Incident details
Operator, cause, commodity and consequences with raw source fields.
HL incident on 2025-10-16 — TX
Operator
Denbury Onshore, Llc
Cause
Equipment Failure
Commodity
Co2 (Carbon Dioxide)
Program
HL
Damage and Injuries
0 fatalities
0 injuries
Property damage (nominal)
$257,000
Incident datetime
2025-10-16 18:50
Report number
Location
TX
Narrative
A release of carbon dioxide occurred at the nejd mlv-40 site on october 16, 2025. The event was first identified when technicians performing maintenance on the mainline valve at mlv-40 observed CO2 leaking from the valve stem area at approximately 6:50 pm ct. Upon notification to the control room, upstream and downstream remote-operated valves were closed. Additional block valves were manually closed to further isolate the segment. Air monitoring was initiated in coordination with local emergency responders, and notifications were made to the appropriate agencies. No injuries, fires, or evacuations occurred, and there were no reported impacts on nearby residents. Operations personnel, in coordination with local emergency agencies, elected to postpone nighttime blowdown activities on october 16 to allow the work to proceed under safer daytime visibility and improved monitoring conditions. Controlled depressurization of the isolated segment began the morning of october 17, starting at mlv-30 and progressing in stages as needed based on blowdown rates and site conditions. Air movers and continuous monitoring were utilized to support plume control, and all actions were conducted under joint oversight with emergency responders to ensure the release was safely mitigated. The investigation into the cause of the release is ongoing.
Detailed record list
Report Received Date
2025-11-14 00:00:00
Iyear
2025
Report Number
20250264
Supplemental Number
41592
Report Type
Original
Operator Id
31627
Name
Denbury Onshore, Llc
Operator Street Address
5851 Legacy Circle Suite 1200
Operator City Name
Plano
Operator State Abbreviation
TX
Operator Postal Code
75024
Local Datetime
2025-10-16 18:50:00
Time Zone
Central
Daylight Savings Ind
No
Location Latitude
31.285384
Location Longitude
-90.509466
Commodity Released Type
Co2 (Carbon Dioxide)
Unintentional Release Bbls
179
Intentional Release Bbls
19229
Recovered Bbls
0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Accident Identifier
Local Operating Personnel, Including Contractors
Operator Type
Operator Employee
Incident Identified Datetime
2025-10-16 18:50:00
System Part Involved
Onshore Pipeline, Including Valve Sites
On Off Shore
Onshore
Status When Identified
Normal Operation, Includes Pauses Between Batches And During Maintenance
Shutdown Due Accident Ind
Yes
Shutdown Datetime
2025-10-16 19:04:00
Still Shutdown Ind
Yes
Communication State Fed Ind
Yes
Party Initiated Communication
Operator
Initial Responder Com Datetime
2025-10-16 19:02:00
On Site Datetime
2025-10-16 18:50:00
Confirmed Discovery Datetime
2025-10-16 18:50:00
Nrc Rpt Datetime
2025-10-16 19:41:00
Nrc Rpt Num
1445639
Additional Nrc Report Numbers
1445804
Ignite Ind
No
Upstream Action Taken
Valve Closure
Upstream Valve Close Datetime
2025-10-16 19:03:00
Upstream Valve Type Ind
Remotely Controlled
Downstream Action Taken
Valve Closure
Downstream Vlv Close Datetime
2025-10-16 19:04:00
Downstream Valve Type Ind
Remotely Controlled
Num Pub Evacuated
0
Pipe Fac Name
Nejd/mlv-040
Segment Name
Nejd Pipeline
Onshore State Abbreviation
Ms
Onshore Postal Code
39652
Onshore City Name
Not Within A Municipality
Onshore County Name
Pike
Designated Location
Milepost
Designated Name
91
Federal
No
Location Type
Originated On Operator-Controlled Property, But Then Flowed Or Migrated Off The Property
Incident Area Type
Aboveground
Incident Area Subtype
Typical Aboveground Facility Piping Or Appurtenance
Crossing
No
Pipe Facility Type
Interstate
Item Involved
Valve
Valve Type
Mainline
Valve Mainline Type
Ball
Valve Manufacturer
Cameron
Installation Year
1985
Manufactured Year
Unknown
Material Involved
Carbon Steel
Release Type
Leak
Leak Type
Seal Or Packing
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
61136
Est Cost Prop Damage
257000
Est Cost Emergency
190000
Est Cost Environmental
0
Est Cost Other
0
Prpty
508136
Num Persons Hosp Not Ovnght
0
Num Injured Treated By Emt
0
Num Resident Building Affctd
0
Num Business Building Affctd
0
Accident Psig
1254
Mop Psig
2207
Mop Cfr Section
Subpart E Pressure Test �195.406(A)(3)
Maop Established Date
1987-10-10 00:00:00
Maop Reversal Flow Ind
No
Accident Pressure
Pressure Did Not Exceed Mop
Pressure Restriction Ind
No
Length Segment Isolated
384806
Internal Inspection Ind
Yes
Operation Complications 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
Operations personnel were on site performing scheduled maintenance at the time of the accident and directly observed the release. The leak was detected and addressed in the field, and there were no alarms, or other control room indications associated with this event.
