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�.��._..� (i. � � :t�.�:` !f _��t� �'.�_4�� ,.�3 .��it_�.. � Asphalt cement is hard at ambient temperatures and liquid only when heated. It is kept hot at an HMA facility so that is can be mixed with the aggregate to form pavement. Should the asphalt cement spill onto the ground, it will harden because it is no longer being heated. Once completely set, it can be picked up and disposed of. For additional safety, asphalt storage tanks, as well as the facility fuel tanks, are typically housed within a concrete wall to contain spills should they ever occur. -��fik`'��k �� f,',�- I � .._ ,�. i-`�� i'x. {�8•:_�`. �l�t ,i{➢`��. There are several components found at HMA facilities, whether they are a batch or continuous mix plant. Aggregate is separated according to size and fed, usually by a front-end loader, into cold feed bins. These bins are used to meter the virgin aggregate to the dryer. The dryer is used to drive off the surface moisture and heat the aggregate in preparation for mixing with the asphalt cement. Mixing may occur within a variety of devices, depending on the type of facility. Environmental controls include a baghouse, which is typically preceded by a primary collector such as a cyclone or inertial separator. Dust augers return the collected particulate matter to the mixer. Liquid asphalt cement is stored in heated tanks that are connected via piping to the mixer. Finished mix is held in storage silos, which are typically insulated and heated to main product temperature until it is loaded into a haul truck. Mix can often be stored for days before discharge. `.'='C�� r` f�! �� kf �"�`. . I =�. �-:f.�'� •�,'� �'F`�.` No. HMA facilities do not generate industrial wastewater, as water is not required during the production process. Storm water discharge permits and retention ponds may be required in some locations to handle runoff from rainfall. Stack emissions from a faciliry do not contaminate groundwater. --