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Due to the fact that the pH is being elevated, it was decided to have sulfuric acid available in the event a pH adjustment was needed prior to the effluent discharging from the system. The chemical and equipment for this procedure is housed in the chemical storage building located on the west side of the west cell as shown on Map 32. • This system will be used only if the effluent approaches the pH discharge limitation of 9.0. hi 2006, the sodium hydroxide system was replaced with an electro-coagulation system which achieves the same result through ionization and agglomeration of particulate iron. The treatment ponds and associated surface facilities and systems will be removed and disturbed areas reclaimed when no longer needed for treatment of mine- water discharge. Reclamation plans for this facility aze summarized on page 2.05-105.1. Eastern Mining District - Dewaterin¢ Borehole The EMD dewatering system consists of two primary components: 1) Dewatering borehole and control building, and 2) Treatment facility. The dewatering borehole was drilled to connect into the sump developed off of the 10- Right entry. Please refer to Map 23, Mine Plan, for the location of the sump. Alight-duty road was constructed to the site, beginning at the treatment facility and terminating at the borehole. The beginning 1,600 feet of this road required new construction, while the remainder of the road involved upgrading of an existing ranch road. The location of the access road is shown on Maps 17 and 18. As shown on the maps, the overall length is approximately 4,600 feet. This location of the initial 1,600 feet of the road differs slightly from the original proposal to improve visibility at the road entrance, enhancing safety for road users. During construction of the road, approximately 6,815 CY of topsoil was windrowed to the side of the road. This volume is based on constructing a road 4,600 feet long, 20 feet wide and salvaging topsoil to a depth of 24 inches. The topsoil was stockpiled adjacent to or windrowed to the side of the road. The stockpiled topsoil was seeded with the pastureland seed mixture applied at the appropriate rate: The finished width of the road is approximately 12 feet and it is covered with approximately 9 to 12 inches of 6-inch pit run and 3 to 4 inches of 1'/z-inch road base or crushed rock. Based on use and regulatory definitions, the initial 700 feet of the road is an access road, and the remaining 3,900 feet of road is a light-duty road. Culverts were installed in the small ephemeral drainages along • the road, where needed. The design calculations for these culverts, numbered EMD-1 through EMD-4, aze presented in Exhibit 8A, Culvert Sizing -EMD Dewatering Facility Access Road. While pemutted for installation of a water treatment facility (see the following text), the only facilities currently existing (2006) aze the EMD (10-Right) borehole and associated light-use road. Reclamation will involve culvert removal and ripping, grading, soil replacement, and revegetation of the borehole pad disturbance and road. The dewatering borehole site consists of a 14-inch borehole, drill-pad, pump and control building, powerlines, and discharge line. The control building is approximately 10 x 10 x 10 feet, and sets on a concrete pad 10 x 10 x 0.5 feet. The drill pad was approximately 100 x 200 feet within which two 10 x 10 x 50 foot mud pits were excavated. A 17.5-inch nominal diameter hole was drilled into the sump area. Approximately 1,350 feet of 14-inch metal casing was installed into the boring, and the annular space grouted. A submersible pump capable of pumping 350 gpm was installed in the casing. Also, a transformer was installed at the site to provide the required power for the pump. The transformer azea is fenced with a 7-foot high security chain-link fence around its perimeter. A powerline, approximately 1.5 miles in length, was constructed to tie this location into TCC's power system. Upon completion of drilling, the mud pits were backfilled with the excavated material. To complete the well installation, an 8-foot length of 8-foot diameter corrugated metal pipe with lid was place around the borehole. The material excavated from the 8-foot diameter pit was spread over the pad. The 6-inch riser pipe from the pump exits the 14-inch casing, and a 90-degree elbow and associated valuing aze attached for directing the discharge pipe into the 8-inch HPDE line going to the settling ponds. HDPE pipe is extremely flexible. With a cold bend radius 160 inches, the pipe can be offset 80 inches vertically over a length of 160 inches. This greatly exceeds any potential offset due to surface subsidence. The piping to the ponds is buried •to minimize freezing problems and runs approximately 4,800 feet to the treatment ponds. MR07-216 2.05-77.1 05/28/07