REV96429

• Permit No: C1994082
• IBM Index Class Name: Revision
• Doc Date: 7/19/1995
• Doc Name: YOAST MINE PN C-94-082 RESPONSE TO DIVISION OF MINERALS & GEOLOGY 07/19/95 ADEQUACY LETTER MR 02
• Type & Sequence: MR2
• Media Type: D
• Archive: No

III IIIIIIIIIIIII III
• YOABT MINE PERMIT C-94-082
RESPONSE TO DIVISION OF MINERALS AND GEOLOGY
07/19/95 ADEQIIACY LETTER
Minor Revision MR-02
1. The text on Page 13-3-8 has been revised to reflect the
correct spillway design.
2. This discrepancy requested that Table 13-8-1 be revised to
include the supporting calculations for weighted curve
numbers for the YB culverts. In the design calculations
for Pond 010, the calculations for each watershed's curve
number is included in Attachment 13-3, Addendum 13-3E. A
new .table for the YB culverts was produced to show which
watersheds correspond with the respective culverts.
The Division requested SCC to use a curve number of 91 for
all topsoil salvaged areas. The tables in Addendum 13-3E
were all revised to reflect this change. Several
watershed curve numbers were increased that were not
accounted for in the following hydrologic designs: Pond
010, Diversions 2 and 3, and Culverts YB-2, YB-3, YB-7,
and YB-8. All designs for these structures have been
revised to reflect the correct watershed information.
• 3. The access road leading to Pond 11 has been removed from
the following exhibits: 12-1, 13-2, and 13-3.
4. Upon further review of Figure Sa, Attachment 16-2 (Tab
16), PWCC confirms the drawdown is directed toward the
southeast and to the northwest, not the west. The non-
concentric pattern of drawdown predicted by the model and
shown in Figure 8a (Attachment 16-2) is expected, owing
largely to complex geologic structure (see Figure 1, Tab
6, Geology) which governs flow in the Trout Creek
Sandstone and the proximity and occurrence of its outcrop
to the south. In addition, operation of SCC's Seneca II-W
production well (Figure 8a, Attachment 16-2, Tab 16) will
influence the pattern of drawdown from the Yoast well into
a non-concentric pattern. For drawdowns greater than 50
feet in the immediate vicinity of the Yoast well, the
drawdowns will mimick a concentric shape; however, for
drawdowns beyond the 50-foot value, effects from geologic
structure and proximity of boundaries become more
pronounced, hence the non-concentric drawdown pattern.
SCC has revised the text on Page 14 of Tab 17 to include a
discussion of the Foidel Creek Mine wells completed in the
Trout Creek Sandstone.
• 6. In a meeting on June 21, 1995, discussions between Kent
Gorham of DMG and Michael Altavilla of SCC occurred about
pit pumpage and dewatering activities. SCC states in Tab
13, Page 6 that pit pumpage will be primarily a seasonal