Egg Harbor Twp, Brigantine and Galloway went 800 E several moons ago. In a effort to improve interops and to promote a central dispatch Atlantic County bought from the 3 towns the towers, etc that where installed and then expanded the system to Downbeach and the western parts of the county.
Atlantc County has talked about central dispatch from at least the mid 70s when they proposed a 4 channel county wide police system that would be color coded (gold band, blue band, etc) with the main tower being located on top of the Atlantic City Race Track grand stands in Mays Landing. That never happened and I don't think central dispatch will happen in my life time.
The big push for the latest 800 E system that had 'interops' was an armed robbery in Pleasantville of the UPS distribution center on Leeds Ave about 9 years ago. Everyone was up in arms that EHT could not talk to Pleasantville and Pville could not talk to Absecon, etc, etc. The joke now is that after all these years Pleasantville is still on 155 VHF and never went 800.
To clarify the earlier post everyone is on the 800 E system with a few exceptions. Most of the FD/EMS that you hear are simulcasts.
Here are the exceptions: Somers Point, Linwood, Pleasantville, Buena Boro, Buena Vista Twp and Estelle Manor all remain on VHF as far as I know. Atlantic City is 800 MOT. I believe Hamilton Twp, EHC, Hammonton & Mullica FD are still on VHF but have been assigned 800 E tgs.