2011-05-02_HYDROLOGY - M1991035

• Permit No: M1991035
• IBM Index Class Name: HYDROLOGY
• Doc Date: 5/2/2011
• Doc Name: Mining Opns. w/Exp. GW
• From: Applegate Group
• To: DRMS
• Permit Index Doc Type: Hydrology Report
• Email Name: AJW
• Email Name: DB2
• Media Type: D
• Archive: No

Applegate
Group, inc.
Res Watei ource Advisors for the West
April 28, 2011
M, AY 09 ?fill
Mr. Tony Waldron
Division of Reclamation, Mining and Safety
1313 Sherman St., Room 215
Denver, CO 80203
Re Response to DRMS Letter Pertaining to Minn Operations witti Ex osed Groundwater
M19.79002 (North Delta Pit); M1982034 (Miller Pit); M19852 (Rich Pit);
M?1986079 (M&G Pit); M1991035 (Bluestone Pit); M1994045 (Bluestone Pit)
Dear Tony:
On behalf of Lafarge West, Inc. (Lafarge), I am writing to respond to the Division of Reclamation;,
Mining, and Safety (DBMS) letter sent to Lafarge on April 30, 2010 regarding mining operations
with .exposed, groundwater. The specific mining operations listed above currently expose,
groundwater. In order to maintain compliance with the requirements of the Colorado Land-
.Re-clamation Act for the Extraction of Construction Materials and the Mineral Roles and Regulations
of the Colorado Mined Land Reclamation Board for the Extraction of Construction Materials;
Lafarge is considering bonding these ` sites- to install a clay liner or slurry wall to prevent future
groundwater exposure. Pursuant to DRMS guidance, Lafarge anticipates that it will have up to three
years to phase in the new bonding for these sites. "
A preliminary estimate of the cost to install a liner was performed for each site., The attached figures
display how the perimeter and depth of the liners were estimated. The 'costs of the liners were
c.ateulated assumi?ig a liner cost of$3:SOper square foot. The estimated liner costs at each site are
summarized below:
., North Delta Pit; $177,450
d .
4 Miller Pit:.$175 175,665
• Rieh. Pit: $271,`,320
• M&G Pit: $655;200
Bluestone Pit.(M 1991035): $1,680,000 -- --
o At this time we are unsure whether the water visible on aerial photos of the area is
exposed groundwater or pooled surface water. Lafarge will be. conducting
investigations in the near term to determine the source of the water:
• Bluestone Pit (M1994045): $ t,129,800
o Again, at this time we are unsure whether the water visible on aerial photos of the
area is e n9--- grOUi,??n Ater or pooled cnrf ;ce ?v2ter.
T?af r ? tic'ill ??? _011d??Ct111b
investigations ?.1in,the near term to determine the source of the water.
1499VVest,120th Avenue, Suite 200 [phone] • Fax [phone]
Denver, Colorado 80234 www.applegategroup.com