The worst fears of the Dakota Access Pipeline protesters have come true: a pipeline has leaked. It was not the controversial Dakota Access Pipeline, but it was fairly close, which adds validity to their argument that the pipeline poses a very real threat to the environment and to their health.

This affected pipeline is the Belle Fourche pipeline in Iowa, and this recent leak brings the issue back into the focus. Reports say that the spill was contained after contaminating six miles of land, and that no drinking water was contaminated, although there was still some damage to the environment. The workers were unable to clean up the site quickly, as the cold weather and rugged terrain hindered their work.

According to the Pipeline and Hazardous Materials Safety Administration, there have been 200 crude oil spills reported per year since 2010, though most are small. This Belle Fourche pipeline spill is the largest in North Dakota since 2013, spilling approximately 180,000 gallons of crude oil into the environment.

The protesters at the Dakota Access Pipeline worry that the equipment to detect a spill will not function properly, and this recent spill does more to validate those fears, as the company did not detect the spill. It was discovered by a local landowner.