Human Interest Everything You Need to Know About the Dakota Access Pipeline Protests Here's what you need to know about the pipeline project and why its being protested. By Tiare Dunlap Published on October 28, 2016 04:29 PM Share Tweet Pin Email Photo: ROBYN BECK/AFP/Getty Months-long protests against a multi-billion dollar oil pipeline project came to a head on Thursday as police in riot gear faced off with protestors. At least 141 people were arrested Thursday night — many of whom were members of the Standing Rock nation and other tribes who are opposed to the construction of the North Dakota Access Pipeline. Protestors say the 1,172-mile conduit that is planned to cross the Missouri River would put their community’s sole water source at risk and destroy sacred Native American sites. Protestors’ months-long efforts to halt construction have garnered the support of celebrities like Leonardo DiCaprio, Susan Sarandon, Mark Ruffalo and Shailene Woodley – who was arrested in early October for her part in the protests. https://www.instagram.com/p/BFNT94sKxOw/ Here’s what you need to know about the pipeline project and why its being protested. What is it? The Dakota Access Pipeline Project (DAPL) is a 1,172-mile conduit that would carry 470,000 barrels of oil a day from the oil fields of western North Dakota to Illinois. The $3.7-billion dollar pipeline would stretch through four states – North Dakota, South Dakota, Iowa and Illinois – and cross three major rivers. Why is it being protested? Native American and environmental groups alike see the pipeline as a major environmental threat. They argue that the Missouri River, one of three major rivers the pipeline would cross, is too precious a water source to risk contamination from an oil spill or leak. “Once that oil gets into our water, life around it will be ruined,” Bobbi Jean Three Legs, a resident of the Standing Rock Reservation who organized a petition against the pipeline, told PEOPLE in August. ROBYN BECK/AFP/Getty The pipeline’s path also takes it through active farmland and forests, though the US Fish and Wildlife Service claims that no “critical habitat” is endangered. A potential pipeline spill would be devastating to any of these environments, and although Energy Transfer Partners maintains that a spill or leak is unlikely, protestors disagree. There were 300 oil pipeline spills between 2012 and 2013 in North Dakota alone, according to the Associated Press. And, although pipelines spill less often than trains do, the International Energy Agency found that pipeline spills, while less frequent, do much more damage in terms of volume spilled. Native American groups are also protesting based on their claims that the pipeline, which is being built near the Standing Rock Sioux Reservation, disturbs sacred sites, infringes on past land treaties and violates tribal sovereignty. ROBYN BECK/AFP/Getty Why is it being supported? Job creation: The pipeline is projected to create an estimated 8,000 to 12,000 temporary construction jobs and 40 permanent operational jobs, according to the project website. Oil independence: Energy Transfer says the pipeline will help to “close the gap between what we produce as a country and what we consume before we can be truly independent of foreign imports.” Economic benefits: Energy Transfer estimates that the pipeline will generate $156 million in sales and income taxes. What is the status of construction? Construction is ongoing and continues to be delayed by protests. Protestors have been camping out at construction sites for months and clashes with police have become increasingly violent in the past few weeks. Law enforcement have begun using concussion grenades, mace and rubber bullets against protestors and police say some protestors have thrown Molotov cocktails. On Thursday, a female protestor was arrested after allegedly firing shots at officers, according to the Seattle Times.