Why are the Sioux and others protesting the project?
The pipeline has united a number of different interest groups with a variety of objections, but Native Americans have been at the center of the opposition. The pipeline would travel underneath the Missouri River, the primary drinking water source for the Standing Rock Sioux, a tribe of around 10,000 with a reservation in the central part of North and South Dakota. Builders of the pipeline insist that they have taken extraordinary measures to safeguard against disaster, but opponents point out that even the safest pipelines can leak. The Pipeline and Hazardous Materials Safety Administration (PHMSA) has reported more than 3,300 incidents of leaks and ruptures at oil and gas pipelines since 2010. And even the smallest spill could damage the tribe’s water supply. The Standing Rock Sioux also argue that the pipeline traverses a sacred burial ground. And while the land being used for the pipeline is not technically on its reservation, tribal leaders argue that the federal government did not adequately engage the Standing Rock Sioux during the permitting process—a requirement under federal law.
http://time.com/4548566/dakota-acces...ng-rock-sioux/