Northern Sakhalin has several onshore oil and gas fields developed by the Russian company Rosneft-Sakhalinmorneftegaz (SMNG) since the 1920's. Oil leaks/spills are common here due to the obsolete equipment, primitive drilling technologies and corroded oil pipelines. Two of the oldest oil fields are Katangly and Okhinskiy that still operates as it did about 75 years ago. These onshore Soviet-era oil companies cause massive pollution and environmental damage.