2013-02-15_HYDROLOGY - M2001005

• Permit No: M2001005
• IBM Index Class Name: HYDROLOGY
• Doc Date: 2/15/2013
• Doc Name: SWSP
• From: OSE
• To: Bishop-Brogden Associates, inc.
• Permit Index Doc Type: Hydrology Report
• Email Name: TC1
• Media Type: D
• Archive: No

Location
T (gpd /ft)
S
X (ft)
W (ft)
Phase 1
40,000
0.087
934
1 ,489
Supply Pond
40,000
0.087
551
1,018
Phase 2
40,000
0.087
471
1,121
Mr. Paul Bruss Page 2
February 13, 2013
evaporative Toss from the exposed ground water, 7.65 acre -feet of water removed via 260,000 tons
of mined product (4% Toss by weight), and 5.0 acre -feet pumped for dust suppression. The area of
exposed ground water from February 1, 2014 — January 31, 2015 is projected to be a maximum of
38.9 acres (consisting of a 23.3 acre pond in Phase 1, a 1.4 acre fresh water supply pond in Phase
2, and a 14.2 acre pond in Phase 2 that only exists when mining ceases and the dewatering pump
is shut off). A monthly breakdown of these amounts for both plan years is given in Table 1,
attached. Total depletions from mining activities are estimated to be 115.53 acre -feet for the 2013
plan year and 130.71 acre -feet for the 2014 plan year.
LAGGED DEPLETIONS
The June 6, 2012 SWSP approval letter required than any future renewal request for this pit
include lagging of the depletions and accretions resulting from the exposed ground water surfaces
to the Arkansas River. Accordingly, the November 2, 2012 renewal request has included lagged
depletions associated to evaporation, dust control, and water removed with the mined material.
Evaporative depletions were lagged individually from each pond based on the exposed ground
water area, dust control depletions were lagged from the fresh water supply pond, and depletions
from water removed with the mined material were lagged from the centroid of the Phase 2 mining
area. The depletions were lagged through use of IDS -AWAS, which utilized the Glover Method
with the following parameters:
Glover Method Input Parameters
T = Transmissivity of aquifer (gallons per day per foot)
S = Specific yield of aquifer
X = Distance between the centroid of the pond or mining area and the Arkansas River (feet)
W = Distance between the Arkansas River and the alluvial boundary (feet)
The cumulative lagged depletions were 114.12 acre -feet over the 2013 plan year and
130.62 acre -feet over the 2014 plan year, and may be found in Table 1, attached.
REPLACEMENTS
The main source of replacement water is based on the 55.2 acres that is now removed from
agricultural production by the mining operation out of the total pro rata share of 89,47 acres of
alfalfa and silage corn historically irrigated with Lester - Attebery Ditch water. A ditch wide analysis
has been completed and the calculated historic consumptive use for the Grisenti parcel was about
220.88 acre -feet per year (2.47 acre -feet per acre). The historic irrigation summary is attached as
Table 2. The 55.2 acres provide an annual stream depletion credit of 136.39 acre -feet (150.28
acre -feet credit during April through October and a return flow obligation of 13.89 acre -feet during
winter months). 60 shares of Twin Lakes Reservoir water will cover the replacement water for the
winter months. As of October 24, 2012, Transit Mix has 55.65 acre -feet in their Twin Lakes
account, which is subject to a 7.81 percent transit loss (0.07% per mile for 111.6 miles) for delivery
to the Grisenti site. The proposed replacement schedule for this plan's approval period is provided
in the attached Table 3.