GD incident on 2014-07-21 — MI

Operator
Dte Gas Company
Cause
Equipment Failure
Commodity
Program
GD
Damage and Injuries
0 fatalities 0 injuries
Property damage (nominal)
$69,970
Incident datetime
2014-07-21 23:40
Report number
Location
MI, OTTAWA
Narrative
Dte gas control received notification at approximately 09:30, july 21, 2014 from grand rapids field technicians that routine maintenance work was being performed at that facility during that day. No alarms or unusual activity were noticed by gas control. At approximately 16:55, an electronic flow computer at georgetown regulating station began sensing false high flow and a false high inlet and outlet pressures. During normal operations, odorant is automatically injected into the grand rapids distribution system based upon volume delivery signals from the flow computer. The false high flow signals from the malfunctioning computer resulted in over-injection of odorant (mercaptan) into the distribution system creating an over-odorized condition. Dte gas control immediately began receiving an alarm for high inlet and outlet pressures. The controller presumed the alarms were activated in the course of the routine work being conducted by grand rapids field technicians. At approximately 17:00, the grand rapids field technicians onsite completed their work, which was not related to any of the flow or pressure devices and left the site unaware that an alarm had been activated at gas control. At approximately 23:40, gas control became concerned they had not received any contact form the grand rapids field technicians since early that morning and contacted an operations supervisor. A second field crew was deployed to georgetown station to investigate, arriving at 00:41 july 22, 2014. At 00:49, the field crew determined the odorant injection system was operating at abnormally high rate and placed the system into standby mode. The field crew contacted the region controls technician who also responded to the georgetown station. The flow computer was reset by the controls technician, the abnormal pressure and flow signals were cleared, and the computer resumed normal operation. At 01:30, the field crew reported to gas control that the odor injection system had been operating at an abnormally high rate over the past several hours. At 05:45, georgetown gate station was isolated from the system in an effort to contain excess odorant from getting into the system. By 08:00, july 23 the event was over and leak complaint volume was back to normal. The abnormal high odorization rate resulted in 610 leak complaints that were responded to and investigated by grand rapids field personnel.
Detailed record list
Occurred At
2014-07-21 23:40:00
Year
2014
Report Received Date
2014-08-20 00:00:00
Iyear
2014.0
Report Number
20140068.0
Supplemental Number
16179.0
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
2014-07-21 23:40:00
Location Street Address
1809 Edson
Location City Name
Hudsonville
Location County Name
Ottawa
Location State Abbreviation
MI
Location Postal Code
49426
Location Latitude
Location Longitude
Nrc Rpt Datetime
2014-07-23 17:00:00
Nrc Rpt Num
Unintentional Release
0.0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Ignite Ind
No
Explode Ind
No
Num Pub Evacuated
0.0
Incident Identified Datetime
2014-07-21 23:40:00
On Site Datetime
2014-07-22 00:41:00
Federal
No
Location Type
Operator-Controlled Property
Incident Area Type
Aboveground
Incident Area Subtype
Typical Aboveground Facility Piping Or Appurtenance (E.g. Value Or Regulator Station, Outdoor Meter Set)
Crossing
No
Pipe Facility Type
Privately Owned
System Part Involved
District Regulator/metering Station
Installation Year
1956.0
Material Involved
Other
Material Details
Flow Computer For Odorant
Release Type
Other
Release Type Details
Over Odorization At Georgetown Gate Station
Class Location Type
Class 3 Location
Est Cost Oper Paid
0.0
Est Cost Prop Damage
69970.0
Est Cost Emergency
5760.0
Est Cost Other
11520.0
Est Cost Other Details
Flaring To Dispose Of Gas With Excessive Levels Of Mercaptan
Est Cost Unintentional Release
0.0
Prpty
87250.0
Commercial Affected
0.0
Industrial Affected
0.0
Residences Affected
0.0
Accident Psig
140.0
Normal Psig
140.0
Mop Psig
145.0
Accident Pressure
Pressure Did Not Exceed Maop
Scada In Place Ind
Yes
Scada Operating Ind
Yes
Scada Functional Ind
Yes
Scada Detection Ind
Yes
Scada Conf Ind
Yes
Accident Identifier
Scada-Based Information (Such As Alarm(S), Alert(S), Event(S), And/or Volume Or Pack Calculations)
Investigation Status
Yes, specify investigation result(s): (select all that apply)
Invest Schedule Ind
Yes
Invest No Control Room Ind
Yes
Invest Incorrect Action Ind
Yes
Invest Maint Ind
Yes
Invest Other Ind
Yes
Invest Other Ind Details
Incorrect Setting Of Flow Rate Alarm;
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
Instrumentation Ind
Yes
Other Control Relief Ind
Yes
Other Control Relief Details
Flow Computer Sensed False High Pressure Reading, Sending An Incorrect Signal To The Odorization Equipment Causing That Device To Activate At An Increased Rate And Resulting In An Elevated Rate Of Mercaptan Injection.
