3.3.2.2 Montana 



Water levels in monitoring wells (6, 7, 9, 13, 16, 17, 19, and 22) that penetrate the Fort Union 

 Formation and/or the Hart Coal Seam rose during 1997 and 1998, and then levelled off or fell between 

 1999 and the end of 2003. Heavy snow accumulation and subsequent melting caused water levels to 

 rise to near record highs in wells 6, 7, 9, 16, 19, and 22 during 2004 and 2005. Water levels in all of 

 these wells except well 9 declined during 2005. There appeared to be no short-term responses to the 

 snow melt in wells 13 and 17, but water levels in these wells have slowly risen since late 2003. 

 Hydrographs from selected Fort Union and Hart Coal Seam wells (6, 7, 17, and 19) are shown in 

 Figure 3.16. Offsets noted in the legend have been applied to the data to separate the traces and make 

 the hydrographs more readable. Hydrographs of selected Fort Union/Hart Coal Seam wells (6, 7, 17, 

 and 19) are shown in Figure 3.16. 



-*»**«^*«<, 



^^^^'^^^^X*^ 





o>OT-c\joO'*mtor-oocnO'-c\jcO'«tincor~-ooO)0'-<Nco5i£><Dh-oo 



r^COOOOpOOCDCOCOQOOOOOO)030>050>0)050>Cn050^CpOOCpCpCpCp 



cccccccccccccccccccccccccccccc 

 ajcC(0<0(Oed(Dcococo<ococo<0<Oeo<oaJ(C(0<0(D<0(OTOroa3<otota 



-3-3-3-3-3-)-3-5-5-3-3-3-)-l-3-J-3-3-3-3-)-3-3-5-J-3-3-3-3-> 



Year 



—•-Well 6 (GWIC 4227: +10 ft offset) -s-Well 7 (GWIC 4267: +7 ft offset) 



-A-Well 17 (GWIC 4297: -3 ft offset) -»*-Well 19 (GWIC 4290: -5 ft offset) 



Figure 3.16 Hydrograph of Selected Wells - Fort Union and Hart Coal Aquifers 



24 



