and limited groundwater modeling is being conducted below the 

 reservoir. Thus far, the FS has narrowed the list of clean up 

 options to six potential alternatives, ranging from no action 

 to complete dam retirement (with stabilization of sediments and 

 reestablishment of a f reef lowing river). Other alternatives 

 include excavation, "institutional controls," chemical stabiliza- 

 tion of sediments and channel isolation (with the reservoir left 

 in place). However, with the recent reauthorization of Superfund 

 and subsequent requirements in the law, portions of the FS will 

 need to be readdressed including a reevaluation of the potential 

 alternatives. 



FUTURE ACTIVITIES ; The Data Report which addresses the recent 

 monitoring and modeling will be completed by early 1987. The 

 FS, including selection of a preferred alternative, will be com- 

 pleted in the summer of 1987 barring any major deficiencies in 

 the data as a result of new requirements from the reauthorization 

 of Superfund. After a 30 day review period, public hearings 

 will be conducted to allow comment on the preferred alternative. 

 Following selection of the preferred alternative, design and -,• 

 implementation of clean-up could begin sometime in 1987. The 

 Superfund activities have a significant bearing on the Montana 

 Power Company's application to the Federal Energy Regulatory 

 Commission for relicensing the dam. (See Study 14.1.) 



PUBLICATIONS AND REPORTS 



Arsenic Source and Water Supply Remedial Action Study, Milltown, 

 Montana. July, 1984. 



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