31 



3.3.3.2 Montana 



Samples were collected from monitoring wells 7, 16, and 24 during 2002. Well 7 is completed in Hart 

 Coal, well 16 is completed in the Fort Union Formation, and well 24 is completed in alluvium. No 

 significant changes in TDS were observed in monitoring wells 7 and 16. The TDS in the alluvium (well 

 24) has returned to the pre-1996 values. Changes in total dissolved solids with time for the above wells 

 are shown in Figure 3.18. 



Total Dissolved Solids 



750 



-Well 7 

 -Well 16 

 -Well 24 



Figure 3.18 Total Dissolved Solids in Samples from Montana Wells. 



