I agree with Billy, try the SC PSA system. Control channels in Aiken county might be 937.7375, 938.1625, 939.7125, 937.7375 and 939.6625. In Lexington Co., try 939.2000 and 938.7000.
The Palmetto 800 talkgroups for Aiken Electric posted in the database are based on some pretty old trunker data. Very well could be outdated and no longer accurate. I had 1 more in addition to those in the database, 5776. Try scanning local sites in open mode and look for active talkgroups with values below 6000. There are probably a lot of active SCE&G groups too, and it'll take some listening to figure out what is what.
Good luck, and make sure to post what you find.