The success of the program is highly dependent on the involvment of local Emergency Management staff. If they don't stand behind you, the firefighters and police won't. if they're giving the course, I can assume they do. In other places, the county or individual municipalities give the courses, and the other one won't recognize it. In my opinion, most police officers are highly distrustful of volunteers they don't know (comes with the job), and takes a little while to get on their side. From what I've heard (limited) the jursidictions that do have active large CERT teams are very very pleased with them.

Continue trying to recruit more. Don't forget about local High Schools and Colleges. Everything these days is a "Do not ask what your country can do for you, ask what you can do for your country"