A badly corroded pipeline around the northern Russian town of Usinsk had been leaking for eight months, contained by a dike erected around the leak site. Severe weather conditions caused this dam to collapse, resulting in the millions of gallons of accumulated oil spilling across the fragile Siberian tundra and into the Kolva River, a tributary of the Pechora River that flows into the Barents Sea. 23 species of flora and fauna were affected by the disaster which polluted 186 km² of grass and marshlands.