THIRTY-FIFTH BIENNIAL REPORT 53 



eliminate solid or other prohibitive substances from such sources have 

 been partially effected and are in progress at many other plants. 



The rapid development of the mining industry has resulted in a 

 major pollution problem. Quartz mills, dredgers and hydraulic opera- 

 tions all produce effluents that menace spawning areas, fish foods, 

 recreational activities, domestic, industrial and agricultural water sup- 

 plies and even navigation. Considerable progress has been made in 

 providing permanent impounding of mill tailings and in the Trinity 

 and Klamath area. The revision of section 482 through the Quinn bill 

 has aided materially in maintaining river clarity for the period from 

 July 1 to November 30. During the restricted season constant patrol has 

 been maintained in cooperation with an engineer assigned by the Gold 

 Producers of California. 



Tailings from bucket and drag line dredges have been particularly 

 difficult to control and due to their tendency to stay in suspension and 

 remain muddy after settling and filtration, the pollution staff under- 

 took research work which resulted in the development of a chemical 

 method of clarification that can be installed and operated at small 

 expense. Recent installations indicate tliat satisfactory clarification f)f 

 the most refractory effluent can be obtained l)y tliis method. 



Tunnel drainage from both active and abandoned mines, causes 

 extensive damage to certain streams due to the presence of acid and 

 metals dissolved from deposits of ore through the action of air and 

 water. The gravest danger from this soui-ce occurs when large volumes 

 of tunnel water are pumped out to dewater a tunnel preparatory to 

 resuming operations at an abandoned shaft. Tn one such instance fish 

 were killed for sixty miles downstream and immediate action was 

 necessary to minimize further damage. 



"While it is not desired to emphasis court action, the record, as 

 shown below, is indicative of the increased attention being given to 

 pollution control. 



POLLUTION CASES 



Fines 

 Period Arrests imposed 



7/1A^-6/30/.S6 14 .^".O 00 



7/1/86-6/30/87 46 2,210 00 



7/1/37-6/30/88 64 6,305 00 



Section 481 of the Fish and (lame Code, on water pollution, is well 

 Avorded and more recent interpretation of its provisions has permitted 

 the control of various substances, obviously damaging to water 

 resources, which had not been considered covered by this section 

 previously. At the present time no changes in its provisions are 

 recommended. 



