Following the successful construction and pre-commissioning completion (including pressure testing, cleaning, drying, filling with nitrogen in order to eliminate any oxygen), Nord Stream has moved to a new milestone by starting the filling of first line with the so-called buffer gas. The fill-in will continue for some four weeks. Before the operation can start in October, the pipeline needs to be filled up with gas to a certain level. This will be the final step in commissioning of the first line, which means that Nord Stream Line 1 is ready to start transporting gas to Europe. After completion of all preparatory works on both ends of the pipeline in Russia and Germany, gas will start flowing through Nord Stream in October 2011.