Preparer Name
R***** F*********
Preparer Title
Manager
Preparer Email
F**********@d********.com
Preparer Telephone
313-389-7755
Preparer Fax
313-389-7757
Authorizer Name
R***** F*********
Authorizer Title
Manager
Authorizer Telephone
313-389-7755
Authorizer Email
F**********@d********.com
Narrative
Dte gas control received notification at approximately 09:30, july 21, 2014 from grand rapids field technicians that routine maintenance work was being performed at that facility during that day. No alarms or unusual activity were noticed by gas control. At approximately 16:55, an electronic flow computer at georgetown regulating station began sensing false high flow and a false high inlet and outlet pressures. During normal operations, odorant is automatically injected into the grand rapids distribution system based upon volume delivery signals from the flow computer. The false high flow signals from the malfunctioning computer resulted in over-injection of odorant (mercaptan) into the distribution system creating an over-odorized condition. Dte gas control immediately began receiving an alarm for high inlet and outlet pressures. The controller presumed the alarms were activated in the course of the routine work being conducted by grand rapids field technicians. At approximately 17:00, the grand rapids field technicians onsite completed their work, which was not related to any of the flow or pressure devices and left the site unaware that an alarm had been activated at gas control. At approximately 23:40, gas control became concerned they had not received any contact form the grand rapids field technicians since early that morning and contacted an operations supervisor. A second field crew was deployed to georgetown station to investigate, arriving at 00:41 july 22, 2014. At 00:49, the field crew determined the odorant injection system was operating at abnormally high rate and placed the system into standby mode. The field crew contacted the region controls technician who also responded to the georgetown station. The flow computer was reset by the controls technician, the abnormal pressure and flow signals were cleared, and the computer resumed normal operation. At 01:30, the field crew reported to gas control that the odor injection system had been operating at an abnormally high rate over the past several hours. At 05:45, georgetown gate station was isolated from the system in an effort to contain excess odorant from getting into the system. By 08:00, july 23 the event was over and leak complaint volume was back to normal. The abnormal high odorization rate resulted in 610 leak complaints that were responded to and investigated by grand rapids field personnel.
