How was the Waste Isolation Pilot Plant chosen to store transuranic waste?

While federal research and other facilities began accumulating radioactive materials generated from defense activities since the beginning of the atomic age, it wasn’t until 1974 that federal and local officials were able to agree on a site for the safe and permanent disposal of some of the waste. Scientists had concluded that a site in southeastern New Mexico near Carlsbad with its deep, underground salt deposits looked promising for demonstrating that radioactive material could be permanently disposed without leaks, spills, or other accidents. The rationale behind selecting a site with salt deposits was the view that the salt would naturally collapse around the waste, thereby encasing it, which would prevent the radioactive material from escaping.