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<br />approximately 3 acres will be disturbed by mining activities and approximately 6 acres <br />for project facilities. Temporary construction disturbance is estimated at about 1 acre. <br />Hagga foams and Havre foams are located on floodplains, valley floors, and low stream <br />terraces. These soils are deep and poorly drained, with moderate to moderately slow <br />permeability and high available water capacity. Slopes are 0 to 5 percent. The water <br />erosion hazard is slight, and the wind erosion hazard is moderate. Hagga foams have a <br />seasonal high water table at a depth of 12 to 24 inches in spring and early summer and <br />are subject to brief periods of flooding. Additional limitations of the Hagga foams <br />include a moderate concentration of salts and alkali in the surface layer that would <br />require revegetation with salt-tolerant species (SCS 1982). Typical topsoils are 27 inches <br />deep. Havre foams have typical topsoil depths of 21 inches and exhibit no limitations <br />relative to soil salvage and reclamation potential. These soil units comprise 38 acres <br />(about 1 percent) at the Piceance Site, none of which will be disturbed by mining <br />activities or project facilities. <br />I.2 Pipeline Corridor <br />Construction activities for installation of the project pipeline will result in temporary <br />disturbance of approximately 267 acres of soils within the permanent right-of-way of <br />the 44-mile-long pipeline corridor. This total does not include 449 acres of temporary <br />disturbance along the wider construction right-of-way, where herbaceous ground cover <br />would be left in place and soils would not be disturbed. Reclamation and revegetation <br />of the pipeline trench area and any other disturbance along the pipeline corridor will <br />take place immediately following pipeline installation. <br />The proposed pipeline corridor from the Piceance Site south to the Parachute Site <br />crosses a large number of soil mapping units. A brief description of the major soil types <br />that would be disturbed is given below; however, characteristics of all mapping units <br />are included in the tables provided. Likewise, the areas of disturbance for the major soil <br />types are mentioned below, while the areas of disturbance for all mapping units are <br />listed in Table I-6. <br />After the pipeline corridor emerges from the Piceance Site, it enters Hatch Gulch, which <br />contains Barcus channery loamy sand (described above) at the lower end and Glendive <br />fine sandy loam at the upper end. Glendive soils are deep, well-drained foams located <br />along drainageways or on alluvial valley floors. Permeability is moderately rapid, and <br />available water capacity is moderate. Slopes are 2 to 4 percent. The water erosion <br />hazard is slight, and the wind erosion hazard is high. The main limitations for this soil <br />are wind erosion and rare periods of flooding. The main limitations for seeding are low <br />precipitation and droughtiness of the soil (SCS 1982). Furthermore, topsoils are rather <br />shallow at 6 inches. These soils are considered fragile. Temporary disturbance of these <br />two soils for pipeline construction, including the occurrence of Glendive soil mentioned <br />below, is estimated at about 64 acres. <br />I-4 <br />