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BECKHAM, LISA

From: BECKHAM, LISA

Sent: Thursday, May 28, 2015 11:32 AM

To: 'Steve Burr'

Cc: Justine Miller; Marina Mejia

Subject: RE: ADEQ Minor NSR in Nonattainment Areas

By June 15 would probably be best. 

Yes, we are definitely considering the comments you submitted on R18-2-334(E) in making our final decision. 

From: Steve Burr [mailto:Burr.Steven@azdeq.gov] 

Sent: Thursday, May 28, 2015 11:04 AM 

To: BECKHAM, LISA 

Cc: Justine Miller; Marina Mejia 

Subject: RE: ADEQ Minor NSR in Nonattainment Areas 

That’s very helpful, thanks. I think I get the gist of it, but I’ll call you if I have any questions. I’m going to go back and look 

at our calculations for SO2, because that 22% was clearly incorrect. I’m surprised that didn’t occur to any of us at the 

time. 

What submission date should we be shooting for in light of your June 30 deadline? 

On a side note, can you tell me if EPA is reconsidering, based on our comments, the proposed limited disapproval of 

R18-2-334(E), which requires the Director to request an AQIA for a source complying with RACT if the specified 

conditions are met? If not, was this something the Region discussed with HQ? 

From: BECKHAM, LISA [mailto:BECKHAM.LISA@EPA.GOV] 

Sent: Thursday, May 28, 2015 10:33 AM 

To: Steve Burr 

Subject: ADEQ Minor NSR in Nonattainment Areas 

Hi Steve, 

As discussed, attached is a pretty basic, rough outline of the kind of additional clarifications your could provide related 

to ADEQ’s minor NSR program under 40 CFR 51.160(e). This is one potential starting point, there are certainly others 

that may work. 

I’m available this afternoon to discuss in more detail if you would like. 

Lisa Beckham 

Environmental Engineer 

Air Permits Office 

EPA Region 9 

(415) 972-3811 
SAMPLE/DRAFT

Additional Clarifications – Basis for Minor NSR Permitting Exemption Thresholds

Summary

As discussed in detail below, ADEQ’s Minor NSR permitting exemption thresholds represent the types 

and sizes of facilities, buildings, structures, and installations that will be subject to review for ADEQ’s 

minor NSR program under 40 CFR 51.160(e) to ensure attainment and maintenance of the NAAQS. 

ADEQ’s permitting exemption thresholds ensure that only those emissions that are inconsequential to 

attainment and maintenance of the NAAQS are exempt from its program. ADEQ’s determination is 

based on (1) a statistical analysis demonstrating the percentage of stationary source emissions ADEQ 

anticipates will be covered by its program, and (2) a review of the air quality issues under ADEQ’s 

jurisdiction and the expected contribution from minor sources and minor modifications.

Statistical Analysis

[General reference to discussion in SIP submittal (maybe a short summary), include table of 

Scenarios 1 and 2, table of final thresholds]

However, as further discussed in the section below, for purposes of New Source Review, 

Scenario 2 does not offer any substantial benefits over Scenario 1.

PM2.5 Threshold

[insert discussion]

Air Quality Conditions in Areas under ADEQ’s Jurisdiction

ADEQ currently has permitting jurisdiction over some areas of Arizona that are attaining the 

NAAQS and some areas that are not. In attainment areas, where the area is currently meeting 

the standard and ADEQ will be implementing an expanded minor NSR program, it is reasonable 

to conclude that those sources that remain exempt from the program are inconsequential to 

attainment and maintenance of the NAAQS. Below, we discuss the appropriateness of the 

permitting exemption thresholds in Scenario 2 in ADEQ’s nonattainment areas.

SO2 Nonattainment Areas

ADEQ has two areas that are currently designated as nonattainment for the SO2 NAAQS –

Hayden and Miami. Each of these areas contain a copper smelter with SO2 emissions of

approximately 10,000 tpy, or more. As such, emission increases less than 20 tpy (ADEQ’s 

permitting exemption threshold for SO2) represent less than 0.2% of the emissions from one of 

these smelters. When compared to these large industrial sources, it is clear that the SO2

emissions exempted from ADEQ’s NSR program will be inconsequential to attainment and 

maintenance of the SO2 NAAQS. In addition, while ADEQ’s statistical analysis showed that only 

approximately 22% of SO2 emissions would be covered by its permitting program, this value 

greatly underestimates the SO2 emissions that are actually captured by ADEQ’s program in its 

SO2 nonattainment areas. Since the analysis was based on data from Maricopa County, which 

does not have the same kinds of large industrial SO2 sources as in ADEQ’s SO2 nonattainment 

areas, the actual emissions exempted by ADEQ’s program will be significantly smaller. 

PM10 Nonattainment Areas
SAMPLE/DRAFT

ADEQ has several PM10 nonattainment areas under its minor source permitting jurisdiction –

Ajo, Hayden, Miami, Nogales, Paul Spur/Douglas, and Yuma. [Reference to the fact ADEQ may 

have major source jurisdiction, but not minor source]

Ajo – [see, e.g. http://www.epa.gov/region9/air/az/ajo/index.html]