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Permit Amendment — Cemex Sandstone Quarry Cemex Sandstone Quarry Permit M- 1977 -361 Exhibit C - Mining Plan C -1 Introduction The Mining Plan as submitted in the current Cemex Sandstone Quarry Mining and Reclamation Permit (M- 1977 -361) will remain substantially unchanged in this permit amendment. The existing permit was initially approved by the Colorado Mined Land Reclamation Board (Board) in September 1978 after passage of the Colorado Mined Land Reclamation Act (CMLRA). The Sandstone Quarry has been mined since 1969 and has been under Cemex ownership since 2001. The objective of this exhibit is to update the Mining Plan to reflect current conditions and plans for future development. The maps in Exhibit E illustrate the current condition and topography of the property (Figure E -1) and the anticipated end -of -mine topography and post - reclamation topography (Figures E -2 and E -3). C -2 Site Geology The sandstone in the Cemex Sandstone Quarry is a quartzitic sandstone that was formed as part of the Dakota Group during the Cretaceous period of geologic history. The Dakota Group consists of non - marine fluvial deposits generally topped with marginal marine deposits. C -3 Mineral Reserves The site was originally a southeast facing hillside with an approximate 3H: 1V slope. The mining operations of the past several decades have created a pit with a floor elevation of 5,350 feet at the lowest point and an aerial extent of approximately 6 acres (Figure E -1). Over the next 10 years, the current pit boundary will be expanded to the southeast to encompass approximately one more acre and the entire pit will be mined to a depth of 5,350 ft. This additional mining will produce approximately 220,000 tons of additional sandstone over the next decade. The 9.99 acre affected area outlined in the original 1977 permit and TR1 will be not exceeded by these mining operations. C-4 Mining Operations Mining has progressed in horizontal benches proceeding to the southwest into the hillside at a rate of 25,000 — 31,000 tons per year. This process will continue over the next 10 years until the resource is exhausted or the resource is no longer needed for cement production at the Cemex Lyons Cement Plant. The sandstone is blasted out of the hillside using suitable explosive agents drilled into the rock in a pattern appropriate for the quantity of rock needed. The blasted rock is loaded into over - the -road trucks and hauled approximately 2 miles northeast to the crusher at the Dowe Flats Quarry. From there the sandstone is transported another two miles via conveyor to the Cemex Lyons Cement Plant where it is used in the production of various cement products. C -5 Mining Schedule Mining at the Sandstone Quarry is on -going on a limited basis with annual production of 25,000 — 31,000 tons per year. Current mining plans for the Sandstone Quarry and the nearby Dowe Flats Quarry anticipate an end to mining within the next 10 years. Mining will continue at the Sandstone Quarry until the resource is exhausted, the Dowe Flats Quarry no longer needs the resource, or the 10 -year permit period has ended. The red - tailed hawk nest that is currently located adjacent to the pit will be monitored prior to blasting and no blasting will be performed when the nest is active. The general guidelines for nest avoidance are February 15 through July 15, but this will be verified by a wildlife biologist in the field prior to blasting. C -6 Concurrent Reclamation Reclamation activities are described in more detail in Exhibit D. While reclamation will primarily be completed in the five years after mining operations are complete, some concurrent reclamation activities Exhibit C C -1 March 2014