"BILLINGS, Mont. — A second large oil spill into Montana's Yellowstone River in less than four years is reviving questions about oversight of the nation's aging pipeline network.

Investigators and company officials on Wednesday were trying to determine the cause of the 40,000-gallon spill that contaminated downstream water supplies in the city of Glendive.

Sen. Jon Tester said Saturday's spill from the decades-old Poplar Pipeline was avoidable, but 'we just didn't have the folks on the ground' to prevent it.

The Montana Democrat told The Associated Press more frequent inspections by regulators are needed, and older pipelines should face stricter safety standards."

Matthew Brown reports for the Associated Press January 21, 2015. [2]

SEE ALSO:

"High Benzene Levels Found After Montana Pipeline Spill" (Aljazeera America) [3]