I know it is a shi##y subject so someone here should have an idea. We have had a couple blockages to deal with and nothing I care to do often. The diagram is close to what I have except the inlet pipe is only about four inches from the first baffle. The first baffle on our tank is shorter with the top just above the bottom of the inlet pipe. When it happened last fall I dug up the access hatch and found toilet paper plugged up between the inlet pipe and the baffle. I thought I might have fixed it by grinding the top of the baffle smooth, very rough casting in that area.
Not using toilet paper is not an option and my wife no longer tosses Kleenex or toilet paper she used to wipe off make-up so just the necessary stuff. If this happens again my idea is to cut back the inlet pipe so there is more space for the toilet paper to drop into the tank and not hang up. It is not the worst thing in the world, I bought a heavy duty snake and I can just pop the plug out of the cleanout by the house and have it cleared in a couple minutes. Any way that is what I have and my idea to deal with it, any suggestions will be welcome but unless it gets worse I am not going to deal with it until the weather is a lot better. Thanks, Jim.