An oil spill from the Keystone pipeline took place in South Dakota Nov. 16, with reports suggesting that some 210,000 gallons of oil have been lost.
TransCanada, the company which operates the pipeline, said the leak was detected within 15 minutes and the pipeline was shut down, according to CNN.
"It is a below-ground pipeline but some oil has surfaced above ground to the grass," Brian Walsh at South Dakota's Department of Environment and Natural Resources told CNN. "It will be a few days until they can excavate and get in borings to see if there is groundwater contamination."
There was no immediate indication that water supplies or wildlife had been affected.
The Keystone pipeline system transports oil from Alberta, Canada, to Oklahoma and Texas. The oil is extracted from tar sands, meaning that it is much thicker than normal oil. Tar sands oil therefore has to be mixed with other harmful chemicals to be transported through pipelines.
"The safety of the public and environment are our top priorities and we will continue to provide updates as they become available," a statement from TransCanada declared.
However, environmental groups responded angrily, saying that events like the Nov. 16 spill show why such pipelines should not be built.
In March, President Donald Trump granted a permit for TransCanada to construct the Keystone XL pipeline, which would transport oil directly from Alberta through Nebraska and other U.S. states to Texas. Trump suggested the pipeline would create jobs, improve national security and cut fuel prices.
"The Nebraska Public Service Commission needs to take a close look at this spill," Rachel Rye Butler of Greenpeace told CNN. "A permit approval allowing Canadian oil company TransCanada to build Keystone XL is a thumbs-up to likely spills in the future."
The Sierra Club also weighed in. Kelly Martin, director of the organization's Beyond Dirty Fuel campaign, stated that the only way to protect communities in Nebraska was "to say no to Keystone XL," ABC News reported.
Regulators in Nebraska are set to make a decision on the Keystone XL project Nov. 20.
Bold Alliance, an activist group that has been fighting the project for nearly 10 years, is still campaigning in Nebraska.
"We want to make sure our fellow Nebraskans know the decision is coming ... and how critical this decision is for property rights and clean water," Jane Kleeb, the group's director, told Reuters.
On the other hand, the Nebraska Chamber of Commerce predicts an additional $150 million in property tax revenue will be brought into the state if construction begins. It also expects Nebraskans' personal incomes to grow by more than $300 million during construction.