What will construction of the pipeline consist of and how long will it take?
Construction of the pipeline is expected to take approximately three years and would be conducted in two “spreads”, meaning construction would begin in two different areas. The pipeline would require a 150-foot right-of-way (ROW) during construction, reduced to a 50-foot ROW during operations. To support construction, temporary airstrips, camps, material sites and pipeline storage yards would be used. An existing airstrip near Farewell may be upgraded. The pipeline construction workforce is expected to peak at approximately 650 workers. All pipeline construction infrastructure, with the possible exception of the Farewell airstrip upgrade, would be fully reclaimed once the pipeline is complete, with a cleanup crew immediately following a trench backfill crew to perform reclamation and install erosion control. No new roads will be retained.
Will the pipeline construction or its operation impact wildlife migration patterns or cause other environmental impacts?
The proposed 315-mile long pipeline would be buried, except at two active fault crossings each approximately 1,300 feet long. Buried pipelines reduce visual impacts and are not barriers to wildlife migration. Reclamation immediately following the completion of construction will greatly limit the duration of any impacts. Invasive species management procedures will be used to reduce the risk of introducing non-native species during the construction process. Construction would be timed to protect wetlands and to minimize impacts on subsistence hunting and fishing, as well as recreational activities.
Will the villages get access to fuel from the pipeline?
Under Alaska law, the pipeline will be an “open access” pipeline, which means that other users may apply for access to unused natural gas delivery capacity. Donlin Gold expects to use approximately 50% of the design capacity of the pipeline. A third party may apply to the Alaska Regulatory Commission for authorization to use excess capacity in the pipeline. Donlin Gold does not intend to operate the pipeline other than for its own needs. Donlin Gold has taken initial steps to determine if there is a third party that would be interested in building and operating the pipeline for Donlin Gold. Donlin Gold will make final decisions on how to proceed with the pipeline when it makes a decision to construct the project.
Is the alternative route being studied by the Corps a better option (environmental and economic)?
Donlin Gold initially proposed to route the pipeline through the Dalzell Gorge. After consultation with the Iditarod Trail Committee, the Doyon Corporation, the Knik Tribe, and other stakeholders in the area, Donlin Gold revised its proposal to avoid the Dalzell Gorge. However, the Corps studied the Dalzell Gorge route as an alternative in the DEIS. This alternative route is being considered because it is feasible and allows comparison of environmental impacts to the original pipeline alternative. Approximately 34 miles of this alternative route would be located in the immediate vicinity of, or cross, the Iditarod Trail. As a reminder, the pipeline would be buried underground.
In addition, based on comments on the Draft EIS from agencies and the public expressing concerns about pipeline crossings of the Iditarod National Historic Trail (INHT) in the Happy Valley area, Donlin Gold investigated and proposed an alternative route option that realigns a segment of the natural gas pipeline away from the INHT. The MP 84.8 to 110 North Option alignment would cross to the north of the INHT before the Happy River crossing and remain on the north side of the Happy River Valley before rejoining the proposed alignment near MP-110 where it enters the Three Mile Valley. The North Alignment would be 24.7 miles long, with one crossing of the INHT and only 0.1 mile physically located in the INHT ROW. The average separation distance from the INHT would be 1 mile.
How can you minimize or mitigate impacts with a buried pipeline (i.e., leaks, etc.)? How can you routinely monitor a buried pipeline?
Buried pipelines are continuously monitored remotely from control rooms where technicians are able to understand and respond to what’s happening underground. Sophisticated sensors located along the pipeline route, send information back to the control room. If the system detects something abnormal, technicians are immediately notified and can manage flow and shut down the pipeline if necessary. Best practice protections to mitigate impacts include regular monitoring, inspection and maintenance via helicopter access, cathodic protection and state-of-the-art leak detection. Regular inspections include the use of “smart pigs” which are machines that are placed into and moved through the pipeline and have sensors that can detect corrosion, pipe wall deformation, and other indications of abnormal conditions that require attention. For Donlin Gold’s pipeline, check valves would be located every 20+ miles. Among the advantages of a natural gas pipeline relative to a diesel or petroleum product pipeline are that it operates at ambient temperature (the gas does not have to be kept warm to flow) and in the very unlikely event of a rupture, natural gas rapidly dissipates into the air unlike petroleum products which remain in soil and water until cleaned up. As a result of these differences, a natural gas pipeline requires fewer disturbances to the land because permanent access and spill response materials are not required to be located along the pipeline after it is installed.
Where will the natural gas be sourced from? Who would operate the pipeline?
Natural gas would be transported approximately 315 miles from an existing gas pipeline tie-in near Beluga, Alaska in the Cook Inlet. The natural gas would be purchased on the open market just as local natural gas consumers in the Anchorage area do currently. We are also evaluating the potential in-State resources in Cook Inlet that look promising. Donlin Gold’s parent companies are evaluating using third party owner-operators to build and operate the pipeline. A Request for Expression of Interest (RFEOI) for third-party participation in the natural gas pipeline was issued to potential candidates in 2015. As anticipated, responses came from experienced and responsible bidders.
How would the gas pipeline be reclaimed after the mine closure?
The State of Alaska and BLM have not determined the future of the pipeline after closure. If decommissioning is required, pipes would be purged and cleaned. All above-ground facilities would be removed, including the compressor station, piping, equipment, fencing, river crossing structures and tanks. The underground pipeline would be capped and left in-place. Cleared land would be contoured as necessary to minimize erosion and revegetated.