Environmental effects of pipeline up for debate

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October 19, 2011 - 7:00pm

Much of the debate over the proposed Keystone XL oil pipeline has centered on the environment. Opponents fear if the pipeline leaks, it could pollute Nebraska's water supply. Advocates of the pipeline say precautions will be taken to make it safe.

Those differences are reflected, in more nuanced terms, in the views of two University of Nebraska-Lincoln professors whose respect for each other still leaves them on opposite sides of the fence regarding the pipeline.
 


John Stansbury


Jim Goeke


MAPS

U.S. Geological Survey

The High Plains Aquifer lies under all or part of eight states


 

UNL School of Natural Resources

The proposed Keystone XL pipeline (in red) would cut across the Sandhills and the Ogallala and High Plains aquifers


UNL School of Natural Resources

Concern over leaks is especially high in areas where the water table is close to the land surface

John Stansbury is a UNL associate professor of environmental and water resources engineering who wrote an analysis of worst- case spills from the proposed pipeline.

Jim Goeke is a hydrologist and professor emeritus from UNL's School of Natural Resources.

Regarding the pipeline, Goeke said, "I think we just have differences of opinion. We come from different sides of the fence."

That fence separates those who think that Keystone XL can operate safely if TransCanada builds it as promised from those who remain unconvinced. Much of the controversy centers on the portion of the pipeline that goes through Nebraska's Sandhills and crosses the High Plains Aquifer and its most important component, the Ogallala Aquifer.

Goeke, who's spent much of his career studying the Ogallala, points out that it's not an underground pool of water. It's a water -saturated rock formation, made up of debris eroded from the Rocky Mountains over at least 20 million years.

According to the State Department's environmental impact study (see below), the aquifer supplies 78 percent of the public water supply and 83 percent of the irrigation water in Nebraska, and smaller but still significant portions in other states.

Goeke said it's vital to keep pollution out of the aquifer, "because if we didn't keep it clean, agriculture as we know it in Nebraska would not be functional."

But Goeke said even if the pipeline leaks, the effect on the aquifer would be limited by a number of factors, beginning with the direction that water moves underground.

"Three quarters of the aquifer lie upgradient from the pipeline," he said. "So that any pollution isn't going to move from east to west because it would be upgradient. So that 75 to 80 percent of the aquifer is off-limits. It's (to the) west and would not be contaminated."

Goeke said that in many other places, layers of silt and clay separate the pipeline route from the aquifer below. And in areas where water rises to the land surface, TransCanada has promised to surround the pipe with extra concrete, rock, or other protective materials. Goeke said while TransCanada asked him to look at the project proposal, the company has not paid him.

Like Goeke, Stansbury also said he was not paid, in his case by pipeline foes, for a report he wrote about environmental risks, although he said they did help him distribute it. Stansbury agreed that some fears about the aquifer are overblown:

"Even a worst-case spill would contaminate a very, very small part of the aquifer," he said. "Some people have incorrectly said that if we have a spill in the aquifer, it will ruin the entire aquifer. That's just absolutely not true.

"But the salient point there probably is, if there is a spill in the aquifer it will contaminate a part of the aquifer, and if that's your part of the aquifer, that's a big deal."

Earlier this year, Stansbury calculated what could happen in the event of a worst-case scenario of an oil spill from the pipeline in the Sandhills. Among the results, he said, could be a plume of carcinogenic benzene polluting nearly 5 billion gallons of water.

To put that amount in perspective, it's a little more than 15,000 acre-feet of water - the amount of water needed to cover an acre of land to the depth of one foot. By comparison, Nebraska's share of the High Plains Aquifer is about 2.25 billion acre-feet, according to Goeke.

Still, the 5 billion gallons of water that could be polluted in Stansbury's scenario could form a plume of polluted groundwater 40 feet deep, 500 feet wide, and 15 miles long.

Goeke said such a plume is quite unlikely.

RELATED
DOCUMENTS

Click here for the 2011 report by UNL professor John Stansbury analyzing worst-case spills scenarios for the pipeline. The specific section described in this story is annotated.


Click here for the State Department Environmental Impact Statement's response to Stansbury's report. The section specifically mentioned in this story is annotated.

The full report can be found here.

"The consolidation and the character of the aquifer, of the Ogallala, would localize any spills. They just couldn't go very far in any sediment, in any direction," he said.

Goeke said under those conditions, water would probably move fewer than 175 feet a year. Stansbury said his discussion of a plume was not a prediction of what would happen, but rather simply an indication of how big an area 5 billion gallons of water could occupy.

"At this point, I certainly don't have enough information to calculate what a plume would look like," he said. "But the really important point here is, neither does anybody else."

Stansbury said the environmental impact statement for the project fails to show any potential plume. That statement was issued by the State Department, which hired consultant Cardno ENTRIX, to help put it together. That company has previously identified TransCanada as a "major client." Critics have said that gives Cardno ENTRIX a conflict of interest; TransCanada has said the firm worked at the direction of the State Department.

The environmental impact statement contains comments from TransCanada disputing Stansbury's critical report, which it calls "opportunistic fear mongering, dressed up as an academic study" (you can find the annotated document at the right).

Stansbury and TransCanada also disagree about the potential for surface water pollution from a pipeline break. His report said a spill into the Platte River could foul water supplies for more than 400 miles. The company's response refers to a 2007 spill into a river in Kansas and says no detectable pollution was found even 20 miles downstream.

Goeke said he thinks the pipeline question should be decided based on science, not emotion-driven politics. He said the situation reminds him of controversy over a low-level radioactive waste disposal site in Boyd county proposed in the 1980s. The School of Natural Resources Survey Division that he worked for helped developer US Ecology identify the site. Goeke thought it was a good one, but the state ultimately rejected it, and later had to refund utilities who wanted to use the site more than $150 million.

"I was of the opinion then that the politics got involved and the science took a walk. And I would hate for that to happen now,' Goeke said.

Stansbury said he agrees with the desire to base the pipeline decision on science.

"Clearly there've been exaggerations and misrepresentations on both sides. And clearly there's been emotions on both sides, and that's dangerous and all that," he said. "I agree completely with Prof. Goeke, we should be relying on the science. My position is the science hasn't been done."

Whether it's been done, and done adequately, may be tested in a lawsuit if the State Department approves the pipeline. That decision is expected by the end of the year.

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