At right is a shot during excavation in the field, taken across the septic tank toward the mouth of the West Trench Extension, as I have called it, in the background.  (Indeed, that is me shoveling in the opening, identifiable by my signature red kerchief).  The heavy white line traces the same profile as appears along the borders of the model at left.  Note at right a plastic sheet over the tank edge and some overburden not yet removed.  The arc of the basins is yet obscured at this early stage; the model is shown as the excavation appeared at end.  Note also red flagged holes in both shots: every attempt at veracity was maintained in creation of the model.