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4 D, i FTAI IO A new tire wash station is being constructed at the Forward Landfill which is scheduled for completion by the end of November 2013. The tire wash station will be used to remove mud from trucks exiting the landfill on rainy days or when muddy conditions exist. The tire wash station is located along the main exit road for the landfill as shown on Figure 1. The tire wash station was designed and constructed in general accordance with TC -3 of the California Stormwater BMP Handbook. It consists of a rectangular concrete basin that is 60 -ft long, 11 -ft wide and I -ft deep. Within the concrete basin are a series of six steel plates that measure approximately 10 -ft wide by 6 -ft long by 5 -inch high. The steel plates have a washboard surface as shown on the attached photos. The plates can be removed from the concrete basin to allow cleaning of the plates and the basin. As shown on Figure 1 and in the attached photos, an 8 -inch Schedule 40 PVC pipe and valve are located midway along the length of the tire wash station on the north side to allow drainage of wash water. The pipe exits the concrete basin in an underground trench that is routed under the entrance road to a lined wash water holding pond. The wash water holding pond is semi -circular with an approximately 50 -ft radius, 4 -ft depth with a 1 -ft freeboard. It is constructed on native soils and lined with a geosynthetic clay liner (GCL) and a PVC geomembrane. Wash water will be evaporated in the holding pond or transferred to the site's sedimentation pond in a water truck as needed. The tire wash station removes mud from the tires of trucks by the shaking of the vehicle as it drives across the steel washboard channels. Approximately six full revolutions of the tires occur as the truck drives through the tine wash station. In addition, the concrete basin is filled to an approximate 7 -inch depth with water from a hose that runs from the water well at the entrance/exit gate to the tire wash station. As trucks drive through the tire wash station, water in the concrete basin washes away the mud on the tires. Mud will be cleared from the tire wash station as needed by filling the concrete basin with clean water and opening the valve to the 8 -inch PVC pipe so the water can drain to the wash water holding pond. A water truck with a pressurized hose will also be used to clean the basin. Trucks exiting the landfill will be directed to the tire wash station during and after rain events until muddy conditions no longer occur. A 5 mph speed sign is posted to allow sufficient residence time during the washing process. In addition, a water truck and street sweeper will be utilized to remove any off-site tracking of mud by trucks using the landfill facility.