Computers and Electronics How often should a septic tank be emptied? How often should a septic tank be emptied? every three to five years What is the normal level of a septic tank? between 8” to 12” How do I find the top of my septic tank? You can locate the lid of your septic tank by poking the ground every few feet with a metal probe. Lids can be buried up to a foot deep on average, so be sure to investigate any bumps that may indicate something is buried underneath.Apr 7, 2020 Related Posts:How big is a septic tank cover?How much is a septic tank top?How long does it take poop to decompose in a septic tank?How do you make a septic tank cover?