GTG incident on 2021-11-05 — MI

Operator
Dte Gas Company
Cause
Incorrect Operation
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities 0 injuries
Property damage (nominal)
$0
Incident datetime
2021-11-05 01:00
Report number
Location
MI
Narrative
(on july 18th, 2024, a supplemental-final was resubmitted per the following request from darren lemmerman, PHMSA investigator, accident investigation division on june 25, 2024: our information resources manager has identified an issue with how the 30-day report calculated the released gas volume and the cost of the gas/mcf. The fix has been implemented and we have been told that if the report is resubmitted as a supplemental final that the error will be corrected. If you could help out, it would be much appreciated.) a relief valve went off at leelanau gate station at approximately 8:35 pm on november 4, 2021 (at this time dte gas was not aware of the release). Dte gas received a call of odor in the air/gas blowing at 1:00 am and dte distribution arrived at 1:20 am. Dte gas transmission operations were called at 1:30 am. The transmission tech arrived at 03:30 am on november 5 and blocked in the relief, as there is no need to protect a lower maop downstream. Only 1 qualified person was available. He had to get a confirmation (from the other tech) to shut it in. The gas continued to be released into the air until approximately 3:30 am on november 5, resulting in odor in the air. This released 5.8 mmcf of gas into the atmosphere, making it reportable to both the state of michigan, PHMSA, and egle. Gas control was given the release to bring the petoskey/traverse city system pressure back up (had been on a pressure reduction to below 500 psig since june, to normal line pressure, generally just above 500 psig ) and started bringing pressure up to around 8:00 pm on november 4, 2021. As part of the traverse city alpena reinforcement program (tcarp), we were installing a brand new station/totally rebuilt an existing station; de-pressurized to install the new frankfort loop pipeline. There are no alarms on this relief (no high-pressure alarm below relief point) which is not unusual. The relief was preset to protect the frankfort pl downstream of leelanau gate in the city of interlochen. It appears like it did protect the system (the relief went off) at approximately 507-513 psig. There was no return to service procedure for the petoskey system to stipulate the need for a relief or the need to block in the relief. The 8" downstream pipeline still had an 812 psig maop and had not yet been derated to 486 psig maop. Therefore, the relief valve should not have been put into service prior to the duration. The root cause was determined to be inadequate procedural adherence to the return to service pressure control procedure (pcp) for the leelanau gate station that took place on september 20, 2021. The intent of the pcp was to run the station on bypass but operations misinterpreted engineering's planned flow path in the pcp and opened a leg of the station piping for purging which allowed this new relief valve to be exposed to this higher pressure once the system was repressurized.
Detailed record list
Report Received Date
2021-12-06 00:00:00
Iyear
2021
Report Number
20210112
Supplemental Number
39788
Report Type
Supplemental Final
Operator Id
Name
Dte Gas Company
Operator Street Address
1 Energy Plaza
Operator City Name
Detroit
Operator State Abbreviation
MI
Operator Postal Code
48226
Local Datetime
2021-11-05 23:15:00
Time Zone
Eastern
Daylight Savings Ind
No
Location Latitude
Location Longitude
-85.83746938
Nrc Rpt Num
Nrc Rpt Datetime
2021-11-05 22:01:00
Additional Nrc Report Numbers
1321391
Commodity Released Type
Natural Gas
Unintentional Release
5800
Intentional Release
0
Accompanying Liquid
0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Status When Identified
Post-Construction Commissioning
Communication State Fed Ind
No
Ignite Ind
No
Num Pub Evacuated
0
Incident Identified Datetime
2021-11-05 01:00:00
On Site Datetime
2021-11-05 01:20:00
Confirmed Discovery Datetime
2021-11-05 01:20:00
On Off Shore
Onshore
Onshore State Abbreviation
Mi
Onshore Postal Code
49643
Onshore City Name
Interlochen
Onshore County Name
Benzie
Designated Location
Not Applicable
Pipe Fac Name
Leelanau Gate Station
Segment Name
Frankfort 8-Inch Pipeline
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
Intrastate
System Part Involved
Onshore Regulator/metering Station Equipment And Piping
Item Involved
Valve
Valve Type
Relief Valve
Installation Year
2021
Manufactured Year
Unknown
Material Involved
Carbon Steel
Release Type
Other
Release Type Details
Gas Was Released Through The Relief Valve As Designed.
