John, the trenching was at $6.40 a foot with corrugated 4" solid and perforated pipe (per my design) as back filled with concrete sand. The site is comprised of mostly sandy soils (located on the shores of a lake)and extremely easy to trench. The grading, repair to existing septic system, and the installation of a five station irrigation system is all extra. Right now the job has already experienced two change orders taking it from $9,800 to approaching $11,500 with a finish time of three more days. Total out of pocket expenses including all equipment rental, labor, irrigation parts, etc is right at $4,189.00. Not bad for myself, two employees and five days of work.