2004-12-16_REVISION - M1977208 ‎(2)‎

• Permit No: M1977208
• IBM Index Class Name: Revision
• Doc Date: 12/16/2004
• Doc Name: Review- CKD Disposal in C Pit
• From: DMG-hhp
• To: DMG-esc
• Type & Sequence: TR5
• Media Type: D
• Archive: No

STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY
Department of Natural Resources
1313 Sherman S[., Room 215
Denver, Colorado 80203
Phone: [phone]
FAX: [phone]
Date: December 16, 2004
To: Erica Crosby
COLORADO
DIVISION O F
MINERALS
GEOLOGY
REC LAMATION•M~NING
SAFETY•SOIENCE
Bill Owens
Governor
Russell George
Executive Director
~ ~ ~j Ronald W. Cattany
From: Harry POSey ~~/Jf 1.,•I/~ Division Director
„~~ ~ V Natural Resource Trustee
Subject: Review of TR-5, CKD Disposal ~ C-Pit; Cemex Inc; Lyons Quany
M-1977-208 /
To abate a high pH problem in C-Pit at the Lyons Quarry, Cemex has proposed a water treatment plan in
case pumping water from the pit is insufficient to alleviate the potential risk to wildlife. Following are a
few comments related to their proposal.
1. The introductory paragraph of the URS report correctly recalls that a prior report indicated there is
no risk to groundwater. However, the Division has asked for proof of that lack of risk in the form
of a monitoring well drilled into the Dakota Sandstone. Nothing in the Operator's citation will be
construed to change the Division's position on the need for a deep monitoring well into the first
aquifer below the site.
2. The proposal under TR-26 has two sections: a cover letter that explains the proposal, and a URS
Corporation "Water Treatment Plan" report attached. Explanations of the Plan in these two
documents are slightly discrepant.
The letter says the pit will be pumped down to the "smallest practical size;" that level, which
apparently is to be 4 feet water depth, will be determined by "pump limitations," and the
remaining pond surface area after pumping "will be significantly smaller than the approximate 7
acres that the [pond] currently covers." After pumping to a 4 foot level - or thereabouts,
presumably -water from A-pit will be used in place of the C-Pit water. After pumping to the
"smallest practical size the water quality of the water remaining in the pit will be analyzed and
compared to the applicable standards..." through consecutive sampling events and, if standards
are met, "the source will be deemed to have been removed." The letter also indicates that
adjustments maybe made to promote pumping even more water from C-pit.
The attached URS report states, however, that "[i]n the event that CEMEX is not able to use all of
the water ponded in the C-Pit, a contingent water treatment plan is provided in this document to
treat the ponded C-Pit water." Thus the two documents are not in agreement over whether water
will be treated or not.
To clear up this discrepancy, the Division will accept that C-Pit will pumped to within
approximately 4 feet of the base of the pit in the vicinity the pump, and that adjustments may or
Office of Office of Colorado
Mined Land Reclamation Active and Inactive Mines Geological Survey