Routine in-service monthly inspections from the ground. External visual inspections of the tank shell, roof, nozzles, and foundation. Ultrasonic thickness inspections of the tank shell. Internal inspections of the tank bottom, shell, roof structure, nozzles, and components. Onstream inspections of the tank bottom. Inspections of floating roof seal systems. Traditional and advanced nondestructive examinations including visual, infrared, laser measurement, magnetic particle, liquid penetrant, radiography, ultrasonic, guided wave, magnetic flux leakage, eddy current, alternating current field measurement, robotic, vacuum box, leak detection, diesel oil, hydrostatic, hardness testing, metallography, and laboratory testing.