Incident details
Operator, cause, commodity and consequences with raw source fields.
GD incident on 2016-08-04 — AL
Operator
Trussville, Utilities Board, City Of
Cause
Locating Issue
Commodity
Natural Gas
Program
GD
Damage and Injuries
0 fatalities
0 injuries
Property damage (nominal)
$128
Incident datetime
2016-08-04 13:42
Report number
Location
AL, JEFFERSON
Narrative
On august 1, 2016 at 1621, we, utilities board city of trussville, were notified by 811 to locate our facilities at 7550 commerce circle, trussville, al 35173 for star construction, a contractor for centurylink, in order for them to excavate a telecommunication line. We located our facilities for the contractor on august 3, 2016. We were notified by the contractor on august 4, 2016 at 1342 that they had hit one of our gas lines at this location and it was on fire. The fire department arrived on the scene at 1347. We arrived on the scene at 1351 to find a gas service line had been hit and was on fire along with the contractor's mini excavator. The fire department protected exposures in the area of the fire while we began to shut down the service line. We pinched the service line off approximately 56 feet from the damaged area to extinguish the fire at 1417. We notified this incident to the alabama public service commission at 1423 and to the national response center at 1446 on august 4, 2016. We talked with the contractor's operator who was excavating the hole and he reported that the gas ignited as soon as the line was hit. He stated that it singed his arm hair, but he was not injured. With the contractor's assistance, we removed the mini excavator's bucket that was still in the approximately 6 1/2 foot long by 3 foot wide excavation to see the extent of the damage. We observed that the bucket had completely severed the 3/4 inch pe gas service line and the 3/4 inch conduit containing electrical wires to the parking lot lights. Also located in the hole were two 3/4 inch pvc sprinkler line with control wires, a 3/4 inch conduit containing electrical wires, and a 2 inch conduit containing telecommunication wires which were not damaged. We measured the distance of the gas service line from locate marks in two locations to determine if the line was located within the tolerance zone of the locate marks. The method we used to determine this was we pulled a tape measure from the locate mark on the parking lot curb next to the excavation and locate mark between the excavation and the road. We pulled another tape 90� off that tape and measured to the center line of the gas service line in two locations. The service line distance at the first location, closest to the parking lot curb, was 23 3/8 inches and the distance at the opposite end of the ditch was 21 inches from the locate mark. From these measurements it was determined that the service line location was not in the tolerance zone of the locate marks. The service line was buried 15 1/2 inches from the top of ground to the top of the service line. After final investigation, it was determined that several further steps in locating and excavation could have been performed to help mitigate the risk of damage to the gas service line: 1. During the locating process instead of inducing a signal to locate the service, a direct connection could have been performed to induce a lower frequency, possibly reducing the chances of interference by the other utilities in the area. 2. The signal could have been " balanced" to verify there was a symmetrical magnetic field for the service line. 3. The contractor could have utilized a non-invasive excavation method to determine the precise location of the gas service line because mechanized equipment was being utilized within the tolerance zone of the locate marks.
