nder normal conditions your septic tank should be pumped every 3 to 5 years, to remove accumulated solids for final disposal in approved facility.  The inlet and outlet baffles should be inspected with each pumping and replaced if necessary.  

For ease of maintenance the homeowner should keep a record in the home file of distances from the building corners to the access cleanout cover. This should be provided to septic tank pumper, however in many cases the pumper may require that the cleanout covers are dug out and exposed prior to their arrival.  The pumper should access the septic tank from the cleanout cover in order to allow the pump hose to access the entire sludge bottom