Nonattainment New Source Review

(NA NSR) Program

Raj Rao

US Environmental Protection Agency

Office of Air Quality Planning and Standards

919-541-5344, rao.raj@epa.gov
2

What is the purpose of this 

discussion?

1. NA NSR Applicability 

3. NA NSR Applicability and Netting Example

2. NA NSR Program Requirements
3

How do we define a 

nonattainment area?

 Areas in which air quality is worse than NAAQS 

levels

 Such NA areas must improve air quality within a 

certain time period
4

Which sources might be subject 

to the major NA NSR program?

 New major sources

 Existing major sources making major 

modifications

 Physical or operational changes at the source

 Change should show significant net emissions 

increase
5

How do we determine if a new source is a 

major source under the NA NSR program?

1. Identify NA pollutants for new source

2. Determine source’s potential to emit (PTE) 

3. Determine applicable major source thresholds

4. Determine if PTE exceeds major source 

threshold for any NA pollutant

5. If so, source is subject to major NA NSR for 

that pollutant
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How do I identify which pollutants 

are nonattainment pollutants?

 Determine if area is in attainment or 

nonattainment for each criteria pollutant emitted 

by the source

 To find this information: 

 Contact the appropriate EPA Regional Office or applicable 

permitting authority

 Search an EPA database such as: www.epa.gov/air/data
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What is the source’s 

potential to emit (PTE)?

 The maximum capacity of source to emit a 

pollutant under its physical and operational 

design

 Based on operating 24/7 (8760 hours/year), unless 

restricted by a permit condition

 Can include effect of emissions controls, if 

enforceable by permit or:

 State Implementation Plan (SIP), 

 Tribal Implementation Plan (TIP) or

 Federal Implementation Plan (FIP) conditions
8

What is the applicable major 

source threshold?

 100 tpy or lower depending on NA severity

Nonattainment Areas

Pollutant Nonattainment Classification Major Source 

Threshold

Ozone Marginal (≥ 0.085 < 0.092 ppm) 100 tpy of VOC or NOx

Moderate (≥ 0.092 < 0.107 ppm) 100 tpy of VOC or NOx

Serious (≥ 0.107 < 0.120 ppm) 50 tpy of VOC or NOx

Severe (≥ 0.120 < 0.187 ppm) 25 tpy of VOC or NOx

Extreme (= 0.187 ppm and up) 10 tpy of VOC or NOx

Particulate Matter 

(10μm)

Moderate 100 tpy

Serious 70 tpy

Carbon Monoxide Moderate (9.1 – 16.4 ppm) 100 tpy

Serious (16.5 and up ppm) 50 tpy

Sulfur Dioxide, Nitrogen 

Oxides, PM2.5 and Lead

Only one nonattainment classification 100 tpy
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When is a modification subject to the major 

NA NSR program?

 When: 

 The proposed project emissions exceed the 

significant emission rate (SER) and 

 The proposed project results in a significant net 

emissions increase (i.e., contemporaneous 

increases and decreases in emissions at the existing 

major source exceed the SER) after a netting 

analysis is performed

 SER Examples:

 40 tpy for VOC, NO2, SO2
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What steps should I follow to do a Netting Analysis?

1. Determine the emissions increase from the proposed project

2. Determine the beginning and ending dates of the 

contemporaneous period as it relates to the proposed 

modification

3. Determine which emissions units at the source experienced a 

physical or operational change that increased or decreased 

emissions during the contemporaneous period

4. Determine which emissions are creditable

5. Determine on a pollutant by pollutant basis, the amount of each 

contemporaneous and creditable emissions increase and 

decrease

6. Sum all contemporaneous and creditable increases and 

decreases with the increase from the proposed project to 

determine if a significant net emissions increase will occur
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1. Determine the emissions increase from the 

proposed project

 If project emissions > significant emissions rate 

(SER), source determines its net emissions 

increase to know if it is a major modification or 

not

 If project emissions < SER, source is exempt 

from review and is not a major modification

 For example, SO2 emissions from proposed 

project are 80 tpy. 80 tpy > 40 tpy SER, thus 

net emissions increase determination needed
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 To determine the source’s net emission increase, we need to define the 

contemporaneous period

 For NA NSR, States generally use 5 calendar years before the source commences 

operation

 For 40 CFR Appendix S, period starts 5 years before the source commences 

construction and ends when the source commences operation

 For example, our SO2 source planned to commence construction in June 

2006 and begin operation in September 2008, the contemporaneous period 

for Appendix S is defined as:

2. Determine the beginning and ending dates of 

the contemporaneous period

June 

2006

Commence 

Construction

June 

2005

June 

2004

June 

2003

June 

2002

June 

2001

June 

2007

June 

2008

Sept. 

2008

Commence 

Operation

80 tpy
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3. Determine which units experienced an increase or 

decrease in emissions during contemporaneous period

 Determine emission increases and decreases associated with a 

physical change or change in the method of operation at the 

source which did not require a PSD permit

 For example, our SO2 source increased its SO2 emissions in 2003 

and decreased its emissions in 2008

June 

2006

Commence 

Construction

June 

2005

June 

2004

June 

2003

June 

2002

June 

2001

Sept. 

