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At the north boundary of the "tertiary exc area" it is appr priate to exercise site-specific discretion and assume the area marked " 3" soil group on th Soils Map should be further down the slope, and out of the permit area. Exhibit C -Pre-Mining & Mining Plan MaQ 5. Closer examination of site conditions has revealed that below the (average) 3-inch root depth of the existing vegetation the surface soil has a significant content of caliche. This, in our opinion warrants our separation of the (average) 3-inch depth of "topsoil" from the underlying relatively inert sub-soil. You may recall the careltaken to isolate topsoil in the demonstration stripping in the southwest quarter of the site du>Jing our on-site inspection with you. This description has been clarified in the enclosed Exhibit I Soils Description. 6. The Initial Mining Phase indeed has four highwalls, three of ~n+hich (east, south & west) are bonded to be permanently back-filled with stripped overburden, topsoiled, and re-vegetated. Although the bond accounts for the entire 3,300 lineal feet ~pf those walls (as it must) in actuality those walls shall be progressively backfilled as overburden is stripped to avoid repetitive handling. The fourth (north) highwall, although intended to be only temporary for the long-range plan, is bonded (as it must be), for slope reduct~on dozing (Exhibit L, Page 26, Item ®). Existing stockpiled overburden is already available fqr part of that effort also. It is impossible to know in advance just how well these overburden reserves will balance, but the guiding principal is to minimize the expensive movement thereof by hauling direct to disposal (whether to backfill or disposal waste). Even in thei(last priority) disposal terrace (or gulch), soils are not disposed of irretrievably, should a need for additional back-filling arise. 7. Being situated on the north slope of the bench, the existing isurface of the footprint of the disposal terrace is primarily talus from the gravelly deposits above, and has no significant rock-free soil. No stripping of the surface is necessary before placing disposal fill. Any temporary stockpile areas in the exc or adjacent areas shall Have the topsoil removed first, except where topsoil is to be stockpiled. 8. Soils, if wasted to the disposal terrace, shall be dozed or dumped from the elevation determined to be the average bottom of the adjacent graved deposits and dozed into the depression. Shaping, grading and topsoiling of the down-slope face shall be delayed until completion of waste operations. 9. The finished slope of the disposal terrace shall be no steeper than 3:1 but may be shallower to make the available material come out even, consisten( with a naturally appearing contoured surface. 10. Surface moisture, if any occurs, is intended to be retained (atad widely disbursed by the flat gradient) on the terrace top for percolation into the soil andj plant growth availability. A small permanent earthen berm shall be incorporated at thg crest for that purpose. If employed the north-facing disposal terrace slope shall be vegetated immediately upon disposal completion to retard runoff and erosion. A straw bale, fabric silt fence, or combination filtration dam shall be employed and maintained in the drainage at the tce of the terrace slope per the required Storm Water Management Plan. 11. Mining shall extend below the sand and gravel deposits to expose the underlying clay, some of which may then be extracted for sale off-site as anther "incidental commodity". Runoff and sedimentation are effectively controlled by the relatively flat grading of the pit floor, prevention of runoff outfall from the new bench, and establishment of a vegetative ground cover, which aids in moisture retention, erosion control, and provides ranch activity grazing. Soil samples are being extracted for analysis and re-vegetation recommendations 2