August 6, 1996

Reply To

Attn Of: AT-082

Martin Bauer, Chief

Construction Permits Bureau

Division of Environmental Quality

Idaho Department of Health

and Welfare

1410 North Hilton

Boise, Idaho 83706-1255

Dear Mr. Bauer:

This is a partial response to your letter of April 5, 1996 to David C. Bray. I apologize for the length of time that it has taken to get a response, but with the recent promulgation of EPA's federal operating permits program (40 CFR Part 71) for Idaho and Alaska, our permit program resources have been directed at completing the interim approvals for those two Title V programs to minimize the time that the federal program will be in effect. It has also taken significant time to track down the most recent guidance on the two specific issues discussed in your letter. We will be able to get back to working in earnest on Idaho's PSD/NSR SIP submittal by the middle of August.

In general, EPA agrees with the conclusions as stated in your letter. However, EPA still has serious concerns about Idaho's approach to the specific issues of when to include fugitive emissions in potential to emit calculations, and how to determine when a major modification has occurred. In order to address these issues, I have enclosed a number of recent EPA guidance documents on these subjects.

First, on the specific issue of counting fugitive emissions for sources in a source category regulated by a section 111 or 112 standard, I have enclosed a copy of a March 1, 1996 letter from Robert G. Kellam, Acting Director, Information Transfer and Program Integration Division, Office of Air Quality Planning and Standards to Donald P. Gabrielson of the Pinal County Air Quality Control District, Arizona. The third item in the letter specifically addresses the requirement for counting fugitive emissions for sources within an NSPS source category even if the source itself is not subject to the NSPS. I've also enclosed three other recent guidance documents on the issue of counting fugitive emissions in major source applicability determinations.

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Along with the March 1, 1996 letter, these four documents address such issues as counting fugitives from co-located listed and non-listed source categories (March 8, 1994 and June 2, 1995 memoranda from Lydia Wegman to Regional Air Office Directors), clarification as to what is considered a "functionally equivalent opening" (April 16, 1996 letter from Cheryl Newton, EPA Region 5 to Paul Dubenetzky, State of Indiana), clarification as to how to determine whether emissions could "reasonably" pass through a stack, vent, or functionally equivalent opening (March 1, 1996 letter from Robert G. Kellam to Donald P. Gabrielson), and clarification as to what fugitive emissions are counted if a source falls within a listed source category (March 1, 1996 letter from Robert G. Kellam to Donald P. Gabrielson). These guidance documents represent EPA's determination as to what is necessary to comply with the requirement of section 302(j) of the Act and, as such, must be followed by any State in order to receive approval of its permit programs for major stationary sources.

Second, on the issue of determining when changes trigger the definition of major modification, I have enclosed a series of five EPA guidance memoranda dating from January 2, 1981 through September 18, 1989 that all address EPA's policy of accumulating emissions for determining whether a "net emissions increase" has occurred. All of these memoranda reaffirm EPA's policy that the determination of the net emissions increase does not include contemporaneous emissions changes unless the plantwide emissions increases from the proposed modification itself would be significant. It is important to note that many of these memoranda indicate that EPA will be revising the PSD/NSR rules to make the rules consistent with the policy, however to date, such revisions have not been made. On the contrary, the proposed revisions to the PSD/NSR rules published on July 23, 1996 make fundamental changes to the definition of major modification which, if promulgated as proposed, would invalidate this policy. As such, while a change to Idaho rules which is consistent with current EPA policy would be approvable as a revision to the Idaho SIP, EPA recommends against making such a change at this time pending the final promulgation of revised EPA regulations.

Because of the priority Title V workload, we have not yet completed our review of the PSD/NSR SIP submittal so are unable to send you detailed comments at this time. For the same reason, we have not yet been able to further investigate the provisions of your current SIP rule which exempt fugitive dust emissions. We will forward the findings of our review as soon as it is completed. However, before we can complete our review, we will need to receive a formal SIP revision submitting the recent revisions to your rules covering periods of excess emissions. I am aware that certain changes to your rules addressing the Part 70 emergency provisions were submitted as revisions to your Title V program submittal, however, no revisions to the SIP excess emission provisions have yet been received by EPA.

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If you have any questions on the status of your SIP submittal, please contact David Bray (206) 553-4253.

Sincerely,

Joan Cabreza

Permits Team Leader

Office of Air Quality

Enclosure

March 1, 1996

Mr. Donald P. Gabrielson

Pinal County Air Quality Control District

Post Office Box 987

Florence, Arizona 85232

Dear Mr. Gabrielson:

Thank you for your letter of October 25, 1995 to Lydia Wegman regarding a clarification of the definition of "regulated pollutant" for the purpose of title V applicability determinations with respect to open-pit mining operations.

Prior to addressing your questions, I would like to apologize for the delay in responding to your letter. It is my understanding that during a discussion with Joanna Swanson of my staff, you indicated that you were more interested in our addressing some of the fundamental issues underlying your questions than in receiving our response by any specified deadline. The issues which you raise in your letter have been reviewed and discussed by staff within the Office of Air Quality Planning and Standards (particularly with people in the new source review and operating permits programs), Region IX, the Office of General Counsel, and the Office of Enforcement and Compliance Assurance. These discussions have delayed our response, but have hopefully resulted in a letter which is more useful to you.