Detailed record list
Occurred At
2016-08-04 13:42:00
Year
2016
Report Received Date
2016-08-19 00:00:00
Iyear
2016.0
Report Number
20160072.0
Supplemental Number
16523.0
Report Type
Supplemental Final
Operator Id
19740
Name
Trussville, Utilities Board, City Of
Operator Street Address
127 Main Street
Operator City Name
Trussville
Operator State Abbreviation
AL
Operator Postal Code
35173
Local Datetime
2016-08-04 13:42:00
Location Street Address
7550 Commerce Circle
Location City Name
Trussville
Location County Name
Jefferson
Location State Abbreviation
AL
Location Postal Code
35173
Location Latitude
33.63905
Location Longitude
-86.5687
Nrc Rpt Datetime
2016-08-04 14:46:00
Nrc Rpt Num
1155350
Commodity Released Type
Natural Gas
Unintentional Release
5.3
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Ignite Ind
Yes
Explode Ind
No
Num Pub Evacuated
0.0
Incident Identified Datetime
2016-08-04 13:42:00
On Site Datetime
2016-08-04 13:51:00
Federal
No
Location Type
Private Property
Incident Area Type
Underground
Incident Area Subtype
Exposed Due To Excavation
Depth Of Cover
15.0
Crossing
No
Pipe Facility Type
Other
Pipe Type Other
Public Utility
System Part Involved
Service
Installation Year
2002.0
Pipe Diameter
1.05
Pipe Specification
Astm D2513
Pipe Manufacturer
Driscoplex
Material Involved
Plastic
Plastic Type
Polyethylene (Pe)
Plastic Sdr
11
Material Pe Pipe Code
2406
Release Type
Other
Release Type Details
Completely Severed By Excavator
Class Location Type
Class 2 Location
Est Cost Oper Paid
65817.0
Est Cost Prop Damage
128.0
Est Cost Emergency
2783.0
Est Cost Other
0.0
Est Cost Unintentional Release
73.0
Prpty
68801.0
Commercial Affected
1.0
Industrial Affected
0.0
Residences Affected
0.0
Accident Psig
41.0
Normal Psig
41.0
Mop Psig
60.0
Accident Pressure
Pressure Did Not Exceed Maop
Scada In Place Ind
No
Accident Identifier
Notification From Third Party That Caused The Incident
Investigation Status
No, the facility was not monitored by a controller(s) at the time of the incident
Employee Drug Test Ind
Yes
Num Employees Tested
1
Num Employees Failed
0
Contractor Drug Test Ind
No
Cause
Excavation Damage
Cause Details
Excavation Damage By Third Party
Ex Party Type
Excavation Damage By Third Party
Prior Notification Ind
Yes
One Call System Ind
Yes
Notify Cga Dirt
Yes
Private Row Ind
Yes
Private Subtype
Private Business
Excavator Type
Contractor
Excavator Equipment
Backhoe/trackhoe
Work Performed
Telecommunications
One Call Notified Ind
Yes
One Call Ticket Num
162142492
Locator Type
Utility Owner
Visible Marks
Yes
Service Interruption
Yes
Service Interruption Hours
24.0
Root Cause Category
Locating Issue
Root Cause Type
Facility Not Marked Due To Incomplete Marks At Damage Location
Preparer Name
B**** S****
Preparer Title
Chief Engineer
Preparer Email
B*****@t*********.com
Preparer Telephone
2056553211
Preparer Fax
2056616051
Authorizer Name
B**** S****
Authorizer Title
Chief Engineer
Authorizer Telephone
2056553211
Authorizer Email
B*****@t*********.com
Narrative
On august 1, 2016 at 1621, we, utilities board city of trussville, were notified by 811 to locate our facilities at 7550 commerce circle, trussville, al 35173 for star construction, a contractor for centurylink, in order for them to excavate a telecommunication line. We located our facilities for the contractor on august 3, 2016. We were notified by the contractor on august 4, 2016 at 1342 that they had hit one of our gas lines at this location and it was on fire. The fire department arrived on the scene at 1347. We arrived on the scene at 1351 to find a gas service line had been hit and was on fire along with the contractor's mini excavator. The fire department protected exposures in the area of the fire while we began to shut down the service line. We pinched the service line off approximately 56 feet from the damaged area to extinguish the fire at 1417. We notified this incident to the alabama public service commission at 1423 and to the national response center at 1446 on august 4, 2016. We talked with the contractor's operator who was excavating the hole and he reported that the gas ignited as soon as the line was hit. He stated that it singed his arm hair, but he was not injured. With the contractor's assistance, we removed the mini excavator's bucket that was still in the approximately 6 1/2 foot long by 3 foot wide excavation to see the extent of the damage. We observed that the bucket had completely severed the 3/4 inch pe gas service line and the 3/4 inch conduit containing electrical wires to the parking lot lights. Also located in the hole were two 3/4 inch pvc sprinkler line with control wires, a 3/4 inch conduit containing electrical wires, and a 2 inch conduit containing telecommunication wires which were not damaged. We measured the distance of the gas service line from locate marks in two locations to determine if the line was located within the tolerance zone of the locate marks. The method we used to determine this was we pulled a tape measure from the locate mark on the parking lot curb next to the excavation and locate mark between the excavation and the road. We pulled another tape 90� off that tape and measured to the center line of the gas service line in two locations. The service line distance at the first location, closest to the parking lot curb, was 23 3/8 inches and the distance at the opposite end of the ditch was 21 inches from the locate mark. From these measurements it was determined that the service line location was not in the tolerance zone of the locate marks. The service line was buried 15 1/2 inches from the top of ground to the top of the service line. After final investigation, it was determined that several further steps in locating and excavation could have been performed to help mitigate the risk of damage to the gas service line: 1. During the locating process instead of inducing a signal to locate the service, a direct connection could have been performed to induce a lower frequency, possibly reducing the chances of interference by the other utilities in the area. 2. The signal could have been " balanced" to verify there was a symmetrical magnetic field for the service line. 3. The contractor could have utilized a non-invasive excavation method to determine the precise location of the gas service line because mechanized equipment was being utilized within the tolerance zone of the locate marks.
