Protesters against the Dakota Access Pipeline have highlighted environmental concerns with its construction. If completed, the pipeline will stretch from the Bakken shale formation in North Dakota, one of the largest oil deposits in the U.S., through South Dakota, Iowa and Illinois. Approximately 7.4 million barrels of oil lie in the Bakken formation, meaning that the pipeline could carry nearly 374.3 million gallons of gasoline per day if built. With its high value, the pipeline was approved by the U.S. Army Corps of Engineers in July 2014, only to be halted by complaints from the Standing Rock Sioux tribe in July of 2016. Members of the tribe claim that the pipeline would threaten the tribe’s environment and destroy consecrated areas.

One of the tribe’s main concerns revolves around the pipeline’s transferring gallons of oil half a mile away from their water source.

“We are on this Earth, and it is part of our culture to respect planet Earth or Mother Earth as much as possible,” Vice Chairman of Viejas Band of Kumeyaay Indians Victor Woods said. “If we look at American history, we never took from the land any more than we needed, and obviously today we are surrounded by all kinds of attempts to utilize any and all resources that are available. There are billions of dollars to be made in oil or transportation.”

While pipeline advocates argue that pipes are a safer alternative to trucks or rail transport, the tribe says that pipelines still have the potential to cause severe damage. For instance, the 20,600-barrel leak from the Tesoro Logistics LP Pipeline in September 2013, one of the largest spills from a North Dakota pipeline, would have grown larger had a farmer not noticed a hole in the pipeline. No major environmental effects resulted from the leak; however, the precedent of such pipeline bursts concern members of the Standing Rock Sioux Tribe.

The Dakota Access Pipeline is projected to pass under the Missouri River according to the proposed plan, meaning that a pipe rupture could cause severe damage to the surrounding environment.

“When looking at the route of the pipeline, there is no consideration for what unknown cultural sites are located adjacent to, underneath, above or in the pipeline,” Woods said. “I think these are very important to any Native American community here in the Continental U.S. or anywhere in the North American region.”

The Pipeline and Hazardous Materials Safety Administration states that more than 3,300 occurrences of leaks and ruptures of U.S. oil and gas pipelines since 2010. Previous oil spills such as the  Kalamazoo River spill in Michigan have cost over $1 billion to clean up. Any oil pollution in the Missouri River could pose an everlasting contamination issue.

Besides contaminated drinking sources, the tribe also argues that the pipeline increases climate change. Constructing additional oil pipelines perpetuates the use of fossil fuels and increases the area’s carbon footprint tenfold. The tribe advocates for the use of renewable sources of energy instead to avoid disturbing the Standing Rock land. Protesters continue to advocate against the pipeline’s construction due to the threats they say it poses for the environment.