REV93882

• Permit No: C1981019
• IBM Index Class Name: Revision
• Doc Date: 12/6/2005
• Doc Name: Review Memo
• From: Dan Mathews
• To: Jim Stark
• Type & Sequence: TR62
• Media Type: D
• Archive: No

allow for sufficiently accurate estimates of available soil volumes for operational and
reclamation purposes. Operator argued that data was adequate (see page 2.04.9-16),
but agreed to monitor soil balance and provide soil balance reports on an annual basis,
as a means of confirming the adequacy of the baseline information. Apparently, the
Division approved deletion of the annual soil balance reporting in association with Permit
Renewal RN-1, in 1987, based on review of the monitoring data that had been provided.
Within this (TR-62) revision application, Operator is requesting to reduce the topsoil
replacement thickness from 18 inches to 8 inches, based on comparison of surveyed soil
stockpile volumes to disturbed acreage not yet topsoiled. The evaluation indicates that
topsoil in stockpile is sufficient to allow an average replacement thickness of only 6.48
inches.
Please provide an explanation of the factors that resulted in the current shortfall
(as compared to original projections). Were original estimates of soil availability
inaccurate? Were inadequate "quality control" practices employed to ensure and
document that all suitable topsoil is salvaged from the various soil types, and that
an "approximately uniform" soil thickness is replaced, in accordance with permit
requirements? What are the current practices for ensuring compliance, and what
changes have been implemented or will be implemented to ensure that
modifications of such magnitude will not be required in the future?
2. Current Table 2.05-1, "Topsoil Schedule for Mining Area", was approved by TR-42 in
1997. The table provides soil balance projections for the permit terms ending in 2002,
2007, and 2013. More detailed projected soil balance information is provided on an
annual basis for 1997 through 2002, on current Table 2.05-2. The projections indicate
that the volume of soil to be salvaged would significantly exceed the volume necessary to
replace the 1.5 foot average replacement thickness, and further indicate that the "excess"
volume would be placed in stockpile.
The current volume of stockpiled soil indicated on revised Table 2.05-1, provided with
TR-62, is approximately 1 million cubic yards less than that projected on the current
version of the table.
Please provide a description and summary of any actual operational data collected
on an annual or periodic basis during the previous and current permit terms,
corresponding to the projections of current Tables 2.05-1 and 2.05-2. Comparison
of "actual" versus "projected" removal acreages and volumes, replacement
acreages and volumes, and stockpiled volumes, would provide some insight into
the reasons for such a large discrepancy in the cumulative volume of topsoil in
stockpile.
3. The TR-62 proposed version of Table 2.05-1 is a survey based topsoil balance for a
particular point in time (October, 2005). If the existing disturbance were to be reclaimed
with the available soil in stockpile, the table would provide sufficient information for
planning purposes. However, in actuality, it appears that surtace disturbance is projected
to continue through at least 2012, and reclamation operations will continue for some time
beyond that. Soil replacement thickness should reflect the best estimate of available soil
volume to be salvaged from areas yet to be disturbed, in conjunction with the current
volume of soil in stockpile. In addition to the "current" topsoil balance provided in
proposed Table 2.05-1, updated versions of the soil balance projections provided in
current Tables 2.05-1 and 2.05-2 should also be provided.
Please provide new topsoil balance projection tables for the remainder of the mine
life, comparable to current Tables 2.05-1 and 2.05-2. Projections should
incorporate salvage volumes estimated for remaining areas to be disturbed, based