| Occurred At | 2016-08-04 13:42:00 |
|---|---|
| Year | 2016 |
| Report Received Date | 2016-08-19 00:00:00 |
| Iyear | 2016.0 |
| Report Number | 20160072.0 |
| Supplemental Number | 16523.0 |
| Report Type | Supplemental Final |
| Operator Id | 19740 PHMSA Enforcement |
| Name | Trussville, Utilities Board, City Of |
| Operator Street Address | 127 Main Street |
| Operator City Name | Trussville |
| Operator State Abbreviation | AL |
| Operator Postal Code | 35173 |
| Local Datetime | 2016-08-04 13:42:00 |
| Location Street Address | 7550 Commerce Circle |
| Location City Name | Trussville |
| Location County Name | Jefferson |
| Location State Abbreviation | AL |
| Location Postal Code | 35173 |
| Location Latitude | 33.63905 Google Maps OpenStreetMap |
| Location Longitude | -86.5687 Google Maps OpenStreetMap |
| Nrc Rpt Datetime | 2016-08-04 14:46:00 |
| Nrc Rpt Num | 1155350 NRC Report How to search |
| Commodity Released Type | Natural Gas |
| Unintentional Release | 5.3 |
| Fatality Ind | No |
| Fatal | 0 |
| Injury Ind | No |
| Injure | 0 |
| Ignite Ind | Yes |
| Explode Ind | No |
| Num Pub Evacuated | 0.0 |
| Incident Identified Datetime | 2016-08-04 13:42:00 |
| On Site Datetime | 2016-08-04 13:51:00 |
| Federal | No |
| Location Type | Private Property |
| Incident Area Type | Underground |
| Incident Area Subtype | Exposed Due To Excavation |
| Depth Of Cover | 15.0 |
| Crossing | No |
| Pipe Facility Type | Other |
| Pipe Type Other | Public Utility |
| System Part Involved | Service |
| Installation Year | 2002.0 |
| Pipe Diameter | 1.05 |
| Pipe Specification | Astm D2513 |
| Pipe Manufacturer | Driscoplex |
| Material Involved | Plastic |
| Plastic Type | Polyethylene (Pe) |
| Plastic Sdr | 11 |
| Material Pe Pipe Code | 2406 |
| Release Type | Other |
| Release Type Details | Completely Severed By Excavator |
| Class Location Type | Class 2 Location |
| Est Cost Oper Paid | 65817.0 |
| Est Cost Prop Damage | 128.0 |
| Est Cost Emergency | 2783.0 |
| Est Cost Other | 0.0 |
| Est Cost Unintentional Release | 73.0 |
| Prpty | 68801.0 |
| Commercial Affected | 1.0 |
| Industrial Affected | 0.0 |
| Residences Affected | 0.0 |
| Accident Psig | 41.0 |
| Normal Psig | 41.0 |
| Mop Psig | 60.0 |
| Accident Pressure | Pressure Did Not Exceed Maop |
| Scada In Place Ind | No |
| Accident Identifier | Notification From Third Party That Caused The Incident |
| Investigation Status | No, the facility was not monitored by a controller(s) at the time of the incident |
| Employee Drug Test Ind | Yes |
| Num Employees Tested | 1 |
| Num Employees Failed | 0 |
| Contractor Drug Test Ind | No |
| Cause | Excavation Damage |
| Cause Details | Excavation Damage By Third Party |
| Ex Party Type | Excavation Damage By Third Party |
| Prior Notification Ind | Yes |
| One Call System Ind | Yes |
| Notify Cga Dirt | Yes |
| Private Row Ind | Yes |
| Private Subtype | Private Business |
| Excavator Type | Contractor |
| Excavator Equipment | Backhoe/trackhoe |
| Work Performed | Telecommunications |
| One Call Notified Ind | Yes |
| One Call Ticket Num | 162142492 |
| Locator Type | Utility Owner |
| Visible Marks | Yes |
| Service Interruption | Yes |
| Service Interruption Hours | 24.0 |
| Root Cause Category | Locating Issue |
| Root Cause Type | Facility Not Marked Due To Incomplete Marks At Damage Location |
| Preparer Name | B**** S**** |
| Preparer Title | Chief Engineer |
| Preparer Email | B*****@t*********.com |
| Preparer Telephone | 2056553211 |
| Preparer Fax | 2056616051 |
| Authorizer Name | B**** S**** |
