From:       Mike Elges <melges@ndep.nv.gov>                                                

                                         

  To:         Chuck French/RTP/USEPA/US@EPA                                                  

                                                                                             

  Cc:         Leo Drozdoff <ldrozdof@ndep.nv.gov>, Colleen Cripps

<CRIPPS@ndep.nv.gov>                                                

                                                                                             

  Date:       03/12/2010 11:08 AM                                                            

                                                                                             

  Subject:                                                                                   

  

Chuck,

As I indicated in my phone message to you yesterday, NDEP met with the mining

industry on Wednesday to further discuss both the federal and state mercury

control programs.  At the conclusion of that meeting, there were a few items that

we wanted to convey to EPA that are relevant to the proposed FMACT rulemaking.  

I’ve outlined those below, and would be happy to discuss them in more detail if

you would like.

TITLE V NOT REQUIRED FOR AREA SOURCES

As part of the federal MACT rulemaking, NDEP understands that EPA must evaluate

whether it is necessary to subject mining operations that constitute area sources

to the Title V program.  As part of its consideration, we wish to point out to

EPA that several mines are currently subject to Title V—in Nevada referred to as

Class I—permit requirements as result of their status as major sources of

criteria pollutant emissions.  There are a number of mining sources that are not

subject to Class I permitting requirements but are subject to Nevada’s Class II

permitting program for non‐major sources.  Class II operating permits are

required to contain, among other things, all applicable emission limitations and

standards, including those operational requirements and limitations that ensure

compliance with the conditions of the operating permit and all requirements for

monitoring, testing and reporting that apply to the stationary source.  Sources

holding Class II permits will be required to incorporate federal MACT standards

and requirements into those permits.

As you are also aware, the Nevada Mercury Control program requires all mining

sources—major and area—to hold mercury operating permits to construct.  These

permits must also contain all applicable requirements concerning controls for

mercury emissions, emission limits and standards and provide an additional permit

mechanism for addressing federal MACT standards.  NDEP believes that these permit

programs provide a strong basis for implementing and enforcing any federal MACT

requirements for the gold mining industry and there would be nothing gained in

terms of improved compliance with such a standard by subjecting these sources to

Title V permitting.  On the other hand, Title V permitting would subject both the

sources and NDEP to significant additional resource burdens.

CONCENTRATE/CARBON METRIC DISCUSSION

Based on discussions between the mining industry and NDEP, and given our current

understanding of the federal MACT standard being consider by EPA, there is a

consensus that the appropriate metric for the Carbon Group should be concentrate.  

This is based on our understanding that a concentrate metric would be defined
consistent with the principles that were discussed at our meeting with EPA on

February 17th; that is, the concentrate metric would (i) include all concentrates

(from EW’s, gravity separation circuits, Merrill‐Crowe process, tank bottoms,

etc.),

(ii) be determined on an “as‐fed” basis, and (iii) be accounted for at both the

facility generated and, in those cases where concentrate is further refined at

another site, the facility to which the concentrate is shipped for further

refining.  Based on existing monitoring requirements and the relationship of

concentrate to the mining process, this appears to be a competent metric for

establishing a mercury emission standard for the Carbon Group.

Notwithstanding the foregoing, some believe that it is necessary to further

review the data in view of the rule as it is actually proposed in order to

completely understanding the implications of using concentrate as a metric so as

to ensure that concentrate will, in fact, provide for an effective metric for

establishing a mercury MACT standard.  Accordingly, the mining industry believes

that the proposed rule should also include carbon as an alternative, but

secondary, option for the metric for the Carbon Group.  As discussed at the

February 17th meeting, a carbon metric would be based on the volume of carbon fed

to the strip circuit.  NDEP does not object to including a carbon metric in the

proposed rule.

Again, if you have any questions or would like to discuss this in more detail

just let me know.

Thanks,

Mike Elges