"Local residents discovered the spill," the spokesman said. "They saw an open valve at the base of a well spewing oil, which was flowing into the river Piltun. After blocking off the flow, they called the local Rosneft subsidiary, Okhaneftegaz, as well as the police."
An inspection team found large pools of oil at the site, and estimated the spill at no less than 700 cubic meters (2,100 cubic feet). An area of no less than two hectares (4.9 acres) has been contaminated.
The head of the local emergencies service said the well has now been sealed off and the oil flow stopped.
An environmental spokesman said the river Pultin is used by several endangered fish species to spawn.
He said that an official notice of the spill, consisting of written and photographic documentation, has been sent to the Sakhalin prosecutor's office, the local government administration, the environmental protection agency and the Sakhalinmorneftegaz oil and gas company.
