Pipeline transport in order to avoid melting the frozen ground by hot petroleum which would result in sinking the pipeline in the ground. Maintenance of pipelines includes checking cathodic protection levels for the proper range, surveillance for construction, erosion, or leaks by foot, land vehicle, boat, or air, and running cleaning pigs, when there is anything carried in the pipeline that is corrosive. US pipeline maintenance rules are covered in Code of Federal Regulations(CFR) sections, 49 CFR 192 for natural gas pipelines, and 49 CFR 195 for petroleum liquid pipelines. In the US, onshore and offshore pipelines used to transport oil and
Construction of the Trans-Alaska Pipeline System cost $1.4 billion. The percentage of the pipeline owned by various companies has changed over time, but as of 2009, the primary owner was BP, which controls 46.93 percent of the pipeline. Second is ConocoPhillips Transportation Alaska Inc. with 28.29 percent, followed in order by ExxonMobil (20.34 percent), Koch Alaska Pipeline Company (3.08 percent), and Unocal Pipeline Company (1.36 percent). The pipeline also has had a human toll. Thirty-two Alyeska or contract workers were killed during the construction project. That figure does not include common carrier fatalities. Since the pipeline began operating in 1977, 10 people have been killed while