Construction of the Trans-Alaska Pipeline System for a fifth, should it become necessary. Holding tanks were planned that had a capacity equal to that of the pipeline, allowing the whole pipeline to be emptied if required. As required by the Pipeline Authorization Act, a ballast-water filtration system had to be designed as well. This system removes oil from tankers' ballast water so it is not released into Prince William Sound—something fishermen feared when the pipeline was proposed. Shortly after the permit was signed, convoys of equipment on snow tractors began heading north, using hardened snow roads and an ice bridge over the Yukon River to reach
Central Asia–Center gas pipeline system pipeline was to start in the second half of 2009. However, the project was mothballed. Central Asia–Center gas pipeline system The Central Asia – Center gas pipeline system is a Gazprom controlled system of natural gas pipelines, which run from Turkmenistan via Uzbekistan and Kazakhstan to Russia. The eastern branch includes the Central Asia - Center (CAC) 1, 2, 4 and 5 pipelines, which start from the south-eastern gas fields of Turkmenistan. The western branch consists of the CAC-3 pipeline and a project to build a new parallel Caspian pipeline. The western branch runs from the Caspian Sea coast of