2012-02-17_PERMIT FILE - M2011040

• Permit No: M2011040
• IBM Index Class Name: PERMIT FILE
• Doc Date: 2/17/2012
• Doc Name: RESPONSE TO TIM CAZIER MEMO
• From: RIMROXK EXPLORATION & DEVELOPMENT
• To: DRMS
• Email Name: GRM
• Email Name: TC1
• Media Type: D
• Archive: No

DIVISION OF RECLAMATION, MINING AND SAFETY
Department of Natural Resources
1313 Sherman St., Room 215 Denver, Colorado 80203 Phone: [phone] FAX: [phone]
John W. Hickenlooper Govemor
Mike King Executive Directo'"
MEMORANDUM
Loretta Pineda Director
To: Russ Means From: Tim Cazier, P.E. Date: October 7, 2011
STATE OF COLORADO
Re: Prince Albert Mine Surface Water Management - General Stormwater Comments, Permit No. M- 2011 -040
The Division of Reclamation, Mining and Safety (DRMS) engineering staff has reviewed the July 20, 2011
Exhibit U, Appendix A, Surface Water Management and Control for the Prince Albert Mine prepared by
Pierce & Associates. The following comments are posed to ensure adequate engineering analyses and
design practices are implemented to eliminate or reduce to the extent practical the disturbance to the
hydrologic balance expected by the mining operation with respect to water quality and quantity in
accordance with Rules 3.1.6(1), 6.4.21(10), and 7.3.1
General Comments:
1. The UTM coordinates (Easting 0676437, Northing 4275888) on page 3, Item 11 of the application
do not appear to coincide with the PLSS location information provided in Item 10, also on page 3
of the application. These UTM coordinates appear to be about 4.6 miles due south of Gateway, CO
and about 19 miles northwest of the site location presented in Fig:ure A.I. Please confirm the UTM
coordinates.
Response - Coordinates for different project supplied have been corrected
2. The four sediment ponds shown on Exhibit U -1 will require dewatering to ensure adequate detention
for successive storms and for maintenance. Please provide some discussion on anticipated
sediment pond dewatering methods and frequency.
Response - Ponds will be dewatered by the operator using a pump /siphon in the event that
successive storms are anticipated
3. It is not stated in the surface water management discussion whether the designs presented are for
operations, reclamation or both. Please note that all detention ponds are required to be designed for
the 100 -year, 24 -hour storm volume for reclamation.
Response - As presented designs were for both. 100 year 24 -hour storm is apparently a new criteria
that was not given at the time the drainage criteria for operations were obtained However, due
to the lower required volumes obtained using the TR -55 methodology, to fulfill the 100 year 24-
hour criteria, the spillways will be blocked at the time reclamation activities commence.