STUDY NUMBER ; 10.2 



ORGANIZATION : University of Montana (UM) - Department of 

 Geology 



TITLE OF STUDY ; Determination of Heavy Metal Contamination 

 in Reservoir Sediment Along the Clark Fork River, Missoula to 

 Heron, Montana 



CONTACTS ; Johnnie Moore - Department of Geology - U of M - 

 243-2341 



Carolyn Johns - Department of Geology - U of M - 

 243-2341 



OBJECTIVE ; Determine the concentration of heavy metals — 

 arsenic, copper, cadmium, iron, lead, manganese and zinc--in 

 the lower river reservoir sediments and compare these to 

 values found in Milltown Reservoir. 



DURATION ; 1984 - 1986 



CURRENT STATUS ; During the summer of 1984, grab samples of 

 reservoir sediments were collected from Milltown ( 27 samp- 

 les), Thompson Falls (7 samples), Noxon Rapids (14 Scimples) 

 and Cabinet Gorge (7 samples). Additionally, core samples, 

 averaging 25 cm in length were collected at Thompson Falls (3 

 cores) and Noxon Rapids (5 cores). Six cores, approximately 

 150 cm in length, were collected at Milltown. Two heavy 

 metal extraction techniques were utilized; acetic acid (25% 

 v/v) and total, which involves a four-hour digestion in hot 

 aqua regia. 



Preliminary results from the acetic acid extractions 



62 



