APPCOR11165

• Permit No: C1994082
• IBM Index Class Name: Application Correspondence
• Doc Date: 6/23/1995
• Doc Name: YOAST ADEQUACY REVIEW HYDROLOGY C-94-082
• From: DMG
• To: LARRY ROUTTEN
• Media Type: D
• Archive: No

iii iiiiiiiiniu iii
•
STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY
Department of Natural Resources
1313 Sherman Sr., Room 215
Denver, Colorado dU207
Phone: [phone]
FA%~ (3U31 832-8106
Date: June 23, 1995
~~~~~
llEPARTMENT OF
NATURAL
RESOURCES
/ Roy Romer
To: Larry Routten c°"ernor
tames S. Lochhead
From: Kent Gorham ~~ e,e<°rve o~reclor
Michael d L°n~;
RE: Yoast Adequacy Review, Hydrology, #C-94-082 °'""°° ohe"°`
As per your request, I reviewed the information submitted by Seneca
Coal Company for the Yoast permit application. I have briefly
summarized my concerns and any resolution to those concerns below.
1. Lack of pit pumpage in the pond design
Mike Altavilla agreed to change the permit text to state that
the SCC will check the condition of the pond prior to pumping
any pit water to the pond. As the pond will not be
constructed till 1996 and any pit water would not exist until
1997, I allowed this rather loose language on one condition.
He agreed to rerun SEDCAD+ design using a base flow
representative of what the operator estimates for pit pumpage
discharge (2 cfs maximum). A member of your team should
probably follow-up on this to ensure it gets done in the near
future. If necessary, I can review any information he might
provide.
2. Tailwater include on trickle tube.
My understanding is that the principle spillway pipe is
designed now to outlet at ground level where tailwater may
exist. If that is the case, I have no concern.
3. Riprap filter layer
My understanding after review of the design and discussion
with the operator is that they will be using a geotextile
under the riprap. This should be confirmed in the field and
verified via the as-built certification submitted by the
operator after pond construction.
4. Permanent Drainage
Due to the narrow, far reaching extent of the proposed
disturbance, very careful attention should be given to the
proposed post-mining configuration, particularly with regard
to the permanent reconstruction of the post-mining