Incident details
Operator, cause, commodity and consequences with raw source fields.
GTG incident on 2021-11-12 — NE
Operator
Northern Natural Gas Co
Cause
Incorrect Operation
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities
0 injuries
Property damage (nominal)
$1,700,181
Incident datetime
2021-11-12 10:30
Report number
Location
NE
Narrative
On november 12, 2021, new valves were being manipulated for commisioning and lubrication. At 10:30, a 30 inch bypass valve was manipulated when then ground was reported to raise and settle with a muffled sound. The on-site personnel evacuated the location to report the event. Initial reporting did not see any pressure changes on scada, and due to extremley high winds, no visual or audible indications could be made of venting gas. A plan was created to reduce pressure to 600 pounds for the b, c and d lines as they were all in common at the location. At 21:00, it was reported that as technicians approached the valve setting, the lel monitoring equipment detected gas approximately 100 yards upwind of the valve assembly. The pipeline was isolated at 1555 on november 14, 2021. Excavation of the valve found that a 1.5 inch diameter body bleed plug was missing, concluding it was not installed or improperly installed.
Detailed record list
Report Received Date
2021-12-01 00:00:00
Iyear
2021
Report Number
20210110
Supplemental Number
36591
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
Local Datetime
2021-11-12 21:00:00
Time Zone
Central
Daylight Savings Ind
No
Location Latitude
42.282001
Location Longitude
-93.28154
Nrc Rpt Num
1321904
Nrc Rpt Datetime
2021-11-12 22:05:00
Additional Nrc Report Numbers
1321930
Commodity Released Type
Natural Gas
Unintentional Release
8375
Intentional Release
2975
Accompanying Liquid
0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Status When Identified
Post-Construction Commissioning
Communication State Fed Ind
Yes
Party Initiated Communication
Operator
Initial Responder Com Datetime
2021-11-12 22:05:00
Ignite Ind
No
Upstream Action Taken
Operational Control
Upstream Oprtnl Cntrl Detail
Pressure Was Reduced Upstream To Safely Approach The Location.
Downstream Action Taken
Operational Control
Downstream Oprtnl Cntrl Detail
Pressure Was Reduced Upstream To Safely Approach The Location.
Num Pub Evacuated
3
Incident Identified Datetime
2021-11-12 10:30:00
On Site Datetime
2021-11-12 10:30:00
On Off Shore
Onshore
Onshore State Abbreviation
Ia
Onshore Postal Code
50122
Onshore City Name
Not Within A Municipality
Onshore County Name
Hardin
Designated Location
Milepost
Designated Name
21.78
Pipe Fac Name
30" Loop Line From Ogden Compressor Station
Segment Name
M521d
Federal
No
Location Type
Operator-Controlled Property
Incident Area Type
Underground
Incident Area Subtype
Under Soil
Other Underground Facilities
No
Crossing
No
Pipe Facility Type
Interstate
System Part Involved
Onshore Pipeline, Including Valve Sites
Item Involved
Valve
Valve Type
Auxiliary Or Other Valve
Installation Year
2021
Manufactured Year
Unknown
Material Involved
Carbon Steel
Release Type
Other
Release Type Details
Body Bleed Plug Was Missing, Causing The Location Of The Release.
Class Location Type
Class 1 Location
Could Be Hca
No
Pir Radius
692
Heat Damage Ind
No
Non Heat Damage Ind
No
Did Occur In Mca Ind
No
Est Cost Oper Paid
0
Est Cost Unintentional Release
39446
Est Cost Intentional Release
14012
Est Cost Prop Damage
1700181
Est Cost Emergency
840
Est Cost Other
0
Gas Cost In Mcf
4.71
Prpty
1754479
Num Persons Hosp Not Ovnght
0
Num Injured Treated By Emt
0
Num Resident Building Affctd
2
Num Business Building Affctd
0
Wildlife Impact Ind
No
Accident Psig
800
Gas Flow In Pipe In Mcf
211
Mop Psig
1000
Mop Cfr Section
192.619(A)(2)
Maop Established Date
1997-11-01 00:00:00
Maop Reversal Flow Ind
No
Accident Pressure
Pressure Did Not Exceed Maop
Pressure Restriction Ind
No
Gas Required Odorized Ind
No
Length Segment Isolated
44246
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
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
Control room had no impact to the incident.
Employee Drug Test Ind
No
Contractor Drug Test Ind
No
Cause
Incorrect Operation
Cause Details
Equipment Not Installed Properly
Operation Type
Equipment Not Installed Properly
Related Failure Follow Ind
Yes
Category Type
Construction
Operator Qualification Ind
No
Io Not Installed Properly Ind
Yes
Io Follow Procedure Ind
Yes
Preparer Name
D**** C*******
Preparer Email
D*************@n****.com
Preparer Telephone
402-398-7439
Authorizer Name
T** C******
Authorizer Telephone
402-398-7715
Authorizer Email
T*************@n****.com
Narrative
On november 12, 2021, new valves were being manipulated for commisioning and lubrication. At 10:30, a 30 inch bypass valve was manipulated when then ground was reported to raise and settle with a muffled sound. The on-site personnel evacuated the location to report the event. Initial reporting did not see any pressure changes on scada, and due to extremley high winds, no visual or audible indications could be made of venting gas. A plan was created to reduce pressure to 600 pounds for the b, c and d lines as they were all in common at the location. At 21:00, it was reported that as technicians approached the valve setting, the lel monitoring equipment detected gas approximately 100 yards upwind of the valve assembly. The pipeline was isolated at 1555 on november 14, 2021. Excavation of the valve found that a 1.5 inch diameter body bleed plug was missing, concluding it was not installed or improperly installed.
