2004-11-16_REVISION - M1977208

• Permit No: M1977208
• IBM Index Class Name: Revision
• Doc Date: 11/16/2004
• Doc Name: Review
• From: DMG-kap
• To: DMG-esc
• Type & Sequence: TR4
• Media Type: D
• Archive: No

STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY
Department of Natural Resources
1313 Sherman St., Room 215
Denver, Colorado 80203
Phone: [phone]
PAX: [phone]
DATE: November 16, 2004
COLORADO
DIVISION OF
MINEBRALS
GEOLOGY
REC LANATION•NINING
SAFETTKCIENCE
eill Owens
Governor
Russell George
Executive Director
TO: Erica Crosby Ronald W. Cattany
Division Director
Natural Resource Trustee
FROM: Kate Pickford
RE: Lyons Quarry, CEMEX, Inc., File No. M-1977-208 Technical Revision
/TR-04 Cement Kiln Dust Disposal in C pit
The Division of Minerals and Geology (DMG) staff has reviewed the new TR-04 proposal for the
CEMEX, [nc. Lyons Quarry, including the cover letter, the Proposed Sampling and Analysis Plan, Lyons
Quarry, and the Evaluation of the Potential Impact of Ponded C-Pit Water on Groundwater Quality in the
Dakota Sandstone. The Division has the following comments related to these reports.
The cover letter composed by John Lohr, Plant Manager, states, "Cemex will submit a ground
water mitigation plan to the Division if an exceedance of any of the five water quality
parameters are observed in three consecutive monitoring events." This statement is made in
reference to the sampling and monitoring of C-pit water, A-pit water, a new, downgradient
monitoring well, a new, downgradient compliance well, and the Off-site Dakota Formation welt.
Division policy requires that a mitigation plan be filed with, reviewed by, and approved by the
Division as a portion of this technical revision. Therefore a mitigation plan must be filed prior
to the Division's approval of TR-04.
2. The cover letter composed by John Lohr, Plant Manager, states, "Cemex will control surface
drainage into C-pit to the extent practical however our analysis indicates that drainage controls
are not warranted. West of C-pit the Boulder Feeder Canal and to some extent the Swede Ditch
essentially function as drainage diversion ditches." The Operator has not yet quantified the
seepage from the above-listed water features into the C-pit. The Division may accept the
conclusion that the Boulder Feeder Canal and Swede Ditch serve as diversion ditches relative to
C-pit, once the degree of seepage from these ditches into C-pit has been established, but the
amount of seepage must be quantified for the Division.
Under Analytical Protocol, the Proposed Sampling and Analysis Plan Lyons Quany states,
"CEMEX proposes to remove thallium from the list of analytical parameters. Past sampling has
shown thallium to be either below detection limit or well below the numeric protection level
standard." The Division does not approve of removal of thallium from the suite of analytes to
be measured in samples taken from the site. Although the thallium levels have been below
standards during past sampling events, the reason for monitoring and sampling at the site is to
continually monitor conditions and identify changes. Additionally, thallium is a marker for
other contaminants and changes in the thallium level might be an indicator of other changes at
the site. Therefore in the interests of continued monitoring of site conditions, the Division
believes that continued analysis of thallium levels in samples is merited.
Office of Office of Colorado
Mined Land Reclamation Active and Inactive Mines Geological Survey