HL incident on 2020-11-04 — TX

Operator
Enbridge Storage (Cushing) L.l.c.
Cause
Incorrect Operation
Commodity
Crude Oil
Program
HL
Damage and Injuries
0 fatalities 0 injuries
Property damage (nominal)
$42,122
Incident datetime
2020-11-04 12:32
Report number
Location
TX
Narrative
On november 4, 2020 at approximately 12:32 pm ct during a routine annual tank inspection, oil was discovered on the internal roof of tank 3012 at the cushing terminal. Approximately 5 barrels of oil was discovered in the bulkheads on the internal floating roof. Given that the oil was contained between the floating roof and the fixed roof, an action plan was developed to take the tank out of service to remove the oil. On december 7, 2020 it was determined that a failure occurred due to incorrect operation after an investigation found that the tanks internal floating roof was set down on its legs multiple times since the last out of service inspection in february of 2014. Further investigation found that the leg height set within the scada system didn't match the leg height on the floating roof in the field which was left in the high (maintenance) position after the last internal inspection. Enbridge's procedures require that the legs be returned to operational (low leg) position. Drawing oil down at operational flow rates while the roof was on its legs caused air to be sucked around the roof seal to form a vapor space under the roof. When the tank was then filled at operational fill rates it caused air to vent through appurtenances as the roof vent is not designed for full flow rate. Over many fill and withdraw cycles this caused oil to spray onto the top side of the floating roof to raise concern and investigate. All crude has been cleaned up and the tank remains out of service for its annual API 653 tank inspection.
Detailed record list
Report Received Date
2020-12-23 00:00:00
Iyear
2020
Report Number
20200339
Supplemental Number
34777
Report Type
Supplemental Final
Operator Id
Name
Enbridge Storage (Cushing) L.l.c.
Operator Street Address
915 N Eldridge Parkway, Suite 1100
Operator City Name
Houston
Operator State Abbreviation
TX
Operator Postal Code
77079
Local Datetime
2020-11-04 12:32:00
Location Latitude
Location Longitude
Commodity Released Type
Crude Oil
Unintentional Release Bbls
5
Recovered Bbls
5
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Accident Identifier
Local Operating Personnel, Including Contractors
Operator Type
Operator Employee
Incident Identified Datetime
2020-11-04 12:32:00
System Part Involved
Onshore Breakout Tank Or Storage Vessel, Including Attached Appurtenances
On Off Shore
Onshore
Shutdown Due Accident Ind
No
Shutdown Explain
Tank Was Taken Out Of Service
On Site Datetime
2020-11-04 12:32:00
Nrc Rpt Num
Nrc Notification Not Required
Ignite Ind
No
Explode Ind
No
Num Pub Evacuated
0
Pipe Fac Name
Cushing Terminal
Segment Name
Tank 3012
Onshore State Abbreviation
Ok
Onshore Postal Code
74023
Onshore City Name
Cushing
Onshore County Name
Lincoln
Designated Location
Milepost/valve Station
Designated Name
Cushing
Federal
No
Location Type
Totally Contained On Operator-Controlled Property
Incident Area Type
Tank, Including Attached Appurtenances
Crossing
No
Pipe Facility Type
Interstate
Item Involved
Tank/vessel
Tank Vessel Subtype
Roof/roof Seal
Tank Type
Atmospheric
Installation Year
1976
Material Involved
Carbon Steel
Release Type
Other
Release Type Details
Floating Roof
Wildlife Impact Ind
No
Soil Contamination
No
Long Term Assessment
No
Remediation Ind
No
Water Contam Ind
No
Could Be Hca
No
Commodity Reached Hca
No
Est Cost Oper Paid
0
Est Cost Gas Released
0
Est Cost Prop Damage
42122
Est Cost Emergency
0
Est Cost Environmental
0
Est Cost Other
0
Prpty
42122
Accident Psig
0
Mop Psig
0
Accident Pressure
Pressure Did Not Exceed Mop
Pressure Restriction Ind
No
Pipeline Function
> 20% Smys Regulated Transmission
Scada In Place Ind
Yes
Scada Operating Ind
Yes
Scada Functional Ind
Yes
Scada Detection Ind
No
Scada Conf Ind
No
Cpm In Place Ind
No
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
Controller actions did not lead to this release and therefore no investigation was necessary
Employee Drug Test Ind
No
Contractor Drug Test Ind
No
Cause
Incorrect Operation
Cause Details
Other Incorrect Operation
Operation Type
Other Incorrect Operation
Operation Details
Incorrect Tank Leg Height Position
Related Failure Follow Ind
Yes
Category Type
Routine Maintenance
Operator Qualification Ind
No
Preparer Name
S**** S****
Preparer Title
Sr Compliance Analyst
Preparer Email
S**********@e*******.com
Preparer Telephone
218-206-5872
Prepared Date
2021-01-28 00:00:00
Authorizer Name
S**** D*****
Authorizer Telephone
715-718-1236
Authorizer Title
Supervisor Us Pipeline Compliance
Authorizer Email
S************@e*******.com
Narrative
On november 4, 2020 at approximately 12:32 pm ct during a routine annual tank inspection, oil was discovered on the internal roof of tank 3012 at the cushing terminal. Approximately 5 barrels of oil was discovered in the bulkheads on the internal floating roof. Given that the oil was contained between the floating roof and the fixed roof, an action plan was developed to take the tank out of service to remove the oil. On december 7, 2020 it was determined that a failure occurred due to incorrect operation after an investigation found that the tanks internal floating roof was set down on its legs multiple times since the last out of service inspection in february of 2014. Further investigation found that the leg height set within the scada system didn't match the leg height on the floating roof in the field which was left in the high (maintenance) position after the last internal inspection. Enbridge's procedures require that the legs be returned to operational (low leg) position. Drawing oil down at operational flow rates while the roof was on its legs caused air to be sucked around the roof seal to form a vapor space under the roof. When the tank was then filled at operational fill rates it caused air to vent through appurtenances as the roof vent is not designed for full flow rate. Over many fill and withdraw cycles this caused oil to spray onto the top side of the floating roof to raise concern and investigate. All crude has been cleaned up and the tank remains out of service for its annual API 653 tank inspection.
