Where Is My Tank

The question is, where is your tank(s) and how deep below grade are the access lids?  To locate your tank:

  1. Get a copy of the as-built drawing from the health department. It should show the size and location of your septic tank(s) and leach field.  See Creates a Septic File under Owner's Manual to learn about as-built drawings.
  2. Measure off the triangulation distances given on the as-built drawing, usually to the center of the inlet chamber lid.
  3. Probe or dig for the lids.  This can be quite difficult if the ground is hard and dry; you may want to pre-soak the ground with a soaker hose for several hours before you start digging.  In most cases, the tank or access lids are within 2’ of the surface
  4. Dig a 30” diameter hole down to the inlet chamber lid.  If your tank is a single chamber tank, it can be properly cleaned through the inlet access lid; but if you have a two chamber tank, you will need to also find the outlet access lid and dig it up.
  5. Open the lid and look for the end wall where the 4” sewer pipe comes into the tank from the house.
  6. Measure off for your tank size, the following distance perpendicular to the entrance end wall of the tank to the center of the outlet chamber lid: 1000 gallon tank = 5.5’-6’; 1250 = 7’; 1500 = 8.5’-9’.
  7. Dig up the outlet chamber access lid.
  8. If you are extraordinarily lucky, the as-built drawing is accurate and you have hit the lids spot on.  If not, keep digging until you find them and correct your drawing.
  9. If your lids are deeper than 8” below grade, you should put risers on to bring the access up to the surface, or at least to 8”.  See Makes Tank Lids Accessible under Owner's Manual.
  10. Put your as-built drawing, properly revised in your septic file.

If you can’t find the tank, either because the drawing is inaccurate or it is deeper than 24”, then you will need to have it located.  Please see Locating Services under Resources.