Employee Drug Test Ind
No
Contractor Drug Test Ind
No
Cause
Equipment Failure
Cause Details
Other Equipment Failure
Eq Failure Type
Other Equipment Failure
Failure Details
Investigation Still Ongoing.
Eq Additional Other Ind
Yes
Eq Additional Other Details
Investigation Still Ongoing.
Preparer Name
J***** O****
Preparer Title
Pipeline Safety Advisor
Preparer Email
J***********@e*********.com
Preparer Telephone
(214)354-6186
Prepared Date
2025-11-14 00:00:00
Authorizer Name
L**** B******
Authorizer Telephone
(346)474-9151
Authorizer Title
Regulatory Compliance Supervisor
Authorizer Email
L**************@e*********.com
Narrative
A release of carbon dioxide occurred at the nejd mlv-40 site on october 16, 2025. The event was first identified when technicians performing maintenance on the mainline valve at mlv-40 observed CO2 leaking from the valve stem area at approximately 6:50 pm ct. Upon notification to the control room, upstream and downstream remote-operated valves were closed. Additional block valves were manually closed to further isolate the segment. Air monitoring was initiated in coordination with local emergency responders, and notifications were made to the appropriate agencies. No injuries, fires, or evacuations occurred, and there were no reported impacts on nearby residents. Operations personnel, in coordination with local emergency agencies, elected to postpone nighttime blowdown activities on october 16 to allow the work to proceed under safer daytime visibility and improved monitoring conditions. Controlled depressurization of the isolated segment began the morning of october 17, starting at mlv-30 and progressing in stages as needed based on blowdown rates and site conditions. Air movers and continuous monitoring were utilized to support plume control, and all actions were conducted under joint oversight with emergency responders to ensure the release was safely mitigated. The investigation into the cause of the release is ongoing.
| Report Received Date | 2025-11-14 00:00:00 |
|---|---|
| Iyear | 2025 |
| Report Number | 20250264 |
| Supplemental Number | 41592 |
| Report Type | Original |
| Operator Id | 31627 PHMSA Enforcement |
| Name | Denbury Onshore, Llc |
| Operator Street Address | 5851 Legacy Circle Suite 1200 |
| Operator City Name | Plano |
| Operator State Abbreviation | TX |
| Operator Postal Code | 75024 |
| Local Datetime | 2025-10-16 18:50:00 |
| Time Zone | Central |
| Daylight Savings Ind | No |
| Location Latitude | 31.285384 Google Maps OpenStreetMap |
| Location Longitude | -90.509466 Google Maps OpenStreetMap |
| Commodity Released Type | Co2 (Carbon Dioxide) |
| Unintentional Release Bbls | 179 |
| Intentional Release Bbls | 19229 |
| Recovered Bbls | 0 |
| Fatality Ind | No |
| Fatal | 0 |
| Injury Ind | No |
| Injure | 0 |
| Accident Identifier | Local Operating Personnel, Including Contractors |
| Operator Type | Operator Employee |
| Incident Identified Datetime | 2025-10-16 18:50:00 |
| System Part Involved | Onshore Pipeline, Including Valve Sites |
| On Off Shore | Onshore |
| Status When Identified | Normal Operation, Includes Pauses Between Batches And During Maintenance |
| Shutdown Due Accident Ind | Yes |
| Shutdown Datetime | 2025-10-16 19:04:00 |
| Still Shutdown Ind | Yes |
| Communication State Fed Ind | Yes |
| Party Initiated Communication | Operator |
| Initial Responder Com Datetime | 2025-10-16 19:02:00 |
| On Site Datetime | 2025-10-16 18:50:00 |
| Confirmed Discovery Datetime | 2025-10-16 18:50:00 |
| Nrc Rpt Datetime | 2025-10-16 19:41:00 |
| Nrc Rpt Num | 1445639 NRC Report How to search |
| Additional Nrc Report Numbers | 1445804 |
| Ignite Ind | No |
| Upstream Action Taken | Valve Closure |
| Upstream Valve Close Datetime | 2025-10-16 19:03:00 |
| Upstream Valve Type Ind | Remotely Controlled |
| Downstream Action Taken | Valve Closure |
| Downstream Vlv Close Datetime | 2025-10-16 19:04:00 |
| Downstream Valve Type Ind | Remotely Controlled |
| Num Pub Evacuated | 0 |
| Pipe Fac Name | Nejd/mlv-040 |
