2002-07-03_PERMIT FILE - M2002004

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Exhibit D clinker. This mixture is then ground to a very fine powder in a process known as finish milling. The • product from the finish mill process is portland cement. Most of the portland cement produced at the facility will be shipped out by railcar. Some of the annual production will be shipped out by truck. The portland cement will be shipped to either distribution terminals or directly to customers. SURFACE WATER MANAGEMENT PLAN Surface water will be managed prior to mining, during mining, and after reclamation using several methods and temporary or permanent facilities. Exhibit D-3 provides an overview of the proposed storm water, management facilities. A description of each facility is provided below and additional design details are provided in Appendix F "Surface Water Management Plan." For the purpose of discussion, these methods are divided into ancillary mining, mining, and reclamation activities. Ancillary Mining Activities Ancillary mining activities requiring surface water management facilities include construction of the access road, railroad spur, borrow area, and plant area.. Surface water management facilities have been developed based on the following goals and objectives: Protect critical transportation facilities. Protect plant operation from storm water run-on. Control runoff from disturbed areas. • . Manage process water. Manage domestic wastewater. Protect Critical Transportation Facilities The access road and railroad spur are important to the operation of the cement manufacturing facility and will be protected from major damages during a 100-year flood event. Culverts are provided where the road and railroad crosses an existing arroyo or creates a sump condition with an embankment. Multiple culverts are specified and are designed with low head (that is, headwater-to-depth ratio of 1.5 or less) to minimize erosive velocities at the outlet. This approach also minimizes turbulence in the transitions into and out of the culverts, because the broad, shallow flow of the natural arroyos is mimicked. Each culvert will have either flared-end-sections or saddle headwalls to facilitate transitions. Erosion at the outlet will be minimized by constructing rock-lined, pre-formed scour basins. Locations and details of the culverts are provided in Appendix F. Storm water runoff from the embankments will be collected in ditches located at the base of the embankment and conveyed to the nearest arroyo culvert. The potential for ditch erosion will be controlled by ditch-check structures (that is, shall rock checks or geo-synthetic check dams with heights up to 2 feet). Embankment slopes will be protected from erosion with vegetation. Steeper slopes will use either geotextile wrap or geogrid reinforcement to protect the slope. Protect the Plant Operation From Storm Water Run On Protection of the cement manufacturing area will include the use of diversion ditches and an internal • storm drainage system. 1180-Mine Permit Exhibits (Jul.03.02)FINAL.dOc D-9 July 3, 2002