How Often Should I Have My Septic Tank Pumped?
As a rule, tanks should be checked for solids buildup every year and pumped every three years.

In practice, however, the lifestyle of the family using the system and the size of the tank influence how often the tank should be pumped.

In any case, do not wait to pump the tank until the plumbing system backs up in your home. Solids overflowing from the tank can seriously damage the soil absorption system.