Class Location Type
Class 2 Location
Could Be Hca
No
Pir Radius
170
Heat Damage Ind
No
Non Heat Damage Ind
No
Did Occur In Mca Ind
Yes
Mca Paved Surface Freeway Ind
Yes
Est Cost Oper Paid
0
Est Cost Unintentional Release
16878
Est Cost Intentional Release
0
Est Cost Prop Damage
0
Est Cost Emergency
1390
Est Cost Other
0
Gas Cost In Mcf
2.91
Prpty
18268
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
507
Gas Flow In Pipe In Mcf
41.46
Mop Psig
812
Mop Cfr Section
192.624(C)(1)
Maop Established Date
2021-08-25 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
No
Accident Identifier
Notification From Public
Investigation Status
No, the facility was not monitored by a controller(s) at the time of the incident
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
The Root Cause Was Determined To Be Inadequate Procedural Adherence To The Return To Service Pressure Control Procedure (Pcp) For The Leelanau Gate Station That Took Place On September 20, 2021. The Intent Of The Pcp Was To Run The Station On Bypass But Operations Misinterpreted Engineering's Planned Flow Path In The Pcp And Opened A Leg Of The Station Piping For Purging Which Allowed This New Relief Valve To Be Exposed To This Higher Pressure Once The System Was Repressurized.
Related Inadequate Proc Ind
Yes
Category Type
Commissioning
Operator Qualification Ind
Yes
Qualified Individuals
Yes, They Were Qualified For The Task(S)
Preparer Name
F***** S****
Preparer Title
Manager Codes And Standards
Preparer Email
F***********@d********.com
Preparer Telephone
3134601681
Local Contact Name
F***** S****
Local Contact Email
F***********@d********.com
Local Contact Telephone
3134601681
Authorizer Name
F***** S****
Authorizer Title
Manager Codes And Standards
Authorizer Telephone
3134601681
Authorizer Email
F***********@d********.com
Narrative
(on july 18th, 2024, a supplemental-final was resubmitted per the following request from darren lemmerman, PHMSA investigator, accident investigation division on june 25, 2024: our information resources manager has identified an issue with how the 30-day report calculated the released gas volume and the cost of the gas/mcf. The fix has been implemented and we have been told that if the report is resubmitted as a supplemental final that the error will be corrected. If you could help out, it would be much appreciated.) a relief valve went off at leelanau gate station at approximately 8:35 pm on november 4, 2021 (at this time dte gas was not aware of the release). Dte gas received a call of odor in the air/gas blowing at 1:00 am and dte distribution arrived at 1:20 am. Dte gas transmission operations were called at 1:30 am. The transmission tech arrived at 03:30 am on november 5 and blocked in the relief, as there is no need to protect a lower maop downstream. Only 1 qualified person was available. He had to get a confirmation (from the other tech) to shut it in. The gas continued to be released into the air until approximately 3:30 am on november 5, resulting in odor in the air. This released 5.8 mmcf of gas into the atmosphere, making it reportable to both the state of michigan, PHMSA, and egle. Gas control was given the release to bring the petoskey/traverse city system pressure back up (had been on a pressure reduction to below 500 psig since june, to normal line pressure, generally just above 500 psig ) and started bringing pressure up to around 8:00 pm on november 4, 2021. As part of the traverse city alpena reinforcement program (tcarp), we were installing a brand new station/totally rebuilt an existing station; de-pressurized to install the new frankfort loop pipeline. There are no alarms on this relief (no high-pressure alarm below relief point) which is not unusual. The relief was preset to protect the frankfort pl downstream of leelanau gate in the city of interlochen. It appears like it did protect the system (the relief went off) at approximately 507-513 psig. There was no return to service procedure for the petoskey system to stipulate the need for a relief or the need to block in the relief. The 8" downstream pipeline still had an 812 psig maop and had not yet been derated to 486 psig maop. Therefore, the relief valve should not have been put into service prior to the duration. The root cause was determined to be inadequate procedural adherence to the return to service pressure control procedure (pcp) for the leelanau gate station that took place on september 20, 2021. The intent of the pcp was to run the station on bypass but operations misinterpreted engineering's planned flow path in the pcp and opened a leg of the station piping for purging which allowed this new relief valve to be exposed to this higher pressure once the system was repressurized.
Report Received Date 2021-12-06 00:00:00
Iyear 2021
Report Number 20210112
Supplemental Number 39788
Report Type Supplemental Final
Operator Id 12408 PHMSA Enforcement
Name Dte Gas Company
Operator Street Address 1 Energy Plaza
Operator City Name Detroit
Operator State Abbreviation MI
Operator Postal Code 48226
Local Datetime 2021-11-05 23:15:00
Time Zone Eastern
Daylight Savings Ind No
Location Latitude 44.65929677 Google Maps OpenStreetMap
Location Longitude -85.83746938 Google Maps OpenStreetMap
Nrc Rpt Num 1321306 NRC Report How to search
Nrc Rpt Datetime 2021-11-05 22:01:00
Additional Nrc Report Numbers 1321391
Commodity Released Type Natural Gas
Unintentional Release 5800
Intentional Release 0
Accompanying Liquid 0
Fatality Ind No
Fatal 0
Injury Ind No
Injure 0
Status When Identified Post-Construction Commissioning
Communication State Fed Ind No
Ignite Ind No
Num Pub Evacuated 0
Incident Identified Datetime 2021-11-05 01:00:00
On Site Datetime 2021-11-05 01:20:00
Confirmed Discovery Datetime 2021-11-05 01:20:00
On Off Shore Onshore
Onshore State Abbreviation Mi
Onshore Postal Code 49643
Onshore City Name Interlochen
Onshore County Name Benzie
Designated Location Not Applicable
Pipe Fac Name Leelanau Gate Station
Segment Name Frankfort 8-Inch Pipeline
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 Intrastate
System Part Involved Onshore Regulator/metering Station Equipment And Piping
Item Involved Valve
Valve Type Relief Valve
Installation Year 2021
Manufactured Year Unknown
Material Involved Carbon Steel
Release Type Other
Release Type Details Gas Was Released Through The Relief Valve As Designed.
