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Exhibit Page 18 Please see Exhibit G, Section G -1. Management of Water During Mining. The operator will manage storm water in accordance with DRMS, CDPHE (WPCD), CDWR, USACE, and landowner requirements. ASSUMPTIONS USED IN MINING PLAN: The mining plan is based on several key assumptions. These assumptions are not intended to imply or claim that certain actions will be done. 1. Annual demand for sand and gravel from this pit is expected to be a max of 70,000 tons or 52,000 cubic yards.5 2. A standard block of approximately 5 acres, (average depth of material mined 10 feet), will yield approximately 93,000 CY (125,000 tons), or roughly twice expected average annual production. 3. Demand and production may vary significantly from year to year, so acreages affected each year may be either larger or smaller than shown in this plan. (Since 2008, private production of sand and gravel from all operations on Hay Camp Mesa have vaned from 70,000 to 100,000 tons per year.) 4. For planning, where annual estimates are needed, use maximum production of 125,000 tons per year and average of 70,000 tons per year.6 5. Based on this assumed maximum /average annual tonnage, and assuming an average gravel deposit 10 feet thick, the life of this pit is between 24 and 96 years (median 48 years), with mining of 2.5 -5 acres each year. 6. Major activities on the site (stripping, mining, stockpiling, etc.) will be done primarily during the summedearly fall period, from July to mid - November. 7. Overburden can range from 10 -20 feet of overburden (primarily clay and 2 " -20" of soil), normally 0 -12 feet, averaging five feet. For planning and estimating purposes, soil averages 3 ". 8. Generally a layer of unusable material (clay and silt) of 1 to 1 -1/2 feet is found between the gravel being mined and the shale bedrock. This outcrops south /downhill of the mining area (obscured by outwash in many places). 9. The water table is not exposed by mining. 10. Based on past mining and construction, in -place material is fairly resistant to erosion but in the long -term must be stabilized. 11. Sand and gravel processing will be done on -site; other plants (ready -mix concrete and hot -mix) may be located for varying times on site for specific projects or general use. These are specifically to be included in the mining plan, and may require further county approvals (and other permits) when actual size /capacity /location is known. Due to lack of water, washing is not expected to be done but is included for planning /permitting purposes. Stripping <200 feet AFFECTED LAND Mining Plant/Work Area Soil placed & seeded (at final grade) Reclaimed & Released 100 ft up to 300 feet 200 -400 feet I Variable average 200 average 300 5 Based on 1.35 tons /CY, for natural dry sand and gravel. 6 This should not be used for permitting calculations for air or water quality or quantities, but is simply a convenience.