SCE brings in vegetation management professionals and apprentices to help following the largest fire in the utility's history.
About 40 miles of distribution line and 900 utility poles went up in flames in one of California's largest wildfires. Four primary lines were either damaged or destroyed in the Station Fire of 2009, which burned nearly 161,000 acres.
Power lines, trees and homes were incinerated in the fire, which knocked out power to customers in the remote mountainous regions. For the last five months, Southern California Edison (SCE) has been devising and putting into action a plan to rebuild the distribution line and restore power.
Before it could move crews into the damaged area to begin restoration work, SCE had to receive clearance from the local jurisdiction, such as the fire department and forestry agencies. The utility worked with the local agencies to send in ground crews to perform a damage assessment. SCE team members evaluated the material needs and extent of the damage.
In addition, they looked at the utility's inventory maps to determine what was once there. The challenge with a fire of this magnitude is that a visual inspection is not often an accurate depiction of what the power system used to look like. Oftentimes, the crews could not even tell where the pole line was because it was literally incinerated, and they could not tell where the service lines came through because the houses had been destroyed so badly.
SCE relied on an aerial patrol because it was impossible to access all the damaged areas on foot. However, the helicopters were not allowed to fly in the burn-zone area because the pilots did not know what was happening over the next hill. This delayed the damage assessment.
When the local jurisdiction lifted certain restrictions, SCE crews began to assess what kind of workforce was needed to coordinate the restoration effort. The terrain and how to approach the work all played into how the utility determined the amount of resources necessary for the restoration.
Crews laid out a strategic plan of how to do the restoration. The utility first sent environmental cleanup and general cleanup crews to remove all of the damaged facilities, burnt poles and incinerated transformers.
The utility then performed survey work to determine the proper locations of the poles. The crews each had a specific function in the restricted areas. For that reason, the utility set up temporary bases to store material and to hold morning briefings with crews. SCE also appointed supervisors and coordinators to work on site to identify how the project would be staged and which sections would be built at what time.
With the large number of crews SCE brought in for the restoration effort, the utility had to take care of lodging needs. SCE brought in resources from outside the area to provide the linemen shelter and meals.
In addition, SCE provided the gear and equipment crews needed to work safely. Since safety is SCE's No. 1 priority, the utility had safety specialists on site to work with the crews during the restoration project.
Another important part of the project was vegetation management. Because the mountains were covered with tall trees, SCE wanted to prevent damaged trees from falling on the new power lines. In addition, the utility needed to clear away incinerated tree limbs and remnants of vegetation in the path of the new line.
To accomplish its vegetation management goals, SCE's in-house vegetation managers partnered with the local forestry department. The local governing agency and forestry department visited the area to assess the line route and determine what vegetation needed to be trimmed or cut in concert with the restoration effort.
Many trees had been damaged or had fallen, so vegetation management workers went through the line section by section and pole by pole. They marked the trees that needed to be trimmed. That way when the linemen restore the line, the damaged trees will not damage the new system or cause any power interruptions.
Working directly with tree-trimming contractors from Asplundh, SCE's vegetation management supervisors oversaw and directed the tree-trimming crews.
Training Support Personnel
After SCE conducted an extensive damage assessment and considered all the vegetation management concerns, the utility trained the crews who were going to enter the damaged area and conduct the restoration effort, which continues today.
Because many of the fire-stricken areas are national forestry areas that are preserved, the linemen have to follow environmental protection protocols when working in the natural environment. For example, they have to be careful when working around the habitat for local wildlife and take care when navigating the mountainous terrain.
Because they cannot walk or drive to certain areas, all the linemen received helicopter support training. During this training, they learned how to get on and off a helicopter. They also needed extensive training on how to dress and prepare for the restoration effort by wearing the proper protective gear.
In addition, the linemen attended sensitivity training in order to be sensitive to the environment as well as the people they would encounter along the way. Many Californians lost all they owned when their homes were burned in the wildfire, so SCE trained the linemen to be sensitive to their emotions and needs during the restoration effort.
Accessing Remote Terrain
One major challenge crews have faced during this effort is accessing the charred line. The mountainous area has several canyon-type access roads. As such, a lot of hiking is required to get into the area, and some of the mountainous area is only accessible by helicopter. The crews have to be flown into work locations and then hike a far distance to where the poles were once located.
Because the linemen often rely on helicopters to transport them to the work site, they sometimes have to contend with changing weather. The weather has to be of such a nature that the helicopters can support operations, and the majority of the restoration has been dependent on helicopter support.
In the winter months, the weather can be unpredictable, and ice, wind, snow and rain are common in the mountainous region. In addition, many of the linemen are not used to working in this remote territory, so that has been a challenge.
When the crews are fortunate enough to have suitable weather conditions, they can proceed with the line restoration. The crews do the best they can to install the poles and lines in their original locations.
Many sections of the line were built 50 or 60 years ago, and because of the erosion of the terrain, it is impossible to put a crew member in the former pole location safely. In these situations, SCE investigates the safest alternative and slightly reroutes the line. However, before installing a pole in a new location, SCE makes sure the pole placement is not causing any environmental concerns in the Angeles National Forest.
SCE also evaluates each area to determine whether to install traditional wood or lightweight steel poles. The decision on which pole to install depends on the terrain and the critical nature of the circuit it feeds. In areas with thick vegetation that are remote and at a high elevation, the linemen are replacing the burnt wood poles with steel poles, which may be more heat resistant to fast-moving fires in the future.
The field crews are also installing these steel poles in areas where they are a primary source feed to critical locations. For the majority of the line, however, the linemen are installing new wood poles to replace the burnt poles.
SCE has already replaced the first section of the line. Because everything was de-energized, it gave the utility an opportunity to give the apprentice linemen exposure to old-fashioned line work. The apprentices were able to set poles, string wire and basically rebuild a line from scratch.
At SCE, young apprentices are not allowed to work on energized conductors, but because the line was not live, they were able to gain experience with pole construction, rigging, deadending, securing conductors and working with helicopters. To give all of its new workers as much knowledge and hands-on training as possible, SCE rotated all of the apprentices through this first phase of the restoration effort.
As of February 2010, SCE was still working on the restoration effort, and it is difficult to forecast when the project will be complete because of changing weather conditions. If the weather cooperates, crews should be able to stay on schedule, but any adverse weather will deter the daily restoration efforts.
At this point, the utility is focusing on restoring power to customers in areas with the most dense population. Most of the customers who live in the remote regions have their own generation and do not depend on the grid. However, it is necessary for SCE to restore power to the customers in the outlying areas who do rely on the utility to supply their electricity.
Because of the significant amount of resources required, SCE is using contractors for the remaining restoration effort. Much of the design and bidding process is now complete, and the restoration efforts on the line are ongoing.
After extensive damage assessment, cleanup and vegetation management, the field crews are now working on rebuilding and repairing the line. Only time will tell, but SCE hopes to never face a fire of this magnitude again. If the utility is hit with another wildfire, however, it can learn from its best practices implemented during the Station Fire.
Gary Shockley (firstname.lastname@example.org) is the district manager of the Monrovia Service Center for Southern California Edison in Monrovia, California. He has been with the utility for 25 years.
Asplundh Tree Expert Co. www.asplundh.com
Companies mentioned in this article:
Southern California Edison www.sce.com