2018-05-22_HYDROLOGY - M1977344

• Permit No: M1977344
• IBM Index Class Name: HYDROLOGY
• Doc Date: 5/22/2018
• Doc Name: Water Monitoring - Groundwater
• From: Christopher Peters
• To: DRMS
• Annual Report Year: 2018
• Email Name: TC1
• Media Type: D
• Archive: No

STATE OF COLORADO
DIVISION OF RECLAMATION, MINING AND SAFETY
Department of Natural Resources 04 -�_ I
1313 Sherman St.,Room 215
Denver,Colorado 80203 n t v> s t o x o f
RECLAMATION
Phone:[phone]MINING
I
FAX:[phone] M I N I N G
—�L—
SAFETY
November 27, 2012 John Hickenlooper '
Governor
Mike King
Executive Director ,
Joe Lamanna
Loretta E Pineda
Holcim(US),Inc. Director
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 DBMS 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: '
Parameter NPL for MW-13 Previously Approved NPL for MW-7
Total Dissolved Solids(TDS) 4,026 mg/f * 3,918 mg/f
Sulfate(SO4) 2,200 mg/f * 2,080 mg/t;
Potassium(K) 13 mg/f *$ 17 mg/f '
Sodium(Na) 274 mg/f y 226 mg/C
Iron(Fe—dissolved) 0.13 mg/f $ 4.5 mg/f
Manganese(Mn-dissolved 0.30 mg/f $ 0.88 mg/f
* 110%of maximum observed value '
$Mean observed value plus 2 standard deviations
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 '
Mined Land Reclamation Denver-Grand Junction•Durango Active and Inactive Mines