Millenacker, D.I., 1989, Introduction to the environmental permitting process for in situ copper mining, in In situ leach mining, Proceedings - Bureau of Mines Technology Transfer Seminars, Phoenix, AZ, April 4, and Salt Lake City, UT, April 6, 1989: U.S. Bureau of Mines Information Circular I.C. 9216, p. 14-17.