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The national environmental fight over the oil sands in Canada has reached a flashpoint in a pipeline battle.

TransCanada wants to build a 2,000-mile pipeline from the oil sands of Alberta to refineries in Texas, known as the Keystone XL.

While supporters say it would create up to 20,000 construction jobs, generate tens of billions of dollars a year in tax revenue and improve energy security, opponents argue it would harm the environment and feed the nation’s addiction to oil.

The $7 billion Keystone XL would cross six states before ending up near the Gulf of Mexico. It would allow oil producers to pump 900,000 barrels a day more from the world’s second-largest oil reserve. The U.S. already gets 2 million barrels of oil per day from Canada which accounts for 20 percent of its imports.

Before TransCanada can build the new pipeline, it needs approval from the U.S. State Department.

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“We’re ready to build this pipeline,” Robert Jones of TransCanada said, “to create tens of thousands of direct jobs.”

The State Department issued its Supplemental Environmental Impact Statement in April citing the benefits of the project and its “limited impact” on the environment.

But in June the Environmental Protection Agency wrote the State Department a letter criticizing the review as “inadequate” because “significant impacts were not evaluated.”

Among the EPA’s concerns: Spill impacts, greenhouse gases and the pipeline route that goes right through a critical aquifer in Nebraska, including the Ogallala Aquifer that serves 30 percent of the nation’s agriculture.

Several groups have launched Tar Sands Action, which is a two week sit-in protest starting Saturday at the White House, where activists are being called on to get arrested during the civil disobedience.

“The keystone XL pipeline puts thousands of miles of our land and waters at risk from toxic spills,” Patty Glick of the National Wildlife Federation says. “Frankly the track record for transporting this fuel is really abysmal.”

Glick and other critics point to recent oil spills in Montana, North Dakota and Michigan.

TransCanada officials say pipelines are the safest way to transport oil. Since opening a pipeline from Alberta to Illinois last year, the company has experienced 14 incidents. All were spills at pump stations, not a broken pipeline.

TransCanada’s Terry Cunha tells Fox News the average amount of oil spilled in 13 of the incidents was five gallons. The largest spill dropped between 350-400 gallons.

Energy analysts on both sides of the border point to energy security as a main selling point. Some believe the Keystone XL pipeline could displace 40 percent of OPEC oil coming from the Persian Gulf. Canada is the biggest U.S. trading partner and a staunch ally.

Alberta’s Energy Minister, Ron Liepert, says oil sands production is ramping way up as the price of crude remains high.

“I can assure that if the United States feels the TransCanada pipeline is not important to get oil to the Gulf Coast,” Liepert said, “there are other markets in the world.”

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