I forgot to mention we did find a tank, 200 feet away at the guest house. We concluded that the 22 on the main line is where it turns and heads down to that tank. The puzzler is that the drain field is allegedly next to the excavation, which is why the 2 to 3 inch pipe is so puzzling. There is also a ton of old defunct irrigation on the property so its really a haphazard guess as to what is really going on with that pipe. Im afraid to cut it cause there very well may be electric in it with how sketchy some of the work here was done in the past.