The pipe is hard to see, but the pipe runs up out of the ground then turns down. I would say this is trap in the line. Has there ever been a time this would of been approved. The house was built in 79. The water heater is a 2000 model. Click to Enlarge 76.68 KB Here is where it runs out the wall in the lower level of the house Click to Enlarge 51.96 KB