Septic drainage pipe - Where to find?

We want to pump out the septic tank, but no one can find it. Previous owner doesn't know where it is, and the health department has no record because the house is so old. We've had various plumbers and septic people out to the house, most of which probed the ground with a stick. One guy snaked...

The pipe that my ac condensation goes to keeps over filling if the AC is on for a certain amount of time. I assume it is clogged, can I just use a liquid to clean this, thanks.

I have recently moved into a house(not new) and put in a washing machine. I have noticed( not like it is hard to miss) that the water very quickly begins backing up out of the drainage pipe and over flows, soaking the dry wall and floor. I believe there was something in the pipe causing a blockage...

Various issues to deal with here, I think. Just moved into a 1 1/2 storey duplex. When draining the kitchen sink, the bathroom sink fills up with waste water and both drain very slowly. The two sinks are opposite one another (separated by a wall), so I assume that they are connected to the same...

My house was built in early 70's..No plastic..I'm putting in a new sink and had to remove the wall pipe that goes into the wall..I needed a longer one. It seem where it goes in behind the wall into the plumbing there was some type of gasket as pieces of it fell out when I removed the pipe..I can...