PERMFILE47451

• Permit No: C1980007A
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: Exhibit 51 Lower Refuse Pile
• Media Type: D
• Archive: Yes

Mountain Coal Company, L.L.C. Exhibit 51
West Elk Mine Lower Refuse Pile
8.0 MONITORING
8.1 Quality Control
MCC will ensure quality control durine [he construction of the various phases of the lower refuse pile.
The quality control will involve MCC personnel and outside seo[echnical consultants to insure the pile is
constructed as described in this report. The lower refuse pile will be compacted [o a minimum density of
90% of Standard Proctor. This will be verified by performingdensity tests as specified in Section 8.-l. Data
obtained during the construction of the pile through the use of the monitoring systems will be reviewed as
described in the followin¢ sections.
8.2 Groundwater,Leachateand Water QualityMonitorins
The measurement of existing groundwater levels and the obtainine of samples suitable for chemical
analysis will be performed on a periodic basis. The baseline well quality data for the wells associated with
the lower refuse pile can be found in Appendix 1. The piezometers installed during the exploratory program
were used until long term water monitorine piezometers were installed to monitor groundwater levels.
Five additional piezometers ("GP" or "MW" series) were installed durine the construction of the pile to
monitorwater tables within the refuse pile. The location of the piezometers are shown on the Phase 1 Map.
These piezometers were installed at each respective location following reclamation of that portion of [he
pile.
The groundwatermonitoringprogram consisted ofmonitoringthefollowingwells:Iv1W-8,MW-9,MW-3,
~; and MW-5. The current monitoring sites, parameters and frequencies can be reviewed on Table 5 in
~ Section ?.04.7 of the MRP in Volume I . The locations of the current monitoring sites are shown on Map
34.
The leachate monitoring program involves the analysis of water from the rock drains by sampling flows
prior [o their collection in sedimentation pond MB-'_'R. However, there is typically not a significant flow
from the underdrainsto obtain a sample. As with the monitoring wells previously discussed, sampling and
analysis are conducted seasonally .and the parameters analyzed are the same as for groundwater wells as
specified in Table 5.
The results of [he hydrologic and leachate monitoring are reported to CDMG in the Annual Hydrology
Report.
8.3 Slope Stability
The lower refuse pile will be monitored during construction to verify the slope stabilit}• analysis performed
as described in Section ~.~. The monitoringsystem is composed of three separate surface monument lines.
Those monuments paralleling the toe were placed approximately 100 feet apart on a straieht line. The first
se[ of alignment monuments were installed alon_ the north toe of the lower refuse pile during construction
of Phase I and ll. Two other alignment systems were constructed in a general north-south direction. These
monuments run up the slope and were placed ~0 feet apart. The monuments were monitored monthly
during the construction of Phases 1 through III and have been monitored quarterly during the remainder of
construction. The monuments are intended to indicate whether the pile or subsurface soils are moving
laterally and whether excessive settlement or heave in the tow area is occurring. MCC personnel and, as
.:~ necessary, an outside geotechnical firm are involved in reviewingthe data. A summary report certified by a
~.
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