(CNN) -- Several thousand barrels of North Slope crude oil spilled into a containment area along the Alaska pipeline Tuesday when an open valve at a pump station allowed oil to overflow a tank, the Alyeska Pipeline Service Company said.

Alyeska said the incident took place about 10:30 a.m. (2:30 p.m. ET) during a planned pipeline shutdown while the company was conducting fire command and valve leak testing at the pump station.

The Alaska Department of Environmental Conservation said a battery failed to control the valve when power was switched from the main grid during Alyeska's tests. The valve has been closed, shutting off the flow, the department said, but the pipeline remains shut down.

The department said the next steps would be to clean up the oil in the containment area, determine the cause of the problem and restart oil flowing in the pipeline. No oil has been reported outside the containment area.

Mark MacIntyre, a spokesman for the Environmental Protection Agency in Seattle, Washington, said two EPA coordinators would arrive on the scene from Anchorage on Wednesday and have a report in the afternoon.

The pump station is near Delta Junction, about 100 miles south of Fairbanks. Ayleska said the lined containment area that took the spill has a capacity of about 104,500 barrels.

Ayleska also said there were no injuries and the pump station was evacuated. An incident management team and other responders were dispatched.

CNN's Nick Valencia contributed to this report.