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Draft EIS out for in-state gas pipeline Alaska Gasline Development Corp. says Alaska Stand Alone Gas Pipeline project out for public comments; Corps holding meetings Kristen Nelson Petroleum News
The U.S. Army Corps of Engineers has published the draft environmental impact statement, or DEIS, for the 737-mile Alaska Stand Alone Gas Pipeline, ASAP, project bringing Alaska North Slope natural gas to Fairbanks and Cook Inlet.
The project sponsor, the Alaska Gasline Development Corp., said the Corps of Engineers will be holding public meetings in 11 Alaska towns; there is a 45-day public comment period. Cooperating agencies are the Alaska Department of Natural Resources’ State Pipeline Coordinator’s Office, the U.S. Coast Guard, the U.S. Department of the Interior’s Bureau of Land Management, Interior’s National Park Service, the U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration and the U.S. Environmental Protection Agency.
The Corps said that in addition to the 24-inch line, there will be 34 miles of 12-diameter lateral pipeline from Dunbar to Fairbanks, a North Slope gas conditioning facility, a straddle and gas off-take facility near Dunbar, a Cook Inlet natural gas liquids extraction plant, one or two compressor stations, three meter stations, 37 mainline valves at intervals not greater than 20 miles, operations and maintenance buildings and construction camps, pipeline yards and material sites.
In addition to facilities covered in the DEIS, the Corps said there would be four aboveground pipelines less than a mile in length connecting the Prudhoe Bay central gas facility to the ASAP gas conditioning facility; those lines would supply natural gas and NGLs and return bi-products.
There would also be processing and distribution of 60 million cubic feet a day of NGLs from the Cook Inlet NGL extraction plant, which could be by pipeline or truck, the fractionation facility and storage and tanker facilities.
Environmental issues Among environmental issues considered in the DEIS are design approaches for the gas pipeline through areas of high seismic activity: placing the pipeline on aboveground sliding supports (such as was done with the trans-Alaska oil pipeline); placing the pipeline in an aboveground berm constructed of low-strength soil; and placing the pipeline in an oversized ditch surrounded by low-strength crushable material or loose granular fill.
Fisheries resources are a concern during construction, the Corps said, and to reduce impacts stream locations known not to have overwintering fish would be constructed in the winter to reduce impacts to fish. Because ice roads across streams can cause ice bridges, damming surface flow and altering fish passage, ice slotting would be implemented after construction before spring break-up to prevent flooding or damming.
While there could be negative impacts to public health during construction, the Corps said those potential impacts were low.
On the up side of public health impacts, assuming a natural gas distribution system is constructed in Fairbanks, the largest public health impact of the project would be during operations — and it would be positive.
Fairbanks is presently a “non-attainment” area for fine particulates, the Corps said. Since natural gas emits fewer pounds of pollutants, particularly fine particulates, than the wood, coal and oil currently used for heating in Fairbanks, substitution of natural gas for heating “would reduce fine particulate emissions in Fairbanks substantially, particularly in winter months when heaters are used extensively and air inversions are frequent.”
The Corps said potential public health benefits in Fairbanks would be “substantial,” and also noted that since natural gas supplied by a pipeline is less expensive than other fuels, “there would be positive economic benefits as well.”
The high cost of fuel in Interior Alaska is one issue a pipeline from the North Slope is intended to address.
Reliability expected to be good As far as reliability, the Corps noted that the number of significant incidents occurring in more than 300,000 miles of natural gas transmission lines nationally “indicates the risk is low for an incident at any given location,” and concludes operation of the proposed ASAP project “would represent only a slight increase in risk to be nearby public.”
If there were a pipeline rupture, the leak detection system would close isolation valves. The Corps said a release would be almost entirely NGL vapor and while an accidental spill of NGLs from a pipeline rupture could include fire and/or explosion of NGL vapors, potential spill impacts are likely to be “short-term and low magnitude due to the volatility of NGL components.”
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