Report Received Date 2020-12-23 00:00:00
Iyear 2020
Report Number 20200339
Supplemental Number 34777
Report Type Supplemental Final
Operator Id 39145 PHMSA Enforcement
Name Enbridge Storage (Cushing) L.l.c.
Operator Street Address 915 N Eldridge Parkway, Suite 1100
Operator City Name Houston
Operator State Abbreviation TX
Operator Postal Code 77079
Local Datetime 2020-11-04 12:32:00
Location Latitude 35.936469 Google Maps OpenStreetMap
Location Longitude -96.751432 Google Maps OpenStreetMap
Commodity Released Type Crude Oil
Unintentional Release Bbls 5
Recovered Bbls 5
Fatality Ind No
Fatal 0
Injury Ind No
Injure 0
Accident Identifier Local Operating Personnel, Including Contractors
Operator Type Operator Employee
Incident Identified Datetime 2020-11-04 12:32:00
System Part Involved Onshore Breakout Tank Or Storage Vessel, Including Attached Appurtenances
On Off Shore Onshore
Shutdown Due Accident Ind No
Shutdown Explain Tank Was Taken Out Of Service
On Site Datetime 2020-11-04 12:32:00
Nrc Rpt Num Nrc Notification Not Required NRC Report How to search
Ignite Ind No
Explode Ind No
Num Pub Evacuated 0
Pipe Fac Name Cushing Terminal
Segment Name Tank 3012
Onshore State Abbreviation Ok
Onshore Postal Code 74023
Onshore City Name Cushing
Onshore County Name Lincoln
Designated Location Milepost/valve Station
Designated Name Cushing
Federal No
Location Type Totally Contained On Operator-Controlled Property
Incident Area Type Tank, Including Attached Appurtenances
Crossing No
Pipe Facility Type Interstate
Item Involved Tank/vessel
Tank Vessel Subtype Roof/roof Seal
Tank Type Atmospheric
Installation Year 1976
Material Involved Carbon Steel
Release Type Other
Release Type Details Floating Roof
Wildlife Impact Ind No
Soil Contamination No
Long Term Assessment No
Remediation Ind No
Water Contam Ind No
Could Be Hca No
Commodity Reached Hca No
Est Cost Oper Paid 0
Est Cost Gas Released 0
Est Cost Prop Damage 42122
Est Cost Emergency 0
Est Cost Environmental 0
Est Cost Other 0
Prpty 42122
Accident Psig 0
Mop Psig 0
Accident Pressure Pressure Did Not Exceed Mop
Pressure Restriction Ind No
Pipeline Function > 20% Smys Regulated Transmission
Scada In Place Ind Yes
Scada Operating Ind Yes
Scada Functional Ind Yes
Scada Detection Ind No
Scada Conf Ind No
Cpm In Place Ind No
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 Controller actions did not lead to this release and therefore no investigation was necessary
Employee Drug Test Ind No
Contractor Drug Test Ind No
Cause Incorrect Operation
Cause Details Other Incorrect Operation
Operation Type Other Incorrect Operation
Operation Details Incorrect Tank Leg Height Position
Related Failure Follow Ind Yes
Category Type Routine Maintenance
Operator Qualification Ind No
Preparer Name S**** S****
Preparer Title Sr Compliance Analyst
Preparer Email S**********@e*******.com
Preparer Telephone 218-206-5872
Prepared Date 2021-01-28 00:00:00
Authorizer Name S**** D*****
Authorizer Telephone 715-718-1236
Authorizer Title Supervisor Us Pipeline Compliance
Authorizer Email S************@e*******.com
Narrative On november 4, 2020 at approximately 12:32 pm ct during a routine annual tank inspection, oil was discovered on the internal roof of tank 3012 at the cushing terminal. Approximately 5 barrels of oil was discovered in the bulkheads on the internal floating roof. Given that the oil was contained between the floating roof and the fixed roof, an action plan was developed to take the tank out of service to remove the oil. On december 7, 2020 it was determined that a failure occurred due to incorrect operation after an investigation found that the tanks internal floating roof was set down on its legs multiple times since the last out of service inspection in february of 2014. Further investigation found that the leg height set within the scada system didn't match the leg height on the floating roof in the field which was left in the high (maintenance) position after the last internal inspection. Enbridge's procedures require that the legs be returned to operational (low leg) position. Drawing oil down at operational flow rates while the roof was on its legs caused air to be sucked around the roof seal to form a vapor space under the roof. When the tank was then filled at operational fill rates it caused air to vent through appurtenances as the roof vent is not designed for full flow rate. Over many fill and withdraw cycles this caused oil to spray onto the top side of the floating roof to raise concern and investigate. All crude has been cleaned up and the tank remains out of service for its annual API 653 tank inspection.

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