Summary: In response to a congressional request, GAO examined the Department of Transportation's (DOT) Office of Pipeline Safety's development of the inspection cycle for natural gas and hazardous liquid pipelines, focusing on whether the: (1) office based the pipeline inspection cycle on sound risk assessments; and (2) Pipeline Inspection Priority Program (PIPP) would identify pipelines with the greatest potential safety risks.
GAO found that: (1) in 1987, the office determined that it should inspect each pipeline inspection unit every 2.5 years; (2) although the office believed that the 2.5-year cycle was reasonable, it did not consider variations in relative safety conditions among individual units; (3) regional chiefs believed that the cycle was too ambitious because of the time required to perform other important compliance activities; and (4) the office expected its field inspectors to conduct 32 investigations per year at an average of 2.5 days per inspection, while field chiefs believed that inspectors needed between 2.5 and 7.5 days to complete an inspection. GAO also found that: (1) the office developed PIPP to identify the relative risk of pipeline companies and units on the basis of weighted safety factors; (2) the office could not ensure the reliability of program data, since it did not provide sufficient training on how to access the computer system or how to assign unit inspection priority codes; (3) pipeline inspectors had no consistent guidance on how to assign unit safety risk priority codes; and (4) the office did not plan to use program data to evaluate its inspection cycle or staffing level.