I'm not sure exactly what the question is here. This is a site on the Palmetto 800 system. I expect that it operates exactly like all other sites. I suspect it carries most/all radio traffic for Berkeley County agencies, along with any state agencies operating in the area (like SCHP), as well as occasional radio traffic from neighboring agencies like Orangeburg County, Williamsburg County, Dorchester County, etc. The fact that it's using 700MHz channels instead of 800MHz channels is not particularly significant as most subscriber radios can support both bands.
I do not believe this is like Charleston County and Beaufort County, where the County runs and manages the system and only allows county agencies to use it (no state agencies). I suspect it's more like Florence and Sumter Counties where the site carries both County and State agencies.
I do wonder if the pre-existing Berkeley County sites (Moncks Corner and Russellville) continue to operate or if either/both were combined with the simulcast site. I haven't see confirmation either way on that question.