Most states do not allow whole tires in landfills for the
following reasons:

Tires that are buried tend to work or "float" their way up
to the top of the landfill and become exposed again.

Exposed whole tires are excellent breeding grounds for
insects, especially mosquitoes

Exposed tires are fire hazards

A typical passenger tire weighs 20 lbs (9.1 kg).
At 229 million scrap tires generated per year,
that equals 4,586,400,000 lbs or 2,293,000 tons