2008

Commence 

Operation

June 

2007

June 

2008

80 tpy
4. Determine which emissions are creditable

 An increase or decrease is not creditable if it has been 

previously relied on for issuing a permit and the permit is in 

effect during the review

 A decrease is creditable only to the extent that it:

 Is “federally-enforceable” from the moment that the actual 

construction begins 

 Occurs before the proposed emissions increase 

 Has the same health and welfare significance as the proposed 

increase from the source

 A source cannot take credit for:

 A decrease that it has had to make, or will make, in order to 

bring an emission unit into compliance

 An emissions reduction from a unit which was permitted but 

never built or operated
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5. Determine the amount of each contemporaneous 

emissions increase or decrease

 On a pollutant by pollutant basis

 Based on difference between old level and new level of emissions 

for each unit

 Past decreases and/or increases in actual emissions based on:

 Average of any two consecutive years in the past 5 for utilities

 Average of any two consecutive years in the past 10 for non-utilities

 For example, SO2 emissions decreases and increases are:

June 

2006

Commence 

Construction

June 

2005

June 

2004

June 

2003

June 

2002

June 

2001

June 

2007

June 

2008

40 tpy

25 tpy 80 tpy

Sept. 

2008

Commence 

Operation
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6. Sum all contemporaneous and creditable increases 

and decreases with the proposed modification

 NEI = PMEI + CEI – CED where:

 PMEI = Proposed modification emissions increase

 CEI = Creditable emission increases

 CED = creditable emission decreases

 For example, NEI = 80 + 25 - 40 = 65 tpy

 65 tpy > 40 tpy SO2 SER, project is a major modification

June 

2006

Commence 

Construction

June 

2005

June 

2004

June 

2003

June 

2002

June 

2001

June 

2007

June 

2008

40 tpy

25 tpy 80 tpy

Sept. 

2008

Commence 

Operation
NA NSR Applicability and Netting 

Exercise
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Existing Source is Installing an 

Engine Testing Facility

 First, determine if source is currently a major source

 Source located in serious ozone nonattainment area

Pollutant PTE (tpy)

NO2 45

CO 900

VOC 355

Nonattainment Areas Major Source Thresholds

Pollutant Nonattainment Classification Major Source 

Threshold

Ozone Serious (≥ 0.107 < 0.120 ppm) 50 tpy of VOC or NOx

Carbon Monoxide Serious (16.5 and up ppm) 50 tpy

Nitrogen Oxides Only one nonattainment classification 

exists

100 tpy
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Existing Source is Installing an 

Engine Testing Facility

 Second, determine if existing source is making a major 

modification

 Source:

 Began construction in March 2006 with a 26 tpy permit limit for VOC

Emission 

Unit

Construction

Date

Potential 

VOC 

Emissions 

Coating Line March 2002 9 tpy

2 Spray Paint

Systems

September

2004

27 tpy each

Constructed following emission units:

Emission Unit Actual VOC Emissions

Degreaser #1 1997 30 tpy

1998 40 tpy

Degreaser #2 1998 28 tpy

1999 26 tpy

2000 0 tpy

2001 0 tpy

2002 0 tpy

Removed following emission units in 2002:
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Existing Source is Installing an 

Engine Testing Facility

 Is the source currently a major one? Yes, for CO and VOCs

 Is the new installation a major modification?

 Step 1: 26 tpy VOC > 25 tpy SER for serious ozone nonattainment areas 

(CAA Section 183), source needs to determine NEI

 Step 2: The contemporaneous period is:

March 

2006

Commence 

Operation

Jan 

2005

Jan 

2004

Jan 

2003

Jan 

2002

Jan 

2001

26tpy
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Existing Source is Installing an 

Engine Testing Facility

 Is the new installation a major modification?

 Step 3, 4, 5: Creditable emission increases and decreases during 

contemporaneous period are:

 Step 6: Determine Net Emission Increases (NEI):

 NEI = 26+ 54 + 9 – 35 – 27 = 27 tpy

 27 tpy VOC NEI > 25 tpy SER for serious ozone nonattainment area

 Source is a major modification

March 

2006

Commence 

Operation

Jan 

2005

Jan 

2004

Jan 

2003

Jan 

2002

Jan 

2001

9 tpy

54 

tpy

35 tpy

27 tpy

26tpy
NA NSR Program Requirements
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What are the major NA-NSR 

program requirements?

 LAER (Lowest Achievable Emission Rate)

 Offsets at prescribed ratios

 Alternative sites analysis

 Statewide facility compliance certification

 Public Involvement
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What is LAER?

 Rate that has been achieved or is achievable for 

defined source

 Rate may be in a permit or regulation

 Requirement does not consider the following:

 Economic

 Energy

 Environmental

 Other factors
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What are emissions offsets and 

what are its requirements?

 Emissions reductions from existing sources to balance 

emissions from proposed new or modified sources 

 Offset must be at least 1:1

 Emissions offsets reductions must be:

 quantifiable, enforceable, permanent and surplus (QEPS)

 from actual emissions – real, no “paper”reductions

 federally enforceable at the time of permit issuance for new 

source

 in effect before the new source can commence operation
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How is alternative sites analysis 

defined?

 Source owner must submit an analysis of:

 Alternative sites

 Sizes

 Production processes

 Environmental control techniques 

 Analysis for such proposed source must 

demonstrate that benefits significantly outweigh:

 the environmental impacts

 social costs imposed as a result of its location, 

construction, or modification
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How is compliance certification 

defined?

 Source owner must certify that all other 

sources in that state that are:

 Owned or operated by the source owner are

 In compliance or 

 On an approved schedule for compliance
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What are the public participation 

requirements?

 Public notice:

 Must be for a 30-day period

 Generally in regional and local newspapers

 All public comments must be considered before 

a final permit is established 

 A Technical Support Document (TSD) generally 

including responses to comments may also be 

available with the final permit