Located in Glen Mills, Pennsylvania, the Residence at Chadds Ford was in the beginning stages of a construction project to build an assisted living facility. Master Locators arrived at the site to confirm the location and depth of utilities running along the shoulder and middle lanes of a busy highway. The purpose of this utility designation was to prepare the client to perform horizontal drilling across the highway. At the conclusion of this project, we provided the client with an electronic sketch and test hole data sheets.
How We Did It
Master Locators used a few devices, including ground penetrating radar (GPR) and electromagnetic scanning (EM), to locate the private utilities running through the scope of work. We were able to locate communication, water and fiber optic lines. The communication line were located with EM and the water line was verified with a drop box. The only line we were not able to locate was the gas line despite using GPR and a two man sweep.
Prior to Master Locators arriving on site, PA OneCall marked the public utility lines with EM. As part of our standard routine, Master Locators verified the One Call markout using GPR and EM prior to beginning the vacuum excavation work. Because One Call does not always use GPR to locate utilities, Master Locators confirms the location of the lines with GPR. In this situation, One Calls markings were about 3 feet off from Master Locators markings.
After completing the mark outs, Master Locators dug with vacuum excavation and found the lines to be right where our technician marked them. Verifying utilities using more than one method is always a better way to ensure the location of the utility. Master Locators performed test pits along the shoulder and in the right lanes of the highway. This was done to confirm the location and depths of all utilities.
Master Locators used a jackhammer and a core drill to break up the concrete, then used air vacuum excavation to do the test pits. Five test pits were done along the shoulder and five in the right lanes of the highway. After the depth and location of the lines were confirmed, the roadway was restored by hot mix asphalt. The Residence at Chadds Ford required a lot from our service technicians and we were able to locate the private utilities for them to continue construction.