The fallout from a ruptured oil pipeline in the Yellowstone River this month is spilling into a larger debate over whether the U.S. should allow the expansion of a pipeline that would carry more crude from Canada's oil sands to American refineries.

The July 1 accident at Exxon Mobil Corp.'s Silvertip pipeline has been taken up by environmentalists and other opponents of TransCanada Corp.'s planned expansion of its Keystone XL pipeline, which is not related to the Exxon pipeline. The U.S. State Department, which must approve the expansion, has said it would make a decision by year's end.

Exxon Mobil Corp will bring in more people to mop up oil from a broken pipeline beneath the Yellowstone River as receding floodwaters reveal new contamination, federal officials said Friday.Also Friday, Montana environmental regulators said the pipeline may have leaked up to 1,200 barrels of oil into the scenic river. That equals 50,400 gallons and is 20 percent higher than prior estimates from Exxon Mobil.

Water levels on the Yellowstone have dropped six feet since the July 1 accident. Hundreds of logjams and debris piles, many coated in a layer of drying crude, now litter its banks and islands.

April 20th, 2010 marks the day the worst oil spill in history occurred. This is the day the Deepwater Horizon offshore drilling rig exploded and spewed approximately 170 million gallons of crude oil into the Gulf of Mexico. This is roughly fifteen times more oil than spilled during the Exxon-Valdez accident off the coast of Alaska in 1989.  The spill lasted for 87 days until BP was able to plug the leaky well and stop the spill of crude.

Over a year later, the Gulf Coast region is still devastated, with both people and animals feeling the effects. Fisherman have lost millions of dollars in Louisiana alone, and will continue to lose money over the next two years. 

On July 6^th EPA issued ExxonMobil an administrative order instructing them to provide information on the circumstances of the spill, conduct appropriate recovery and remediation actions, and perform ongoing environmental sampling. The order also requires ExxonMobil to provide a work plan which is currently being reviewed by the state of Montana, EPA, and other agency partners. Once approved, the work plan will be publicly available.