Despite controversies circling the outcome of the Keystone XL and Dakota Access oil pipelines, President Donald Trump signed orders on Jan. 24 to move forward with their construction.

Along with signing the executive order for the pipeline on Tuesday, Trump also officiated that workers will use domestic-made materials to build U.S. oil pipelines. Trump made the order to streamline construction regulations and shorten the process for environmental reviews.

The order faces criticism from protestors, as the Dakota Access pipeline is set to run under Lake Oahe in North Dakota, which is only half a mile upstream from treaty-designated Sioux territory. When completed, the $3.7 billion pipeline will be 1,172 miles long, extending through North Dakota, South Dakota, Iowa, and Illinois.

Contestants to the pipeline believe it proposes a high risk of infecting the river, thus violating treaty rights. If there is a leak in the pipeline, the oil will infect the Missouri River, which is the second longest river in North America.

In the Standing Rock Sioux Tribe’s original federal complaint to the U.S. Army Corps of Engineers, the tribe two claims. The first recognizes that the tribe’s land is a part of the National Historic Preservation Act, and that any damage done to the federal waters, including the Missouri River, is against NHPA compliance. Additionally, the water near the tribe is of significant historical and cultural essence to the Sioux tribe, furthering the complaint.

The second claim is that the pipeline is authorized to discharge into waters that are part of the Tribe’s lands. If true, this violates the NHPA and the National Environmental Policy Act.

Standing Rock Sioux Tribe Chairman Dave Archambault said President Trump is required to honor the tribe’s treaty rights.

“Americans know this pipeline was unfairly rerouted towards our nation and without our consent,” he said. “The existing pipeline route risks infringing on our treaty rights, contaminating our water, and the water of 17 million Americans downstream.”

Numerous environmental groups stand alongside the Sioux Tribe, including NextGen Climate President Tom Steyer. He claims President Trump is placing “corporate interests ahead of American interests.”

“The pipelines are all risk and no reward, allowing corporate polluters to transport oil through our country to be sold on the global market while putting our air and water at serious risk,” he said.

Although the pipelines face major opposition, many people support the move, including Sen. Heidi Heitkamp (D-ND) and Sen. Joe Manchin (D-WV). Manchin explained he supports the Keystone XL pipeline because the U.S. needs more jobs. He was an original cosponsor of the legislation that approved the Keystone XL Pipeline.

“With a majority of American in support of the Keystone XL pipeline’s construction, I’m glad we are finally moving forward with this important project,” he said.

The Keystone XL project is an extension of the Keystone Pipeline. It will carry crude oil approximately 1,200 miles from Canada through Texas to the Gulf of Mexico. Despite environmental concerns, pro-pipeline advocacy groups say the pipelines are safe to move oil. They also claim the benefits outweigh the risks, as the pipelines will generate more than $100 million dollars.

While it remains unconfirmed, contestants claim Trump invested in the pipeline construction companies Energy Transfer Partners and Phillips 66. In 2016, his 2016 federal disclosure forms showed he owned between $15,000 and $50,000 in stock in ETP. They also show he owns between $100,000 and $250,000 in Phillips 66. The documents show that Trump collects interest, dividends, and capital gain from ETP and interest from Phillips 66.