2011-05-02_HYDROLOGY - M2000016

• Permit No: M2000016
• IBM Index Class Name: HYDROLOGY
• Doc Date: 5/2/2011
• Doc Name: Mining Opns. w/Exp. GW
• From: Applegate Group
• To: DRMS
• Permit Index Doc Type: Hydrology Report
• Email Name: AJW
• Email Name: PSH
• Media Type: D
• Archive: No

Appi'gate
Grou
Water Resource Advisors ;or the-West
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April 28, 2011 _ 4AY 0 ? l i l'
Dien of AwkiAof otwa
IN&V and s?
Mr. Tony Waldron
Division of Reclamation, Mining and Safety
1313 ShermanSt.; Room 215
Denver, CO 80203
Re: Response to DRMS Letter Pertaining to _Mining Operato s with Exposed .
Groundwater
?142006016 (Riverbend Operation) '
Dear Tony:
On behalf of Lafarge West, Inc. (Lafarge), I am writing to respond to the Division of
Reclamation, Mining, and Safety (DRMS) letter sent to Lafarge 'on April 30, 2010 regarding
mining operations with' exposed groundwater. As shown in the-attached " figure, the Riverbend
Operation currently has! a small amount of groundwater exposed within the permit boundaries
(appr6 ximately,9.8 acres) with plans to expose significantly more groundwater at some point in
the future. At this time, Lafarge does not anticipate exposing additional groundwater at the
Riverbend Operation for at least 20 years.
The Riverbend Operation is currently included in Lafarge's South P1atte'Combined Substitute
Water Supply Plan (SWSP). The replacement-source in that plan consists of 249 acre-feet per
year of consumable effluent from'Aurora that was traded to Lafarge in exchange for 1.75 shares
in the Brighton Ditch Company. The Aurora trade agreement provides more than enough water
to replace depletions from the existing groundwater `exposure at the Riverbend:Operation. If
required by the Division of Water Resources,' Lafarge would be willing to sign an affidavit
dedicating sufficient Aurora trade water to the-South Platte Combined SWSP to offset the
evaporation from the current Riverbend Operation groundwater exposure.
Because Lafarge does not anticipate' exposing additional groundwater at this site for 20 Years or
more, Lafarge. believes' that no further action is required at this time. Prior to exposing .
groundwater, Lafarge will identify a method to maintain, compliance for this site, be it a decreed
augmentation plan, increased bond 'for lining and/or backfilling or some other solution:.
1499 West 120th Avenue Suite; 200 [phone] • Fax [phone] -
Denver, "Colorado 80234 www.applegategroup.com