Filling old open pit mines with mining wastes has many advantages. I recognize there are many disadvantages too, mostly to do with the cost. Here is a short record of one I had forgotten until reminded thereof by stumbling across a link while trawling the web. I quote from the Spook Fact Sheet:

The Spook Disposal Site is unique among UMTRCA sites because the disposal cell is completely buried. An open pit uranium mine, approximately 1,600 feet long, 500 feet wide, and 100 feet deep was located adjacent to the former upgrading plants. Contaminated material, including mill tailings, pond sludge, and building debris, were encapsulated in the south-central part of the mine excavation. The cell contains approximately 315,000 cubic yards of contaminated material with a total activity of 125 curies of radium-226. Stockpiles of overburden material around the perimeter of the mine were used to fill the pit after the disposal cell was completed.

Well I recall the arguments that swirled around the decision to put the mill tailings back in the pit. The folk who deserve credit for the decision include fellow engineers with whom I have lost touch: Ron Rager – I last heard from him when he was working in Boise, Idaho for MK Fergusson; Berg Keshian – I last heard from him when he was in Grand Junction consulting to the DOE on ongoing UMTRA activities; and Ned Larson – I last heard from him when he was with the DOE in Washington DC.

I was delighted to read the June 2006 report on a site inspection that established that all is well at the site. This case history is another demonstration that mines can be rehabilitated.