Users of a trunk system operate on talk groups. Each common group of user has it's own talk group assigned.
In the case of the Oceann County System, Bay Head & Mantoloking Police are dispatched for calls on the Police North Talk Group, 288. They also use the Police North Mobile Talk Group, 352 if they have something to discuss between themselves or with dispatch so as not to tie up the dispatch talk group. Bay Head units are designated 201 to 299. Mantoloking units are 1901 to 1999. Island Heights PD uses the Police West Talk Group, 512 for dispatch. They share it with Lakehurst PD. Island Heights units are 1000 to 1099 and Lakehurst are 1301 to 1399.
Lavalette Fire Department (Station 69) is dispatched on the County UHF Fire Dispatch frequency 508.1875 PL 71.9. All of the FD that are dispatched by county are dispatched on this frequency except for Lakehurst (Station 62) and Lakehurst Naval Air Station (Station 63), for mutual aid to Lakehurst. They are dispatched on County Low Band Fire Dispatch 33.7800 PL 146.2. Lakehurst and the Naval Air Station operate on either County Low Band Fire 4, 33.980 PL 146.2 or County Low Band Fire 7, 33.020 PL 146.2 (not sure on that one).
Lavallette FD operates on the County Trunk System Fire Zone 1 Talk Group 20512, You will also hear other departments on the same talk Group, but Lavallette units are 69xx.
Bay Head & Mantoloking FDs are dispatched on the 508.1875 PL 71.9 frequency and their primary fire ground/operations frequency is 506.7125 DPL 223 (The County Conventional Lakewood Fire Repeater). Their secondary fireground frequency is 507.2625 DPL 223.
All of the information, complete and up to date, pertaiining to Ocean County and the trunk system can be found at the two links below:
http://www.forums.scan-nj.com/index.php?showtopic=239
The basic trunk system information is located at the top of the page and further down, after the conventional frequency information, you will find more specific information pertaining to the trunk system talk groups.
http://www.eastcoastscanning.com/viewtopic.php?t=6
I don't know how familiar you are with trunk systems, but here is a link that explains about them and how they work.
http://www.police-scanner.info/scanning/trunked-radio-systems.htm
I may have given you some info you already have. If you have any more questions, post and we'll help you.