GTG incident on 2025-10-27 — TX

Operator
Chandeleur Pipe Line, Llc
Cause
Corrosion Failure
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities 0 injuries
Property damage (nominal)
$316,000
Incident datetime
2025-10-27 10:41
Report number
Location
TX
Narrative
On thursday, october 16, 2025, at approximately 20:30, chandeleur pipe line, (third coast), was contacted by the united states coast guard regarding alleged bubbles with no sheen on the surface of the water in block 42 of the brenton sound area in the gulf of america near the chandeleur 16� natural gas pipeline and a natural gas pipeline owned and operated by enbridge. Third coast initiated its investigation regarding the nrc report. Following the initial investigation, third coast determined the reported natural gas release did not appear to originate from the chandeleur pipeline because of the lack of any material reductions in pressure and no apparent operational abnormalities on the chandeleur pipeline. Third coast then contacted the uscg to relay third coast�s conclusion that its initial investigation did not appear to indicate the chandeleur pipeline was the source of the reported natural gas release. On saturday, october 18, third coast was contacted by enbridge, which stated that, during its investigation related to the nrc report, enbridge determined the source of the reported natural gas release was likely to be the chandeleur pipeline. In response, third coast contacted all producers on the chandeleur pipeline to initiate shut-in procedures of the chandeleur pipeline and to divert flows of natural gas from the chandeleur pipeline to alternate pipelines. On sunday, october 19, at approximately 04:00, third coast completed the shut-in of the chandeleur pipeline. Third coast performed a 10-hr. Static pressure test on the chandeleur pipeline that was completed on sunday afternoon. The chandeleur pipeline held pressure with no pressure drops for the full duration of the static pressure test. Following the completion of the static pressure test, third coast notified uscg and bsee to provide the results of the static pressure test and restarted the chandeleur pipeline. On tuesday, october 21, bsee contacted third coast regarding ongoing bubbles on the surface of the water in vicinity of the location identified in the nrc report. In response, third coast shut-in the chandeleur pipeline. Due to adverse weather and sea conditions, third coast was unable to return to the location of the reported ongoing natural gas release until monday, october 27. On monday, october 27, divers identified natural gas seeping from the concrete coating on the chandeleur pipeline located approximately 10 ft from a jumper line connection between the chandeleur pipeline and a pipeline texas eastern transmission pipeline (�tetco�). The divers closed the jumper line valve to fully isolate the chandeleur pipeline and began to remove the concrete coating to confirm the location. The diving vessel was forced to leave location due to weather but was able to return the following morning on october 28. On october 28, the divers completed the removal of the concrete coating on the chandeleur pipeline and confirmed the location of the seeping natural gas at the 6 o�clock position of the chandeleur pipeline. On october 28, at approximately 11:16, third coast placed a call to the nrc it was reported that the nrc system was down, and no reports could be taken or generated. On october 28, at approximately 16:35 , third coast placed another call to the nrc (nrc# 1446522). On october 30, third coast provided the nrc with a 48-hour update (nrc# 1446736). On october 31, third coast installed a plidco clamp at the location of the seeping natural gas on the chandeleur pipeline, and the valves were then opened, and third coast performed a leak test. Third coast did not observe any further seepage of natural gas from the chandeleur pipeline during the leak test. Third coast then installed sandbags and concrete mats on the area of the chandeleur pipeline at issue. Approximately 784 mcf of natural gas was released from the chandeleur pipeline.
