Nathan VanderklippeNext to a sun-stained red flag that marks the planned route of the Keystone XL pipeline, Leon Weichman kneels on his Nebraska hay field. Moisture spots his jeans. It has barely rained in 30 days in this arid part of the central U.S., yet the grasses are thick and green. The soil is black and damp.This field is naturally irrigated by the subterranean reaches of a vast underground formation called the Ogallala Aquifer that underlies the heart of America. It is half the size of British Columbia and filled with freshwater.Mr. Weichman says he has slept uneasily for three years, knowing that the red flag portends a time when up to 830,000 barrels of oil could course through his field each day.“If we couldn’t use this water, this area would just be vacated.” Mr. Weichman says. “We couldn’t raise livestock here. We couldn’t use crops here. It would just be done.”Now the Ogallala has inspired a fierce battle over oil, turning Keystone XL into a symbolic dividing line for opponents and supporters of Canada’s oil sands. The red flags marking the route have come to delineate an increasingly bitter fight between those who tout the economic and strategic benefits of a giant resource of North American crude and those who see the oil sands as an unacceptable environmental threat.To critics, Keystone XL is not just a risk to Nebraska’s water treasure. It represents the rapid growth in Alberta’s oil sands and the harmful greenhouse gas emissions the industry is creating.Opponents are mobilizing around the goal of “blocking the expansion of this incredibly dangerous carbon bomb,” says Bill McKibben, a high-profile climate campaigner who has helped organize White House protests against Keystone XL. The pipeline project has raised awareness of the Alberta oil sands – “just how much carbon there was up there, and that heavily exploiting the tar sands would be ‘game over’ for the climate.”For supporters, the pipeline represents a chance for the U.S. to secure needed oil supply from a friendly source. And the U.S. labour and business community sees Keystone XL as a critical indicator of the country’s ability to shake off a prolonged period of economic malaise and high unemployment.“If we can’t get this built, we’re not going to get anything built,” Karen Harbert, president of the U.S. Chamber of Commerce Energy Institute, told a Calgary audience last week. “This is a big litmus test.”That test is nearing resolution. Between now and year’s end, the U.S. State Department will decide whether Keystone XL is in the American national interest. Some time in December, it expects to either approve or deny a presidential permit for the pipeline.In that decision lies major consequences for Canada. Keystone XL is a critical link for shipments between the oil sands and the enormous refining complex in the U.S. Gulf Coast. The pipeline stands to open a spigot out of the oil sands that will clear the way for nearly a decade of growth, worth tens of billions of dollars to Canada’s economy. The project promises to help sustain tens of thousands of jobs north of the border in an industry generating vast sums of government tax and royalty revenue.The pipeline has backing in the highest levels of the Canadian industry and politics. Prime Minister Stephen Harper called Keystone XL a “no-brainer” for the U.S.Read more here.