Agenda - 10-14-1993 - D 1 - Laserfiche WebLink

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will be collected regularly and disposed of away from the site. During periods of high rainfall runoff. any clarified overflow from the sedimentation pond will be discharged to Phil's Creek. No explosives are stored at the site. Materials used in blasting operations are transported to the site on the morning of the day they are to be used and unused materials are returned to the supplier that afternoon. See Section 3.5.7 for more details concerning the use of explosives at the site. Certain hazardous materials are used at the asphalt plant. The largest quantities are asphaltic cement and diesel fuel. Lubricants and solvents are also used but in small quantities. The diesel fuel is stored on site in a 10,000 gallon above ground storage site. The asphalt plant area is sloped so any spill from these tanks would be contained on-site within a spill containment basin The product produced at the asphalt plant is asphaltic concrete. The principle ingredients of asphaltic concrete are dried aggregate (stone) and asphalt cement. The aggregate must be dried to at most 1% moisture content to produce an adequate asphaltic concrete. This is an important step in the process since asphalt cement will not adhere to water. Drying is accomplished in a drying drum that rotates while a large diesel fuel burner provides a flame that dries the aggregate Asphalt cement in its natural state is a highly viscous semi-solid and therefore must be heated to approximately 300°F so it can flow smoothly and mix with the aggregate. Asphaltic cement in its unheated state is a semi-solid odorless material which is black in color. This material Will not present an environmental hazard should a spill occur since the asphaltic cement will turn into a semi-solid once it coots and can be easily recovered. Asphaltic cement is insoluble in water and, since it is a semi-solid, it will not penetrate the ground to contaminate soils or groundwater The cement is stored on site in two 18,000 gallon above ground storage tanks. The tanks are heated by several coils of fuel oil that wrap around the tank. One benefit of the installation of a modern plant will be the lessened fire hazard. The present plant is the only one left in the Nello Teer organization that has an external heating system for the base material. Because it is external to the storage tank, it must achieve very high tempera:'.•es in order to raise the temperature of the stored asphalt enough to make it liquid. The new internal heating system requires temperatures only half as high as the external system and, being fully enclosed, does not present the fire hazard of the old external system. Its lower operating temperature also prevents cooking of the heat-transfer tubes, another fire hazard. Exhaust gasses from the asphalt plant are passed through the baghouse system thereby cleaning 3-22