Incident details
Operator, cause, commodity and consequences with raw source fields.
GTG incident on 2022-11-19 — TX
Operator
Columbia Gulf Transmission, Llc
Cause
Equipment Failure
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities
0 injuries
Property damage (nominal)
$0
Incident datetime
2022-11-19 13:45
Report number
Location
TX
Narrative
Columbia gulf transmission, llc, a tc energy company, operates and maintains stanton compressor station located in stanton, kentucky. On saturday november 19th, 2022 a tc energy cleaning contractor heard gas venting into the atmosphere while performing their duties at stanton compressor station. The contractor immediately contacted compressor station personnel; the station personnel responded to the gas release at stanton compressor station and addressed the unintended release of natural gas that was venting from unit 108 blowdown discharge stack. The station personnel inspected and secured the area to ensure that it was safe; then then identified valves to isolate the gas line. The line was isolated at 14:30 eastern time. Once the line was isolated the station operating personnel began troubleshooting the issue. All alarms were cleared at the control panel, functional tests were completed with no new errors generated to ensure normal operation of the station. Preliminary investigation identified the probable cause that led to this unintended release at unit 108 was due to a loss of power to a programmable logic controller (plc) and relay failure. The loss of power to this plc caused the compressor unit blow down valve (aov 8810) to remain open. The valve remained open for 50 minutes resulting in an estimated total gas lost of 5,328.8 mcf. The pressure of the line at the time of the incident was 779 lbs. Relay k340-2b did not unlatch from its n/c state after losing its power or de-energized state to n/o which would have allowed unit suction/discharge valves to become closed or into a fail to close/shut phase per design. This would have prevented gas from venting to atmosphere via unit four inch blown down silencer stack. With power restored & relay replaced, the remaining section of circuit was tested to make sure proper panel feedback, continuity test to yard valves components was verified and successful.
Detailed record list
Report Received Date
2022-12-14 00:00:00
Iyear
2022
Report Number
20220130
Supplemental Number
38087
Report Type
Supplemental Final
Operator Id
2620
Name
Columbia Gulf Transmission, Llc
Operator Street Address
700 Louisiana St. Suite 700
Operator City Name
Houston
Operator State Abbreviation
TX
Operator Postal Code
77002
Local Datetime
2022-11-19 14:48:00
Time Zone
Eastern
Daylight Savings Ind
Yes
Location Latitude
37.888497
Location Longitude
-83.861524
Nrc Rpt Num
1353001
Nrc Rpt Datetime
2022-11-19 15:21:00
Additional Nrc Report Numbers
1353101
Commodity Released Type
Natural Gas
Unintentional Release
5328.8
Intentional Release
0
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
No
Shutdown Explain
Incident Was Isolated At 14:30
Communication State Fed Ind
No
Ignite Ind
No
Num Pub Evacuated
0
Incident Identified Datetime
2022-11-19 13:45:00
On Site Datetime
2022-11-19 14:00:00
On Off Shore
Onshore
Onshore State Abbreviation
Ky
Onshore Postal Code
40380
Onshore City Name
Not Within A Municipality
Onshore County Name
Powell
Designated Location
Not Applicable
Pipe Fac Name
Stanton Compressor Station
Segment Name
Unit 108 Blowdown Valve Aov-8810
Federal
No
Location Type
Operator-Controlled Property
Incident Area Type
Aboveground
Incident Area Subtype
Typical Aboveground Facility Piping Or Appurtenance
Crossing
No
Pipe Facility Type
Interstate
System Part Involved
Onshore Compressor Station Equipment And Piping
Item Involved
Valve
Valve Type
Auxiliary Or Other Valve
Installation Year
2001
Manufactured Year
Unknown
Material Involved
Carbon Steel
Release Type
Other
Release Type Details
Unintentional Valve Release.
Class Location Type
Class 2 Location
Could Be Hca
No
Pir Radius
88
Heat Damage Ind
No
Non Heat Damage Ind
No
Did Occur In Mca Ind
Yes
Mca Buildng Human Occupy Ind
Yes
Est Cost Oper Paid
0
Est Cost Unintentional Release
26857
Est Cost Intentional Release
0
Est Cost Prop Damage
0
Est Cost Emergency
240
Est Cost Other
0
Gas Cost In Mcf
5.04
Prpty
27097
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
779
Gas Flow In Pipe In Mcf
170286
Mop Psig
1007
Mop Cfr Section
Other
Mop Cfr Section Details
Ansi 600 Valve
Maop Established Date
2001-02-01 00:00:00
Maop Reversal Flow Ind
No
Accident Pressure
Pressure Did Not Exceed Maop
Pressure Restriction Ind
No
Gas Required Odorized Ind
No
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
Contractor Working For The Operator
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
At this time the cause of the incident was due to plc power and relay failure, not control room action.
