Steve Jensen says: "I believe the vaguely shaped, East-West oriented structure(s) crossing the trench most likely is the Watson conduit. The Watson conduit was encased in concrete whose shape was determined by the surrounding soil acting as a 'form' at the instant of the pour. Hence the irreguler shape.
"In addition, there may have been a need to flatten out the 2 over 2 configuration to a 4-wide configuration to squeeze the conduit bank through a tight vertical clearance in the vicinity of the trench in the photo. David Millman might be able to offer a little insight re: was Vace looking specifically at what he thought was the Watson conduit; I believe David might have taken the original snapshot."
Photo: Dave Millman, via Steve Jensen.