2013-06-03_HYDROLOGY - M1977208

• Permit No: M1977208
• IBM Index Class Name: HYDROLOGY
• Doc Date: 6/3/2013
• Doc Name: CEM-004 Sulfate & Chloride Report
• From: CEMEX
• To: DRMS
• Permit Index Doc Type: Hydrology Report
• Email Name: MAC
• Media Type: D
• Archive: No

//C cmcx
Mr. Michael Cunningham
/ Environmental Protection Specialist
Division of Reclamation, Mining and Safety
1313 Sherman Street, Room 215
Denver, Colorado 80203
Re: CEMEX Lyons Mine Permit M- 1977 -208
, f'M -004 Sulfate & Chloride Report
Dear Mr. Cunningham:
May 29, 2013
Via Certified Mail
799880848401 p
Return Receipt RequesteRECEIVED
UN 03 2013
Division of Reclamation,
Mining & Safety
As a follow -up to our previous conversations, CEMEX Lyons Cement Plant submits the
following information in regard to sampling initiatives performed for Monitoring Well CEM -
004. Information gathered in the first quarter of 2013 relating to the Monitoring Well CEM -004
(23 feet below grade) indicated that two monitoring parameters, sulfate and chloride, were
greater than the monitoring goals identified in Technical Revision 11 (TR -11). CEMEX
communicated the issue promptly and conducted additional sampling at Monitoring Well CEM -
004 and at C -Pit. The purpose of this letter is to provide the results of this additional monitoring
and to recommend a path forward.
Background
The CEMEX Lyons Cement Plant generates cement kiln dust (CKD) as part of the cement
production process. The CKD is either returned to the production process, sold as product to
vendors, or used as backfill for reclamation in a previously mined quarry pit. Authorized on -site
disposal of CKD in C -Pit has been taking place since 1998. Water accumulates in low areas of
C -Pit. The C -Pit water is sampled along with two monitoring wells: CEM -001 and CEM -004.
A compliance well (CEM -005) has also been drilled at the edge of the CEMEX property to
assess whether C -Pit water is migrating in the groundwater. As of the date of this letter, no water
has accumulated in the compliance well. The CEM -004 well is an alluvium well and is 23 feet
deep.
Monitoring goals for CEM -004 for chloride and sulfate are 250 mg /1. The data for samples
collected on February 7, 2013 were 478 mg /1 chloride and 1,630 mg /1 sulfate. CEMEX initially
notified you of this information by phone on February 22, 2013, two days after receiving the data
from the laboratory. On February 26, 2013, an e -mail was sent outlining additional monitoring
that CEMEX planned to conduct. On April 25`h 2013 a report/letter was submitted which
discussed the outcome of the additional monitoring.
Upon receipt of the results, CEMEX immediately requested the laboratory reanalyze the
February 7, 2013 sample and then collected additional samples of the groundwater in CEM -004.
The repeat analysis of the February 7, 2013 sample did not show any significant differences so
only the original analyses are being provided. Additional groundwater samples were collected
on February 21, 2013, March 6, 2013, April 10, 2013, and April 25, 2013. The groundwater