Mr. Paul Bruss, P.E
<br />March 24, 2016
<br />Page 2 of 6
<br />Well perrinit no. 61509-F corresponds to Phases 1 and 2 and limits that portion of the
<br />operation to evaporation from 12.0 acres of exposed water, water removed from 900,000
<br />tons of material (26.52 acre-feet annually), and dust control (17.76 acre-feet annually).
<br />Application receipt no. 3664433 was received by this office to change/expand the use of well
<br />Permit no. 61509-F and will be evaluated subsequent to approval of this SWSP. Well Permit
<br />No. 75997-F corresponds to Phase 7 and limits that portion of the operation to evaporation
<br />from 5 acres of exposed water and 29.4 acre-feet annually (4% water content by weight of
<br />1,000,000 tons) of water removed from mined material (or the amounts covered under a
<br />Water Court approved plan for augmentation or SWSP approved by the State Engineer,
<br />whichever is more restrictive).
<br />In accordance with the letter dated April 30, 2010 from the Colorado Division of Reclamation,
<br />Mining, and Safety ("DRMS"), all sand and gravel mining operators must comply with the
<br />requirements of the Colorado Reclamation Act and the Mineral Rules and Regulations for the
<br />protection of water resources. The April 30, 2010 letter from DRMS requires that you provide
<br />information to DRMS to demonstrate you can replace long term injurious stream depletions
<br />that result from mining related exposure of ground water. According to the renewal request,
<br />the long term plan for the site is for a storage reservoir in Phase 2, which already has an
<br />approved slurry wall, and to backfill Phases 1 and 7 to a ground surface elevation at least two
<br />feet higher than the ground water table. Therefore, please provide an explanation and/or
<br />documentation that a financial warranty sufficient to cover the cost of backfilling Phases
<br />1 and 7 that meets the Division of Water Resources requirements for preventing ground
<br />water exposure has been filed, in accordance with approach no. 1 of the April 30, 2010
<br />letter from DRMS, with the next SWSP renewal request.
<br />DEPLETIONS
<br />Annual site depletions consist of 154.3 acre-feet of gross evaporative losses, 11.0 acre-feet of
<br />pumping for dust control, and 7.4 acre-feet of water removed in the mining product, for a
<br />total depletion of 172.7 acre-feet for each of the plan years (February 1, 2016 through
<br />January 31, 2017 and February 1, 2017 through January 31, 2018). The monthly distribution
<br />of the values and the lagged effects on the Arkansas River, are detailed on your Tables 1-4,
<br />which are attached. The lagged depletions were calculated individually for each Phase of the
<br />operation based on the characteristics below.
<br />Location
<br />Transmissivity
<br />(gpd/ft)
<br />Specific
<br />Yield
<br />Distance to
<br />River (ft)
<br />Distance to Alluvial
<br />Boundary (ft)
<br />Phase 1
<br />97,100
<br />0.15
<br />1,032
<br />2,647
<br />Phase 2
<br />97,100
<br />0.15
<br />964
<br />2,206
<br />Phase 7
<br />97,100
<br />0.15
<br />420
<br />2,250
<br />Lagging factors for each of the Phases were calculated using the Glover Method, normalized
<br />to the number of months required for 95% of depletions to affect the river, and are provided
<br />in the following table.
<br />1313 Sherman Street, Room 821, Denver, CO 80203 P 303.866.3581 F 303.866.3589 www.water.state.co.us :i
<br />John W. Hickentooper, Governor 1 Robert Randall, Interim Executive Director ,,v'( , h ,,/ .f
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