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Nebraska Water Scientists Warn of Oil Pipeline's Risk, Call for More Study

A single study by the U.S. Geological Survey in Minnesota is the sole source for what scientists know about crude oil behavior in aquifers

Jun 15, 2011

WASHINGTON—Great Plains states are risking an unknown level of environmental and economic hurt if the U.S. State Department persists in routing a controversial tar sands pipeline atop the Ogallala Aquifer without further study.

That is the scientific warning coming from a pair of University of Nebraska professors with expertise in groundwater flow and contamination.

In a June 6 letter to Secretary of State Hillary Clinton (attached below), the two scientists laid out how their state’s fragile sandhills region is particularly vulnerable to crude oil pollution from a pipeline spill and why a research information gap needs to be closed.

Their concerns align with those expressed by Environmental Protection Agency authorities in their recent harsh critique of the State Department’s second attempt to draft an environmental review of the proposed $7 billion Keystone XL pipeline.

TransCanada’s 1,702-mile Keystone XL is slated to pump diluted bitumen from Alberta, Canada’s tar sands mines across Nebraska and five other states to Gulf Coast oil refineries via a 36-inch diameter underground pipeline.

“Uncertainty about crude oil plume behavior in waters of the Nebraska sandhills region has practical implications,” wrote John Gates, an assistant professor in the Department of Earth and Atmospheric Sciences, and Wayne Woldt, an associate professor in Biological Systems Engineering and the School of Natural Resources. “We feel that it is highly desirable to study contaminant risks in the sandhills in a more thorough and systematic way.”

Gates and Woldt urged the State Department to allow scientists and engineers to undertake a study using field data and numerical modeling to outline exactly how an oil spill would affect the sandhills and devise strategies to safeguard the region’s aquifer, streams, lakes and wetlands.

When asked how long such a study might take, Woldt told SolveClimate News in an interview, “If these were easy questions to answer I think they would have been answered already.”

Minnesota Study Not Enough

Woldt’s and Gates’s two-page letter was among 100,000-plus comments sent in response to the State Department’s mid-April release of its “supplemental draft environmental impact statement” of Keystone XL, department spokesman Harry Edwards said in an interview. That comment period closed June 6.

In separate interviews, both Nebraska professors agreed that the State Department was correct in citing a single study by the U.S. Geological Survey in Minnesota as the sole source for what scientists know about crude oil behavior in aquifers. More than 30 years later, scientists are still learning from that 1979 spill that occurred northwest of Bemidji.

But Gates stressed that comparing probable rates of contaminant spreading and degradation in two such vastly different geographies is a classic apples- to-oranges exercise.

“The analogies between the sandhills and the Bemidji area break down in a lot of ways,” Gates said.

What Makes the Sandhills Unique

Alberta-based TransCanada has proposed routing 92 miles of pipeline through Nebraska’s sandhills. Unique conditions that make the region susceptible to oil contamination include very permeable sandy soils, groundwater hovering near the surface and a network of abundant groundwater-fed lakes and marshes.

“Hydrologic studies in the sandhills have already shown that all of the conditions are right for producing very short lag times between a pipeline crude oil release and water contamination,” Gates and Woldt wrote in their letter. “Because lakes and streams in the sandhills are fed almost exclusively by groundwater, risks are not limited to the aquifer, but extend to surface water as well.”

The two scientists complimented the State Department for making it clear that in Nebraska, 64 percent of the groundwater wells are within one mile of the Keystone XL route. That figure drops to just 10 percent in each of the other states—Montana, South Dakota, Kansas, Oklahoma and Texas.

Gates and Woldt say their research indicates that a similarly high percentage of Nebraska’s wetlands are along the proposed pipeline route.

“Groundwater is a pretty mysterious thing for most people because you can’t see it,” Gates said, referring to water hidden below visible lakes, rivers, streams and wetlands. “But the groundwater contaminant potential in Nebraska’s sandhills is head and shoulders above all others.”

“People don’t understand the connection in the sandhills,” he continued. “All of those wetlands and rivers are supported by groundwater. The interaction between the two is vast and copious. They are intimately connected.”

In the Cornhusker State, the treasured dunes and lakes of the sandhills and the Ogallala Aquifer are inseverably intertwined. For instance, the wetness of the sandhills region makes it the most productive recharge zone for the aquifer.

Nationwide, the massive but shallow aquifer covers roughly 174,000 square miles of the Great Plains in eight states stretching from South Dakota to New Mexico.

The Ogallala is credited with supplying 78 percent of the water supply and 83 percent of the water for irrigation in Nebraska. Cereal crops and cattle that count on “irrigated agriculture” contribute $3.5 billion annually to the state’s coffers.

“Agriculture and the agriculture business sector are about one-third of Nebraska’s economy,” Gates said. “Water is the resource that underpins all of that.”

State Department Sorts Pro and Con Comments

Gates and Woldt Letter on Keystone SDEIS.pdf32.21 KB
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