Employee Drug Test Ind
No
Contractor Drug Test Ind
No
Cause
Equipment Failure
Cause Details
Malfunction Of Control/relief Equipment
Eq Failure Type
Malfunction Of Control/relief Equipment
Power Failure Ind
Yes
Eq Additional Other Ind
Yes
Eq Additional Other Details
No Other Cause Identified.
Preparer Name
C*** O S*******
Preparer Title
Compliance Specialist
Preparer Email
C************@t*******.com
Preparer Telephone
2814099257
Authorizer Name
P*** S******
Authorizer Title
Manager
Authorizer Telephone
304-550-4866
Authorizer Email
P***********@t*******.com
Narrative
Columbia gulf transmission, llc, a tc energy company, operates and maintains stanton compressor station located in stanton, kentucky. On saturday november 19th, 2022 a tc energy cleaning contractor heard gas venting into the atmosphere while performing their duties at stanton compressor station. The contractor immediately contacted compressor station personnel; the station personnel responded to the gas release at stanton compressor station and addressed the unintended release of natural gas that was venting from unit 108 blowdown discharge stack. The station personnel inspected and secured the area to ensure that it was safe; then then identified valves to isolate the gas line. The line was isolated at 14:30 eastern time. Once the line was isolated the station operating personnel began troubleshooting the issue. All alarms were cleared at the control panel, functional tests were completed with no new errors generated to ensure normal operation of the station. Preliminary investigation identified the probable cause that led to this unintended release at unit 108 was due to a loss of power to a programmable logic controller (plc) and relay failure. The loss of power to this plc caused the compressor unit blow down valve (aov 8810) to remain open. The valve remained open for 50 minutes resulting in an estimated total gas lost of 5,328.8 mcf. The pressure of the line at the time of the incident was 779 lbs. Relay k340-2b did not unlatch from its n/c state after losing its power or de-energized state to n/o which would have allowed unit suction/discharge valves to become closed or into a fail to close/shut phase per design. This would have prevented gas from venting to atmosphere via unit four inch blown down silencer stack. With power restored & relay replaced, the remaining section of circuit was tested to make sure proper panel feedback, continuity test to yard valves components was verified and successful.
| Report Received Date | 2022-12-14 00:00:00 |
|---|---|
| Iyear | 2022 |
| Report Number | 20220130 |
| Supplemental Number | 38087 |
| Report Type | Supplemental Final |
| Operator Id | 2620 PHMSA Enforcement |
| Name | Columbia Gulf Transmission, Llc |
| Operator Street Address | 700 Louisiana St. Suite 700 |
| Operator City Name | Houston |
| Operator State Abbreviation | TX |
| Operator Postal Code | 77002 |
| Local Datetime | 2022-11-19 14:48:00 |
| Time Zone | Eastern |
| Daylight Savings Ind | Yes |
| Location Latitude | 37.888497 Google Maps OpenStreetMap |
| Location Longitude | -83.861524 Google Maps OpenStreetMap |
| Nrc Rpt Num | 1353001 NRC Report How to search |
| Nrc Rpt Datetime | 2022-11-19 15:21:00 |
| Additional Nrc Report Numbers | 1353101 |
| Commodity Released Type | Natural Gas |
| Unintentional Release | 5328.8 |
| Intentional Release | 0 |
| 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 | No |
| Shutdown Explain | Incident Was Isolated At 14:30 |
| Communication State Fed Ind | No |
| Ignite Ind | No |
| Num Pub Evacuated | 0 |
| Incident Identified Datetime | 2022-11-19 13:45:00 |
| On Site Datetime | 2022-11-19 14:00:00 |
| On Off Shore | Onshore |
| Onshore State Abbreviation | Ky |
| Onshore Postal Code | 40380 |
| Onshore City Name | Not Within A Municipality |
| Onshore County Name | Powell |
| Designated Location | Not Applicable |
| Pipe Fac Name | Stanton Compressor Station |
| Segment Name | Unit 108 Blowdown Valve Aov-8810 |
| Federal | No |
| Location Type | Operator-Controlled Property |
| Incident Area Type | Aboveground |
| Incident Area Subtype | Typical Aboveground Facility Piping Or Appurtenance |
