The lead editorial in today's Arizona Daily Star (Tucson) endorsed the idea of filling abandoned mines with used tires. The paper opined that "Throwing tires into mines doesn't come without its own risks, but the state must weigh the threat of possible pollution against the danger that more people could die."
The idea was first proposed by State Mine Inspector Joe Hart to the Legislature earlier this year but concerns over degradation of the tires and impacts on groundwater pretty much sidetracked the concept.
The Star resurrected the idea because the State seized as many as 10 million tires in the town of Mobile southwest of Phoenix, after shutting down a tire recycling operation on state lands. The question is what to do with one of the largest inventories of tires in the region. [above, Google Earth view of Envirotech International Industries site near Mobile, AZ]
The paper's editorial may breath new life into burying them in old mines, but I expect the environmental challenges to remain.