A Locating Case Study: Trash to Treasures
Our team at Trinity often deals with sites that have seen a lot of changes. In this case study, we’ll take a look at the first quarter of an ongoing two-day utility locating job, focusing around site investigations and radio detection. Our client is planning to perform excavation work primarily around existing well, electric and sanitary sewer utilities. The site was once a junkyard, full of glass bottles and broken goods, but is now home to a surplus store that auctions used excess government property for resale, auction and reuse.
The day started by meeting up with our technicians, locating lead James Dukenfield and assistant Justin Ross. When I got to the site, they were just getting set up to start the locating process. There were previous marks already on the ground from previous markouts done by another locating team. When faded marks are found on the ground, they can be used as a starting point for further investigations.
The front of the site consisted of electrical power lines along the nearby highway along with a seemingly disconnected pole towards the front of the building. We walked around the site, consisting of a newer building, a fence surrounding the back, and a very large, open yard once used for junk. In the open field around the building sat a well surrounded by yellow bollards near another nearby well. The abandoned well between the bollards had faced issues in the past, leading to a new well being installed a few feet away. There were also eight electric charging stations attached to the building that were a focus. The extent of the job seemed to go outside of the limit of disturbance listed on the plans, but we quickly found out from the site contact where most of the work was occurring. The client we’re performing the work for is looking to install an entrance into the existing fenced area, with the large open field once used to hold junk becoming the home for a warehouse in the future (pictured below). With all of this in mind, our team went to work.
I started with Justin, locating electrical lines in the front side of the building. He brought up that utilities often go outside of the scope of work, and with lines stretching down the front portion of the road, making sure there weren’t any unknown connections from this line into the property was an important step. “You have to investigate all of the features outside of the scope of work, because they could always come in. Some of the utilities never enter the scope, but you have to cancel that out,” James mentions. One of the connections was to a box near the main driveway, which was found to connect through the parking lot to the building’s electrical room inside later in the investigation process. From there we went to the back to meet with James to discuss the well situation.
The new well was made of a plastic material that would be much harder to locate using standard radio detection. With unfavorable GPR scanning conditions due to rain the previous night causing wet soil, the closest bet to locating this well line would be on the second day of locating after the rain has passed. The biggest concern was not damaging the well line, however. The electric lines powering the well were the biggest danger, potentially causing electrocution if struck. Using a radio transmitter connection to the abandoned well’s electric line, we found that the old well’s electrical lines were tied into the new well, connecting it to the building’s power. Alongside this, Justin was able to locate where the EV charging station lines connected to each of the chargers.
Next was a sanitary sewer line directly behind the building. James put on a pair of puncture resistant gloves, opened a manhole, and used a duct rod and a RD8200 electromagnetic locator to determine the direction of three sanitary sewer cleanouts. Based on previous marks, these lines were expected to keep going straight and turn 90 degrees into an underground storage tank. However, we found that this line went into the tank on an angle between the EV charging stations. A similar situation was found in the opposite direction: the plans and the previous marks showed this line turning 90 degrees directly into the third cleanout between two air conditioning units. Only a couple feet deep at most, the original marking showed the line traveling under a bollard (pictured below).
The final investigations for this portion of the project focused around unknown lines around the building. We went inside to study the layout of the building’s utility feeds, confirming the electrical room and bathroom mentioned earlier. Behind the current building once stood two other buildings to support the original junkyard’s operations, confirmed by the building staff. In this area, James and Justin were able to find additional electric lines that required further investigations. There’s also the seemingly disconnected pole mentioned earlier. Hooking up to this pole revealed a line that traveled around the backside of the building and potentially leading towards the road.
These lines were marked as unknown for now, until ground penetrating radar scans could be completed during further investigations. James and Justin brought up locating efforts expected throughout the rest of the project: Creating drafts of plans in the event of expected storms, further investigations into the source of the unknown GPR scans, two-man sweeps, and a perimeter scan of the site to ensure no other unexpected utilities are entering the property. If you’re in need of utility locating services, our team at Trinity Subsurface can investigate using a number of methods. Check out our website to find out about all of the services we offer to support your construction and utility projects.
