PERMFILE137192

• Permit No: M2006003
• IBM Index Class Name: Permit File
• Doc Date: 1/6/2006
• Doc Name: New 112c Appl.
• From: Hall-Irwin Corporation
• To: DMG
• Media Type: D
• Archive: No

evaporation, or 45.5 inches. Monthly evaporative losses are determined using percentages
specified by the State Engineer's Office for locations below 6,300 feet. The nearest weather
station is in Brighton where the average annual precipitation is 14.55. Effective precipitation,
that part of historical precipitation which was consumed by native vegetation on land to be
covered by water surface, is conservatively estimated to be 70 percent of the total
precipitation. The annual average effective precipitation at the property is estimated to be
10.19 inches. When subtracting the effective precipitation from the gross evaporation yields,
the net annual evaporation is 35.32 inches, or 2.94 acre-feet per acre. The annual amount
of evaporation from open water surfaces is 4.41 acre-feet.
Mining Production & Operations: Hall-Irwin expects to extract a maximum of 800,000 tons
annually of aggregate material from the site. The water retained in the 800,000 tons will be
replaced pursuant to the Substitute Water Supply Plan (SWSP). The total annual amount of
water retained in the gravel product from mining activities totals 23.54 acre-feet.
In addition, an estimated 3.31 acre-feet of water per year will be used for dust control based
(approximately) on 6,000 gallons per day for 20 days per month for 9 months.
Annually the total evaporative and operational losses from mining activities (open water
surface evaporation, water retained in the aggregate product, dust suppression) totals 31.26
acre-feet of depletion which must be augmented. All depletions were lagged to the South
Platte River using the lagging factors approved by the State Engineer pursuant to on-going
Substitute Water Supply (SWSP) approvals.
(e) Indicate the projected amounts of the water sources to supply project water
requirements
The following information was provided by Forrest Leaf, P.E. of Leaf Engineering, Inc.:
Replacement Water: During the extraction of aggregate resources from this site,
replacement water will provide via an ongoing SWSP for the adjacent Baseline Resource site
(M-97-058). The source of replacement water for depletions will be reusable municipal
effluent leased from the Consolidated Mutual Water Company (CMWC) and Laramie--Fox
Hills non-tributary well. The State Engineer must approve a SWSP every two years. These
approvals require that the applicant provide a detailed explanation of the mining operations,
a quantification of all mining activities and subsequent depletions and all legally available
replacement sources.
(f) Affirmatively state that the Applicant has acquired or applied for a National Pollutant
Discharge Elimination System permit from the Water Quality Control Division
The Operator will apply for a National Pollutant Discharge Elimination System (NPDES)
permit from the Water Quality Control Division of the Colorado Department of Public Health
and Environment prior to discharging water from the site.
Hall-Irwin Corporation -Parker/Dersham Sand and Gravel Mine - MLRB 112 Permit Application
Exhibi! G - 2