The Job
As part of the Line 2 Decommissioning project for Piedmont Natural Gas (a Duke Energy subsidiary), an existing 12-inch gas main required abandonment in place. The project, located in Pembroke, North Carolina, involved nine different crossings under NCDOT-managed roads and railroad rights-of-way. CJGeo was contracted by Northstar Energy Services Inc. to perform cellular grouting for these segments to meet NCDOT structural requirements for abandoned utilities.
PNG Line 2 Decomissioning
The Challenge
The primary scope involved filling specific portions of the gas line that ran beneath critical transportation infrastructure. Because these segments were located under active roads and rail lines, ensuring a complete fill was essential to prevent future settlement or sinkhole development. Traditionally, long-distance pipe abandonment often requires frequent “daylighting” or the installation of intermediate bulkheads to ensure the material travels the full length of the pipe. These additional excavation points increase costs, extend timelines, and create more surface disruption within the NCDOT right-of-way.
The Solution
CJGeo utilized an NCDOT-approved 30 PCF cellular grout mix (NCDOT Mix 14UNO30ALRCE) to decommission the crossings. The high flowability of the cellular grout allowed the crew to fill entire road crossings from a single injection point without the need for intermediate bulkheads. This approach significantly reduced the time on-site for both CJGeo and the general contractor. Over the course of three shifts, 145 cubic yards of material were placed. All nine pipe segments were filled successfully with no incomplete runs, ensuring a stable and permanent abandonment that met all regulatory standards.
Speak With An Expert
If you need to abandon utility lines under critical infrastructure, cellular grout provides a reliable, high-flow solution that minimizes excavation. CJGeo has extensive experience meeting DOT specifications for pipe abandonment across the Gas T&D market. Contact us today to learn how our specialized materials and pumping capabilities can streamline your next decommissioning project.
