We have a "three bedroom" (1973) ranch in Rhode island. We had the tank pumped the
First time..when the house was about 20 years old. Two adults, clothes washing machine, and NO dish washer.
We now have the tank pumped every 3-5 years whether it needs it or not. Cheap insurance. The last time we pumped it was when a neighbor had to replace his leach field for about $20K. His new leech field looked very high tech....not just a few PVC pipes and sand like the old days.
Our last pumping 3 years ago was $205. incl disposal (1200 gallons) and senior's discount. NB