In 1992, The New York Times reported that University of Alaska researcher Dan O'Neill had discovered* documents detailing thousands of pounds of radioactive soil which had been buried in the Point Hope area in 1962. The soil, left over from nuclear testing in Nevada, was being used to examine the effect of radioactivity in the Arctic. The areas where the soil was buried were unmarked, and residents of nearby villages were not informed.
The nuclear waste was cleaned up in response to this report, but non-radioactive waste remained. Alaska Dispatch News reported in 2014 that "rusted-out pipes, wires, and even a rotting fire extinguisher" were still lying on the tundra. The Department of Energy was working on continuing to clean up the area, as of the most recent update to the article in late 2016.
* Dan O'Neill discovered the documents while writing a book, The Firecracker Boys. I wanted to use it as a reference for this project, but it's been checked out at the Rasmuson Library for the past month, which makes me wonder if someone else is doing a project on the same topic and managed to get to it first.