2017-04-06_INSPECTION - M1980244 ‎(2)‎

• Permit No: M1980244
• IBM Index Class Name: Inspection
• Doc Date: 4/6/2017
• Doc Name: Response
• From: Newmont / CC&V
• To: DRMS
• Email Name: AME
• Media Type: D
• Archive: No

Corrective action #2:
The Operator shall, within 120 days of the signature date of this inspection report, provide to the
Division the laboratory results of such analyses, include a report summarizing the results,
describing where the material will be moved to accordingly, and providing an estimated timeline
for completion.
CC& V's response: Due to the potential for metal mobility focus was given to obtaining TCLP
results with a Total Metals analyses; the results are found in Attachment 1. With the exception of
Barium, all results were at the practical quantification level (PQL). In fact, TCLP results
indicated elements As, Ba, Cd, Cr, Pb, Hg, Se, and Ag were between 2 and 3 orders of
magnitude lower than the regulatory limits set for the procedure indicating that only a trace
concentration of these elements exist in the rock material.
The Net Neutralizing Potential (NNP), or the potential for a rock mass to neutralize acid, was
determined for each of the sampling locations. All six samples were analyzed for acid generation
potential and acid neutralizing potential. A summary of the Acid Base Accounting (ABA)
laboratory results can be seen below in Table I whilst a fill report analyses are found in
Attachment 1. All samples were found to have a NNP between 0 and -20.
Based ort literature from Fey (1003), NNP values between -20 kg/ton CaCO3 and 20 kg1lon
CaCO3 are considered in the range of uncertainty whether acid will be generated or remain a
neutral pH. Any sample with NNP <20 is potentially acid generating, while any sample with
NNP > -20 might not generate acid (de Wet, 1012).
Table 1 : Chicago Tunnel Acid Base Accounting (ABA) Summary
Sample Location
Acid Generation Potential
(t CaCOVM)
Acid Neutralization
Potential
t CRC03/gt
Net Neutralizing Potential
(t CaCOWIM)
#1
19.1
5.0
-14.1
#2
14.7
5.0
-9.7
#3
15.6
7.0
-8.6
#4
11.3
6.0
-5.2
#5
10.0
5.0
-5.0
#6
11.3
6.0
-5.2
CC&V estimates approximately 5,000 tons of development rock material is present in the piles
shown in Figure 1. Given the short residence time of the rock material and its very low
likelihood for metal mobility away from the piles, CC&V proposed to address the final
management of the identified stockpiles within the Cresson Project Amendment 12 submission,
due to be submitted to the State in mid -2017. Options currently being considered for the
management of the material include;
• Insittr reclamation of the material;
• Relocation of the material
PortalrAdit Buttressing); or
• Relocation of the material
ECOSA).
to an appropriate location at the Chicago Tunnel Site (Eg
to an appropriate location at the Cresson Project Site (eg