The talkgroups on the Land Air System that are used for Public Safety are completely encrypted. There is no way for the end users to turn off the encryption. The conventional NXDN frequencies for public safety for Sevier County were also encrypted when they upgraded a lot of the radios in Sevier County. They are programmed that way in the Sevier and Jefferson County radios. You can montior these in Sevier County for Public Safety other than TACN: INTERAGENCY (460.500), SEVIER FIRE PAGE, MED 9 (PAGING & BACKUP), SEYMOUR FIRE DISPATCH, and GATLINBURG FIRE RESCUE ANALOG (PAGING). Seymour Vol. Fire also uses TACN but it is used for secondary comms like talkaround and sometimes for incidents as well. GSMNP VHF frequencies are also a good one to program for Sevier County they sometimes repeat what comes across land air. They also have use of TACN which is linked to their VIPER Talkgroup.
Also, Cocke County Sheriffs Office can still be heard on their NXDN conventional frequency and their analog frequencies. Jefferson County Fire and Rescue agencies are still paged off their analog repeaters. You can also still monitor White Pine Police, White Pine Fire, and Baneberry Fire on NXDN conventional (Land Air is not their communications provider) within Jefferson County.
One more thing, I would keep an eye out for some changes because there is some talk of a user on the Land Air Trunking System leaving the system for the TACN system because the administration of that agency wants to be on the system that the Troopers use and have those type of radios. There is talk of it happening in a couple of years but nothing is official yet.