Provide and install specified oil / water separator vault assembly and sewer piping. Provide Oldcastle Precast 660-SA-550, 550-gallon API style oil water separator base assembly and standard top including oil baffles or approved equal. Connect inlet to existing wash bay outlet pipe, connect outlet to existing 4-inch building sewer line. The existing sewer line is located with white paint on site and is estimated to be 5 feet deep at the tie in location. Contractor shall pothole by method to ensure no damage to existing sewer to determine location and grade of existing sewer. All new piping to be 4” schedule 40 PVC sewer pipe, set at 2% slope, bedded and backfilled in ¾” minus aggregate and compacted in 6-inch lifts. Saw cut existing 8-inch-thick concrete and or asphalt as necessary to install oil / water separator and sewer piping trench lines. Excavate as necessary to provide 6-inch compacted level base of ¾” minus aggregate to set the tank on. Provide all necessary fittings, connectors, cleanouts, tracer wire, and components for a fully operational and compliant system. The top of the tank lid shall be ½” above the high point of existing adjacent concrete surface. Backfill with ¾” minus rock, compact and place 6- inch concrete patch back to connect tank lid to existing adjacent surfaces and patch over trench lines. The excavation work will require a cultural monitor to be present to monitor all excavation. ODOT will provide the monitor. Contractor is required to coordinate the work schedule with ODOT and provide a minimum two weeks’ notice prior to starting work to allow time to schedule the cultural monitor.