| Authorizer Title | Chief Engineer |
| Authorizer Telephone | 2056553211 |
| Authorizer Email | B*****@t*********.com |
| Narrative | On august 1, 2016 at 1621, we, utilities board city of trussville, were notified by 811 to locate our facilities at 7550 commerce circle, trussville, al 35173 for star construction, a contractor for centurylink, in order for them to excavate a telecommunication line. We located our facilities for the contractor on august 3, 2016. We were notified by the contractor on august 4, 2016 at 1342 that they had hit one of our gas lines at this location and it was on fire. The fire department arrived on the scene at 1347. We arrived on the scene at 1351 to find a gas service line had been hit and was on fire along with the contractor's mini excavator. The fire department protected exposures in the area of the fire while we began to shut down the service line. We pinched the service line off approximately 56 feet from the damaged area to extinguish the fire at 1417. We notified this incident to the alabama public service commission at 1423 and to the national response center at 1446 on august 4, 2016. We talked with the contractor's operator who was excavating the hole and he reported that the gas ignited as soon as the line was hit. He stated that it singed his arm hair, but he was not injured. With the contractor's assistance, we removed the mini excavator's bucket that was still in the approximately 6 1/2 foot long by 3 foot wide excavation to see the extent of the damage. We observed that the bucket had completely severed the 3/4 inch pe gas service line and the 3/4 inch conduit containing electrical wires to the parking lot lights. Also located in the hole were two 3/4 inch pvc sprinkler line with control wires, a 3/4 inch conduit containing electrical wires, and a 2 inch conduit containing telecommunication wires which were not damaged. We measured the distance of the gas service line from locate marks in two locations to determine if the line was located within the tolerance zone of the locate marks. The method we used to determine this was we pulled a tape measure from the locate mark on the parking lot curb next to the excavation and locate mark between the excavation and the road. We pulled another tape 90� off that tape and measured to the center line of the gas service line in two locations. The service line distance at the first location, closest to the parking lot curb, was 23 3/8 inches and the distance at the opposite end of the ditch was 21 inches from the locate mark. From these measurements it was determined that the service line location was not in the tolerance zone of the locate marks. The service line was buried 15 1/2 inches from the top of ground to the top of the service line. After final investigation, it was determined that several further steps in locating and excavation could have been performed to help mitigate the risk of damage to the gas service line: 1. During the locating process instead of inducing a signal to locate the service, a direct connection could have been performed to induce a lower frequency, possibly reducing the chances of interference by the other utilities in the area. 2. The signal could have been " balanced" to verify there was a symmetrical magnetic field for the service line. 3. The contractor could have utilized a non-invasive excavation method to determine the precise location of the gas service line because mechanized equipment was being utilized within the tolerance zone of the locate marks. |
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