Crazy septic system. What is this?

[aoreidmarr]

So, I'm doing a leach field repair. The repair itself is easy enough. I just have to replace a section of abs. But I've never seen a system like this before, and I'd like to understand it. If you look in the picture, that white pipe to the right is regular 4" perforated pvc coming from the septic tank. But then it transitions to abs, goes up at a 45, then horizontal, and then goes into an elbow and then straight down into something. The soil is filled with roots and rocks so I haven't tried to dig any deeper. There's also a concrete mount around the pipe near the top of the 45 section.The only thing I can think of is that it's all some sort of overflow mechanism. Do any of you know what the hell this is?

 

[Hockiologist]

Probably a spillover to the next field line. The small rise ensures line is full capacity before flowing to next line.

 

[aoreidmarr]

Probably a spillover to the next field line. The small rise ensures line is full capacity before flowing to next line.

That’s exactly what it was. Thanks for the response.