REV106584

• Permit No: M1988112
• IBM Index Class Name: Revision
• Doc Date: 7/17/1997
• Doc Name: PROPOSED PERMIT CONDITION VALUES FOR MONITORING WELLS MR4 M11R & M15 SAN LUIS PROJECT M-88-112
• From: DMG
• To: BRUCE HUMPHRIES
• Type & Sequence: TR15
• Media Type: D
• Archive: No

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STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY
Depanmeni o1 Natural Resources I~~~~
1313 Sherman 51 ,Room 215
Denver, Colorado 80203
Phone [phone]
FAY. 1303) 832 8106
DEPAkTMENT OF
NATURAL
RESOURCES
Roy Romer
To: H. Bruce Humphries, James Stevens governor
` lames 5 Lochhead
From: James Dillie E~ecurrve Direcbr
Michael B Long
i Division Director
Date: July 17, 1997
Re: Proposed Permit Condition Values for Monitoring Wells M-4R, M-11R, and M-15, San Luis
Project, M-88-112
As required, BMRI submitted the proposed permit condition values for the referenced wells.
As approved in TR-15, permit condition values for the new wells would be set using the greater
of measured values, which are not outliers (according to the Dixon method), during the first year
of monthly/bi-monthly baseline data collection or the table standazds. Permit condition values
would be established for five (5) indicator parameters (iron, manganese, total dissolved solids,
sulphate and pH plus WAD cyanide in M-4R and M-15).
As noted, BMRI proposes to comply with table standards at the M-4R point of compliance for all
five (5) indicator parameters even though pH was slightly elevated in May and June, 1996. 'The
8.71 and 8.78 readings would have exceeded the established table standard limit for pH during
those months. Also, pH measured 5.50 in April, 1997. This is the upper table standard limit. In
addition, pH measurements were below 8.0 only 2 of the 10 monitoring periods. But, if BMRI
proposes to comply with table standards at the M-4R point of compliance, I think we should
approve their request.
BMRI proposes to comply with table standards for all but TDS at the M-11 R point Of
compliance. During the twelve month monitoring period, TDS ranged from 478ppm (April, 97)
to 660ppm (July, 96) at the M-11 R well It appears it will very difficult [o meet TD$ table
standazd limits at this site so BMRI proposes to set the permit condition value at 660ppm. If this
value is not an outlier 1 recommend approving the proposed value. However, if it is determined
that the 660ppm value is an outlier, the Division should approve the next highest value, SSOppm,
which was measured in May, 1996 (if that is not an outlier). I recommend the Division approve
using table standards for iron, manganese, sulphate and pH at the M-1 I R point of compliance.
For M-I5, BMRI proposes to comply with table standards for iron, sulphate and pH. However,
BMRI proposes permit condition values of .1 lppm for manganese and 600ppm for TDS.
Elevated levels of manganese, above table standards, were detected 5 out of the 10 monitoring