How Often Should Septic Tanks Be Pumped?

In 35 years we've only needed to pump our septic tank once.  However, I've heard they should be pumped every 4 to 5 years.  Is there any truth to this?  We have t3- bathroom home in Texas with the usual dishwasher and disposer in the kitchen, washer and dryer, etc. 

The Money Pit Answer

It's generally a good idea to pump the average 1500 gallon septic tank every 4 to 5 years.  Pumping the tank provides an opportunity to remove solids that otherwise haven't been distrib to the septic fields, while keeping healthy bacterial balance in - which ensures that waste continues to degreade as it's designed by do.