Jobs producing bonanza or planet killing behemoth? That’s how the political debate over the construction of the 1,700-mile Keystone XL pipeline from Alberta, Canada, to the Gulf of Mexico is being framed. The Keystone pipeline would be used to transport about 500,000 barrels of oil daily derived from Canadian oil sands to refineries on the Gulf coast. Canada is already the largest source of “foreign” oil, providing the U.S. with about 2 million barrels per day.

The U.S. Chamber of Commerce claims [PDF] that building the pipeline will eventually result in the creation of 250,000 jobs and boost investment in the U.S. by $20 billion. Environmentalists assert that the pipeline is, in the words of global warming activist Bill McKibben, “a 1,700-mile fuse to the biggest carbon bomb on the continent” and that tapping the oil sands would mean “essentially game over” for the climate. Carbon bomb? McKibben is rhetorically highlighting the fact that the 170 billion barrels of petroleum locked in Canadian oil sands is second only to Saudi Arabia’s 260 billion barrel reserve. Since the pipeline crosses the border, President Barack Obama must decide whether or not to approve the pipeline, placing him directly on the horns of an election dilemma—which constituency to alienate: unemployed workers or environmental activists?

The largest concern of environmental activists is the climate change implications of burning petroleum products derived from Canadian oil sands. However, an October 10 Washington Post editorial, “Keystone XL pipeline is the wrong target for protesters,” points out that if Americans won’t allow the pipeline to be built and buy Canadian oil, then the Chinese and other countries surely will buy it. Two other pipeline companies are in the preliminary stages of developing more pipeline capacity to Canada’s west coast where tankers can load and carry the oil to global markets. Shipping by tanker boosts the emissions of carbon dioxide that contribute to the global warming that the protesters are so worried about.

If fears of global warming are not enough to stop the pipeline, activists cite other concerns, most prominently that pipeline leaks would contaminate the Ogallala aquifer that underlays the Great Plains. The Ogallala aquifer contains about the same amount of water as Lake Huron and stretches over 174,000 square miles in eight states. The pipeline would cross through Nebraska, which accounts for about two-thirds of the volume of Ogallala groundwater.

Left-leaning radio talk show host Thom Hartmann recently claimed, “If this pipeline was to be either blown up by people with nefarious intent or just good old fashion broke and nobody noticed it for a while and that oil got into that Aquifer, that’s the end of safe drinking water and agricultural water for 20 million people.” Some locals also worry about pipeline leaks. "A leak in the Keystone pipeline could conceivably contaminate the entire Ogallala Aquifer, in turn, disrupting the agricultural economy of Nebraska," said David Hutchinson, a Nebraska organic rancher as reported by Reuters. Sounds pretty dire.

University of Nebraska hydrologist Jim Goeke recently pointed out in an op-ed that the pipeline route is over the eastern part of the aquifer. The Ogallala aquifer slopes downward from west to east such that water in the aquifer flows downhill from west to east (at 150 to 300 feet per year). Unless water begins to flow uphill, the eastern route of the pipeline means that up to 80 percent of aquifer is safe from any oil spill contamination from the pipeline.

Goeke notes, in addition, that an aquifer is not like a lake or other open body of water; it is contained in a jumble of different kinds of rock, sands, and soils. “The variability of the aquifer's rock layers means that any spill would be contained within a very small area of that 25 percent of the aquifer to the east of the pipeline,” claims Goeke. Why? Because of some rock and soil layers are relatively impermeable to oil and would block the flow of oil below the surface. Goeke bases this conclusion on a 25-year study by the U.S. Geological Survey of a pipeline oil spill near Bemidji, Minnesota.

In 1979, an oil pipeline burst near Bemidji, spewing about 10,700 barrels of oil across about two acres of land. Most of the oil was recovered, but some 2,500 barrels percolated into ground reaching the shallow water table. In 1983, the U.S. Geological Survey set up the National Crude Oil Spill Fate and Natural Attenuation Research Site at Bemidji to study the evolution of oil spills in the environment.

The U.S. State Department’s Environmental Impact Statement (EIS) issued [PDF] in August for the Keystone XL pipeline project cited the ongoing Bemidji oil spill study noting, “While the conditions at Bemidji are not fully analogous to the Sand Hills region [of Nebraska through which the pipeline would pass], extensive studies of the Bemidji spill suggest that impacts to shallow groundwater from a spill of a similar volume in the Sand Hills region would affect a limited area of the aquifer around the spill site.” The EIS further observed, “In no spill incident scenario would the entire Northern High Plains Aquifer system be adversely affected.” 

Natural processes including biodegradation in which native microbes convert the petroleum into carbon dioxide, methane, and other products are attenuating the spilled oil underground. Since 1979, the oil itself has flowed 160 feet downgrade from the spill site while dissolved hydrocarbons have moved about 660 feet. As a result of these natural processes, the Bemidji spill has apparently reached equilibrium [PDF] and has stabilized. Based on the research from the Bemidji site, U.S. Geological Survey researcher Geoffrey Delin told InsideClimateNews that he thinks any dissolved hydrocarbons from a Keystone XL pipeline break that percolates into groundwater would probably remain within 1,000 feet of the spill point.

In order to allay spill fears, the operators of the Keystone XL pipeline have now offered to encase the pipeline in a concrete jacket where it crosses shallow aquifers and to put up a $100 million performance bond to cover any clean up costs. No industrial process is without risk and spills will happen. Make no mistake: Oil spills are nasty. But what amounts to scaremongering that a leak in the Keystone XL pipeline would “end safe drinking water” in Nebraska and “contaminate the entire” Ogallala aquifer sadly traduces science in an attempt to pursue environmentalist politics by other means.

Ronald Bailey is Reason's science correspondent. His book Liberation Biology: The Scientific and Moral Case for the Biotech Revolution is now available from Prometheus Books.

Disclosure: My travel expenses to visit Alberta's oil sands were covered by the American Petroleum Institute. The API did not ask for nor does it have any editorial control over my reporting of this trip or on this issue.