REP28844

• Permit No: C1982057
• IBM Index Class Name: Report
• Doc Date: 4/11/2006
• Doc Name: 2005 AHR Review Letter
• From: Dan Mathews
• To: Sandy Brown
• Annual Report Year: 2005
• Permit Index Doc Type: Hydrology Report
• Media Type: D
• Archive: No

STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY
Department of Natural Resources
7 313 Sherman St., Room 215
~ C O L D RA D O
Denver, Colorado Bo203 '~
' DIVISION o r
Phone: [phone] > s (Vl ~ ~ & A L $
FAX: [phone]
GEOLOGY
DATE: A rll ~ ~
2006
P RECLA NATION•MI NING
, SAf ETY~SCIENCE
TO: Sandy Brown and Mik o
ula
y Bill
/~\\
/
~
FROM: Dan Mathews Owens
Governor
/
\ Russell George
\ Executive Director
RE: 2005 W ater Year Annual Hydrology Report

Seneca II-W Mine, Permit No. C-1982-057 Ronald W. Canany
Division Director
Natural Resource Trustee
I have completed an initial review of the 2005 AHR for Seneca II-W. As usual, the report was
thorough and comprehensive. Monitoring appears to have been conducted in compliance with
permit specified schedules at approved sites, and the report includes appropriate data
presentation and discussion/evaluation of observed compliance with relevant standards and PHC
projections.
The report narrative was properly updated this year to reflect monitoring plan changes associated
with TR-52, approved 5/29/05. Data was included for the new W-25 series wells. Surtace water
analytical reports prepared after the TR-52 approval date included "potentially dissolved" analytes
for a number of constituents, and "total recoverable" iron, as approved in TR-52 (to correspond to
new CDPHE stream classification standards).
As in previous years, there are a few exceedances of water use standards at several sites, for
various parameters. Also, a few of the wells had TDS values that exceeded PHC projections.
will let Mike evaluate the significance of these exceedances.
On page 20 of the narrative, SCC reports that Spring 48 "now seeps over a widespread area and
[flow] cannot be measured". Last year's report indicated that a "plumbing break" had prevented
monitoring of this spring, which seemed to imply that the problem with obtaining a flow
measurement was temporary. The language this year sounds like the situation may be
permanent. If determination of flow is important for this location, we may need to request that
measures be taken to allow for determination of flow. Mike's input requested.
Please request Mike Boulay to do the PHC compliance review.
-Office of OfFlce of Colorado
Mined land Reclamation Active and Inactive Mines Geological Survey