Incident details
Operator, cause, commodity and consequences with raw source fields.
GTG incident on 2025-08-01 — MI
Operator
Dtm Appalachia Gathering, Llc
Cause
Equipment Failure
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities
0 injuries
Property damage (nominal)
$0
Incident datetime
2025-08-01 00:00 UTC
Report number
Location
MI
Narrative
A significant operational change occurred at dt midstream�s major delivery point for ags. Flow was cut significantly with no notification to dtm which caused ags pressure to rise. The relief valve on the discharge of the cooper�s run dehy lifted when the pressure reached 1160 psig (setpoint 1218 psig per previous inspection). The relief functioned properly other than the slightly early lift. Dtm was alerted by a production contractor working in the area. Dtm's on-call technician went to site, verified system pressure was under maop, and shut the relief block valve to reset the relief. They then monitored the relief to ensure no repeat releases occurred. The relief was function tested and confirmed to be lifting at 1160 psig. The setpoint was reset to 1218 psig and successfully function tested and returned to service.
Detailed record list
Report Received Date
2025-08-01 00:00:00
Iyear
2025
Report Number
20250084
Supplemental Number
41200
Report Type
Supplemental Final
Operator Id
39003
Name
Dtm Appalachia Gathering, Llc
Operator Street Address
500 Woodward Ave Suite 2900
Operator City Name
Detroit
Operator State Abbreviation
MI
Operator Postal Code
48226
Time Zone
Eastern
Daylight Savings Ind
Yes
Location Latitude
39.702296
Location Longitude
-80.19848
Nrc Rpt Num
1436736
Additional Nrc Report Numbers
1436930
Commodity Released Type
Natural Gas
Unintentional Release
7400
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
Relief Valve Was Reset. System Still Operating Below Maop.
Communication State Fed Ind
No
Ignite Ind
No
Upstream Oprtnl Cntrl Detail
Relief Which Lifted Early Was Shut In And Reset. Maop Was Not Exceeded.
Downstream Oprtnl Cntrl Detail
Relief Which Lifted Early Was Shut In And Reset. Maop Was Not Exceeded.
Num Pub Evacuated
0
On Off Shore
Onshore
Onshore State Abbreviation
Wv
Onshore Postal Code
26521
Onshore City Name
Not Within A Municipality
Onshore County Name
Monongalia
Designated Location
Not Applicable
Pipe Fac Name
Cooper's Run Dehy
Segment Name
Appalachia Gathering System
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 Compressor Station Equipment And Piping
Item Involved
Dehydrator/drier/treater/scrubber
Installation Year
Unknown
Manufactured Year
Unknown
Material Involved
Carbon Steel
Release Type
Other
Release Type Details
Relief Valve Actuation.
Class Location Type
Class 1 Location
Could Be Hca
No
Pir Radius
578
Heat Damage Ind
No
Non Heat Damage Ind
No
Did Occur In Mca Ind
No
Est Cost Oper Paid
0
Est Cost Unintentional Release
25012
Est Cost Intentional Release
0
Est Cost Prop Damage
0
Est Cost Emergency
1580
Est Cost Other
0
Gas Cost In Mcf
3.38
Prpty
26592
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
1160
Gas Flow In Pipe In Mcf
60000
Mop Psig
1218
Mop Cfr Section
192.619(A)(2)
Maop Established Date
2013-11-13 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
Type C Gathering
Scada In Place Ind
Yes
Scada Operating Ind
Yes
Scada Functional Ind
Yes
Scada Detection Ind
No
Scada Conf Ind
No
Accident Identifier
Notification From Public
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
No visibility over relief valve position. System pressure was under alarm limits.
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
Relief Valve Ind
Yes
Eq Additional Other Ind
Yes
Eq Additional Other Details
Setpoint Drift.
Preparer Name
K*** D********
Preparer Title
Specialist
Preparer Email
K*************@d**********.com
Preparer Telephone
8107282233
Local Contact Name
S**** W*********
Local Contact Email
S****************@d**********.com
Local Contact Telephone
3042762929
Authorizer Name
P***** C******
Authorizer Title
Director Of Codes And Regulatory
Authorizer Telephone
(313) 774-2406
Authorizer Email
P*************@d**********.com
Narrative
A significant operational change occurred at dt midstream�s major delivery point for ags. Flow was cut significantly with no notification to dtm which caused ags pressure to rise. The relief valve on the discharge of the cooper�s run dehy lifted when the pressure reached 1160 psig (setpoint 1218 psig per previous inspection). The relief functioned properly other than the slightly early lift. Dtm was alerted by a production contractor working in the area. Dtm's on-call technician went to site, verified system pressure was under maop, and shut the relief block valve to reset the relief. They then monitored the relief to ensure no repeat releases occurred. The relief was function tested and confirmed to be lifting at 1160 psig. The setpoint was reset to 1218 psig and successfully function tested and returned to service.
