 The western line had not been smart-pigged since 1998 and an eastern section of pipe had not been tested since 1992.Instead, BP relied on imprecise spot checks of the line using methods such as ultrasound testing.On August 7, BP announced data from a smart pig run completed in late July revealed severe corrosion and 16 anomalies in 12 locations in an oil transit line on the eastern side of the oil field.