2015-10-07_REVISION - M2001038 (3)

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Daylighting mud and directional drilling mud delivered to the Site must originate from locations where the source of the material is native or natural materials and only clean water is used in the process. The daylighting mud and directional drilling mud should be included as "other inert solids" in the definition. Both the daylighting and directional drilling mud allowed at the Site have been moved from the subsurface with high pressure water and a pneumatic air induction vacuum. The vacuum places the mixture of subsurface earthen inert material into a containment vessel. The containment vessel is a mixture of the earthen inert material and water. This type of daylighting mud and directional drilling mud will require special handling to separate the water from the earthen inert material and is described in Section 4.16.1. Drilling mud and directional drilling mud that is a specialty mixture designed for a specific drilling application are not considered inert materials and will not be received at the Site. 5.6 MATERIAL PLACEMENT As indicated previously (Section 4.3), the Site will be filled in phases, progressing from north to south. Regular deliveries of imported inert materials will be delivered to the Site and unloaded on level ground near the areas being filled. Imported inert material, will be placed in one lift across the area being filled. Fill material will be placed by pushing material into the excavation from the top of the excavated slope with a front end loader. Compaction will take place during the filling process, as heavy trucks and equipment traverse over the fill. 5.6.1 Daylighting and Directional Drilling Mud Handling Daylighting and directional drilling mud that meets the description of inert materials in Section 4. 10.1 will be placed as follows: An evaporation channel, approximately 400 feet in length, will be constructed with, a drop in elevation of more than 20 feet (50 foot initially), from ground surface to the bottom of the fill area. This evaporation channel will be constructed 40 feet wide, with check dams spaced approximately at 100 foot intervals along the channel length. The elevation difference between each consecutive check dam will be approximately 10 feet. The mud slung will be unloaded at the upper end of the evaporation channel, with solids settling behind the check dams. The average pan evaporation rate for the Site area, during the traditional construction season (April through October) is approximately 6.7 inches per month. This evaporation rate over the 400 -foot evaporation channel, will allow for evaporation of the majority of water derived from the mud slung, prior to the slung reaching the lower end of the channel. If standing water develops in the lower reaches of the evaporation channel, that water will be pumped back to the top of the pan evaporation channel or removed and used on-site for dust suppression. Evaporation channels as described above will be used in all four mine area phases. A diagram of the evaporation channel is shown in Appendix IV attached. Bennett Sand & Gravel Pit#2 Inert Fill Page 15 of 30 MOLEN & ASSOCIATES, LLC August 3, 2015