8.b) Tiller 2008-2014 hydrograph with threshold_newGROUNDWATER ELEVATIONS AND EXCAVATION THRESHOLD
5/2008- 10/09/14
TILLER MINE
SCANDIA, MINNESOTA
930.00
920.00
0116 117
in 900.00
E
M
r-
.2 890.00
to
d
W
880.00
870.00
860.00 ,
7 57, 7 A, 7 Q, 7 Q, 7 57, 7 St, 7 A, 7 its 7 St, 7
0�7 77 0�7 77 0�7 72i 0�7 7S 0�7 757 0�7 7R 0�7 7S 0�7 76 0�7 7> 0,7
006 �O� 7�0, X08 7�OS OQ `�/Oy X70 v'�70 �j7 s7�77 X72 R�7�, /7up s-7�, �.7 6-7St '7S ��75
Date
♦ PZ -4 PZ -5 A MW -1 0 MW -2 (aband. June 2011) x PZ -6 Prod Well PZ -3 Pond
Note: Anomalous water level measurements in PZ -6 on May 12,
2014 and PZ -3, PZ -5, and PZ -6 on June 18, 2014 presumed to
be measurement error per communication with Tiller staff.
50 Feet
Excavation cannot go greater than 50 ft below the lowest water table
elevation (915.87 ft amsl) measured in PZ -4 in 2008, which is the
baseline established in the groundwater protection plan. This
threshold elevation was calculated at 865.87 ft amsl based on the
October 30, 2008 PZ -4 water level measurement.
V
865.87 feet amsl
860.00 ,
7 57, 7 A, 7 Q, 7 Q, 7 57, 7 St, 7 A, 7 its 7 St, 7
0�7 77 0�7 77 0�7 72i 0�7 7S 0�7 757 0�7 7R 0�7 7S 0�7 76 0�7 7> 0,7
006 �O� 7�0, X08 7�OS OQ `�/Oy X70 v'�70 �j7 s7�77 X72 R�7�, /7up s-7�, �.7 6-7St '7S ��75
Date
♦ PZ -4 PZ -5 A MW -1 0 MW -2 (aband. June 2011) x PZ -6 Prod Well PZ -3 Pond