The pipeline's impact on the environment has been controversial. A number of Native Americans in Iowa and the Dakotas, including the Meskwaki and several Sioux tribal nations, have opposed the pipeline under the assertion that it would threaten sacred burial grounds as well as the quality of water in the area. A protest at the pipeline site in North Dakota near the Standing Rock Indian Reservation drew international attention shortly after the announcement of this project. In September 2016, construction workers bulldozed a section of land that the tribe had identified as sacred ground, and when protesters entered the area, security workers used attack dogs which bit at least six of the protesters. The incident was filmed and viewed by several million people on YouTube and other social media.