•	Where should the analytical quantification of "regulated emissions" occur?

Under this general question, you raise a particular question relative to Lydia Wegman's October 16, 1995 memorandum entitled "Definition of Regulated Pollutant for Particulate Matter for Purposes of Title V." Specifically, you ask where the quantification of PM-10 (particles with an aerodynamic diameter less than or equal to a nominal 10 micrometers) should occur for purposes of title V applicability.

As you know, a source is determined to be a major source under title V based on its potential to emit. The October 16, 1995 memorandum was intended to provide guidance on what pollutant to consider in determining title V applicability, not to change the procedure for calculating potential to emit.

Nevertheless, if actual emissions are used as the basis for determining the potential to emit for a source, then these emissions should be measured at the point where emissions are released.

•	For regulatory purposes, which emissions are "fugitive?"

Under this topic, you ask for the proper interpretation of fugitive emissions in relation to Lydia Wegman's memorandum of March 8, 1994 entitled "Consideration of Fugitive Emissions in Major Source Determinations." You specifically ask whether "the fact that some sources have actually installed capture-and- control systems on various crusher, screen, and conveyor drop facilities necessarily dictate that emissions from all such facilities be treated as non fugitive?" As noted in the October 21, 1994 memorandum from John Seitz, which you cite, entitled "Classification of Emissions from Landfills for NSR Applicability Purposes," the use of collection technology by certain sources in a source category creates a presumption that collection is reasonable for all such sources in that category. As a result, although the use of capture-and-control systems on various pieces of equipment would not necessarily dictate that emissions from all such equipment in that category should be treated as non fugitive, the presumption would be that these emissions are non fugitive.

•	Do sources fairly characterized as falling within the "source category" to which a pre-August 7, 1980 new source performance standard (NSPS) applies, but which sources are "grandfathered" around the NSPS applicability provisions, also need to include "fugitive" emissions in making a major source determination?

Fugitive emissions are to be included in major source determinations if a facility or source falls within a source category which has been listed pursuant to section 302(j) of the Act. Whether a facility has been regulated as an affected facility, and/or whether it is modifying or under construction, does not determine whether its fugitive emissions are to be counted in determining whether the source as a whole is major under title V. Rather, if a facility or source falls within a source category which has been listed pursuant to section 302(j) of the Act, then all fugitive emissions of any "air pollutant" [as EPA defines the term for purposes of 302(g) of the Act] from that facility or source are to be included in a title V applicability determination.

In regard to the aggregation of unlisted sources of fugitive emissions with listed sources of fugitive emissions for purposes of determining whether a source is a major source, please refer

to Lydia Wegman's memorandum of June 2, 1995 entitled "EPA Reconsideration of Application of Collocation Rules to Unlisted Sources of Fugitive Emissions for Purposes of Title V Permitting." This memorandum states that EPA is currently reconsidering its application of the collocation language in 40 CFR, part 70 as it applies to unlisted sources of fugitive emissions. Due to this reconsideration, EPA's interpretation of the part 70 collocation language (as announced in the preamble of the May, 1991 proposed part 70 rule) is no longer binding with respect to unlisted sources of fugitive emissions.

Nevertheless, absent a binding interpretation from EPA, permitting authorities have discretion in interpreting what part 70's collocation language requires with respect to unlisted sources of fugitive emissions. For example, permitting authorities have discretion to include fugitive emissions from sources outside of a listed source category, that are collocated with the affected facility, when they are determining whether the source as a whole is major under title V. Moreover, it is important to note that EPA is not reconsidering or rescinding its interpretation of the collocation provisions of the new source review regulations with respect to unlisted sources of fugitive emissions.

•	To the extent that merely falling within a source category subject to a pre-August 7, 1980 NSPS does not inherently require inclusion of all "fugitive" emissions in a major source determination, which "fugitive" emissions at a facility are rendered "regulated" as a result of the actual installation of new facilities affected by a pre-August 7, 1980 NSPS?

As described above, fugitive emissions from a facility or source are to be included in major source determinations if the facility or source falls within a source category which has been listed pursuant to section 302(j) of the Act. As a result, the specific questions you raise need to be answered according to whether the facilities or operations in question fall within a source category listed pursuant to section 302(j).

In addition to the above questions, it is my understanding that, based on discussions you have had with Joanna Swanson of my staff, one NSPS of concern for a source in your district is the NSPS for metallic mineral processing plants (40 CFR, part 60, subpart LL). The information which you provided to our office regarding this source has been forwarded to Keith Brown in the Office of Enforcement and Compliance Assurance, the office responsible for NSPS applicability determinations. Mr. Brown will be contacting you in the near future; however, for future reference, Mr. Brown can be reached at (202) 564-7124.

I appreciate this opportunity to be of service and trust this information will be helpful to you. Please understand these responses are intended solely as guidance as to how EPA would interpret its regulations in your situation, and are based on the information you have provided to EPA.

Sincerely,

/s/

Robert G. Kellam

Acting Director

Information Transfer and Program

Integration Division