PERMFILE52972

• Permit No: M2005066
• IBM Index Class Name: Permit File
• Doc Date: 4/17/2006
• Doc Name: Adequacy review #2
• From: DMG esc
• To: Asphalt Paving Company
• Media Type: D
• Archive: No

STATE OF COLOIZA~DO
DIVISION OF MINERALS AND GEOLOGY
Department of Natural Resources
1373 Sherman St., Room 215
penv~~ Golo~do 80203
Phone: (303) 86(x3567
FAX: [phone]
DATE: April 14, 2006
TO: Erica Crosby, Cazl Mount
FROM: Tom Schreiner .~1-
COLORADO
D I V I F I O N O F
MINERALS
GEOLOGY
[ECUNATION•NININO
[AFFTT•[GI[NC[
Bill Owens
Go~srtlor
Rrer[II George
ExecvdMe Director
Ronald w. Cmany
Divfston Director
NaNnl Resouna TnMee
RE: Hydrology Review, "Wallenberg West Sand & Gravel Mine'; Asphalt Paving Company
File M-2005-066, Class: Permit
This memo contains remaining adequacy review comments from the Division's Hydrology
Review of the "Walenberg West Sand & Gravel Mine" Regular 112 Application for 135
permitted acres and reclamation to developed water resources, File No. M-2005-066. These
comments area based on review of the original permit application as well as Apri15, 2006
adequacy response provided by the applicant.
6.4.3 EXHIBIT D - Minin¢ Plan
2. The Applicant projects a dischazge rate of 2.5 to 10 cfs for process water discharged offsite to
either the Brighton Ditch or a water conveyance easement flowing towards the South Platte
River. Prior to approval, the applicant will need to specify the design flow capacity of either the
Brighton Ditch or water conveyance easement and verify that either structure has the capacity to
receive the anticipated de-watering flows of up to 10 cfs. Also, the applicant will need to locate
on a Mine Plan Map where the point of discharge will be, provide a schematic showing how the
mine water will be dischazged into either structure, and provide sufficient detail to demonstrate
that discharge of mine water offsite will not result in excessive erosion or offsite damage. (The
Division recommends that the applicant include representative cross sectional designs of the
Brighton Ditch or water easement structure to clarify their design flow capacity and capability to
receive mine de-watering flows). Please respond.
6.4.7 EXHIBIT G -Water Information
6. In accordance with Rule 3.1.6(1), the applicant will need to affirmatively state that the planned
de-watering activities will not result in a negative impact on the normal operation of the Brighton
Ditch. Also, the applicant shows on Exhibit C-3, Mine Plan that the Phase 1 excavation will be
two hundred (200} feet away from the Brighton Ditch. The Division recommends that the
applicant locate and mark the 200 foot setback prior to excavation in this azea. Please respond.
t~ce of t~ffice of Colorado
Mined Wnd Reclamation Active and Inactive Mines Geological Survey