Class Location Type Class 2 Location
Could Be Hca No
Pir Radius 170
Heat Damage Ind No
Non Heat Damage Ind No
Did Occur In Mca Ind Yes
Mca Paved Surface Freeway Ind Yes
Est Cost Oper Paid 0
Est Cost Unintentional Release 16878
Est Cost Intentional Release 0
Est Cost Prop Damage 0
Est Cost Emergency 1390
Est Cost Other 0
Gas Cost In Mcf 2.91
Prpty 18268
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 507
Gas Flow In Pipe In Mcf 41.46
Mop Psig 812
Mop Cfr Section 192.624(C)(1) View CFR 49 §192
Maop Established Date 2021-08-25 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 No
Accident Identifier Notification From Public
Investigation Status No, the facility was not monitored by a controller(s) at the time of the incident
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 The Root Cause Was Determined To Be Inadequate Procedural Adherence To The Return To Service Pressure Control Procedure (Pcp) For The Leelanau Gate Station That Took Place On September 20, 2021. The Intent Of The Pcp Was To Run The Station On Bypass But Operations Misinterpreted Engineering's Planned Flow Path In The Pcp And Opened A Leg Of The Station Piping For Purging Which Allowed This New Relief Valve To Be Exposed To This Higher Pressure Once The System Was Repressurized.
Related Inadequate Proc Ind Yes
Category Type Commissioning
Operator Qualification Ind Yes
Qualified Individuals Yes, They Were Qualified For The Task(S)
Preparer Name F***** S****
Preparer Title Manager Codes And Standards
Preparer Email F***********@d********.com
Preparer Telephone 3134601681
Local Contact Name F***** S****
Local Contact Email F***********@d********.com
Local Contact Telephone 3134601681
Authorizer Name F***** S****
Authorizer Title Manager Codes And Standards
Authorizer Telephone 3134601681
Authorizer Email F***********@d********.com
Narrative (on july 18th, 2024, a supplemental-final was resubmitted per the following request from darren lemmerman, PHMSA investigator, accident investigation division on june 25, 2024: our information resources manager has identified an issue with how the 30-day report calculated the released gas volume and the cost of the gas/mcf. The fix has been implemented and we have been told that if the report is resubmitted as a supplemental final that the error will be corrected. If you could help out, it would be much appreciated.) a relief valve went off at leelanau gate station at approximately 8:35 pm on november 4, 2021 (at this time dte gas was not aware of the release). Dte gas received a call of odor in the air/gas blowing at 1:00 am and dte distribution arrived at 1:20 am. Dte gas transmission operations were called at 1:30 am. The transmission tech arrived at 03:30 am on november 5 and blocked in the relief, as there is no need to protect a lower maop downstream. Only 1 qualified person was available. He had to get a confirmation (from the other tech) to shut it in. The gas continued to be released into the air until approximately 3:30 am on november 5, resulting in odor in the air. This released 5.8 mmcf of gas into the atmosphere, making it reportable to both the state of michigan, PHMSA, and egle. Gas control was given the release to bring the petoskey/traverse city system pressure back up (had been on a pressure reduction to below 500 psig since june, to normal line pressure, generally just above 500 psig ) and started bringing pressure up to around 8:00 pm on november 4, 2021. As part of the traverse city alpena reinforcement program (tcarp), we were installing a brand new station/totally rebuilt an existing station; de-pressurized to install the new frankfort loop pipeline. There are no alarms on this relief (no high-pressure alarm below relief point) which is not unusual. The relief was preset to protect the frankfort pl downstream of leelanau gate in the city of interlochen. It appears like it did protect the system (the relief went off) at approximately 507-513 psig. There was no return to service procedure for the petoskey system to stipulate the need for a relief or the need to block in the relief. The 8" downstream pipeline still had an 812 psig maop and had not yet been derated to 486 psig maop. Therefore, the relief valve should not have been put into service prior to the duration. The root cause was determined to be inadequate procedural adherence to the return to service pressure control procedure (pcp) for the leelanau gate station that took place on september 20, 2021. The intent of the pcp was to run the station on bypass but operations misinterpreted engineering's planned flow path in the pcp and opened a leg of the station piping for purging which allowed this new relief valve to be exposed to this higher pressure once the system was repressurized.

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