Grease collection can be anything from daily to every 6 months, depending on your buyer and your volume generated.
Anything that comes out of a grease trap you do NOT want to store inside the building.
At a minimum, old fryer grease needs to refrigerated (about 7 days max) or frozen (indefinite storage).
Most restaurants don't have the available fridge or freezer space to store waste product, and it's generally not acceptable to co-mingle product for consumption with product for disposal. Your establishment could be written up on the spot if a health inspector found it being stored together, labeled or not.
The stuff really belongs outside of the building.
It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.