2011-06-23_REPORT - C1980001

• Permit No: C1980001
• IBM Index Class Name: Report
• Doc Date: 6/23/2011
• Doc Name: 2010 AHR Review
• From: Rob Zuber
• To: Janet Binns
• Annual Report Year: 2010
• Permit Index Doc Type: Hydrology Report
• Email Name: JHB
• Email Name: RDZ
• 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]
Inter - office Memorandum
STATE OF COLORADO
To: Janet Binns
From: Rob Zuber RPM
Subject: Review of 2010 Annual Hydrology Report for Edna Mine (Permit # C -1980 -001)
Date: June 23, 2011
The 2010 Annual Hydrology Report (AHR) for Edna Mine, prepared for Chevron Mining Inc. by WWC
Engineering, was received by the Division of Reclamation, Mining and Safety (Division) on February 17,
2011. The Division finds the 2010 AHR in compliance with the following applicable rules.
Rule 4.05.1 Hydrologic Balance – General Requirements
Previous analysis by the Division has found that mining activities at Edna Mine have minimized
disturbances to the hydrologic balance and post - mining land use has not been adversely affected. The
disturbances that have been observed in water quantity and quality parameters are the minimum to be
expected at a surface coal mining operation.
The data in the 2010 AHR do not conflict with the previous analysis. The data reported in the 2010 AHR
is spring and seep data (sampling of other surface and groundwater sites has been discontinued as noted
below), and this data does not indicate significant increases in pollutant concentrations in 2010 over
previous years. Specific Conductivity values measured in the field in 2010 are not considerably higher
than in previous years, although the values for one seep, SE -30, have been rising over the last few years
and should be closely monitored.
For the three springs (SPR -1, SPR -3, and SPR -11) and one seep (SE -23) that exhibited large flows
(approximately 20 gallons per minute or greater), additional laboratory analyses were performed to obtain
concentrations of the following parameters: Dissolved Al, Ca, Fe, Mg, Dissolved Mn, K, Na, HCO3, NH
Cl, NO Ortho -P, and SO No significant increases in 2010 data were observed for any of the
parameters. Some notable examples:
• Iron (Fe) – all values reported for 2010 were below detection limits.
• Dissolved Manganese (Mn) – Three of the values were below detection or very low. One value,
for SPR -1, was slightly higher than previous years (1.17 mg/1) but still less than the effluent limit
for Outfall 004A (1.55 mg/1).
• Sulfate (SO4) – all values reported for 2010 were very similar to values in previous years.
The Division review of the 2010 AHR included a comparison of reported data to applicable Federal and
State water quality statutes, regulations, standards, and effluent limitations. The data in the 2010
Discharge Monitoring Reports for the two outfalls at Edna Mine, Outfall 004A and Outfall 007A, were
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