HYDRO27180

• Permit No: C1982057
• IBM Index Class Name: Hydrology
• Doc Date: 3/1/1990
• Doc Name: SENECA II-W HYDROLOGIC MONITORING FN C-82-057
• From: MLRD
• To: PEABODY COAL CO
• Permit Index Doc Type: CORRESPONDENCE
• Media Type: D
• Archive: No

• . iii iiiiiiiiiiiii iii
STATE OF COLORADO

MINED LAND RECLAMATION DIVISION
Deparimenl of Natural Resources
1313 Sherman St., Room 215
Denver. CO 80203
303 666-3567
Fa X. 303 632-6106
March 1, 1990
Mr. Ted Smith
Peabody Coal Company
1300 South Yale
Flagstaff. AZ 86001
Re: Seneca II-W Hydrologic Monitoring, File C-82-057
Dear Mr. Smith:
I have reviewed the letter prepared February 9, 1990, summarizing discussions
we had in January about baseline monitoring at Seneca II-W and Yoast. I would
like to confirm that the basic content of the letter reflects my understanding
of our discussion. However I would like to elaborate in greater detail on
some of the points which were made. The following numbering system references
the February 9, 1990 letter:
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Roy Romer,
Governor
FreOR Bama.
Dwision Gre^_ior
Seneca II-W: Items 1 and 2 and Yoast: Item 5
Each of these items references the installation of alluvial wells in
areas of "true" alluvium within a half mile from proposed sediment
ponds. We had no discussion in January about the nature of "true"
alluvium. Rather, I indicated that alluvial valley floor identification
is based on a number of factors including geological material, method of
transport, historic land use, size of tract and its capacity to be worked
with agricultural tools and the capability of the land to support
sub-irrigation and fl pod irrigation. Please review our regulations on
alluvial valley floors (Rules 1.04.10, 2.07.6(2)(k), and 4.24), and call
if you have any further questions.
Additionally, while there is no reference to an alluvial valley floor
reconnaissance study in this letter, we did discuss the extent of such a
study. I indicated that a field reconnaissance survey should include all
alluvial valley floors which could be affected by the mine.
Seneca II-W: Item 4
When installing wells in the II-W south area, please locate the wells as
near as possible to the downgradient perimeter of the pits.
Yoast: Item 2
I understood from our telephone conversations that there are three
underburden wells among the U. S.G. S. sites. Additional monitoring of the
underburden may be required depending on the results of the monitoring
from these sites and the behavior of the underburden in adjacent areas.