Detailed record list
Report Received Date
2025-11-24 00:00:00
Iyear
2025
Report Number
20250129
Supplemental Number
41617
Report Type
Original Final
Operator Id
Name
Chandeleur Pipe Line, Llc
Operator Street Address
Third Coast Midstream, Llc Po Box 1227
Operator City Name
Houston
Operator State Abbreviation
TX
Operator Postal Code
77251
Local Datetime
2025-10-16 17:06:00
Time Zone
Central
Daylight Savings Ind
Yes
Location Latitude
Location Longitude
Nrc Rpt Num
Nrc Rpt Datetime
2025-10-28 16:35:00
Additional Nrc Report Numbers
1445636, 1446736
Commodity Released Type
Natural Gas
Unintentional Release
784
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
Yes
Shutdown Datetime
2025-10-19 04:00:00
Restart Datetime
2025-10-31 12:00:00
Communication State Fed Ind
No
Ignite Ind
No
Upstream Action Taken
Valve Closure
Upstream Valve Close Datetime
2025-10-28 22:00:00
Downstream Action Taken
Valve Closure
Downstream Vlv Close Datetime
2025-10-19 04:00:00
Num Pub Evacuated
0
Incident Identified Datetime
2025-10-27 10:41:00
On Site Datetime
2025-10-27 05:00:00
Confirmed Discovery Datetime
2025-10-28 10:41:00
On Off Shore
Offshore
Pipe Fac Name
Chandeleur Pipeline
Segment Name
Mp 42-L To Pascagoula Refinery (Bsee 3476)
Off Water Depth
20
Off Accident Origin
On The Outer Continental Shelf (Ocs)
Ocs Type
Ocs-Gulf Of America
Off Ocs Area
Brenton Sound
Off Ocs Block
42
Off Area Accident Type
Below Water, Pipe Buried Or Jetted Below Seabed
Pipe Facility Type
Interstate
System Part Involved
Offshore Pipeline, Including Riser And Riser Bend
Item Involved
Pipe
Pipe Type
Pipe Body
Pipe Diameter
16
Puddle Weld Ind
No
Pipe Wall Thickness
0.375
Pipe Smys
46000
Pipe Specification
Api 5l X 46
Pipe Seam Type
Seamless
Pipe Manufacturer
Republic Steel
Pipe Coating Type
Other
Pipe Coating Details
Concrete
Coating Applied Ind
No
Installation Year
1969
Manufactured Year
1969
Material Involved
Carbon Steel
Release Type
Leak
Leak Type
Pinhole
Class Location Type
Class 1 Location
Could Be Hca
No
Pir Radius
400
Heat Damage Ind
No
Non Heat Damage Ind
No
Did Occur In Mca Ind
No
Est Cost Oper Paid
0
Est Cost Unintentional Release
2297
Est Cost Intentional Release
0
Est Cost Prop Damage
316000
Est Cost Emergency
100000
Est Cost Other
0
Gas Cost In Mcf
2.93
Prpty
418297
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
930
Gas Flow In Pipe In Mcf
192000
Mop Psig
1440
Mop Cfr Section
192.619(A)(1)
Maop Established Date
1984-07-25 00:00:00
Maop Reversal Flow Ind
No
Accident Pressure
Pressure Did Not Exceed Maop
Pressure Restriction Ind
No
Gas Required Odorized Ind
No
Upstream Valve Type Ind
Manual
Downstream Valve Type Ind
Remotely Controlled
Length Segment Isolated
121440
Internal Inspection Ind
No
Other Restrictions Ind
Yes
Operation Complications Ind
Yes
Low Flow Ind
Yes
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
Other
Accident Details
Other 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
A review of the accident determined that there were no control room actions that contributed to the event
Employee Drug Test Ind
No
Contractor Drug Test Ind
No
Cause
Corrosion Failure
Cause Details
Internal Corrosion
Internal External
Internal Corrosion
Int Visual Exam Results
Not Cut Open
Int Other Corrosion Ind
Yes
Int Corrosion Type Details
Pinhole Corrosion
Int Field Exam Basis Ind
Yes
Int Low Point Pipe Loc Ind
Yes
Corrosion Inhibitors
No
Corrosion Lining
No
Cleaning Dewatering
Not Applicable - Not Mainline Pipe
Corrosion Coupons
Not Applicable - Not Mainline Pipe
Collected Data Ind
No
Has Hydrtst Conduc Before Ind
No
Direct Asmnt Conducted
No
Non Destructive Exam Ind
No
Preparer Name
N****** P********
Preparer Title
Manager Pipeline Regulatory Compliance
Preparer Email
N*********@t**********.com
Preparer Telephone
3462413368
Authorizer Name
N****** P********
Authorizer Title
Manager Pipeline Regulatory Compliance
Authorizer Telephone
3462413368
Authorizer Email
