STUDY NUMBER ; 3.1 



ORGANIZATION ; Montana Department of State Lands (MDSL) 



TITLE OF STUDY ; Aquatic Resource Studies Associated with ASARCO's 

 Rock Creek Project 



CONTACT(S) ; Kit Walther - Montana Department of State Lands, 



Helena - 444-2074 



Jim Vashro - Montana Department of Fish, Wildlife 

 and Parks, Kalispell - 755-5505 



OBJECTIVE: Establish baseline water quality, water quantity, 

 fishery and other biological conditions for Rock Creek, Sanders 

 County, Montana. 



DURATION ; 1984 - 1987 



CURRENT STATUS ; ASARCO is proposing to develop a silver-copper 

 deposit in the Cabinet Mountains, approximately five miles north- 

 east of Noxon. The site is beneath the Cabinet Mountains Wilder- 

 ness Area near St. Paul and Chicago Peaks. Mining, and most 

 of the crushing and ore concentrating, would occur underground 

 within a room-and-pillar excavation. Tailings would be slurried 

 to a tailings dam, located one quarter mile from the Clark Fork 

 River. 



In April, 1985, WESTTECH, a consulting firm hired by ASARCO, 

 finalized a study plan for the collection of baseline aquatic 

 resource data within the Rock Creek Drainage. Sampling began 

 in the spring of 1985. Ten surface water stations will be sampled 

 seasonally (biweekly during spring) for the analysis of 33 major 

 water quality parameters, including common ions, nutrients and 

 heavy metals. (To achieve maximum detection limits, carbon fur- 

 nace techniques will be utilized for the heavy metal analysis.) 



At least eleven groundwater monitoring wells will be install- 

 ed; several of these will be monitored quarterly for the same 

 water quality parameters analyzed during the surface water collec- 

 tions. All presently existing wells and springs within the pro- 

 ject area will be sampled for their water quality and water yield. 



Seven aquatic invertebrate and periphyton stations will 

 be sampled three times per year, during pre-runoff, summer low 

 flow and autumn. Species present and their abundance will be 

 reported. Diversity indices will be calculated. 



The Montana Department of Fish, Wildlife and Parks will 

 conduct baseline fishery resource investigations on Rock Creek 

 and on the Clark Fork River above and below the confluence of 

 Rock Creek. Fish population estimates will be conducted at five 



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