2009-10-16_PERMIT FILE - M2009082 (12)

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a pit run material, or it can be a combination of coarse and fine aggregates, with or without mineral filler. The binder material used is normally asphalt cement but can also be an asphalt emulsion or one of a variety of modified materials. Various additives, including liquid and powdered materials, can also be incorporated into the mixture. Activities at these sites may include the following: raw material unloading into stockpiles or storage tanks, raw material feed to plant, material hatching, raw material storage area, recyclable asphalt disposal area, truck wash out, and water supply and settling lakes. ? READY MIXED CONCRETE, CENTRAL BATCHING These operations mix sand, gravel, cement, and water together to form ready mix concrete, which is then hauled to off-site construction projects. The raw materials are made up of sand, gravel, cement, water and additives. The sand and gravel is either stored in stockpiles located outside and fed into the plant via loaders and conveyors, or it is stored directly in a series of hoppers located directly above the central plant. The remainder of the raw materials is stored in tanks to protect them from exposure to moisture and temperature until they are pumped into the mixer. Once the raw materials are fed into the central mixer and combined to form Ready Mix concrete, the final product is placed within trucks and removed from the site. ? READY MIXED CONCRETE, DRY BATCHING These operations apportion out a mix of sand, gravel, cement, and water together, which is then mixed within the truck to form Ready Mixed concrete that is hauled to off-site construction projects. The raw materials are made up of sand, gravel, cement, water and additives. The sand and gravel is either stored in stockpiles located outside and fed into the plant via loaders and conveyors, or it is stored directly in a series of hoppers located directly above the central plant. The remainder of the raw materials is stored in tanks to protect them from exposure to moisture and temperature until they are pumped into the mixer. Dry hatching then apportions out and dumps the raw materials into the concrete truck-mounted mixer where it is continually agitated and mixed to keep it from hardening before it arrives on the assigned job site. ¦ EQUIPMENT FUELING Diesel and/or gasoline tanks may be located on site for fueling of equipment, or equipment may be wet-lined as needed. Off-site vendors refill tanks as needed. ? EQUIPMENT MAINTENANCE The site contains a shop area where necessary maintenance can be conducted for site equipment. Typical chemicals associated with maintenance, such as used oil, antifreeze, motor oil, hydraulic oil, brake fluid, etc, may be stored on site as needed. All chemicals are stored in such a manner as to prevent materials from mixing with stormwater or being accidentally discharged off site or to waters of the U.S. Parsons Mine Storm Water Management Plan Page 5 of 19