N*********@t**********.com
Narrative
On thursday, october 16, 2025, at approximately 20:30, chandeleur pipe line, (third coast), was contacted by the united states coast guard regarding alleged bubbles with no sheen on the surface of the water in block 42 of the brenton sound area in the gulf of america near the chandeleur 16� natural gas pipeline and a natural gas pipeline owned and operated by enbridge. Third coast initiated its investigation regarding the nrc report. Following the initial investigation, third coast determined the reported natural gas release did not appear to originate from the chandeleur pipeline because of the lack of any material reductions in pressure and no apparent operational abnormalities on the chandeleur pipeline. Third coast then contacted the uscg to relay third coast�s conclusion that its initial investigation did not appear to indicate the chandeleur pipeline was the source of the reported natural gas release. On saturday, october 18, third coast was contacted by enbridge, which stated that, during its investigation related to the nrc report, enbridge determined the source of the reported natural gas release was likely to be the chandeleur pipeline. In response, third coast contacted all producers on the chandeleur pipeline to initiate shut-in procedures of the chandeleur pipeline and to divert flows of natural gas from the chandeleur pipeline to alternate pipelines. On sunday, october 19, at approximately 04:00, third coast completed the shut-in of the chandeleur pipeline. Third coast performed a 10-hr. Static pressure test on the chandeleur pipeline that was completed on sunday afternoon. The chandeleur pipeline held pressure with no pressure drops for the full duration of the static pressure test. Following the completion of the static pressure test, third coast notified uscg and bsee to provide the results of the static pressure test and restarted the chandeleur pipeline. On tuesday, october 21, bsee contacted third coast regarding ongoing bubbles on the surface of the water in vicinity of the location identified in the nrc report. In response, third coast shut-in the chandeleur pipeline. Due to adverse weather and sea conditions, third coast was unable to return to the location of the reported ongoing natural gas release until monday, october 27. On monday, october 27, divers identified natural gas seeping from the concrete coating on the chandeleur pipeline located approximately 10 ft from a jumper line connection between the chandeleur pipeline and a pipeline texas eastern transmission pipeline (�tetco�). The divers closed the jumper line valve to fully isolate the chandeleur pipeline and began to remove the concrete coating to confirm the location. The diving vessel was forced to leave location due to weather but was able to return the following morning on october 28. On october 28, the divers completed the removal of the concrete coating on the chandeleur pipeline and confirmed the location of the seeping natural gas at the 6 o�clock position of the chandeleur pipeline. On october 28, at approximately 11:16, third coast placed a call to the nrc it was reported that the nrc system was down, and no reports could be taken or generated. On october 28, at approximately 16:35 , third coast placed another call to the nrc (nrc# 1446522). On october 30, third coast provided the nrc with a 48-hour update (nrc# 1446736). On october 31, third coast installed a plidco clamp at the location of the seeping natural gas on the chandeleur pipeline, and the valves were then opened, and third coast performed a leak test. Third coast did not observe any further seepage of natural gas from the chandeleur pipeline during the leak test. Third coast then installed sandbags and concrete mats on the area of the chandeleur pipeline at issue. Approximately 784 mcf of natural gas was released from the chandeleur pipeline.
