146 Bulletin 80 



Solid Wastes 



Following this request, the writer began a study of the prob- 

 lem in May, 1904, which resulted in the publication of Bulletin 

 53 of the Arizona Agricultural Experiment Station, September 

 20. 1906. This publication established the fact that irrigating 

 sediments, in general, may be beneficial or harmful according to 

 their composition and physical character and to the manner of 

 their disposition in or upon the soil. If allowed to accumulate 

 upon the surface of the soil in the form of more or less im- 

 pervious silt-blankets, their influence, by limiting the supply of 

 water and air to the soil, is notably harmful. In the case of 

 the mining wastes from the Clifton-Morenci district, which are 

 particularly plastic and "tight" in character, the damage done 

 was found to be greater than that resulting from sediments aris- 

 ing from ordinary erosion. It was determined that the damage 

 from these wastes, particularly to alfalfa and other crops which 

 cannot receive constant and thorough cultivation, was of an in- 

 creasingly serious character. 



The farmers of Graham County, represented by one of their 

 number, finally brought suit against the Arizona Copper Com- 

 pany. Limited, for discharging tailings into their irrigating 

 water-supply. The case was decided in the District Court of 

 Graham County in favor of the farmers, and an order was issued 

 in November, 1907. effective May 1. 1908. restraining the mining 

 companies from discharging "slimes, slickens or tailings" into 

 Chase Creek, the San Francisco River, or the Gila River. The 

 case was appealed to the territorial Supreme Court where, how- 

 ever, the decision was confirmed in ]\Iarch, 1909. The case was 

 again appealed by the Arizona Copper Company to the Supreme 

 Court of the United States, where it was again and finally de- 

 cided in favor of the farmers on June 16. 1913. 



During and since the occurrences above mentioned, large 

 quantities of solid wastes have been impounded by the copper 

 companies in settling basins constructed for their storage in the 

 district. Recent investigations by the companies indicate a pos- 

 sibility that with copper at 15 cents a pound these stored tailings, 

 which average about 0.85 per cent copper, may be profitably 

 I'cworked. 



