REV07143

• Permit No: C1996083
• IBM Index Class Name: Revision
• Doc Date: 8/4/2006
• Doc Name: Adequacy & Comment Review Letter
• From: DMG
• To: Bowie Resources, LLC
• Type & Sequence: TR43
• Media Type: D
• Archive: No

mining contours for the new borrow area. If BRL is proposing a variance from the requirements of
Rule 4.14.1(2), that all disturbed areas are returned to their approximate original contour, BRL needs
to submit supporting documentation as required by the rule.
The Division has no further concems. BRL provided a revised Map 18, Postmining Topography,
with the July 7, 2006 submittal. In that submittal, BRL did not propose a variance from
approximate original contour.
4. The SEDCAD runs submitted with the new drainage plan suggest a minimum ditch depth of0.44'for
the West Diversion. On Figure 3, BRL has committed to a minimum ditch depth of0.4'. The same is
true for ditches F3, FI /, F16, F13, and F2; in that BRL has proposed ditch depths less than those
recommended by the SEDCAD program. Please revise Figure 3 to show minimum ditch depths at
least as deep as those suggested in the SEDCAD runs, and compliance with Rule 4.05.3(1)(e) and
4.05.3(7)(6).
The Division has no further concerns. The minimum ditch depths, stated in feet, listed on Figure 3
are rounded up or down to one decimal place since measuring ditch depths in the Feld to two
decimal places is impractical.
In reviewing the gob pile area drainage plan and sediment pond details provided to address Rule
4.05.6(3), it was not apparent whether BRL anticipates any contribution ofwater from the gob pile
underdrain system. Has BRL observed any water flowing from the underdrain system?
The Division has no further concerns. The operator does not believe groundwater has or will enter
the gob pile underdrain system. Field inspections by the operator and by Division personnel have
not revealed any groundwater entering this underdrain system.
6. BRL estimates that the capacity of Pond F is 3.95 acre feet, and that the runoffand sediment volumes
resulting from a 10 year, 24-hour rainfall event (design event, as required by Rule 4.05.6(3)(a))
would tota13.91 acre feet, leaving 0, 04 acre feet of excess storage capacity in the pond. The Division,
while acknowledging that this design does meet the minimum requirements of the rules, would
strongly recommend that BRL consider resizing this pond to allow far additional storage. We believe
it would be d~cult to meet effluent requirements with this little excess storage.
Page 2.05-32 of the permit application discusses the cleaning and dewatering practices currently
utilized far the ponds. BRL should add to this section a commitment to install markers at Pond F that
clearly show the required sediment cleanout level and maximum water level that could occur while
still allowing ample storage for the design event.
BRL declined to resize Pond F, although it did commit to the installation of markers for sediment
cleanout and for maximum water level. Concerning meeting sediment compliance requirements,
the primary discharge tube is attached to a flexible hose and float so that pond discharge water is
taken off of the top of the water pool, rather than from near the bottom.
However, the Division has one concern with the revised pond F hydrology designs. As stated in
item number 8 of the cover letter for TR-43, the pond F hydrology designs assume that the first
two benches of gob pile no. 2 are covered with soil material. As of July 2006, there was no cover
material on gob pile no. 2. Therefore, the Division believes that the pond F hydrology designs