The scenic Yellowstone River has suffered its second sizable oil spill in four years, prompting truckloads of drinking water to be shipped into the eastern Montana city of Glendive. The latest spill is not expected to affect Yellowstone National Park, about 350 miles upstream.

Some oil from the weekend spill got into a water supply intake along the river that serves about 6,000 people in Glendive, according to preliminary tests at the city's water treatment plant. The sample showed elevated levels of volatile organic compounds, predominantly benzene, that would explain the odor in tap water, officials at the plant said. The potential health risks are uncertain until further testing is complete, they said.

"There will be more sampling from more