APPENDIX H 



-jun-e. ?-■?. /^'?S 



Ml 



Horse Mine Dam eroded 



by roiioff from heavy rams 



Bv CARLA BECK 



Tribune SUff Writer 



The old Mike Horse Mine Dam, actually 

 a huge mound of mine tailings backing up 

 an old «-dimert pond, was eroded by 

 runoff irom a recent intense rainstorm, 

 sending quantities of tailings into the 

 headwaters of the Blackfoot River. 



Formerly a White Hope Mines Inc. 

 property, it is now owned by Anaconda 

 Co. It is located in the Heddleston Mining 

 District, 18 miles east of Lincoln and 

 about three miles south of Montana 

 Highway 200. 



According to second-hand accounts, this 

 is what apparently happened. During a 

 rainstorm the night of June 19. a landslide 

 blocked a diversion ditch that earned 

 w3ter artjund the old tailings deposit. It 

 also plugged an outlet for a drainage that 

 intercepted clean water at the head of the 

 pond. The water then could not go out the 

 normal outlets so it topped the tailings 

 and eroded a large channel through the 

 tailings. 



Max Boiz of the Water Quality Bureau 

 of the Department of Health and En- 

 vironmental Sciences said Anaconda 

 crews have been at the site repairing the 

 diversion ditch and reopening the old 

 drainage outlet. 



Frank Laird, head of environmental 

 engineering for .Anaconda's General Min- 

 ing Division. Tucson, flew by company 

 plane into Butte Thursday noon. He was 

 reponed en route to the Mike Horse area 

 Thursday afternoon and could not be 

 reached for comment. Jim Adier, Butte, 

 who handles all exploratory work m the 

 Heddleston and Stillwater, including land 

 mine reclamation, also could not be 

 reached. 



An Anaconda official who did not want 

 his name used said his information was 

 sketchy at this point but that an engineer 

 and others were examining the area to 

 determine the best method of preventing 

 funher deterioration as well as deciding 

 what should be done with the material 

 that's been displaced. 



James A. Posewitz, chief of the En- 

 vironment and Information Division of 

 the State EV^p.'inment of Fish and Game, 

 said he could not fault Anaconda for not 

 getting after the problem. 



Bou said no damage assessment could 

 be made at this lime. He said what the 

 bureau fears is that the tailings, all as- 

 sociated with metallic mining, will react 

 with the water to form an acid condition 

 and also release to.\ic metals into the 

 water. He said there could be no: only the 

 immediate problem of suspended 

 material but also the Inngierm problem 

 due to toxicity. 



"I can assure you there is substantial 

 stream damage due to the ruptured dam. 

 Ho'.i.e\er, v.'e won't know the actual de- 

 tails until we have the opportunity to get 

 in there and evaluate the stream over a 

 period of time. Fortunately, we have good 

 water quality records from the past and 

 records of biological conditions, so we can 

 compare and make a judgment. It w;ll 

 take several _\-ears to really under?tai')d 

 what effect this has had. We're hopmg the 

 effects won't be as bad as it looks now," 

 Bot; said. 



Botj !s hoping the high stream flow will 

 mitigate the damage somewhat. He has 

 sun'eyed the damage from the air and 

 below Landers Fork the gray tailings 

 could not be distinguished from the 

 muddy wa'er of the ruer. 



"it's my opinion those tailings will go 

 many miles down the Black'oC'i and the 

 Clark Fork. A lot won't deposit in the 

 stream bottom but will be carried a great 

 distance and be deposited ;n such rmall 

 quantuies that they won't be a prc'rlem," 

 he explained, emphasizing th.-.t the worst 

 problem will be near the dam. 



A-61 



