Incident details
Operator, cause, commodity and consequences with raw source fields.
HL incident on 2024-12-11 — TX
Operator
Enbridge Energy, Limited Partnership
Cause
Equipment Failure
Commodity
Crude Oil
Program
HL
Damage and Injuries
0 fatalities
0 injuries
Property damage (nominal)
$29,144
Incident datetime
2024-12-11 00:00 UTC
Report number
Location
TX
Narrative
During a routine walkthrough at cambridge station on november 11, 2024, at approximately 6:46 am cst, an enbridge technician noticed what appeared to be product staining an area of gravel near the unit 4 discharge valve outside of the line 6 pump building. The control center was immediately contacted, and the line 6 pumping station was shut down and isolated. Due to assumed costs of the repair, a call was placed to the nrc at 7:24 am cst (nrc report #1416053). Through excavation of the area, it was determined that a below grade bolted flange connection on the discharge valve (cb-6-udv-41) was the source of the release. The gasket was replaced and after re-torquing the flange the station was pressurized to monitor the flange. After confirming the repair, the station was returned to service. Contaminated soil generated during the initial repair activities was separated and disposed of at a licensed disposal facility. A 48-hour update to the nrc was made on november 13, 2024, at 7:03 am cst (nrc report #1416251). After completion of the repair, third party soil-sampling and investigation activities were conducted to determine the extent of the impacted area. Because of infrastructure located near the release site hydro-excavation became the main option for soil removal until it was safe to use other equipment. As soil sampling and removal progressed, the volume of product released was determined to be greater than that of the original estimates. Based on the current volume estimates and observed release rate prior to the repair, this flange was likely leaking for an extended period of time. Investigation activities to date have shown that the extent of product impacts are confined to the facility, localized near the release site, and that no potable water wells or surface water features have been impacted. Moving forward, additional site investigation and remediation will be completed under the wisconsin dnr remediation and redevelopment program. The root cause was determined to be a failed gasket at a flanged connection. Two of the contributing factors are related to the date of installation in the early 1970s: calibrated torquing equipment with precise measurements were not readily available or used; and that the installed gasket had no inner ring. To prevent reoccurrence, below grade flanged connections exposed during site remediation had their torque verified or were re-torqued to current enbridge standards. In addition, enbridge is following its event analysis process and facility integrity management plan to review other sites with below grade flanges of the same vintage. This review will assist in determining if there are any signs of similar potential risk. If any such issues are found, pvc monitor poles will then be installed in these locations so that they can be routinely monitored during station checks. Based on the findings of these exploratory reviews, further investigations may take place at other locations.
Detailed record list
Report Received Date
2024-12-11 00:00:00
Iyear
2024
Report Number
20240288
Supplemental Number
40402
Report Type
Supplemental Final
Operator Id
11169
Name
Enbridge Energy, Limited Partnership
Operator Street Address
915 N Eldridge Parkway, Suite 1100
Operator City Name
Houston
Operator State Abbreviation
TX
Operator Postal Code
77079
Time Zone
Central
Daylight Savings Ind
No
Location Latitude
43.007346
Location Longitude
-88.948112
Commodity Released Type
Crude Oil
Unintentional Release Bbls
1650
Recovered Bbls
960
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Accident Identifier
Local Operating Personnel, Including Contractors
Operator Type
Operator Employee
System Part Involved
Onshore Pump/meter Station Equipment And Piping
On Off Shore
Onshore
Status When Identified
Normal Operation, Includes Pauses Between Batches And During Maintenance
Shutdown Due Accident Ind
Yes
Communication State Fed Ind
No
Nrc Rpt Num
1416053
Additional Nrc Report Numbers
1416251
Ignite Ind
No
Notify Qualified Indiv Ind
Yes
Oil Spill Removal Org Ind
No
Num Pub Evacuated
0
Pipe Fac Name
Cambridge Station
Segment Name
6-Udv-41
Onshore State Abbreviation
Wi
Onshore Postal Code
53523
Onshore City Name
Cambridge
Onshore County Name
Jefferson
Designated Location
Milepost
Designated Name
304.57
Federal
No
Location Type
Totally Contained On Operator-Controlled Property
Incident Area Type
Underground
Incident Area Subtype
Under Soil
Depth Of Cover
36
Crossing
No
Pipe Facility Type
Interstate
Item Involved
Valve
Valve Type
Auxiliary Or Other Valve
Installation Year
1973
Manufactured Year
Unknown
Material Involved
