This is the side of the extension where the drain turns 90 degrees and heads toward the front of the house with another black plastic inspection chamber which is vaguely located near the base of those scrap doors leaning near the corner.   Over this area we intend to build a serious patio. I expect the pipe will again be just be covered by backfill, nothing graded. But will be a lot deeper than the first section. Wondering if this will need redoing before we build the patio.