### July 17, 2012

Rochelle Boyd USEPA Mailroom (D243-02) US Environmental Protection Agency Office of Air Quality Planning and Standards 109 T.W. Alexander Drive Research Triangle Park, NC 27711

Re: Comment Clarification Request, July 13, 2012; Secondary Aluminum MACT Proposed Rule

Dear Ms. Boyd:

This letter is in response to the Comment Clari fication Request received by email July 13, 2012. The questions are:

1) What frequency of furnace designation switches does Kaiser consider necessary and why? Do you have records of how often these switches occur, if your current permit allows it? Due to enforceability of subpart RRR, we cannot allow unlimited switches. The original rule did not prohibit the switching of furnace designations, but the rule was not set up to accommodate such occurrences.

As the U.S. Environmental Protection Agency ( EPA) knows the issue of alternate operating scenarios is very important toKaiser Aluminum Fabricated Products, LLC (Kaiser). Kaiser pursued an applicability determinati on to clarify the application ofalternative operating scenarios under Subpart RRR beginning in August in 2009. After exchanges of letters explaining the necessity of alternative operating scenarios and extensive discussion with EPA an appropriate applicability determination letter was issued by EPA February 16, 2012. The letter (attached) provides necessary operating fl exibility without unnecessary re strictions of frequency of classification changes. The letter does not menti on any issues of enforceability with the current rule or related to the applicab ility determination. Ka iser believes any additional restrictions beyond those requirements specif ied in the applicability dete rmination are unnecessary and inconsistent with EPA’s policy of accommodating s ources with flexible operating requirements. EPA reiterated this policy in th e preamble to the Flexible Ai r Permitting Rule (74 FR 51418, 51419 (October 6, 2009)). In the preamble EPA so ught to “reaffirm opportunities within the existing regulatory framework to encourage wider use of FAP [Flexible Air Permitting] approaches” and allow facilities “to be marketresponsive while ensu ring equal or greater environmental protection than that ac hieved by conventional permits”.

9141 Interline Avenue, Suite 1A Baton Rouge, Louisiana 70809-1956 Tel (225) 231-5119 Fax (225) 231-5113 www.kaiseraluminu m.comRochelle Boyd U.S.EPA July 17, 2012 Page 2



### Additionally, restrictions on furnace classi fication frequency would be inconsistent with the alternative operating scenario provisions of Title V (40 CFR 70.6(a)(9)). EPA has made no assertion that the alternative operating scenario provisions of Title V, without frequency restrictions, are not enforceable.

Kaiser has provided EPA with explanations of the need for alte rnative operatin g scenarios in order to respond to maintenance outages and to market conditions several ti mes in the past. Our letter to George T. Czerniak dat ed June 9, 2011 (attached) contai ns an explanation of the need for flexibility. Also, our letter to you dated Ja nuary 18, 2012 (attached), which was included with our comments on the proposed rule, contains an explanation. An explanation of the need for alternative operating scenarios wi thout frequency restriction in our April 13, 2012 comments on the proposed rule. We explained that maintenance outages and changing marking conditions cannot always be predicted so there is no pla nned frequency of changes. Any restrictions beyond the requirements of the February 16, 2012 applicability determination would hinder operation flexibility without any additional envi ronmental benefit. Please refer to the two attached letters for more detailed information in answer to your first question.

In particular, Kaiser’s intends to operate the me lting furnace at our Kalamazoo, Michigan facility as a Group 1 furnace with add-on control to the maximum extent possible. We would operate it as a furnace without add-on cont rol, relying on work practices to achieve compliance with massbased emission limits, only when planned or unplanned maintenance out ages, and when scrap market conditions necessitate such operation. Th is operating mode may not be applicable to all facilities that use alternative operating scenarios, butit is the basis for Kaiser’s pursuit of the applicability determination over t he past 3 years. The common element in use of alternate operating scenarios in permits isthe need for operating flexibility without the encumbrance of frequent permit modifications.

In answer to your second question, the Michigan Department of Environm ental Quality (MiDEQ) would not include alternative operating scenarios in the Kala mazoo facility permit without concurrence from EPA. Kaiserpursued the applicability dete rmination in order to obtain concurrence. The issue was litigated in the United States Court of Appeals for the Sixth District, resulting in the February 16, 2012 applicabili ty determination letter from EPA. Once the applicability determination was iss ued Kaiser applied for a permit m odification in incorporate a Group 2 operation scenario and re ceived the modified permit May 14, 2012. Kaiser modified the OM&M Plan, SSM Plan and Baghous e Malfunction Abatem ent Plan as required and submitted them to MiDEQ in late May. Prior to that timethe option to change furnace classification was unavailable to Kaiser.

