Pacific Gas & Electric Company Rio Dell Feeder 352395524 Project

The Project is limited to two borings (Eastern HDD and Western HDD), each of which will facilitate the installation of 1,400 feet of underground conduit for 12kV transmission lines under the Eel River using Horizontal Directional Drilling (HDD) methods. Specialized drilling machines (American Auger DD-330 and DD-200 HDD Rigs) will be used to directionally bore the conduit along a subsurface path. HDD activities will involve the use of Work Areas established to the north and south of the river channel. These areas will require light vegetation mowing; no tree trimming or removal will be required. One working area will contain an entry pit and drilling equipment, while the other working area will contain the exit pit. In this case, two 11-foot by 11-foot bell holes will be excavated, one at each end of the planned underground route. At the entry pit, a steerable drill stem will be used to bore a pilot hole to the exit pit. A drill bit will be advanced, utilizing a bentonite-based drilling fluid with additives, until it reaches the receiving point. From the exit point a reamer will be affixed to the drilling pipe, enlarging the boring as the equipment is reversed for retrieval, concurrently pulling up 16-inch diameter high-density polyethylene casings through the enlarged boring under the Eel River. The bore pits will be filled and compacted after drilling is complete. Cover depth of the drill is anticipated to be a minimum of 50 feet beneath the streambed within the river channel. Materials, equipment, vehicle staging, and storage areas will be established within previously disturbed areas within PG&E’s right-of-way or on private lands. Staging and storage areas will be situated to avoid discharge to the river and riparian area. Worksite access will be established via pre-existing access routes. Equipment required to perform the work includes: a backhoe; and excavator; a primary/pullback HDD rig; a secondary/intersect HDD rig; a 5,000 gallon vacuum truck with at least 400 feet of 4-inch diameter suction hose and sufficient disposal containers; a Vec-loader; a 1,000-gallon vacuum tank with pressure washer; and a mud recycling unit.