24” Gas Line Project

Energy Land & Infrastructure, LLC (ELI) worked with the Operator to route, design, and install almost 49,000 linear feet of 24-inch transmission pressure pipeline and an Over-Pressure Protection (OPP) Station across several counties in North Carolina. The new pipeline was installed to supply an existing steam fired power plant with natural gas to serve as an alternate fuel source during the production of electricity.

ELI staff was given a general route for the proposed pipeline in the project proposal. Desktop evaluations coupled with pedestrian field surveys were completed to come up with the final routing of the new pipeline.  Challenges to the routing included topography, residential and commercial developments, landowner resistance to grant of easements and a 3000+ foot lake crossing. The team worked with the stakeholders to understand the constraints and agree on an alignment to move forward into design. During this time, a desktop review of streams and wetlands, threatened and endangered species, cultural resources, potential hazardous materials sites, public lands, and recreational sites was prepared. A list of proposed project permits, and agency coordination was included in the desktop review.

Once the route was determined, ELI staff continued the planning process with field survey and design. The design included the OPP station, located immediately downstream of the Supplier’s delivery station, a 24-inch skid mounted pig launcher and pig receiver at either end of the pipeline, and one fully automated main line valve assembly at the midpoint. AC Mitigation design was required to protect the pipeline from electrical faults since the pipeline alignment follows an existing high-voltage power line corridor.

The project included three horizontal directional drills, two of which exceeded 3,000 feet in length. The longest drill, measuring feet close to 3,820 linear feet, crossed an existing man-made lake and the elevation difference from the drill entry/exit points to the bottom of the drill path measured 240 vertical feet.  Most of the drill was through solid rock and was successfully completed without incident. The project also included a crossing of several rail spur tracks that was executed by removing the spur tracks to allow for an open trench pipeline crossing and replacing the tracks and railbed after backfilling the trench.