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 COLORA.DO
Department of Natural Resources
1313 Sherman St.,Room 215 C O L O R A D O
Denver,Colorado 80203 D l V 1 S I o N o r
Phone.[phone] RECLAMATION
FAX-(303)B32-8106 MINING
SAFETY ,
November 27,2012 John W.Hickenlooper
C,ovemor
Mike Kra
Executive Director
Joe Lamanna Lo►ette 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 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;
Parameter NPL for MW-13 Previously Approved NPL for MW-7
Total Dissolved Solids(TDS) 4,026 mg/Z * 3,918 mgtf
Sulfate(SO,) 2,200 mg/t 2,080 mg/Z
Potassium(K) 13 mg/f *$ 17 mg/Z
Sodium(Na) 274 mg/e 226 mg/Z
Iron(Fe-dissolved) 0 13 mg/Z $ 4.5 mg/Z
Manganese(Mn-dissolved 0.30 mg/Z $ 0.88 mg/Z
*110%of maximum observed value
t 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