| Crossing | No |
| Pipe Facility Type | Interstate |
| System Part Involved | Onshore Compressor Station Equipment And Piping |
| Item Involved | Valve |
| Valve Type | Auxiliary Or Other Valve |
| Installation Year | 2001 |
| Manufactured Year | Unknown |
| Material Involved | Carbon Steel |
| Release Type | Other |
| Release Type Details | Unintentional Valve Release. |
| Class Location Type | Class 2 Location |
| Could Be Hca | No |
| Pir Radius | 88 |
| Heat Damage Ind | No |
| Non Heat Damage Ind | No |
| Did Occur In Mca Ind | Yes |
| Mca Buildng Human Occupy Ind | Yes |
| Est Cost Oper Paid | 0 |
| Est Cost Unintentional Release | 26857 |
| Est Cost Intentional Release | 0 |
| Est Cost Prop Damage | 0 |
| Est Cost Emergency | 240 |
| Est Cost Other | 0 |
| Gas Cost In Mcf | 5.04 |
| Prpty | 27097 |
| 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 | 779 |
| Gas Flow In Pipe In Mcf | 170286 |
| Mop Psig | 1007 |
| Mop Cfr Section | Other View CFR 49 §192 |
| Mop Cfr Section Details | Ansi 600 Valve |
| Maop Established Date | 2001-02-01 00:00:00 |
| Maop Reversal Flow Ind | No |
| Accident Pressure | Pressure Did Not Exceed Maop |
| Pressure Restriction Ind | No |
| Gas Required Odorized Ind | No |
| 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 | Contractor Working For The Operator |
| 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 | At this time the cause of the incident was due to plc power and relay failure, not control room action. |
| Employee Drug Test Ind | No |
| Contractor Drug Test Ind | No |
| Cause | Equipment Failure |
| Cause Details | Malfunction Of Control/relief Equipment |
| Eq Failure Type | Malfunction Of Control/relief Equipment |
| Power Failure Ind | Yes |
| Eq Additional Other Ind | Yes |
| Eq Additional Other Details | No Other Cause Identified. |
| Preparer Name | C*** O S******* |
| Preparer Title | Compliance Specialist |
| Preparer Email | C************@t*******.com |
| Preparer Telephone | 2814099257 |
| Authorizer Name | P*** S****** |
| Authorizer Title | Manager |
| Authorizer Telephone | 304-550-4866 |
| Authorizer Email | P***********@t*******.com |
| Narrative | Columbia gulf transmission, llc, a tc energy company, operates and maintains stanton compressor station located in stanton, kentucky. On saturday november 19th, 2022 a tc energy cleaning contractor heard gas venting into the atmosphere while performing their duties at stanton compressor station. The contractor immediately contacted compressor station personnel; the station personnel responded to the gas release at stanton compressor station and addressed the unintended release of natural gas that was venting from unit 108 blowdown discharge stack. The station personnel inspected and secured the area to ensure that it was safe; then then identified valves to isolate the gas line. The line was isolated at 14:30 eastern time. Once the line was isolated the station operating personnel began troubleshooting the issue. All alarms were cleared at the control panel, functional tests were completed with no new errors generated to ensure normal operation of the station. Preliminary investigation identified the probable cause that led to this unintended release at unit 108 was due to a loss of power to a programmable logic controller (plc) and relay failure. The loss of power to this plc caused the compressor unit blow down valve (aov 8810) to remain open. The valve remained open for 50 minutes resulting in an estimated total gas lost of 5,328.8 mcf. The pressure of the line at the time of the incident was 779 lbs. Relay k340-2b did not unlatch from its n/c state after losing its power or de-energized state to n/o which would have allowed unit suction/discharge valves to become closed or into a fail to close/shut phase per design. This would have prevented gas from venting to atmosphere via unit four inch blown down silencer stack. With power restored & relay replaced, the remaining section of circuit was tested to make sure proper panel feedback, continuity test to yard valves components was verified and successful. |
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