REP16533

• Permit No: C1980007
• IBM Index Class Name: Report
• Doc Date: 8/23/1996
• Doc Name: REVIEW OF 1993 & 1994 ANNUAL HYDROLOGY REPORTS WEST ELK MINE PN C-80-007
• From: DMG
• To: MOUNTAIN COAL CO
• Permit Index Doc Type: HYDROLOGY REPORT
• Media Type: D
• Archive: No

Ms. Christine Johnston
Mountain Coal Company
Page 11
August 23, 1996
13. Under Section 1.5.3 Groundwater Inflows, there is not sufficient information
provided to support the calculation of natural inflow (8.7 acre feet as shown
in Table 1.6-1). Please clarify how 8.7 acre feet was calculated. For example,
the report states "inflows of 35-SO gallons per minute were measured during
a three week period". At 50 gallons per minute, this would account for as
much as 4.6 acre feet of the total 8.7 acre feet within only three weeks of the
entire water year. Please revise the text under Groundwater Inllows to
provide duration of flows in order to substantiate the total natural inflow
estimate provided in Table 1.6-1.
14. There are no Exhibits provided in the 1994 AHR. Please change Exhibit 3
to Figure 3 in the last paragraph of Section 1.5.5.
15. Water quality of the mine inflows should not be .characterized by the
discharge from MB-1 (refer to last paragraph of page IS). MB-1 treats mine
surface water runoff and the water stored in the pond is treated prior to
discharge. Likewise, MB-2R treats surface water runoff from the refuse pile
and adjacent disturbed areas and any discharge from the tinderdrain. As
stated on page 24 under Mine Water, "discharge from ponds would normally
be dominated by water quality characteristics of disturbed area runoff'. Thus,
discharge from MB-1 and MB-2R should not be used to characterize mine
water quality. As previously stated, the Division recommends that mine
inflow water quality be characterized by sampling and analyzing the water at
the end of the pipe prior to discharge to either MB-1 or MB-2R.
16. The last paragraph on page 17 states that quality parameters of pond MB-2R
are presented in Appendix D, Table D-2. Table D-2 presents "Water Analysis
Report North Fork Gunnison Above Mine". Please clarify this and provide
a revised page 17.
17. Please correct Table F-1 in Appendix F. The baseline minimum values shown
are greater than the baseline maximum values throughout the table. In future
AHRs please perform quality assurance/quality control checks on laboratory
and field data that is transcribed from lab/field reports to AHR report tables.
Please submit a revised Table F-1.
18. In the last paragraph of page 19 it states that "samples from well SG-1 were
within the range of baseline parameters except for conductivity". "Fhe Division
disagrees with this interpretation. For example, the maximum baseline value
for iron as presented in Table H-1 is 0.690 mg/I. Three samples collected