Laserfiche WebLink
(d) Thickness of Deposit: The marble to be quarried is approximately 300 feet thick <br /> (true perpendicular thickness) in the vicinity of the affected area. The marble seam dips to the <br /> west at approximately 53 degrees with a strike of approximately North 26 degrees West. <br /> (e) Minin¢Operation Components: The primary components of the operation within <br /> the affected area consist of the existing quarry portal entry driven by CYMC in 1990, three large <br /> historic quarry entries from earlier operations, a quarry water discharge system, access roads, <br /> marble waste piles, and a sediment control structure. There also exists a 10,000 gallon diesel <br /> fuel tank and a semi-trailer mounted diesel-electric generator on the site. No significant <br /> additions to facilities or roadways are envisioned for Sierra's operations. All of these <br /> components are shown on Exhibit E: Mining Plan Map. <br /> I <br /> During the spring runoff period, excess water seeps and drains into the quarry from <br /> cracks in the marble formation. This water is of high quality and is pumped out of the quarry <br /> during the spring runoff season at a rate that has never exceeded 100 gallons per minute <br /> (according to CYMC discharge records filed with the state). Water is stored underground in <br /> settling ponds and is used in the stone cutting operations for dust control and cooling. Excess <br /> water is pumped to a point just south of the south quarry entry. The water is allowed to flow into <br /> the marble waste pile where some natural filtration occurs. It follows the topography to a <br /> sediment control structure at the toe of the waste pile. The water eventually drains into Yule <br /> Creek below this area. Pumping volumes will not exceed 100 gallons per minute. <br /> Sierra plans to allow public access to the quarry entries during operations, when such <br /> access will not endanger quarry personnel or the public, and if the access trail is open to the <br /> public. Sierra will take appropriate measures to protect both quarry personnel and the public. <br /> Such measures will include fencing around the active waste dump areas, temporary or permanent <br /> fences in the quarry entries, and warning signs and fences to discourage public access to unsafe <br /> areas. <br /> (f) Surface Disturbance: The area disturbed from past operations within the affected <br /> area is estimated at approximately 4.0 acres. This area includes the existing waste piles, the <br /> entries, and the access road to the south of Entry No. 3 leading to the area directly to the east of <br /> the No. 5 Prospect Tunnel. For an operation lasting 20 years at an average envisioned <br /> production rate of 10,000 tons per year, approximately 200,000 cubic yards of waste rock will be <br /> generated and added to the waste piles. The surface area added to the existing waste piles is <br /> estimated at approximately three acres (assuming an average depth of 40 feet). The approximate <br /> final limits of the waste piles is shown on Exhibit E: Reclamation Plan Map. <br /> (g) Roads: There are no improvements or new roads envisioned for access to the <br /> affected area. Access is via 3 miles of public road from the Town of Marble, then via 1800 feet <br /> of private road on Sierra controlled private property to the northern edge of the affected area. <br /> Access roads on site already exist from prior operations. These roads lie exclusively on the <br /> 16 <br />