2012-11-27_HYDROLOGY - M1977344

• Permit No: M1977344
• IBM Index Class Name: HYDROLOGY
• Doc Date: 11/27/2012
• Doc Name: REVISED GROUNDWATER MONITORING PLAN
• From: DRMS
• To: HOLCIM
• Email Name: TC1
• Email Name: TAK
• Email Name: BMK
• Media Type: D
• Archive: No

DIVISION OF RECLAMATION, MINING AND SAFETY
Department of Natural Resources
1313 Sherman St., Room 215
Denver, Colorado 80203
Phone: [phone]
FAX: [phone]
November 27, 2012
Joe Lamanna
Holcim (US), Inc.
3500 Highway 120
Florence, CO 81226
Re: Portland Limestone Quarry, Permit No. M- 1977 -344, Revised Groundwater
Monitoring Plan
Mr. Lamanna:
The Division of Reclamation, Mining and Safety (DRMS) has reviewed your proposed standards
for MW -13 (reference Holcim letter to DRMS dated July 7, 2010). The data collected from MW -13
is intended to supplement data collected from MW -7. The DRMS approved numeric protection
levels (NPLs) for MW -7 on February 24, 2009.
The DRMS determines NPLs based on the five quarters of monitoring data initially collected from a
proposed monitoring well, not from nearby or upgradient wells. The selected NPL is typically the
larger of two values: 110 percent of the maximum concentration of a constituent of interest
observed during the five quarters of monitoring; or the mean observed concentration of the
constituent plus two standard deviations. Based on the five quarters of data provided by Holcim for
MW -13, the DRMS has determined the following NPLs are appropriate:
Mined Land Reclamation
Parameter
Total Dissolved Solids (TDS)
Sulfate (SO
Potassium (K)
Sodium (Na)
Iron (Fe – dissolved)
Manganese (Mn - dissolved
* 110% of maximum observed value
1 Mean observed value plus 2 standard deviations
NPL for MW -13
4,026 mg/E *
2,200 mg/E *
13 mg/E *$
274 mg/E *
0.13 mg/E
0.30 mg/E $
STATE OF COLORADO
Previously Approved NPL for MW -7
3,918 mg/E
2,080 mg/E
17 mg/E
226 mg/E
4.5 mg/E
0.88 mg/E
COLORADO
D I V I S I O N O F
RECLAMATION
MINING
— &—
SAFETY
John W. Hickenlooper
Governor
Mike King
Executive Director
Loretta E Pineda
Director
Holcim will continue to monitor MW -12 (background) and MW -7 (west compliance well), and
provide results for the above parameters on an annual basis. When observed parameters in MW -7
and/or MW -13 (east compliance well) exceed the NPL by more than 10 percent, Holcim will
increase the monitoring frequency to semi - annually.
Office of Office of
Denver • Grand Junction • Durango Active and Inactive Mines