Quantum2 -
If the garbage is removed once daily, I wouldn't focus on AC so much as exhaust ventilation. No scientific evidence to back this claim, but bacterial growth between a 60°F room and an 80°F room probably wouldn't be orders of magnitude different in a 24-hour period. With a daily turnaround of trash from this space, a majority of growth might occur at the various points of origin of the trash rather than the dumpster location.
Current standards for exhaust for odorous or potentially hazardous areas is 1 cfm per square foot, and you will want to make up air at about .8 cfm per square foot to keep the space negative relative to surrounding areas. Most of these areas I've seen are in loading docks or areas where room conditions (e.g., open bay doors) would preclude full air conditioning.
I agree with provisions for drainage and a daily wash-down.