Carbon Steel
Release Type
Leak
Leak Type
Connection Failure
Wildlife Impact Ind
No
Soil Contamination
Yes
Long Term Assessment
Yes
Remediation Ind
Yes
Soil Remed Ind
Yes
Water Contam Ind
Yes
Groundwater Contam Ind
Yes
Amount Released
0.1
Rel Water Name
Na - Groundwater
Could Be Hca
Yes
Commodity Reached Hca
Yes
Other Pop Ind
Yes
Other Pop Yes No
Yes
Est Cost Oper Paid
0
Est Cost Gas Released
115500
Est Cost Prop Damage
29144
Est Cost Emergency
33052
Est Cost Environmental
1115006
Est Cost Other
0
Prpty
1292702
Num Persons Hosp Not Ovnght
0
Num Injured Treated By Emt
0
Num Resident Building Affctd
0
Num Business Building Affctd
0
Accident Psig
308
Mop Psig
876
Mop Cfr Section
Subpart E Pressure Test �195.406(A)(3)
Maop Established Date
1971-10-14 00:00:00
Maop Reversal Flow Ind
No
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
Yes
Cpm Operating Ind
Yes
Cpm Functional Ind
Yes
Cpm Detection Ind
No
Cpm Conf 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
There were no alarms associated with this event due to the rate and duration of the release being lower than the detectable threshold of the active alarm systems. Release was identified by field personnel, who initiated the appropriate response to this event, and the initial estimated volume released did not meet the requirements to conduct an investigation.
Employee Drug Test Ind
No
Contractor Drug Test Ind
No
Cause
Equipment Failure
Cause Details
Non-Threaded Connection Failure
Eq Failure Type
Non-Threaded Connection Failure
Other Non Threaded Ind
Gasket
Eq Additional Other Ind
Yes
Eq Additional Other Details
Degraded Gasket/connection Loosened Over Time
Preparer Name
S**** S****
Preparer Title
Advisor Regulatory Compliance
Preparer Email
S**********@e*******.com
Preparer Telephone
7153953620
Prepared Date
2025-01-10 00:00:00
Authorizer Name
L*** S**********
Authorizer Telephone
7153941584
Authorizer Title
Supervisor Regulatory Compliance
Authorizer Email
L***************@e*******.com
Narrative
During a routine walkthrough at cambridge station on november 11, 2024, at approximately 6:46 am cst, an enbridge technician noticed what appeared to be product staining an area of gravel near the unit 4 discharge valve outside of the line 6 pump building. The control center was immediately contacted, and the line 6 pumping station was shut down and isolated. Due to assumed costs of the repair, a call was placed to the nrc at 7:24 am cst (nrc report #1416053). Through excavation of the area, it was determined that a below grade bolted flange connection on the discharge valve (cb-6-udv-41) was the source of the release. The gasket was replaced and after re-torquing the flange the station was pressurized to monitor the flange. After confirming the repair, the station was returned to service. Contaminated soil generated during the initial repair activities was separated and disposed of at a licensed disposal facility. A 48-hour update to the nrc was made on november 13, 2024, at 7:03 am cst (nrc report #1416251). After completion of the repair, third party soil-sampling and investigation activities were conducted to determine the extent of the impacted area. Because of infrastructure located near the release site hydro-excavation became the main option for soil removal until it was safe to use other equipment. As soil sampling and removal progressed, the volume of product released was determined to be greater than that of the original estimates. Based on the current volume estimates and observed release rate prior to the repair, this flange was likely leaking for an extended period of time. Investigation activities to date have shown that the extent of product impacts are confined to the facility, localized near the release site, and that no potable water wells or surface water features have been impacted. Moving forward, additional site investigation and remediation will be completed under the wisconsin dnr remediation and redevelopment program. The root cause was determined to be a failed gasket at a flanged connection. Two of the contributing factors are related to the date of installation in the early 1970s: calibrated torquing equipment with precise measurements were not readily available or used; and that the installed gasket had no inner ring. To prevent reoccurrence, below grade flanged connections exposed during site remediation had their torque verified or were re-torqued to current enbridge standards. In addition, enbridge is following its event analysis process and facility integrity management plan to review other sites with below grade flanges of the same vintage. This review will assist in determining if there are any signs of similar potential risk. If any such issues are found, pvc monitor poles will then be installed in these locations so that they can be routinely monitored during station checks. Based on the findings of these exploratory reviews, further investigations may take place at other locations.
