This report provides the program plan, costs and schedule, and engineering-design specifications for an in situ copper leaching field experiment at the Asarco-Freeport McMoran joint venture Santa Cruz site in Casa Grande, Arizona. The field experiment is based on a unit cell concept of direct scale-up to a commercial-scale design which was developed for this site using the algorithms and computer program contained in the draft generic in situ copper mine design manual. The field experiment unit cell design includes integrated testing of two 5-spots and an sx-ew plant with supporting environmental permitting activities. The field experiment has a maximum capacity of 50 gpm and 1,095 tpy copper production. The unit cell consists of a plan of 160 by 320 ft; 160-ft producer-to- producer spacing; well depth of 2,220 ft; leach interval of 322 ft averaging 0.70 pct copper. The time frame of the field experiment is 44 1/2 months at a cost of $15,939,616.