The trash is integral to the game's story/lore. Yes, really. Doctor Dee, the guy who worked at Alpha before us, realized what was going on, kind of vent insane, stopped giving a fucking and trashed the place.
If you hate cleaning get a broomba. It should help you with that. Also buy the mop. Don't use the sponge. Cleaning anything with a sponge (with the exception of sink and toilet) takes WAY too god damn long.