure Test Val
0
Collected Data Ind
Yes
Axial Magnetic Flx Lkg Ind
Yes
Geometry Deformation Ind
Yes
Axial Recent Year
2020
Axial Rcnt Propul Method
Free Swimming
Axial Rcnt Attuned Detect
Metal Loss
Axial Rcnt Atnd Dtct Metal
High Resolution
Geometry Recent Year
2020
Geometry Rcnt Propul Method
Free Swimming
Geometry Rcnt Resolution
High Resolution
Geometrt Rcnt Measur Cups
No Cups
Has Hydrtst Conduc Before Ind
No
Direct Asmnt Conducted
Yes, But The Point Of The Accident Was Not Identified As A Dig Site
Direct Asmnt Pnt Not Idntf Yr
2020
Asmnt Confirmatory Rcnt Year
2020
Asmnt Confirmatory Rcnt Ind
Yes
Non Destructive Exam Ind
No
Pwf Construction Ind
Yes
Pwf Installation Ind
Yes
Preparer Name
D**** C*******
Preparer Title
Sr. Engineer Ii
Preparer Email
D*************@n****.com
Preparer Telephone
4023987439
Authorizer Name
T** C******
Authorizer Telephone
4023987715
Authorizer Email
T*************@n****.com
Narrative
On november 7, 2023, a technician identified a grade 3 leak while performing a leak survey on a cased crossing. No ppm was measured in the atmosphere, but the technician was able to detect 580 ppm when the cap for the vent on the cased crossing was removed and a probe was inserted in the vent stack. On november 8, 2023, an ethane detector was used to confirm whether the ppm was natural gas or not. Ethane was confirmed and the ppm had increased to 3,037 inside the vent stack and 56 ppm at atmosphere due to an increase in flow from the previous day. A plan to isolate the segment was implemented while the engineering department started to develop a repair plan. On november 9, 2023, the engineering department concluded that repair costs would exceed the reporting threshold and the nrc was notified as soon as possible after that determination. The leak was stopped on november 22, 2023, after a line stop was installed downstream of the leak, to limit the amount of gas released to the environment. The crossing will be replaced with a new hdd and is scheduled to be completed mid-december 2023. Lab report indicates cracklike indications on the original 1948 construction sleeves and welds.
| Report Received Date | 2023-12-06 00:00:00 |
|---|---|
| Iyear | 2023 |
| Report Number | 20230112 |
| Supplemental Number | 39279 |
| Report Type | Supplemental Final |
| Operator Id | 13750 PHMSA Enforcement |
| Name | Northern Natural Gas Co |
| Operator Street Address | 1111 South 103rd Street |
| Operator City Name | Omaha |
| Operator State Abbreviation | NE |
| Operator Postal Code | 68124 |
| Time Zone | Central |
| Daylight Savings Ind | No |
| Location Latitude | 37.592543 Google Maps OpenStreetMap |
| Location Longitude | -99.413753 Google Maps OpenStreetMap |
| Nrc Rpt Num | 1383910 NRC Report How to search |
| Additional Nrc Report Numbers | 1384001 |
| Commodity Released Type | Natural Gas |
| Unintentional Release | 10.7 |
| Intentional Release | 500 |
| Accompanying Liquid | 0 |
| Fatality Ind | No |
| Fatal | 0 |
| Injury Ind | No |
| Injure | 0 |
| Status When Identified | Normal Operation, Includes Pauses During Maintenance |
| Shutdown Due Accident Ind | Yes |
| Communication State Fed Ind | No |
| Ignite Ind | No |
| Upstream Action Taken | Valve Closure |
| Downstream Action Taken | Valve Closure |
| Num Pub Evacuated | 0 |
| On Off Shore | Onshore |
| Onshore State Abbreviation | Ks |
| Onshore Postal Code | 67109 |
| Onshore City Name | Not Within A Municipality |
| Onshore County Name | Kiowa |
| Designated Location | Milepost |
| Designated Name | 0.22 |
| Pipe Fac Name | Mullinville To Macksville |
| Segment Name | M670b |
| Federal | No |
| Location Type | Pipeline Right-Of-Way |
| Incident Area Type | Underground |
| Incident Area Subtype | Other |
| Incident Area Details | Casing |
| Depth Of Cover | 240 |
| Other Underground Facilities | No |
| Crossing | Yes |
| Railroad Crossing Ind | Yes |
| Railroad Type | Cased |
| Pipe Facility Type | Interstate |
| System Part Involved | Onshore Pipeline, Including Valve Sites |
| Item Involved | Pipe |
| Pipe Type | Pipe Body |
| Pipe Diameter | 24 |
| Puddle Weld Ind | No |
| Pipe Wall Thickness | 0.281 |
| Pipe Smys | 42000 |
| Pipe Specification | Api 5lx |
| Pipe Seam Type | Longitudinal Erw - Unknown Frequency |
| Pipe Manufacturer | Ao Smith |
| Pipe Coating Type | Coal Tar |