| Report Received Date | 2024-12-11 00:00:00 |
|---|---|
| Iyear | 2024 |
| Report Number | 20240288 |
| Supplemental Number | 40402 |
| Report Type | Supplemental Final |
| Operator Id | 11169 PHMSA Enforcement |
| Name | Enbridge Energy, Limited Partnership |
| Operator Street Address | 915 N Eldridge Parkway, Suite 1100 |
| Operator City Name | Houston |
| Operator State Abbreviation | TX |
| Operator Postal Code | 77079 |
| Time Zone | Central |
| Daylight Savings Ind | No |
| Location Latitude | 43.007346 Google Maps OpenStreetMap |
| Location Longitude | -88.948112 Google Maps OpenStreetMap |
| Commodity Released Type | Crude Oil |
| Unintentional Release Bbls | 1650 |
| Recovered Bbls | 960 |
| Fatality Ind | No |
| Fatal | 0 |
| Injury Ind | No |
| Injure | 0 |
| Accident Identifier | Local Operating Personnel, Including Contractors |
| Operator Type | Operator Employee |
| System Part Involved | Onshore Pump/meter Station Equipment And Piping |
| On Off Shore | Onshore |
| Status When Identified | Normal Operation, Includes Pauses Between Batches And During Maintenance |
| Shutdown Due Accident Ind | Yes |
| Communication State Fed Ind | No |
| Nrc Rpt Num | 1416053 NRC Report How to search |
| Additional Nrc Report Numbers | 1416251 |
| Ignite Ind | No |
| Notify Qualified Indiv Ind | Yes |
| Oil Spill Removal Org Ind | No |
| Num Pub Evacuated | 0 |
| Pipe Fac Name | Cambridge Station |
| Segment Name | 6-Udv-41 |
| Onshore State Abbreviation | Wi |
| Onshore Postal Code | 53523 |
| Onshore City Name | Cambridge |
| Onshore County Name | Jefferson |
| Designated Location | Milepost |
| Designated Name | 304.57 |
| Federal | No |
| Location Type | Totally Contained On Operator-Controlled Property |
| Incident Area Type | Underground |
| Incident Area Subtype | Under Soil |
| Depth Of Cover | 36 |
| Crossing | No |
| Pipe Facility Type | Interstate |
| Item Involved | Valve |
| Valve Type | Auxiliary Or Other Valve |
| Installation Year | 1973 |
| Manufactured Year | Unknown |
| Material Involved | Carbon Steel |
| Release Type | Leak |
| Leak Type | Connection Failure |
| Wildlife Impact Ind | No |
| Soil Contamination | Yes |
| Long Term Assessment | Yes |
| Remediation Ind | Yes |
| Soil Remed Ind | Yes |
| Water Contam Ind | Yes |
| Groundwater Contam Ind | Yes |
| Amount Released | 0.1 |
| Rel Water Name | Na - Groundwater |
| Could Be Hca | Yes |
| Commodity Reached Hca | Yes |
| Other Pop Ind | Yes |
| Other Pop Yes No | Yes |
| Est Cost Oper Paid | 0 |
| Est Cost Gas Released | 115500 |
| Est Cost Prop Damage | 29144 |
| Est Cost Emergency | 33052 |
| Est Cost Environmental | 1115006 |
| Est Cost Other | 0 |
| Prpty | 1292702 |
| Num Persons Hosp Not Ovnght | 0 |
| Num Injured Treated By Emt | 0 |
| Num Resident Building Affctd | 0 |
| Num Business Building Affctd | 0 |
| Accident Psig | 308 |
| Mop Psig | 876 |
| Mop Cfr Section | Subpart E Pressure Test �195.406(A)(3) View CFR 49 §192 |
| Maop Established Date | 1971-10-14 00:00:00 |
| Maop Reversal Flow Ind | No |
| 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 | Yes |
| Cpm Operating Ind | Yes |
| Cpm Functional Ind | Yes |
| Cpm Detection Ind | No |
| Cpm Conf 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 | There were no alarms associated with this event due to the rate and duration of the release being lower than the detectable threshold of the active alarm systems. Release was identified by field personnel, who initiated the appropriate response to this event, and the initial estimated volume released did not meet the requirements to conduct an investigation. |
| Employee Drug Test Ind | No |
| Contractor Drug Test Ind | No |
| Cause | Equipment Failure |
