Results of the surface soil sampling (in milligrams per 

 kilogram [mg/kg]) are provided in Table 3-9. Typical 

 concentrations in natural soils are provided for comparative 

 purposes. The following trends emerged from this study 

 (Tetra Tech 1987) : 



• Concentrations of heavy metals and arsenic 

 decreased with increasing distance from the 

 smelter. 



• Soil contamination is most pronounced in the 

 prevailing wind directions (to the northeast up 

 the Deer Lodge Valley and to the southwest up the 

 Mill Creek Valley) . 



• At all sample sites except the tilled sites, the 

 metals were concentrated in the to 2-inch 

 interval . 



• At the tilled sites, metal concentrations were 

 similar in the to 2-inch and 2 to 10-inch 

 intervals and considerably lower than those in the 

 to 2-inch increment at the untilled station in 

 the pair. 



• The heavy metals and arsenic have not moved beyond 

 ten inches. Most of the values in the 10 to 25- 

 inch increment were below detection limits or 

 within the range for uncontaminated soils. 



In the area immediately surrounding the smelter (within 

 one to three miles) , much of the land is devoid of vegetation 

 or very sparsely vegetated. This could be due to heavy 

 metals and arsenic contamination but may also be due to poor 

 soil moisture conditions, poor macronutrient status, or some 

 combination of the above. Most of this land is owned by the 

 Anaconda Minerals Company. 



Farther away from the smelter, vegetation is well 

 established and land uses, such as growing crops, are not 

 precluded despite above-normal metals levels. It appears 

 that tillage results in lower levels and a more even 

 distribution of metals in the upper ten inches of the soil 

 profile, which may allow successful establishment of crops. 

 However, it has not been clearly documented whether heavy 

 metal contamination in the Deer Lodge Valley has resulted in 

 reduced crop yields. One study, performed by Munshower 

 (1977) while the Anaconda Smelter was still in operation, did 

 assess cadmium contamination in the Deer Lodge Valley. He 

 compared cadmium levels in soils, plants, and animals from a 

 site 15 miles northeast of the smelter with those from a 

 control site near Bozeman, Montana (Gallatin Valley) . 



3-38 



