Venturing into Gas Pipeline Vegetation Management

By Dustin Lauf, Project Manager
Bill Spencer, Senior Consulting Utility Forester
Aaron Goodpasture, Senior Consulting Utility Forester

Recently, CNUC began providing long-term gas pipeline inspection services, which is in an area of vegetation management that, to some, may still be less common than utility line inspections. The program we are now working on is still in the beginning stages and is still developing with aspirations to become a best-in-class program. Our purpose is to assist the program in various ways to ensure a safe and reliable system for our client and their customers.

Finding the talent
Since the gas pipeline program was different from our typical electrical work, we had to determine what skills determined a “qualified applicant” for this line of work. It was unclear what this looked like on paper. We started by modeling our desired employees fairly closely to candidates we select to work on the electric side.

Although tree knowledge is a very important aspect for any inspector, it was also vital to have a person with the right attitude and communication skills for this program. The average client is typically informed when it comes to tree operations as it relates to the electrical side, however, we knew the gas side would become a more delicate process. Having someone with the right skill set to communicate the objectives of the program was imperative. If the inspectors could clearly explain the goals and processes to customers then we knew this would put the client at ease. In addition, any and all ISA certifications were considered when it came to selecting the right person for the job.

Another avenue we explored while searching for experienced candidates were individuals in the gas pipeline industry. With the drilling industry scaling back in Southern California, we had a fair amount of applicants with many years of experience with pipeline inspections. Whether it was oil or high pressure gas lines, it didn’t matter. These individuals had experience locating and working with pipes in a way that only a select few had – giving us an “insider” perspective.

Operational intelligence
After we determined our team, we shifted our focus to what the day-to-day operations would look like. The data team investigated each division and then assigned each inspector a section of line on their tablet. We started out with dual patrols until we were able to get our feet wet. Each inspector was given the appropriate equipment and tools needed – tablet loaded with the gas transmission geographic information system (GTGIS) map, a property layers and assessor’s parcel numbers (APN), and a highly accurate GPS unit that gets within 4 centimeters of the GTGIS layer. Since the inspectors had been given key pieces of information, they were then able to begin foot patrol.

Each inspector patrolled 100 percent of the given section of line and inputted tree information into the inspection record. The supplied patrol standards and flow charts outlining what trees can stay and which cannot, depending on where they fall in comparison to the pipe, was a piece of information given from the utility that was very important to follow. We ran into challenges when the GPS unit was unable to get a clear signal due to heavy overcast or tree canopy and weren’t giving an accurate location of where the pipeline was. In this case, we referred to the supplied field markings (i.e. paint, flags, paddles). These gave us our line of sight and allowed us to continue on the vegetation inspections. Unlike electric which is overhead and viewable, gas pipeline is rarely visible and primarily under ground. Using a range finder or logger’s tape, and our Global Navigation Satellite System (GNSS) receiver to line up the distance between the vegetation and pipeline helped determine if a tree may be obstructing the utility or whether an emergency team need to access to the pipeline. Any vegetation needing removal required an owner’s consent and signature. The biggest difference between electrical and gas work, is being able to physically point out a tree or any vegetation encroaching on electrical overhead lines, whereas the gas property owner must be convinced that there is a pipeline beneath the ground that their tree could possibly be hindering.

Mobile workforce solutions
There are a variety of software options that can be used for this type of inspection. This particular client chose to work with Terra Spectrum Technologies (TST) and their iOS-based software called PlannerVM™. Unlike other “off the shelf” programs, this software is very functional and user-friendly, and can be configured to achieve our program goals. We are using the iOS-based application on our tablets and inputting trees is as easy as sliding a finger across the screen. It uses ESRI-integrated GIS mapping software to locate the pipe. Because certain vegetation requires different prescriptions based on its proximity to the pipe, it is important that we fully utilize the modern geospatial technology available. Trees and vegetation that require work are recorded as “vegpoints” with the latitude and longitude, so they can be easily located by the tree contractors. These vegpoints have all the necessary information such as address, ownership, and any other special equipment needed or comments. In the future, our ultimate goal is to have the tree contractor utilizing the same software platform, which would allow them to see the data we captured on a prior date and execute the prescribed work. This would lead to a more efficient workflow and significant cost savings for our client.

Looking up, looking down and looking toward the future
While there are many differences that make this project unique and challenging, the similarities have helped ease the transition. One of the biggest differences we noticed from an inspection perspective was the fact that you are looking down instead of looking up, and in most cases you can’t actually see the facilities. The program is still very new and most of our client’s customers are not aware of it. This typically requires more explanation during the notification process. Also, a majority of the work to be done requires removing trees rather than trimming them, so all of the work requires a customer signature, further slowing down the process. Beyond that, the program overall has a very similar feel to the electric side – patrol and inspect the utilities, educate and inform the customer, and promote public safety and service reliability.