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project is estimated at 11,150 cy) to one side of the 50 foot pipeline construction corridor; excavation of the <br />pipeline trench using atrack-hoe, with temporary placement of the excavated material on the opposite side of the <br />trench; placement, connection, and bedding of the pipe; backfilling and compaction of the excavated material <br />around the pipe; re-spreading of the soil material; and re-seeding using the standard rangeland seed mixture. <br />Because the soil materials will be replaced immediately after pipeline placement, as construction advances, <br />stabilization measures are not necessary. <br />Where the pipeline crosses under Fish Creek, jacking pits will be excavated adjacent to the creek, while <br />maintaining a minimum 5-foot buffer between the near edge of the pits and the crest of the stream bank, and the <br />pipeline will be bored or jacked under the creek. Protective measures (BMP's) at the crossing location will include <br />placement of stream buffer zone mazkers at any point where the pipeline corridor is within 50 feet of the stream <br />buffer zone prior to any activity; completion of the work during low-flows; placement of silt fence or anchored <br />straw bales at least 50 feet downstream to catch any sediment released prior to initiation of work; placement of <br />sediment control materials (straw wattles or silt fence) azound the entire side and near stream perimeters of the <br />jacking pit disturbance areas; restrictions on storage or transfers of petroleum products within the buffer zone, and <br />reclamation of the affected azeas immediately following completion of pipeline installation. Construction and <br />sediment control details aze shown by the design drawings in Exhibit 490. <br />No. 7 North Escaue Shaft (Section 20, TSN. R86V~ <br />A 1,066 foot escape borehole shaft was constructed into the No. 7 entry of North Mains to allow emergency <br />evacuation of personnel from the development sections of the 9-Right and 10-Right gateroads. The construction of <br />the shaft utilized raise drilling techniques. It is anticipated that the escape shaft will be utilized for approximately <br />ten years. The site is shown on Figure 23, General Location of Escape Shaft. <br />The drilling of the shaft resulted in minimal surface disturbance. A drill pad approximately 200 x 200 feet was <br />constructed at the resulting site in 1,450 CY of cut and fill. Available topsoil was salvaged and stockpiled for <br />future reclamation of the site immediately northeast of the drilled pad. Approximately 18 inches of topsoil derived <br />from Cochetopa Loam is available for salvaging (222 CY). Casing and other drilling supplies were stockpiled on <br />the borehole pad. <br />After topsoil removal, two mud pits 10 x 10 x 7.5 feet were dug adjacent to the drillhole. Drilling fluids and <br />cuttings were discharged into the adjacent pits; allowing settling in one pit, with water decanting into the adjacent <br />pit. Drilling muds were used during the course of drilling the surface collar and pilot hole. <br />The surface collar was approximately 5.0 feet in diameter, and the pilot hole was 11 inches in diameter. The collar <br />was comprised of two components; a surface concrete pad and a liner or casing that extends to bedrock. A concrete <br />centering base is at the bottom of the liner. <br />The concrete pad was poured around the liner and was approximately 14x 10 x 2 feet, however, the liner extends <br />through the pad, reducing the amount of concrete needed to construct the pad. Approximately 8.9 CY of concrete <br />was required to construct the pad. <br />After the collar and liner were in place and the pilot hole was completed, raise-boring methods were used to <br />complete the hole. The hole was reamed to a fmal diameter of 4.33 feet and a 48-inch diameter steel casing was <br />cemented in place from 50 feet below the bottom of Twentymile Sandstone to the top of the concrete centering pad. <br />The remainder of the casing below the cement hangs in the hole. The hole is approximately 1,100 feet in depth. <br />The 4-foot diameter casing extrudes 4 to 6 inches out of the concrete surface pad. A cap to regulate intake air flow <br />was installed. A fence was installed around the drill pad to prevent access by cattle, after completion of the hole. <br />Access was derived from an existing light-use road running up to an old electrical borehole. A series of culverts <br />were placed under the existing road as shown on Figure 23, General Location of Escape Shaft. The design for the <br />culverts can be found in Exhibit 8D, Escape Shaft/Light-Duty Road Culvert Design. TCC constructed an additional <br />25-foot wide road at a 4 percent grade to access the site. The 1,300-foot long road is graveled with 0.5 feet of 6- <br />•inch pit-run gravel. <br />MR07-224 2.05-45.7 10/17/07 <br />