Any pool that has a slide will have a lifeguard (when the slide is open). Most, if not all, quiet pools do not have lifeguards. Currently, no pool at OKW has a lifeguard. Once the slide is added to the main pool, that one will have a guard on duty.
I think the All-Star/Pop Century pools don't have slides but because of their large size do have lifeguards -- someone please let me know if that's correct or not.