septic tank maitenance - pumping out req'd?

[notrub]

Is it necessary to ever empty a (DAP-DOP ? brand) septic tank that is little used and only ever has poop flushed into it.  No grease, oil, soap or anything except people poop.  There is a large soak away for liquids (pee) and flush water.  I put a bag of that dry compost product in there about every year.   I am under the impression that under these circumstances the 1000 L tank itself will biodegrade the solids and will never need to be emptied by pumping into a truck.  Is this true?  I have buried my tank and do not have easy access to it so pumping will mean digging a hole down to it to find the lid.   I have not found any documented evidence that this is true but I have heard, from time to time, that this can be true.  Any comments please?  Thanks in advance.

[DeputyDavid]

DOS tank maybe?  I have three. Have heard people tell me they haven?t had to pump theirs in 12 or more years. You should have a 1? pipe coming out of the ground for venting the tank, a 4?pipe for the septic truck to access in case solids do need to be pumped out or the heavy rain fills it up. The outlet should go to a leech field or in my case I have 2 sets of the large cement rings five high that the black tank drains into the first set then overflow to second set then out to the field if it gets that full. Hope this helps.

If it is a tank with the plastic mesh inside to let the bacteria grow on, you will not be able to pump it out from the big lid you have to access through the 4” hole.

[notrub]

Thanks for that.  There is a mesh on top, I think, but my vent pipe comes off the feeder pipe some distance away.  A person in France told me they had not pumped out their tank for over 20 or 25 years and never had a problem.  So, your comment is the one I wanted to read, thanks.  We have 2 toilets and a 1000 L tank for each as they are at opposite ends of the house.  Thanks again, B