The pipeline was ruptured on February 3 about 20 km (12 miles) from the Daghestani village of Belidzhi, causing about 100 metric tons (733 barrels) of crude to leak from the pipe, with 5 metric tons (37 barrels) seeping into the Rubas River which flows into the Caspian.
Laboratory tests confirmed that levels of crude oil in the sea exceeded the maximum permissible quantity by 320 times.
A deputy head of a regional department of Russia's environmental watchdog, Zapir Magomedov, described the damage from the oil spill as "considerable."