2011-05-02_HYDROLOGY - M1985218

• Permit No: M1985218
• 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: BMK
• Media Type: D
• Archive: No

R
Applegate
Group, Inc.
Water Resource Advisors for the West
April 28, 2011
Mr. Tony Waldron wi-Sa#e.'y
Division of Reclamation, Mining and Safety
1313 Sherman St., Room 215
Denver; CO 80203
Re: Response to DRMS Letter Pertaining to Mining Operations with Exposed Groundwater
M1979002, (North - Delta Pit); M1982034 (Miller Prt) _ 1.985218 _ (Rich Pit)•
M1986079 (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.(DRMS) 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 -
Reclamation Act for the Extraction of Construction Materials and the Mineral Rules 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 toDRMS 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
calculated assuming a liner cost of $3.50 per square foot. The estimated liner costs `at each site are
summarized below:
oe North Delta Pit: $177,450
•: Miller Pit: $175,665
"Rich Pit: $271,320
• M&G,Pit: $655,200
• Bluestone Pit (M1991035): $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): $1,129,800
o :--Again, at this time we are unsure whether the water visible on aerial photos of the
area is exposed grn,rt,d?Ater or pooled Sur!ace water. 1 lfa!'ge ,,,i11 he coiidtlcting
investigations in the near term `to-determine the source of the water.
1499 West 120th Avenue, Suite 200 [phone] • Fax [phone]
Denver, Colorado 80234
www.applegategroup.com