Dang it. I forgot to mention the two in one tank issue. :duh::duh::duh: I thought about it on my previous post but the thought flew off somewhere.
Our tank, and I think most newer septic tanks have two tanks in the structure. One is for solids and the other for liquids. The outlet from the house goes into the the solid tank and eventually the liquids flow into the second tank. Per our local code ONLY the liquid tank has to have an access riser. :shocked: When the septic tank is pumped the SOLIDS need to be removed but this requires access to the other tank via a different access. This access does NOT have to have a riser per code but it is the side of the tank that needs to be pumped!
WHY the code does NOT require both risers is beyond me. The reason the code requires the one access riser is because that tank has the outflow to the septic field and our tanks have a filter. The code wants to make sure that the filter can be easily checked and cleaned by having the easy access otherwise if the filter becomes clogged, then stuff will start to backup into the house.
A dishonest tank pumper will only pump out the liquid side of the tank and leave the solids behind. Pun intended.

If you have a septic tank that has two sides/tanks, make sure the solids are pumped.
Later,
Dan