2011-04-29_PERMIT FILE - M2011001 ‎(21)‎

• Permit No: M2011001
• IBM Index Class Name: PERMIT FILE
• Doc Date: 4/29/2011
• Doc Name: Adequacy Review Response thru Att. 5.
• From: Tetra Tech
• To: DRMS
• Media Type: D
• Archive: No

TETRA TECH
April 27, 2011
Ms. loana Comaniciu, P.E.
Department of Natural Resources
Division of Water Resources
1313 Sherman Street, Suite 818
Denver, CO 80203
RE: Response to Comments Regarding Lafarge West, Inc., Iverson Mine
DRMS File M-2011-001
Dear Ms. Comaniciu:
We received a copy of your memo dated February 2, 2011 regarding Lafarge West, Inc.'s Iverson
Mine project. Below is a listing of your comments followed by our responses:
The proposed operation will still consume ground water by: evaporation, dust control, reclamation,
water remove in the mined product, processing, and dewatering. Prior to initiation of these uses of
ground water, the applicant will need to obtain either a gravel pit or other type of well permit, as
applicable. However, prior to obtaining a permit, an approved water supply plan or decreed plan for
augmentation is required. Our records show that a well permit application and associated temporary
substitute water supply plan have not been submitted to the State Engineer's Office.
Lafarge acknowledges this is comment and commits to providing the required information prior to
operations commencing on-site.
Prior to approving a well permit, the applicant must conduct a field inspection of the site and
document the locations of all wells within 600 feet of the permit area. The applicant must then obtain
a waiver of objection from all well owners with wells within 600 feet of the permit area or request a
hearing before the State Engineer.
Tetra Tech conducted a field inspection and we identified 2 Iverson wells within 600. Lafarge will
obtain the required waivers 6 months prior to mining.
If water will be used for any purpose at this site, the applicant will need to document that the water
was obtained from a legal source, or the water was diverted in priority under a water right decreed
for such industrial use.
Lafarge acknowledges this comment and commits to providing the required information prior to
operations commencing on-site.
If stormwater runoff is intercepted by this operation and is not diverted or captured in priority, it must
be released to the stream system within 72 hours. This may require a discharge permit from
CDPHE-WQCD. Otherwise, the operator will need to make replacements for evaporation.
The Iverson Mine is being mined as a dry pit so any rainwater that collects in the pit will be
immediately dewatered with groundwater. Attached please find a copy of the discharge permit from
CDPHE.
1900 S. Sunset Street, Suite I-F Longmont, CO 80501
Tel [phone] Fax [phone] www.tetratech.com