APPCOR10177

• Permit No: C1994082
• IBM Index Class Name: Application Correspondence
• Doc Date: 3/14/1995
• Doc Name: YOAST MINE C-94-082 PERMIT APPLICATION
• Media Type: D
• Archive: No

----~~~ 59. This question has not yet been address>ed.
60. Three copies of the "Water Riqhts Investigation and Plan for
Augmentation for the Yoast Mine" are included with this
response package for inserting into Attachment 16-1, Tab 16,
Volume VIII of the Yoast PAP. The Plan has recently been
submitted to the District Court for Water District 57 for
approval. Or:ce SCC receives documentation of approval from
the court, the documentation will be forwarded to DMG.
61. The average pit inflow rate for the Wa:dge coal and overburden
units on the Grassy Creek side was calculated by dividing the
D'V total pit in:Elow for the four years (Years 1996 to 1999 on
Tables 17-2 and 17-3) by the total number of days of pit
inflow calculated for the overburden {1244992 gals/633 days =
1967 gals/day), since a majority of the annual inflow totals
are from the overburden. The numbers are different than those
originally submitted for the average z•ate of pit inflow on the
Grassy Creek side for the reasons cited in the response to
Question 57c.
//Q 62. As was discussed during the February 1, 1995 meeting in
~~ 63. SCC has revised the discussion regarding the peak of TDS
.~Q 64. CDMG interpreted the language on Page 45 of Tab 17 to imply
YY~~~• that removal of the ponds will change or eliminate the impact
of spoil di:charge on Annand Draw and Grassy Creek. SCC's
original language only intended to qualify the duration of the
impact. The language has been reviseed to further clarify the
intent of tY:e language.
~(~ Denver, GeoTr-ans, Inc. has written a proprietary digital model
for SCC to calculate pit inflows. .All input values to the
model are pr~asented in Attachment 17--2 and all output values
are shown on Tables 17-2 through 17-!i.
~l/ concentration for the spoil discharge in the subsection titled
"Water Chemistry and Flow Inferences Based on Seneca II
Monitoring Results". The revised portion provides elaboration
of SCC's interpretation of the lysimeter data, and references
chemical reactions controlling the TDS values measured at the
USGS lysimeter sites.
~~ 65. The original Table 17-2 showed the incorrect units for
transmissivi.ty. The correct units (ft~/day) for
transmissivi.ty are included on Tables 17-2 through 17-5.
~j 66. See SCC's response to comment No. 45~.
N/A During the February 1, 1995 meeting between SCC and CDMG
personnel iri Denver, the CDMG requested SCC to expand the last
full paragr~iph on Page 14 of the PHC: (Tab 17) to clarify the
reestablishment of ground water flow in replaced spoil
16