REUTERS Natural gas stocks in Ukraine&#39;s underground storage facilities (USFs) have increased by 65.6%, to 14.513 billion cubic meters (bcm) since April 5, when Ukraine started pumping natural gas to refill its reserves. As of July 13, 2019, gas reserves in the country&#39;s USFs were 21.5% up against 11.9 bcm reported on the same date last year. The storages are filled by 46.8%, according to the state-run gas transmission system operator Ukrtransgaz. In particular, 69.62 million cubic meters (mcm) of gas was injected into the storage facilities on July 13 alone. Read alsoEU recognizes Nord Stream 2, TurkStream as "levers of Russia&#39;s pressure": Naftogaz CEO As UNIAN reported earlier, on April 5, 2019, Ukraine started pumping gas into underground storage facilities. 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.