Kaiser notified MiDEQ on July 12, 2012 of a change of classification from Group 1 furnace with add-on control to Group 2 due to a baghouse system malfunction. Subs equently, Kaiser notified

MiDEQ on July 14, 2012 of the change back to Group 1. Due to the long delay in obtaining alternate operating scenario provisions on the permi t this is the only time Kaiser has had the flexibility to continue furnace ope ration during a baghou se system outage.Rochelle Boyd U.S.EPA July 17, 2012 Page 3



### Kaiser urges EPA not to promulgate the unnecessa ry and unsupported restrictions on the use of alternative operating scenar ios that were included in the propos ed rule. The current rule, along with clarifications incl uded in the February 16, 2012 applicability determination are sufficient to assure compliance with the mass-based emission limits of Subpart RRR and provide necessary flexibility to operating facilitie s. Any additional restriction provides no additional environmental benefit and is inconsistent with E PA’s stated goal of providing operational flexibility when equal compliance is achieved.

Kaiser would be happy to meet wit h you concerning this issue and others addressed in our April 13, 2012 comments. Please call me at 225-231-5116 or email me at bill.vinzant@kaiseral.com to establish a mutually convenient time for a meeting.

Very truly yours,

J. W. Vinzant Manager, Corporate Envi ronmental Affairs

cc: Scott Throwe, U.S.EPA, by email Roger Crawford, Kaiser, by email Charles M. Denton, Barnes& Thornburg LLP, by email Tony Sullivan, Barnes & Thornburg LLP, by email

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- RETURI\I RECEIPT REQUESTED 1\10. 7001 2510 0000 18444982

January 18, 2012

Rochelle Boyd USEPA Mailroom (0243-02) US Environmental Protection Agency Office of Air Quality Planning and Standards 109 T.W. Alexander Drive Research Triangle Park, NC 27711

Re: Secondary Aluminum MACT Alternative Operating Scenarios

Dear Ms. Boyd:

This letter is in response to your request during our January 17, 2012 conference call for Kaiser Aluminum Fabricated Products, LLC (Kaiser) to comment on EPA's plans to impose frequency limits (once every six months) on changes between operating scenarios for aluminum furnaces in the forthcoming proposed changes to Secondary Aluminum MACT (40 CFR Part 63 Subpart RRR).

Kaiser believes this restriction unnecessarily adversely affects facilities' operational flexibility without providing any environmental benefit. The current rule allows facilities to make necessary process changes as long as the facility operates consistent with its Operation, Monitoring and Maintenance Plan, and meets the numerical emission limits and other requirements of Subpart RRR. These provisions are consistent with the alternate operating scenario provisions of Title V (40 CFR 70.6(a)(9)).

There are many reasons that a facility might need to change from Group 1 with add-on control device operation to Group 1 without add-on control device mode or Group 2 mode including, material availability, control device malfunction or planned maintenance. Once the need has passed the facility will need to change back to routine operation. Restricting these changes would limit a facility's ability to react to operational needs or changing market conditions. These restrictions are likely to unnecessarily lead to production curtailment or shutdowns. As long as the facility meets the numerical emission limits there is no environmental benefit to these restrictions.

9141 Interline Avenue, Suite 1A Baton Rouge, Louisiana 70809-1956 Tel (225) 231-5119 Fax (225) 231-5113 www.kaiseraluminum.comRochelle Boyd U.S.EPA January 18, 2012 Page 2

It is particularly troublesome that the rule changes might limit operating mode changes due to control system malfunctions or to changes from operation without add-on control to operation with add-on control. In the first instance an operation that could otherwise comply with emission limits would have to curtail operations with no environmental benefits. In the latter case a facility that makes a change from operation with add-on control to operation without add-on control could not return to operation with add-on control until the 6 month period had run. These are just two examples of unnecessary disruption of operations with no environmental benefit.

Kaiser encourages EPA not to include unnecessary regulatory restrictions in the forthcoming proposed rule and allow facilities operation flexibility within the framework of the numerical emission limits, and the operating, monitoring, reporting and recordkeeping requirements of the current rule.

Roger Crawford and I would be happy to discuss this with you and Scott Throwe prior to issuing the proposed rule if you think it would be useful for resolving this issue. Please call me at 225-231-5116 or email me at bill.vinzant@kaiseral.com to establish a mutually convenient time for a conference call.

J. W. Vinzant Manager, Corporate Environmental Affairs

cc: Scott Throwe, U.S.EPA, by email Roger Crawford, Kaiser, by email Charles M. Denton, Barnes & Thornburg LLP, by email