| Cause Details | Non-Threaded Connection Failure |
| Eq Failure Type | Non-Threaded Connection Failure |
| Other Non Threaded Ind | Gasket |
| Eq Additional Other Ind | Yes |
| Eq Additional Other Details | Degraded Gasket/connection Loosened Over Time |
| Preparer Name | S**** S**** |
| Preparer Title | Advisor Regulatory Compliance |
| Preparer Email | S**********@e*******.com |
| Preparer Telephone | 7153953620 |
| Prepared Date | 2025-01-10 00:00:00 |
| Authorizer Name | L*** S********** |
| Authorizer Telephone | 7153941584 |
| Authorizer Title | Supervisor Regulatory Compliance |
| Authorizer Email | L***************@e*******.com |
| Narrative | During a routine walkthrough at cambridge station on november 11, 2024, at approximately 6:46 am cst, an enbridge technician noticed what appeared to be product staining an area of gravel near the unit 4 discharge valve outside of the line 6 pump building. The control center was immediately contacted, and the line 6 pumping station was shut down and isolated. Due to assumed costs of the repair, a call was placed to the nrc at 7:24 am cst (nrc report #1416053). Through excavation of the area, it was determined that a below grade bolted flange connection on the discharge valve (cb-6-udv-41) was the source of the release. The gasket was replaced and after re-torquing the flange the station was pressurized to monitor the flange. After confirming the repair, the station was returned to service. Contaminated soil generated during the initial repair activities was separated and disposed of at a licensed disposal facility. A 48-hour update to the nrc was made on november 13, 2024, at 7:03 am cst (nrc report #1416251). After completion of the repair, third party soil-sampling and investigation activities were conducted to determine the extent of the impacted area. Because of infrastructure located near the release site hydro-excavation became the main option for soil removal until it was safe to use other equipment. As soil sampling and removal progressed, the volume of product released was determined to be greater than that of the original estimates. Based on the current volume estimates and observed release rate prior to the repair, this flange was likely leaking for an extended period of time. Investigation activities to date have shown that the extent of product impacts are confined to the facility, localized near the release site, and that no potable water wells or surface water features have been impacted. Moving forward, additional site investigation and remediation will be completed under the wisconsin dnr remediation and redevelopment program. The root cause was determined to be a failed gasket at a flanged connection. Two of the contributing factors are related to the date of installation in the early 1970s: calibrated torquing equipment with precise measurements were not readily available or used; and that the installed gasket had no inner ring. To prevent reoccurrence, below grade flanged connections exposed during site remediation had their torque verified or were re-torqued to current enbridge standards. In addition, enbridge is following its event analysis process and facility integrity management plan to review other sites with below grade flanges of the same vintage. This review will assist in determining if there are any signs of similar potential risk. If any such issues are found, pvc monitor poles will then be installed in these locations so that they can be routinely monitored during station checks. Based on the findings of these exploratory reviews, further investigations may take place at other locations. |
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