December 2013
Attachment C
Pond Sizing Calculations
113-82323
J:\11JOBS\113-82323 Bear Lodge Mine\Surface Water\November 2013\Pit Dewatering Pond\SedBasin_1.xls
m
3
/day
2725.5
gpd
720000
gpm
500
Influent TSS
mg/L
1500
Effluent TSS
mg/l
35
Mass of Sludge without Anaerobic Decomposition
kg/yr
1,457,391
Ratio of Fixed Solids to VSS
-
0.00
Volatile Solids
kg/yr
-
Fixed Solids
kg/yr
1,457,391
Volatile Solids Reduction
%
0%
Sludge Accumulation
years
1
VSS decomposition
years
1
VSS @ yr 1
kg/yr
-
Total SS Mass @ yr 1
kg @ yr 1
1,457,391
Total Solid Mass @ yr 1
kg
1,457,391
Detention Time
days
2
m
3
5,451
gallons
1,440,000
ac-ft
4.4
Lagoon Depth
m
1.00
m
2
5,451
ft2
58,653
Mass of Accumulated Sludge / Area
kg/m
2
267
Density of Sludge
kg/m
3
1.06
Average Compaction
%
15%
Sludge Bank Depth
m
1.68
m
2.68
ft
8.80
Length to width ratio
3.0
ft
419.5
m
127.9
ft
139.8
m
42.6
Laminar Velocity
ft/s
0.0024
Laminar Velocity Contingency
-
0.50
Adjusted Laminar Velocity
ft/s
0.0036
Settling Velocity
ft/s
0.0076
Settling Velocity - Adjusted Laminar Velocity
ft/s
0.0039
Water Storage
ac-ft
4.4
Sediment Storage
ac-ft
7.4
Total Required Storage
ac-ft
11.8
Width
Sedimentation Basin
Influent Parameters
Flow
Volume
Total Lagoon Depth
Surface Area
Length