| Report Received Date | 2025-08-01 00:00:00 |
|---|---|
| Iyear | 2025 |
| Report Number | 20250084 |
| Supplemental Number | 41200 |
| Report Type | Supplemental Final |
| Operator Id | 39003 PHMSA Enforcement |
| Name | Dtm Appalachia Gathering, Llc |
| Operator Street Address | 500 Woodward Ave Suite 2900 |
| Operator City Name | Detroit |
| Operator State Abbreviation | MI |
| Operator Postal Code | 48226 |
| Time Zone | Eastern |
| Daylight Savings Ind | Yes |
| Location Latitude | 39.702296 Google Maps OpenStreetMap |
| Location Longitude | -80.19848 Google Maps OpenStreetMap |
| Nrc Rpt Num | 1436736 NRC Report How to search |
| Additional Nrc Report Numbers | 1436930 |
| Commodity Released Type | Natural Gas |
| Unintentional Release | 7400 |
| 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 | Relief Valve Was Reset. System Still Operating Below Maop. |
| Communication State Fed Ind | No |
| Ignite Ind | No |
| Upstream Oprtnl Cntrl Detail | Relief Which Lifted Early Was Shut In And Reset. Maop Was Not Exceeded. |
| Downstream Oprtnl Cntrl Detail | Relief Which Lifted Early Was Shut In And Reset. Maop Was Not Exceeded. |
| Num Pub Evacuated | 0 |
| On Off Shore | Onshore |
| Onshore State Abbreviation | Wv |
| Onshore Postal Code | 26521 |
| Onshore City Name | Not Within A Municipality |
| Onshore County Name | Monongalia |
| Designated Location | Not Applicable |
| Pipe Fac Name | Cooper's Run Dehy |
| Segment Name | Appalachia Gathering System |
| 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 Compressor Station Equipment And Piping |
| Item Involved | Dehydrator/drier/treater/scrubber |
| Installation Year | Unknown |
| Manufactured Year | Unknown |
| Material Involved | Carbon Steel |
| Release Type | Other |
| Release Type Details | Relief Valve Actuation. |
| Class Location Type | Class 1 Location |
| Could Be Hca | No |
| Pir Radius | 578 |
| Heat Damage Ind | No |
| Non Heat Damage Ind | No |
| Did Occur In Mca Ind | No |
| Est Cost Oper Paid | 0 |
| Est Cost Unintentional Release | 25012 |
| Est Cost Intentional Release | 0 |
| Est Cost Prop Damage | 0 |
| Est Cost Emergency | 1580 |
| Est Cost Other | 0 |
| Gas Cost In Mcf | 3.38 |
| Prpty | 26592 |
| 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 | 1160 |
| Gas Flow In Pipe In Mcf | 60000 |
| Mop Psig | 1218 |
| Mop Cfr Section | 192.619(A)(2) View CFR 49 §192 |
| Maop Established Date | 2013-11-13 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 | Type C Gathering |
| Scada In Place Ind | Yes |
| Scada Operating Ind | Yes |
| Scada Functional Ind | Yes |
| Scada Detection Ind | No |
| Scada Conf Ind | No |
| Accident Identifier | Notification From Public |
| 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 | No visibility over relief valve position. System pressure was under alarm limits. |
| 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 |
| Relief Valve Ind | Yes |
| Eq Additional Other Ind | Yes |
| Eq Additional Other Details | Setpoint Drift. |
| Preparer Name | K*** D******** |
| Preparer Title | Specialist |
| Preparer Email | K*************@d**********.com |
| Preparer Telephone | 8107282233 |
| Local Contact Name | S**** W********* |
| Local Contact Email | S****************@d**********.com |
| Local Contact Telephone | 3042762929 |
| Authorizer Name | P***** C****** |
| Authorizer Title | Director Of Codes And Regulatory |
| Authorizer Telephone | (313) 774-2406 |
| Authorizer Email | P*************@d**********.com |
| Narrative | A significant operational change occurred at dt midstream�s major delivery point for ags. Flow was cut significantly with no notification to dtm which caused ags pressure to rise. The relief valve on the discharge of the cooper�s run dehy lifted when the pressure reached 1160 psig (setpoint 1218 psig per previous inspection). The relief functioned properly other than the slightly early lift. Dtm was alerted by a production contractor working in the area. Dtm's on-call technician went to site, verified system pressure was under maop, and shut the relief block valve to reset the relief. They then monitored the relief to ensure no repeat releases occurred. The relief was function tested and confirmed to be lifting at 1160 psig. The setpoint was reset to 1218 psig and successfully function tested and returned to service. |
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