Kalispell Line Valve 5 to 6 Loop Natural Gas Pipeline Project

Tag : Natural Gas Valve
The purpose and need for this projectis to increase capacity and supply and to maintain reliable naturalgas service to the Kalispell and Flathead Valley area ofnorthwestern Montana. The integrity of the existing 10-inchdiameter pipeline, constructed in 1962, is good, but NWE projectsthat its capacity will be reached within two years due to thecontinuing strong population growth in the Flathead Valley area.The existing pipeline is the Flathead Valley's only source ofnatural gas. During the past several years, the demand for naturalgas has increased in western Montana as a result of steadypopulation and economic growth. Kalispell, the largest town to beserviced by the proposed pipeline, grew from a population of 11,917in 1990 to 19,432 in 2006.
The proposed action includes construction and the long-termoperation and maintenance of approximately 12 miles of 12-inchdiameter steel pipe from an existing natural gas valve station nearMarias Pass on the Continental Divide westward to another existingvalve station near the junction of Bear Creek and the Middle ForkFlathead River. Approximately 11 miles of the new pipeline would beon National Forest System land and one mile would be on privatelands in the central portion of the project area. The project arealies within the Hungry Horse Ranger District of the FlatheadNational Forest.
The new loop pipeline would be installed underground andgenerally parallel the existing natural gas pipeline that iscurrently authorized under a SUP to NWE. NWE would attempt to buildthe new pipeline as close as feasibly and technically possible tothe existing line, but may have to diverge in some locations due toterrain, BNSF railroad tracks, highway right-of-way (ROW),environmental concerns, other utilities, engineering needs, orother technical factors. A portion of the new pipeline may need tobe constructed in an inventoried roadless area due to a combinationof these factors.
The authorized ROW for the existing pipeline in this area is 50feet wide. The proposed action would require up to an additionaltemporary 50-foot wide working ROW to construct the new pipeline,with a final 50-80 foot total long-term operational ROW. Theproposed action would, wherever possible, utilize the existingcleared, authorized 50 foot ROW to minimize the amount of newvegetation clearing and to combine maintenance access points.Pipeline operations require that the ROW remain free of heavy treecover. Within the ROW, native forbs and shrubs would be maintainedfor the lifespan of the pipeline. Noxious weeds would be monitoredand abated throughout the lifespan of the authorized use. The totalnew area affected for the 11 miles of ROW on National Forest landwould be less than approximately 70 acres.
Underground installation would be conducted to comply withDepartment of Transportation (49 CFR 192.327) and NWE standards.Pipeline burial depths would allow for 42 inches of soil cover innormal soil, 60 inches at stream crossings, and 48 inches nearpublic roads and railroads. Bedrock installations would be coveredto a depth of 30 inches.
Areas of temporary disturbance would include temporary use areasfor equipment and materials staging and construction access routes.Some of these would be on private lands. Native grasses andherbaceous plants would be restored in all areas where grounddisturbance or vegetation removal occurs. Revegetation progresswould be monitored for two growing seasons or until 80% nativecover is achieved.