REUTERS Natural gas stocks in Ukraine&#39;s underground storage facilities (USFs) have increased by 2.5 times, to 21.683 billion cubic meters (bcm) since April 5, when Ukraine started the season of pumping natural gas into storages. As of October 26, 2019, gas reserves in the country&#39;s USFs were 27% up from the figure reported as of October 26, 2018. The USFs are now filled by 70%, according to the state-run gas transmission&nbsp;system operator Ukrtransgaz. In particular, 54.09 million cubic meters (mcm) of gas was injected into the storage facilities on October 26 alone. As UNIAN reported earlier, Ukraine on April 5 started the season of pumping natural gas into its underground storage facilities. Read alsoBrussels to host gas transit talks of Europe, Ukraine, Russia on Oct 28 By the start of the 2018-2019 heating season, Ukraine had accumulated 17.2 bcm of gas in its underground storage facilities, which was a record high natural gas stock over the past six years. UNIAN memo. Ukrtransgaz operates 12 underground gas storages (USFs) with a total storage capacity of about 31 bcm. The USFs are an integral part of Ukraine&#39;s gas supply system and gas transit through its territory. The company is also the operator of trunk gas pipelines carrying gas from Russia to the EU. Ukrtransgaz is wholly owned by NJSC Naftogaz of Ukraine.