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The sand is removed by undercutting with a front end loader. This causes the wall of sand to collapse with a reverse rotation. Further collapse of the wall produces a slope that is very near the angle of repose. This type of mining ie only allowed where the equipment operator can easily back • away from the collapsing wall. On this site, such a safety outlet is always maintained. The wall always collapses with a reverse rotation, so there is ao chance equipment would be buried by the sand. It never falls outward. The sand is then loadedi~ trucks and hauled to the processing plant. If the safety outlet ie not available then the san~mined in shallow lifts so safety is not compromised. Mining sand in lifts is avoided wherever possible because of its eatra eapense. MATERIAL PROCESSING: Phase 4W contains the processing facilities. Most of the material that goes through the processing plant is mined at this operation. Occasionally, limestone aggregate and "river rock" mined at Castle Concrete's operations (Castle Concrete is a sister company of Transit Mis) is also processed at this location. The processing involves mainly screening and washing with a limited amount of crushing. Eaactly how much processing any particular material receives depends on the nature of the products being produced. The washing process removes undesirable fine particles from the product. These fine particles are settled in a clarifier that utilizes a flocculent to quickly remove the fines from the water. Flocculent is basically a bi-polar soap molecule. In high concentrations, flocculants can have tonic effects on fish living in surface streams, but the low concentrations used in normal clarifier operations are safe. Furthermore, at this site, no discharge to surface streams occurs. The flocculent is EPA approved. The clarifier tank is essentially like a water storage tank. It is about 16 feet high and about • 70 feet in diameter. The tank rests on a concrete pad that is two to three feet thick. Ezhibit E, Reclamation Plan, addresses the reclamation of this pad in detail. The pad will not be removed in the reclamation, but will be buried when the stockpile area is bacld'illed and graded. The sediment, which is essentially very muddy water, is then pumped to the settling ponds. Water in these ponds is allowed to evaporate and seep into the ground. Very little flocculent can be found in the ground seepage because most of it is tied up in the electrostatic and molecular attachment to fine particles washed from the sand and gravel. In time the floceulant degrades into harmless chemicals and the bipolar nature of the molecules is lost. The only danger to water pollution would occur if the sediment basin broke and discharged the sediment and flocculent into a stream channel. However, the fine sediment would be far more hazardous to the stream biota than the flocculent. All sedimentation on this site occurs in closed basins. Discharge to streams is impossible. The distance of the operation from Fountain Creek, the nearest stream channel, further protects the stream. Product is stockpiled adjacent to the processing plant. Distribution, either by Transit Mia or more commonly by the customers, occurs from that stockpile area. A scale and scale house is Located on the southern end of Phase 4W where the customers are billed for the amount of product taken. The stockpile area is in a closed basin. No discharge from this area into any drainages would be possible unless a storm were to occur that would fill this basin (about 25 acres) with water to a depth of over 10 feet. Although not impossible, no such storm has ever occurred in this area in recorded history. • West of Academy Mining Plan Page D-4