Inspection of buried process piping is different from above ground process piping because significant external deterioration can be caused by corrosive soil conditions and the inspection is much more difficult due to the inaccessibility of the piping. However, as difficult as it may be, buried piping MUST be inspected to determine its external surface condition. The facility has to develop an inspection plan(s) that takes into consideration the effectiveness of the cathodic protection, if any exists, whether the pipe was coated, and on inspection information obtained from one or more of the following methods: