Yes. South Carolina requires DES approval and a permit to install a septic system on any property not served by public or community sewer, and the county cannot issue a building permit without that septic approval already in place.
Getting there starts with a site evaluation: soil type, slope, bedroom count, and the location of wells, property lines, surface waters, buildings, and driveways all get reviewed before a
permit to construct is issued. Once the system is built, an inspector comes back out to verify the installation matches what was approved before the final operating permit is signed off. Skipping this process isn't a shortcut. It's a system that can't legally be tied into the house, and a problem that surfaces the moment you try to sell.