2000-04-21_PERMIT FILE - M2000002

• Permit No: M2000002
• IBM Index Class Name: Permit File
• Doc Date: 4/21/2000
• Doc Name: ADEQUACY ISSUES LAFARGE INC TANABE PIT M-2000-002
• From: DMG
• To: HARRY POSEY
• Media Type: D
• Archive: No

III IIIIIIIII'111111
999
STATE OF COLORP~DO
H I~
DIVISION OF MINERALS AND GEOLOGY
Department o! Natural Resources
1313 Sherman SI., Room 215
Denver, Colorado 80203
Phone: [phone]
FAX: [phone]
Apri121, 2000
To: Tom Schreiner 1'~
From: Harry Posey i~~~ ~~~~}/
Subject: Adequacy Issues: Lafarge Inc., Tanabe Pit, M-2000-002
DIVISION OF
MINERALS
GEOLOGY
RECLAMATION
MINING•SAFETY
Bill Owens
Governor
Greg E. Walther
E>te<mwe Director
Michael8 Long
Division Director
This memo follows our meeting today with Laura Williams and Larry Kimmel of EPA and Pam
Acre of Tattle-Applegate. This review addresses questions about groundwater chemistry, alone.
I have not reviewed other issues such a slope stability, water rights, right of ways, etc.
COMMENTS
Several letters of concern and my review house questions aboLlt the following:
• mining within a contaminated aquifer;
• whether groundwater had been tested for contaminants including diisopropylmethyl
phosphonate (DIMP), methyl chloride, other volatile organic compounds, parathion, DD'f,
marathion, atrizine, non-chlorinated hydrocarbons including ethyl benzine, and xylene.
• need for an NPDES discharge permit;
• potential for withdrawal of existing off-site groundwater contaminants into the mining site
through pumping.
The following addresses these concerns in order.
A. Potential eroundwater contamination.
On review of maps and documents prepared for EPA, it is apparent that the proposed operation
occupies an area near former and perhaps present groundwater plumes containing DIMP, and is
neaz a formerly-mapped plume containing TTCLE. DIMP in excess of 8 parts per billion (ppb)
existed in groundwater a few hundred feet northeast of the proposed pit as recently as 1997 in a
plume that has been shrinking for several years. Detectable DIMP also existed in groundwater
coincident with the western portion of th eproposed operation as recently as 1996; however, this
plume did not appear in 1997 reports. TTCLE was reported as recently as 1996 in an area
approximately '/< mile southwest of the proposed site, but apparently has not been reported since.
Except for DIMP and TTCLE, according to Williams and Kimmel, none of the other
contaminants named in letters to the Division have been identified within or in [he near vicinity
of the proposed operation. Because groundwater is being pumped from several locations on the