Commercial food service is a different animal, the tank sees far more grease and solids than a house does, so residential intervals don’t apply at all. Slow kitchen drains are worth acting on immediately given what a closure costs you. We run a small place too and use Rock Solid for Septic Tank Cleaning in Spartanburg on a set schedule rather than waiting for symptoms, which has kept us out of trouble. Ask for the disposal documentation each time, you’ll want it if DHEC ever asks. And get the grease trap interval reviewed at the same time, the two problems tend to travel together. Keep copies of every service record on site as well, it makes any inspection conversation far shorter.