Occurred At 2014-07-21 23:40:00
Year 2014
Report Received Date 2014-08-20 00:00:00
Iyear 2014.0
Report Number 20140068.0
Supplemental Number 16179.0
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 2014-07-21 23:40:00
Location Street Address 1809 Edson
Location City Name Hudsonville
Location County Name Ottawa
Location State Abbreviation MI
Location Postal Code 49426
Location Latitude 42.882085 Google Maps OpenStreetMap
Location Longitude -85.829144 Google Maps OpenStreetMap
Nrc Rpt Datetime 2014-07-23 17:00:00
Nrc Rpt Num 1090032 NRC Report How to search
Unintentional Release 0.0
Fatality Ind No
Fatal 0
Injury Ind No
Injure 0
Ignite Ind No
Explode Ind No
Num Pub Evacuated 0.0
Incident Identified Datetime 2014-07-21 23:40:00
On Site Datetime 2014-07-22 00:41:00
Federal No
Location Type Operator-Controlled Property
Incident Area Type Aboveground
Incident Area Subtype Typical Aboveground Facility Piping Or Appurtenance (E.g. Value Or Regulator Station, Outdoor Meter Set)
Crossing No
Pipe Facility Type Privately Owned
System Part Involved District Regulator/metering Station
Installation Year 1956.0
Material Involved Other
Material Details Flow Computer For Odorant
Release Type Other
Release Type Details Over Odorization At Georgetown Gate Station
Class Location Type Class 3 Location
Est Cost Oper Paid 0.0
Est Cost Prop Damage 69970.0
Est Cost Emergency 5760.0
Est Cost Other 11520.0
Est Cost Other Details Flaring To Dispose Of Gas With Excessive Levels Of Mercaptan
Est Cost Unintentional Release 0.0
Prpty 87250.0
Commercial Affected 0.0
Industrial Affected 0.0
Residences Affected 0.0
Accident Psig 140.0
Normal Psig 140.0
Mop Psig 145.0
Accident Pressure Pressure Did Not Exceed Maop
Scada In Place Ind Yes
Scada Operating Ind Yes
Scada Functional Ind Yes
Scada Detection Ind Yes
Scada Conf Ind Yes
Accident Identifier Scada-Based Information (Such As Alarm(S), Alert(S), Event(S), And/or Volume Or Pack Calculations)
Investigation Status Yes, specify investigation result(s): (select all that apply)
Invest Schedule Ind Yes
Invest No Control Room Ind Yes
Invest Incorrect Action Ind Yes
Invest Maint Ind Yes
Invest Other Ind Yes
Invest Other Ind Details Incorrect Setting Of Flow Rate Alarm;
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
Instrumentation Ind Yes
Other Control Relief Ind Yes
Other Control Relief Details Flow Computer Sensed False High Pressure Reading, Sending An Incorrect Signal To The Odorization Equipment Causing That Device To Activate At An Increased Rate And Resulting In An Elevated Rate Of Mercaptan Injection.
Preparer Name R***** F*********
Preparer Title Manager
Preparer Email F**********@d********.com
Preparer Telephone 313-389-7755
Preparer Fax 313-389-7757
Authorizer Name R***** F*********
Authorizer Title Manager
Authorizer Telephone 313-389-7755
Authorizer Email F**********@d********.com
Narrative Dte gas control received notification at approximately 09:30, july 21, 2014 from grand rapids field technicians that routine maintenance work was being performed at that facility during that day. No alarms or unusual activity were noticed by gas control. At approximately 16:55, an electronic flow computer at georgetown regulating station began sensing false high flow and a false high inlet and outlet pressures. During normal operations, odorant is automatically injected into the grand rapids distribution system based upon volume delivery signals from the flow computer. The false high flow signals from the malfunctioning computer resulted in over-injection of odorant (mercaptan) into the distribution system creating an over-odorized condition. Dte gas control immediately began receiving an alarm for high inlet and outlet pressures. The controller presumed the alarms were activated in the course of the routine work being conducted by grand rapids field technicians. At approximately 17:00, the grand rapids field technicians onsite completed their work, which was not related to any of the flow or pressure devices and left the site unaware that an alarm had been activated at gas control. At approximately 23:40, gas control became concerned they had not received any contact form the grand rapids field technicians since early that morning and contacted an operations supervisor. A second field crew was deployed to georgetown station to investigate, arriving at 00:41 july 22, 2014. At 00:49, the field crew determined the odorant injection system was operating at abnormally high rate and placed the system into standby mode. The field crew contacted the region controls technician who also responded to the georgetown station. The flow computer was reset by the controls technician, the abnormal pressure and flow signals were cleared, and the computer resumed normal operation. At 01:30, the field crew reported to gas control that the odor injection system had been operating at an abnormally high rate over the past several hours. At 05:45, georgetown gate station was isolated from the system in an effort to contain excess odorant from getting into the system. By 08:00, july 23 the event was over and leak complaint volume was back to normal. The abnormal high odorization rate resulted in 610 leak complaints that were responded to and investigated by grand rapids field personnel.

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