| Segment Name | Nejd Pipeline |
| Onshore State Abbreviation | Ms |
| Onshore Postal Code | 39652 |
| Onshore City Name | Not Within A Municipality |
| Onshore County Name | Pike |
| Designated Location | Milepost |
| Designated Name | 91 |
| Federal | No |
| Location Type | Originated On Operator-Controlled Property, But Then Flowed Or Migrated Off The Property |
| Incident Area Type | Aboveground |
| Incident Area Subtype | Typical Aboveground Facility Piping Or Appurtenance |
| Crossing | No |
| Pipe Facility Type | Interstate |
| Item Involved | Valve |
| Valve Type | Mainline |
| Valve Mainline Type | Ball |
| Valve Manufacturer | Cameron |
| Installation Year | 1985 |
| Manufactured Year | Unknown |
| Material Involved | Carbon Steel |
| Release Type | Leak |
| Leak Type | Seal Or Packing |
| 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 | 61136 |
| Est Cost Prop Damage | 257000 |
| Est Cost Emergency | 190000 |
| Est Cost Environmental | 0 |
| Est Cost Other | 0 |
| Prpty | 508136 |
| Num Persons Hosp Not Ovnght | 0 |
| Num Injured Treated By Emt | 0 |
| Num Resident Building Affctd | 0 |
| Num Business Building Affctd | 0 |
| Accident Psig | 1254 |
| Mop Psig | 2207 |
| Mop Cfr Section | Subpart E Pressure Test �195.406(A)(3) View CFR 49 §192 |
| Maop Established Date | 1987-10-10 00:00:00 |
| Maop Reversal Flow Ind | No |
| Accident Pressure | Pressure Did Not Exceed Mop |
| Pressure Restriction Ind | No |
| Length Segment Isolated | 384806 |
| Internal Inspection Ind | Yes |
| Operation Complications 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 | Operations personnel were on site performing scheduled maintenance at the time of the accident and directly observed the release. The leak was detected and addressed in the field, and there were no alarms, or other control room indications associated with this event. |
| Employee Drug Test Ind | No |
| Contractor Drug Test Ind | No |
| Cause | Equipment Failure |
| Cause Details | Other Equipment Failure |
| Eq Failure Type | Other Equipment Failure |
| Failure Details | Investigation Still Ongoing. |
| Eq Additional Other Ind | Yes |
| Eq Additional Other Details | Investigation Still Ongoing. |
| Preparer Name | J***** O**** |
| Preparer Title | Pipeline Safety Advisor |
| Preparer Email | J***********@e*********.com |
| Preparer Telephone | (214)354-6186 |
| Prepared Date | 2025-11-14 00:00:00 |
| Authorizer Name | L**** B****** |
| Authorizer Telephone | (346)474-9151 |
| Authorizer Title | Regulatory Compliance Supervisor |
| Authorizer Email | L**************@e*********.com |
| Narrative | A release of carbon dioxide occurred at the nejd mlv-40 site on october 16, 2025. The event was first identified when technicians performing maintenance on the mainline valve at mlv-40 observed CO2 leaking from the valve stem area at approximately 6:50 pm ct. Upon notification to the control room, upstream and downstream remote-operated valves were closed. Additional block valves were manually closed to further isolate the segment. Air monitoring was initiated in coordination with local emergency responders, and notifications were made to the appropriate agencies. No injuries, fires, or evacuations occurred, and there were no reported impacts on nearby residents. Operations personnel, in coordination with local emergency agencies, elected to postpone nighttime blowdown activities on october 16 to allow the work to proceed under safer daytime visibility and improved monitoring conditions. Controlled depressurization of the isolated segment began the morning of october 17, starting at mlv-30 and progressing in stages as needed based on blowdown rates and site conditions. Air movers and continuous monitoring were utilized to support plume control, and all actions were conducted under joint oversight with emergency responders to ensure the release was safely mitigated. The investigation into the cause of the release is ongoing. |
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