I'm getting insight like I never expected on what happens AFTER you flush the toilet. Being out in the country, we are on a septic system. I'm not sure what I pictured as a septic tank, but it wasn't this:
This big concrete box is our septic tank. And if you REALLY want to, you can access the inside through these port holes on top.
The sewage flows from the house into one side of the box. Here is what the inside looks like (um...this picture is sideways and I can't fix it, so cock your head to the right)
Although the far wall looks solid, it ends about 2/3 of the way up the wall of the tank. The sewage pours into the first side. As the first half fills, the solids sink, and the liquids flow over the divider. Once the liquids reach the level of the "out pipe" on the far side, they flow out to the leach field, a series of perforated pipes out in in our pasture.
In a perfect world, the solids break down and the system is self-sustaining. In reality, the solid side usually has to be pumped out every so often. And those portholes are how it's done!
So now you know the scoop on the poop. Tell your friends!