2022-05-10_GENERAL DOCUMENTS - M1993041

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Dowe Flats Quarry Soils and Geology Report the NRCS, the reclamation plan was developed for the best use of perennial vegetation cover to be used for livestock grazing and/or wildlife habitat. During mining, the suitable growth media (A horizon and some of the upper B horizon) have been salvaged and stockpiled and the growth media stockpiles have been temporarily revegetated until used to prevent loss from wind and water erosion. No areas outside of the original mining boundary will be disturbed, as a result of the activities proposed in this permit extension application and growth media stripped in the future will be stockpiled and stabilized, as before. There is sufficient growth media currently stockpiled to reclaim all currently disturbed areas per the currently approved reclamation plan. 2.3 Soil Impacts and Mitigation The pre-mining land use at Dowe Flats area was largely agricultural, either under cultivation, or having previously been plowed and planted to European or Asian forage species for livestock grazing. The only native grassland was along the HiCal Ridge on the west side of the mining area. According to the NRCS at the time of the original permit application, the historical agricultural land uses were not recommended for these soils due to erosion hazard and slow permeability, rather the highest use of these soils was native perennial vegetation for support of livestock grazing, or wildlife habitat, or both. They further found that the soils on the Dowe Flats property had suffered degradation of surface horizon thickness as a consequence of being cultivated. While the pre-mining soil profiles were lost during salvage, stockpiling, and replacement, the areas that have been reclaimed to date have developed a vegetation cover that should allow soil development to proceed beyond what it was able to reach with the pre-mining agricultural use. To date, CEMEX, Inc. has reclaimed over 158 acres of previously disturbed areas on the Dowe Flats property. For the past 10 years, CEMEX, Inc. has conducted annual vegetation monitoring of these areas. Quantitative vegetation cover and species diversity data collected on the reclaimed areas have been compared to an undisturbed reference vegetation community just west of the Dowe Flats property boundary. In 2021, total vegetation cover on the reclaimed areas averaged 55.6% compared in 50% on the reference area. Desirable species cover (native species as well as cultivated species commonly used in improved pasture plantings) on the reclaimed areas was 50.3% compared to only 36%on the reference. A total of 46 species (33 desirable and 13 undesirable) were observed along the transects in the reclaimed areas. This compared well to 44 species (32 desirable and 12 undesirable) on the reference area. The reclamation effort has been successful and, as a result, this diverse reclaimed grassland community is already providing wildlife habitat for the deer and elk regularly observed on the property. 3 Geology In 1985, a study was completed by Fox Consultants that provided a detailed summary of the geologic setting of the Dowe Flats area. This report addressed regional and local bedrock stratigraphy and structural geology and was used for the planning and execution of subsurface explorations and engineering investigations prior to mining. More details of that report can be found in the original Dowe Flats application prepared by SHB AGRA in 1993. 3 May 2, 2022