TAILINGS are waste materials from a mining operation. As such they still contain minerals of economic value. Since Freeport Indonesia began operation in Papua province in the early 1970s, millions of tons of tailings have been produced by the company, increasing in volume from 7.275 tons per day in 1973 to 31.040 in 1988, and 223.100 this year. The waste materials are dumped into Ajkwa River in what is known as Modified Ajkwa Deposition Area. The