Refinery units have two main areas, the inside battery limits (ISBL) and the outside battery limits (OSBL). The ISBL equipment consists of the modular units supplied by PCC. However, a facility requires significant support facilities to the process equipment that are considered the OSBL. These OSBL features include civil work (clear, back-fill and level the site), roads, security fencing, landscaping, concrete foundations, buildings (office, control, shop, etc.), storage tanks, truck loading rack, facility piping, power generation, electrical power distribution, area lighting, fire protection system, compressed air, nitrogen, water treatment, oily water treatment, and wastewater treatment.