2007-11-07_HYDROLOGY - M1977300

• Permit No: M1977300
• IBM Index Class Name: HYDROLOGY
• Doc Date: 11/7/2007
• Doc Name: Hydrologic evaluation of mine closure & reclamation
• From: Whetstone Associates
• To: Cotter Corpoartion
• Media Type: D
• Archive: No

Schwartzwalder Mine -Hydrologic Evaluation of Mine Closure and Reclamation 38
Table 16. Mine Void Volumes and Observed Inflow Rates During Reblling

Level
Bottom
Elevation

(ft)
Top
Elevation

(R)
Void
Volume

(ft~) Rate of
Water
Level
Rise
(ft/day) Days to
Fill
Level Calculated
Inflow
Rate

(gPm)
Above Steve 6602 6949 2,568,698 --- --- --'
200 6479 6601 609,236 --- --- ---
300 6352 6478 669,047 0.32 440.2 8.7
400 6245 6351 498,698 0.19 299.3 4.7
500 6118 6244 756,206 0.60 238.3 18.7
600 5993 6118 985,274 0.68 183.8 27.8
700 5861 5993 2,360,088 0.63 208.4 58.8
800 5764 5861 256,162 0.88 109.9 12.1
900 5660 5764 2,284,199 0.47 220.0 53.9
1000 5556 5660 1,013,990 1.40 74.3 70.8
1100 5453 5556 784,829 1.96 52.6 77.4
1200 5351 5453 458,321 3.06 33.3 71.4
1300 5246 5351 621,218 3.01 34.8 92.6
1400 5140 5246 125,914 3.60 29.4 22.2
1500 5035 5140 1,273,234 2.57 40.8 162.0
1600 4929 5035 1,174,644 1.85 57.2 106.7
1700 4824 4929 1,061,254 2.17 48.3 114.1
1800 4718 4824 213,873 8.72 12.2 91.3
1900 4598 4718 3,438,490 2.22 54.2 329.4
Notes: Inflow rates for each level were calculated as void volume divided by time to fill.
--- =mine has not filled to top of level
Based on the observed rate of mine flooding and plots comparing the rate of inflow and rise in water level
to elevation and mine void volumes, the following conclusions can be made:
1. The plot of the water level in the mine versus time forms a smooth and predictable curve in spite of
large variations in mine volume between levels (Figure 21).
2. The average rate of rise of the mine pool decreased over time from 5.7 ft/day during the initial
filling of the 1,900 and 1,800 levels to about 0.7 ft/day during filling of the 900 to 600 levels and
about 0.3 ft/day filling the 300 and 400 levels. Above the 300 level, the rate of rise of the mine
pool decreased from 0.29 ft/day to less than 0.025 ft/day.
3. Changes in mine volume between levels does not appear to affect the rate of water level rise to a
significant extent. The Rz correlation between the rate of rise and void volume is weak (0.0819)
with a negative slope
4. The volumetric rate of inflow has a moderate positive correlation with increasing mine volume (RZ
= 0.4634). In other words, the volumetric inflow (gpm) tends to increases or decrease with the
volume of the mine workings. This relationship is probably a function of the increased "effective
radius" of levels with extensive workings which intercept groundwater over a larger area.
4109B.071116 Whetstone Associates