Alaska is vast, with a lot of open ground, but it seems like transportation projects in the state--be it roads, railroads or pipelines--can't help but cross over or under each other while traversing the same natural corridors.
Preliminary plans for the proposed 800-mile North Slope natural gas pipeline south to Cook Inlet show it would cross the trans-Alaska oil pipeline 12 times, the Dalton Highway 22 times, the Parks Highway 12 times, Alaska Railroad tracks four times, and the Elliott and Kenai Spur highways one time each.
And don't forget the natural transportation routes. The line would cross the Nenana River in four locations, just once for the Yukon River. All told, the mid-May 2015 version of the proposed pipeline route includes 446 waterbody crossings. Some are rivers, some are creeks, some smaller than that. Some are much larger, such as almost 30 miles across Cook Inlet.
Over two dozen Alaska LNG team members and contractors met with 60 federal, state and municipal agency personnel this spring in Anchorage to discuss the project's latest revisions to the proposed natural gas pipeline route from the North Slope to Nikiski on the Kenai Peninsula.
Adjusting Pipeline Route
The project teams reported they have made multiple adjustments to the pipeline route since filing the first draft route with the Federal Energy Regulatory Commission (FERC) in February. It's all about finding the best path for the pipeline to move North Slope gas 800 miles across the state to reach the liquefaction plant in Nikiski.
The project is undergoing the engineering and design phase, working toward a late-summer 2016 FERC application. The federal agency regulates LNG plant construction and operations and will prepare the project's environmental impact statement.
While seeking feedback from government regulatory agencies at the all-day session, the Alaska LNG team listed the optimal engineering criteria for pipeline route selection: stable ground, good drainage, and flat or gentle slopes.
"We try to stay on the high ground every place we can," a team leader said.
All the while, the team is aiming for the shortest distance between two points while avoiding--as much as possible--fault lines, wetlands, frost-heave soils, power lines, fiber optic cables, visual impacts, cultural sites and private land.
The pipeline execution team reported they would like to keep the 42-inch, high-pressure gas line at least 200 feet away from the trans-Alaska oil pipeline, particularly to allow gas line construction equipment to maneuver a safe distance from the aboveground oil line. But some pinch points will require closer spacing.
"In many cases, the oil...