| Report Received Date | 2021-12-01 00:00:00 |
|---|---|
| Iyear | 2021 |
| Report Number | 20210110 |
| Supplemental Number | 36591 |
| 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 |
| Local Datetime | 2021-11-12 21:00:00 |
| Time Zone | Central |
| Daylight Savings Ind | No |
| Location Latitude | 42.282001 Google Maps OpenStreetMap |
| Location Longitude | -93.28154 Google Maps OpenStreetMap |
| Nrc Rpt Num | 1321904 NRC Report How to search |
| Nrc Rpt Datetime | 2021-11-12 22:05:00 |
| Additional Nrc Report Numbers | 1321930 |
| Commodity Released Type | Natural Gas |
| Unintentional Release | 8375 |
| Intentional Release | 2975 |
| Accompanying Liquid | 0 |
| Fatality Ind | No |
| Fatal | 0 |
| Injury Ind | No |
| Injure | 0 |
| Status When Identified | Post-Construction Commissioning |
| Communication State Fed Ind | Yes |
| Party Initiated Communication | Operator |
| Initial Responder Com Datetime | 2021-11-12 22:05:00 |
| Ignite Ind | No |
| Upstream Action Taken | Operational Control |
| Upstream Oprtnl Cntrl Detail | Pressure Was Reduced Upstream To Safely Approach The Location. |
| Downstream Action Taken | Operational Control |
| Downstream Oprtnl Cntrl Detail | Pressure Was Reduced Upstream To Safely Approach The Location. |
| Num Pub Evacuated | 3 |
| Incident Identified Datetime | 2021-11-12 10:30:00 |
| On Site Datetime | 2021-11-12 10:30:00 |
| On Off Shore | Onshore |
| Onshore State Abbreviation | Ia |
| Onshore Postal Code | 50122 |
| Onshore City Name | Not Within A Municipality |
| Onshore County Name | Hardin |
| Designated Location | Milepost |
| Designated Name | 21.78 |
| Pipe Fac Name | 30" Loop Line From Ogden Compressor Station |
| Segment Name | M521d |
| Federal | No |
| Location Type | Operator-Controlled Property |
| Incident Area Type | Underground |
| Incident Area Subtype | Under Soil |
| Other Underground Facilities | No |
| Crossing | No |
| Pipe Facility Type | Interstate |
| System Part Involved | Onshore Pipeline, Including Valve Sites |
| Item Involved | Valve |
| Valve Type | Auxiliary Or Other Valve |
| Installation Year | 2021 |
| Manufactured Year | Unknown |
| Material Involved | Carbon Steel |
| Release Type | Other |
| Release Type Details | Body Bleed Plug Was Missing, Causing The Location Of The Release. |
| Class Location Type | Class 1 Location |
| Could Be Hca | No |
| Pir Radius | 692 |
| Heat Damage Ind | No |
| Non Heat Damage Ind | No |
| Did Occur In Mca Ind | No |
| Est Cost Oper Paid | 0 |
| Est Cost Unintentional Release | 39446 |
| Est Cost Intentional Release | 14012 |
| Est Cost Prop Damage | 1700181 |
| Est Cost Emergency | 840 |
| Est Cost Other | 0 |
| Gas Cost In Mcf | 4.71 |
| Prpty | 1754479 |
| Num Persons Hosp Not Ovnght | 0 |
| Num Injured Treated By Emt | 0 |
| Num Resident Building Affctd | 2 |
| Num Business Building Affctd | 0 |
| Wildlife Impact Ind | No |
| Accident Psig | 800 |
| Gas Flow In Pipe In Mcf | 211 |
| Mop Psig | 1000 |
| Mop Cfr Section | 192.619(A)(2) View CFR 49 §192 |
| Maop Established Date | 1997-11-01 00:00:00 |
| Maop Reversal Flow Ind | No |
| Accident Pressure | Pressure Did Not Exceed Maop |
| Pressure Restriction Ind | No |
| Gas Required Odorized Ind | No |
| Length Segment Isolated | 44246 |
| 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 | 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 | Control room had no impact to the incident. |
| Employee Drug Test Ind | No |
| Contractor Drug Test Ind | No |
| Cause | Incorrect Operation |
| Cause Details | Equipment Not Installed Properly |
| Operation Type | Equipment Not Installed Properly |
| Related Failure Follow Ind | Yes |
| Category Type | Construction |
| Operator Qualification Ind | No |
| Io Not Installed Properly Ind | Yes |
| Io Follow Procedure Ind | Yes |
| Preparer Name | D**** C******* |
| Preparer Email | D*************@n****.com |
| Preparer Telephone | 402-398-7439 |
| Authorizer Name | T** C****** |
| Authorizer Telephone | 402-398-7715 |
| Authorizer Email | T*************@n****.com |
| Narrative | On november 12, 2021, new valves were being manipulated for commisioning and lubrication. At 10:30, a 30 inch bypass valve was manipulated when then ground was reported to raise and settle with a muffled sound. The on-site personnel evacuated the location to report the event. Initial reporting did not see any pressure changes on scada, and due to extremley high winds, no visual or audible indications could be made of venting gas. A plan was created to reduce pressure to 600 pounds for the b, c and d lines as they were all in common at the location. At 21:00, it was reported that as technicians approached the valve setting, the lel monitoring equipment detected gas approximately 100 yards upwind of the valve assembly. The pipeline was isolated at 1555 on november 14, 2021. Excavation of the valve found that a 1.5 inch diameter body bleed plug was missing, concluding it was not installed or improperly installed. |
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