Report Received Date 2025-11-24 00:00:00
Iyear 2025
Report Number 20250129
Supplemental Number 41617
Report Type Original Final
Operator Id 39201 PHMSA Enforcement
Name Chandeleur Pipe Line, Llc
Operator Street Address Third Coast Midstream, Llc Po Box 1227
Operator City Name Houston
Operator State Abbreviation TX
Operator Postal Code 77251
Local Datetime 2025-10-16 17:06:00
Time Zone Central
Daylight Savings Ind Yes
Location Latitude 29.46676 Google Maps OpenStreetMap
Location Longitude -89.0501 Google Maps OpenStreetMap
Nrc Rpt Num 1446522 NRC Report How to search
Nrc Rpt Datetime 2025-10-28 16:35:00
Additional Nrc Report Numbers 1445636, 1446736
Commodity Released Type Natural Gas
Unintentional Release 784
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 Yes
Shutdown Datetime 2025-10-19 04:00:00
Restart Datetime 2025-10-31 12:00:00
Communication State Fed Ind No
Ignite Ind No
Upstream Action Taken Valve Closure
Upstream Valve Close Datetime 2025-10-28 22:00:00
Downstream Action Taken Valve Closure
Downstream Vlv Close Datetime 2025-10-19 04:00:00
Num Pub Evacuated 0
Incident Identified Datetime 2025-10-27 10:41:00
On Site Datetime 2025-10-27 05:00:00
Confirmed Discovery Datetime 2025-10-28 10:41:00
On Off Shore Offshore
Pipe Fac Name Chandeleur Pipeline
Segment Name Mp 42-L To Pascagoula Refinery (Bsee 3476)
Off Water Depth 20
Off Accident Origin On The Outer Continental Shelf (Ocs)
Ocs Type Ocs-Gulf Of America
Off Ocs Area Brenton Sound
Off Ocs Block 42
Off Area Accident Type Below Water, Pipe Buried Or Jetted Below Seabed
Pipe Facility Type Interstate
System Part Involved Offshore Pipeline, Including Riser And Riser Bend
Item Involved Pipe
Pipe Type Pipe Body
Pipe Diameter 16
Puddle Weld Ind No
Pipe Wall Thickness 0.375
Pipe Smys 46000
Pipe Specification Api 5l X 46
Pipe Seam Type Seamless
Pipe Manufacturer Republic Steel
Pipe Coating Type Other
Pipe Coating Details Concrete
Coating Applied Ind No
Installation Year 1969
Manufactured Year 1969
Material Involved Carbon Steel
Release Type Leak
Leak Type Pinhole
Class Location Type Class 1 Location
Could Be Hca No
Pir Radius 400
Heat Damage Ind No
Non Heat Damage Ind No
Did Occur In Mca Ind No
Est Cost Oper Paid 0
Est Cost Unintentional Release 2297
Est Cost Intentional Release 0
Est Cost Prop Damage 316000
Est Cost Emergency 100000
Est Cost Other 0
Gas Cost In Mcf 2.93
Prpty 418297
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 930
Gas Flow In Pipe In Mcf 192000
Mop Psig 1440
Mop Cfr Section 192.619(A)(1) View CFR 49 §192
Maop Established Date 1984-07-25 00:00:00
Maop Reversal Flow Ind No
Accident Pressure Pressure Did Not Exceed Maop
Pressure Restriction Ind No
Gas Required Odorized Ind No
Upstream Valve Type Ind Manual
Downstream Valve Type Ind Remotely Controlled
Length Segment Isolated 121440
Internal Inspection Ind No
Other Restrictions Ind Yes
Operation Complications Ind Yes
Low Flow Ind Yes
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 Other
Accident Details Other 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 A review of the accident determined that there were no control room actions that contributed to the event
Employee Drug Test Ind No
Contractor Drug Test Ind No
Cause Corrosion Failure
Cause Details Internal Corrosion
Internal External Internal Corrosion
Int Visual Exam Results Not Cut Open
Int Other Corrosion Ind Yes
Int Corrosion Type Details Pinhole Corrosion
Int Field Exam Basis Ind Yes
Int Low Point Pipe Loc Ind Yes
Corrosion Inhibitors No
Corrosion Lining No
Cleaning Dewatering Not Applicable - Not Mainline Pipe
Corrosion Coupons Not Applicable - Not Mainline Pipe
Collected Data Ind No
Has Hydrtst Conduc Before Ind No
Direct Asmnt Conducted No
Non Destructive Exam Ind No
Preparer Name N****** P********
Preparer Title Manager Pipeline Regulatory Compliance
Preparer Email N*********@t**********.com
Preparer Telephone 3462413368
Authorizer Name N****** P********
Authorizer Title Manager Pipeline Regulatory Compliance
