The need for environmental scientists to address the effects of tar-sands mining in Canada (Nature 468, 476; 2010) should be extended to the impacts of downstream operations.

Communities across the northern High Plains region of the United States are concerned about the risks of piping crude oil from Canadian tar sands across ecologically sensitive prairie and through an important recharge zone of the Ogallala Aquifer — the route of the proposed Keystone XL pipeline through the Nebraska Sand Hills.

The public debate is being conducted largely in the absence of scientific evidence about risks to water resources and aquatic ecosystems. This causes misinformation to circulate: for example, local stakeholders commonly believe that any oil released from a ruptured pipeline could contaminate the entire High Plains groundwater supply — based on the widespread misconception of an aquifer as an underground lake. Others, by contrast, believe that spilled oil would be harmlessly sequestered in the aquifer.

Much of the blame for these misconceptions must be down to poor communication with the public by scientists. However, scientists themselves are often hampered from providing technical input because of their limited access to data — as has happened with the Keystone XL proposal. Important data pertaining to this have not been divulged to the public, such as the fluid chemical composition and the maximum pipeline leakage volumes.

Disclosure of relevant data must be comprehensive if the risks associated with the pipeline are to be properly assessed.