| Coating Applied Ind | Yes |
| Installation Year | 1948 |
| Manufactured Year | 1946 |
| Material Involved | Carbon Steel |
| Release Type | Leak |
| Leak Type | Crack |
| Class Location Type | Class 1 Location |
| Could Be Hca | No |
| Pir Radius | 466 |
| Heat Damage Ind | No |
| Non Heat Damage Ind | No |
| Did Occur In Mca Ind | No |
| Est Cost Oper Paid | 0 |
| Est Cost Unintentional Release | 18 |
| Est Cost Intentional Release | 852 |
| Est Cost Prop Damage | 1990000 |
| Est Cost Emergency | 0 |
| Est Cost Other | 0 |
| Gas Cost In Mcf | 1.704 |
| Prpty | 1990870 |
| Num Persons Hosp Not Ovnght | 0 |
| Num Injured Treated By Emt | 0 |
| Num Resident Building Affctd | 0 |
| Num Business Building Affctd | 0 |
| Wildlife Impact Ind | No |
| Accident Psig | 620 |
| Gas Flow In Pipe In Mcf | 8100 |
| Mop Psig | 708 |
| Mop Cfr Section | 192.619(A)(1) View CFR 49 §192 |
| Maop Established Date | 1948-08-01 00:00:00 |
| Maop Reversal Flow Ind | No |
| Accident Pressure | Pressure Did Not Exceed Maop |
| Pressure Restriction Ind | No |
| Gas Required Odorized Ind | No |
| Upstream Valve Type Ind | Manual |
| Downstream Valve Type Ind | Manual |
| Length Segment Isolated | 75404 |
| Internal Inspection Ind | Yes |
| Operation Complications Ind | No |
| Pipeline Function | Transmission System |
| 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 | Yes, specify investigation result(s): (select all that apply) |
| Invest No Control Room Ind | Yes |
| Invest No Controller Ind | Yes |
| Employee Drug Test Ind | No |
| Contractor Drug Test Ind | No |
| Cause | Material Failure Of Pipe Or Weld |
| Cause Details | Design-, Construction-, Installation-, Or Fabrication-Related |
| Pwjf Failure Type | Design-, Construction-, Installation-, Or Fabrication-Related |
| Field Exam Ind | Yes |
| Metallurgical Ind | Yes |
| Other Factor | Yes |
| Other Factor Details | Original Construction, Girth Weld Reinforcement Crack |
| Additional Crack Ind | Yes |
| Post Constr Pressure Test Val | 0 |
| Collected Data Ind | Yes |
| Axial Magnetic Flx Lkg Ind | Yes |
| Geometry Deformation Ind | Yes |
| Axial Recent Year | 2020 |
| Axial Rcnt Propul Method | Free Swimming |
| Axial Rcnt Attuned Detect | Metal Loss |
| Axial Rcnt Atnd Dtct Metal | High Resolution |
| Geometry Recent Year | 2020 |
| Geometry Rcnt Propul Method | Free Swimming |
| Geometry Rcnt Resolution | High Resolution |
| Geometrt Rcnt Measur Cups | No Cups |
| Has Hydrtst Conduc Before Ind | No |
| Direct Asmnt Conducted | Yes, But The Point Of The Accident Was Not Identified As A Dig Site |
| Direct Asmnt Pnt Not Idntf Yr | 2020 |
| Asmnt Confirmatory Rcnt Year | 2020 |
| Asmnt Confirmatory Rcnt Ind | Yes |
| Non Destructive Exam Ind | No |
| Pwf Construction Ind | Yes |
| Pwf Installation Ind | Yes |
| Preparer Name | D**** C******* |
| Preparer Title | Sr. Engineer Ii |
| Preparer Email | D*************@n****.com |
| Preparer Telephone | 4023987439 |
| Authorizer Name | T** C****** |
| Authorizer Telephone | 4023987715 |
| Authorizer Email | T*************@n****.com |
| Narrative | On november 7, 2023, a technician identified a grade 3 leak while performing a leak survey on a cased crossing. No ppm was measured in the atmosphere, but the technician was able to detect 580 ppm when the cap for the vent on the cased crossing was removed and a probe was inserted in the vent stack. On november 8, 2023, an ethane detector was used to confirm whether the ppm was natural gas or not. Ethane was confirmed and the ppm had increased to 3,037 inside the vent stack and 56 ppm at atmosphere due to an increase in flow from the previous day. A plan to isolate the segment was implemented while the engineering department started to develop a repair plan. On november 9, 2023, the engineering department concluded that repair costs would exceed the reporting threshold and the nrc was notified as soon as possible after that determination. The leak was stopped on november 22, 2023, after a line stop was installed downstream of the leak, to limit the amount of gas released to the environment. The crossing will be replaced with a new hdd and is scheduled to be completed mid-december 2023. Lab report indicates cracklike indications on the original 1948 construction sleeves and welds. |
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