Authorizer Telephone 3462413368
Authorizer Email N*********@t**********.com
Narrative On thursday, october 16, 2025, at approximately 20:30, chandeleur pipe line, (third coast), was contacted by the united states coast guard regarding alleged bubbles with no sheen on the surface of the water in block 42 of the brenton sound area in the gulf of america near the chandeleur 16� natural gas pipeline and a natural gas pipeline owned and operated by enbridge. Third coast initiated its investigation regarding the nrc report. Following the initial investigation, third coast determined the reported natural gas release did not appear to originate from the chandeleur pipeline because of the lack of any material reductions in pressure and no apparent operational abnormalities on the chandeleur pipeline. Third coast then contacted the uscg to relay third coast�s conclusion that its initial investigation did not appear to indicate the chandeleur pipeline was the source of the reported natural gas release. On saturday, october 18, third coast was contacted by enbridge, which stated that, during its investigation related to the nrc report, enbridge determined the source of the reported natural gas release was likely to be the chandeleur pipeline. In response, third coast contacted all producers on the chandeleur pipeline to initiate shut-in procedures of the chandeleur pipeline and to divert flows of natural gas from the chandeleur pipeline to alternate pipelines. On sunday, october 19, at approximately 04:00, third coast completed the shut-in of the chandeleur pipeline. Third coast performed a 10-hr. Static pressure test on the chandeleur pipeline that was completed on sunday afternoon. The chandeleur pipeline held pressure with no pressure drops for the full duration of the static pressure test. Following the completion of the static pressure test, third coast notified uscg and bsee to provide the results of the static pressure test and restarted the chandeleur pipeline. On tuesday, october 21, bsee contacted third coast regarding ongoing bubbles on the surface of the water in vicinity of the location identified in the nrc report. In response, third coast shut-in the chandeleur pipeline. Due to adverse weather and sea conditions, third coast was unable to return to the location of the reported ongoing natural gas release until monday, october 27. On monday, october 27, divers identified natural gas seeping from the concrete coating on the chandeleur pipeline located approximately 10 ft from a jumper line connection between the chandeleur pipeline and a pipeline texas eastern transmission pipeline (�tetco�). The divers closed the jumper line valve to fully isolate the chandeleur pipeline and began to remove the concrete coating to confirm the location. The diving vessel was forced to leave location due to weather but was able to return the following morning on october 28. On october 28, the divers completed the removal of the concrete coating on the chandeleur pipeline and confirmed the location of the seeping natural gas at the 6 o�clock position of the chandeleur pipeline. On october 28, at approximately 11:16, third coast placed a call to the nrc it was reported that the nrc system was down, and no reports could be taken or generated. On october 28, at approximately 16:35 , third coast placed another call to the nrc (nrc# 1446522). On october 30, third coast provided the nrc with a 48-hour update (nrc# 1446736). On october 31, third coast installed a plidco clamp at the location of the seeping natural gas on the chandeleur pipeline, and the valves were then opened, and third coast performed a leak test. Third coast did not observe any further seepage of natural gas from the chandeleur pipeline during the leak test. Third coast then installed sandbags and concrete mats on the area of the chandeleur pipeline at issue. Approximately 784 mcf of natural gas was released from the chandeleur pipeline.

All rights reserved. Copyright © by ClearPHMSA