Prions are misfolded proteins, not viruses or bacteria. They don't degrade with normal environmental cycles, can't be killed by typical disinfectants, and accumulate in soil. Once a property has CWD, the prion load only increases over time.
This is why state wildlife agencies impose carcass-transport restrictions, ban supplemental feeding in CWD zones, and conduct culling programs. See your state's disease risk pages for current zones and regulations.