2018-01-31_HYDROLOGY - M1977208

• Permit No: M1977208
• IBM Index Class Name: Hydrology
• Doc Date: 1/31/2018
• Doc Name Note: Revised Groundwater Monitoring Plan 4th Quarter 2017 Monitoring Data
• Doc Name: Water Monitoring - Groundwater
• From: CEMEX
• To: DRMS
• Type & Sequence: TR12
• Email Name: AME
• Media Type: D
• Archive: No

Z/CC-MEX
January 30, 2018
Ms. Amy Eschberger
Division of Reclamation, Mining and Safety
Environmental Protection Specialist
1313 Sherman Street, Room 215
Denver, Colorado 80203
RECEIVED
JAN 31 2018
DMSION OF RECLAMATION
MINING AND SAFETY
Via FEDEX
TRK #7713 3776 3928
Re: CEMEX Lyons Mine Permit M-1977-208
Technical Revision No. 12, Revised Groundwater Monitoring Plan
Fourth Quarter 2017 Monitoring Data
Dear Ms. Eschberger:
This letter transmits the surface water and groundwater data associated with the sampling of the
cement kiln dust disposal area (C -Pit). This report includes data from the C -Pit ponded water and
related groundwater monitoring for the third quarter of 2017, covering the reporting period from
October 1, 2017 to December 31, 2017. Table 1 presents data for the last four quarters.
Compliance monitoring water samples were collected on October 11, 2017 from the CEM-oo1 and
CEM -o04 groundwater monitoring wells, and from the C -Pit ponded water. The inspection of
groundwater monitoring well CEM -005 on October 11, 2017 indicated that there was not enough
water volume to collect a representative sample.
The samples collected from C -Pit ponded water and the groundwater monitoring wells were
analyzed for pH, chloride, sulfate, total dissolved solids, selenium, and thallium. The reported pH
data is based on the pH analysis performed at the time of sample collection in the field (Table 1).
The measured pH at groundwater monitoring well CEM -004 and analytical results for chloride,
sulfate, total dissolved solids (TDS), selenium and thallium from the October 11, 2017 groundwater
sample were within the target levels prescribed by TR -12, as shown in Table 1. However, pH
measurement of 8.58 s.u. from the CEM 004 sample indicated a slightly higher level than the
CEM005 trigger of 8.5 s.u.
In addition, a Stiff Diagram of the groundwater cation/anion data from CEM -o04 compared to the
average and 901h percentile of the cation/anion concentrations from the last four quarterly samples
of C -Pit data is provided in Figure 1 for reference. As shown in Figure 1 and consistent with past
reports, the signature for CEM -o04 continues to be significantly different from that of C -Pit.