HYDRO31114

• Permit No: C1981010
• IBM Index Class Name: Hydrology
• Doc Date: 7/11/2002
• Doc Name: Memo on Musgrave Well
• From: TAK
• To: JHB
• Permit Index Doc Type: Correspondence
• Media Type: D
• Archive: No

STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY
Department of Natural Resources
1313 Sherman St., Room 215
Denver, Colorado 80203
Phone: [phone]
FAX: [phone]
Memorandum
DIVISION OF
MINERALS
GEOLOGY
RECLAMATION
MINING•SAFETY
Date: JUIy 11, 2002 Rill Owens
Governor
I Greg E Watcher
From: Tom Kaldenbach Executive Director
Ronald W. Cattany
To• Janet Binns Acting Division Director
Re: Musgrave well near the Trapper Mine, Permit C-81-010
Introduction - I have attempted to identify the cause of the change in water quality in the
Musgrave well. The change has been described as a brownish red stain, sulfur odor, and
bad taste. My approach to identifying the cause of the change was to: 1) determine if the
Musgrave well is in the predicted subsurface flow path of coal spoil leachate, if any has
been generated by nearby mining, and 2) attempt a chemical match of the Musgrave well
water and coal spoil leachate.
Musgrave well location relative to mining -The well's completion report on file with the
Office of the State Engineer indicates it produces water from the uppermost 10 feet of the
3`a White Sandstone. DMG sampled the well on 5/7/02. The nearest coal mine
monitoring well is Trapper's well 81-03a located about one-half mile northeast of the
Musgrave well. The Musgrave well could be within the predicted flow path of any
leachate flowing from the Trapper Mine's Browning Pit, based on the map of the 3`a
White's potentiometric surface in Trapper's 2001 annual report. The Browning pit was
backfilled in the late 1980s. It is not known if the Browning pit has generated leachate
because there is no spoil monitoring well in the pit. Also, Trapper's only 3`a White
Sandstone monitoring well (well GE-3) that is between the Musgrave well and the
Browning pit does not provide reliable data because its perforated interval straddles the
2"a White Sandstone and the 3`a White Sandstone. The Musgrave well probably is not
within the flow path of any of the mining that occurred at the Empire Mine.
Musgrave well sample results -The cation/anion balance in the analysis had a 7%
difference, an acceptable amount. The sample was asulfate-calcium-magnesium-
bicarbonate type water. The dominant anion was sulfate. Total dissolved solids
concentration was 1900 mg/1; sulfate was 870 mg/1. Metals included iron (1.85 mg/1),
magnesium (155 mg/1), and manganese (0.178 mg/1). The manganese or iron
concentration could cause the reported stain. The manganese concentration could cause
the bad taste.
Comparison of Musgrave well sample results with Trapper's coal spoil leachate -
Trapper monitors leachate quality in four wells on the mine. Although none of the wells