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1 L_J 3.3.3 Trenching Operations After the working area is prepared, trenching operations will begin. Trenches will be excavated with a backhoe along most of the pipeline corridor. Under some circumstances, awheel-ditcher may be used. The wheel-ditcher can excavate a trench width of approximately 28 inches although width will vary with different types of ditchers or setups. Gentle topography and fine-textured soils might allow use of awheel-ditcher, while a backhoe can be used in almost all soils. Trenches will be open for several days (the estimated average is 5 days) until the pipe is placed and backfilling is completed. The depth of the trench will vary with the conditions encountered. The cover from the top of the pipe to ground level will generally be 36 inches, except in areas where significant rocks exist where this distance may be reduced to 30 inches. Rock that is placed back into the trench will be crushed to a maximum diameter of 5 inches. In some cases, the pipeline trench may be 5 to 10 feet deep, e.g., where the proposed pipeline passes under existing pipelines, roads, or other obstacles. Ramps that can be negotiated by livestock or wildlife will be placed across the trench at intervals not to exceed 1 mile wherever the continuous pipeline trench is not interrupted by a road or pipeline crossing. The excavated trench will be ' inspected every morning for livestock or wildlife that may have fallen in during the night. 1 1 1 Steep, rocky terrain has been identified at four locations: 1) at the upper end of Hatch Gulch, 2) immediately south of the second Piceance Creek crossing, 3) at the northern end of Barnes Ridge, and 4) at Davis Point. In rocky terrain, arock- trencher (also known as a rock-saw or crock-hammer) will be used to minimize environmental disturbance. Backhoe hydraulic rams will assist in rock excavation where rock-trenchers are ineffective. No blasting is planned for excavation of these areas because of the close proximity of the existing ngl pipelines. A possible exception is the section off the east face of Davis Point, which is a steep slope that is not in close proximity to any underground pipelines. • Pipelines and Facilities Crossings: Prior to conducting the centerline survey, crews usually locate buried facilities to avoid damaging them during the construction process. The Yankee Gulch Project pipelines will generally cross beneath other pipelines and other utility lines. A backhoe and hand labor is used to excavate the pipeline trench in such areas to allow passage of the new pipeline under the existing pipelines. Additional TUAs will be necessary for these areas. Affected ROW holders will be contacted prior to construction (see Section 3.1.1). Locations of adjacent pipelines will be confirmed using the ONE CALL system or similar underground utilities location system. This is intended to locate all ~ipeLre Woemavon Survrery 16 YaWue GWch Sodium Mirmrals 14o~ect Amman Soda. L LP.