Dan Dix presented, The Complexities of New Source Review Air Permitting – A Case Study" at the 4C Conference in Austin, TX in February 2016.

1. 3/2/2016 Page 1
The Complexities of New Source Review Air
Permitting – A Case Study
The Complexities of New Source Review
Air Permitting – A Case Study
Dan Dix
Technical Manager
610.422.1118
ddix@all4inc.com
Kristin Gordon, P.E.
Houston Office Director
281.937.7553 x301
kgordon@all4inc.com

2. 3/2/2016 Page 2
The Complexities of New Source Review Air
Permitting – A Case Study
Case Study Agenda
• Identifying the Project
• Identifying the Air Permitting Landscape
• Identifying the Major Applicable Air Permitting Regulations
• Unique Solutions to Air Permitting Issues
• Schedule
• Air Permit Received and Lessons Learned
• Additional Lessons Learned on Similar Air Permitting Projects

3. 3/2/2016 Page 3
The Complexities of New Source Review Air
Permitting – A Case Study
Identifying the Project
• Construction of 830 MW combined cycle natural gas-fired power block
at existing 535 MW power plant facility
• Proposed power block consisted of the following emissions sources
• Two (2) combustions turbines with heat recovery steam generators
• Natural gas-fired auxiliary boiler
• 12-cell evaporative cooling tower
• Ultra low sulfur diesel (ULSD) fuel as backup

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The Complexities of New Source Review Air
Permitting – A Case Study
Identifying the Air Permitting Landscape
• Located in area classified as in attainment with all of the national
ambient air quality standards (NAAQS) except the following:
• Located in ozone transport region (OTR) therefore ozone precursors, nitrogen
oxides (NOx) and volatile organic compounds (VOCs) regulated as
nonattainment area
• During application development fine particulate (PM2.5) NAAQS for the county
was undergoing attainment redesignation from nonattainment to attainment
• PM2.5 precursors include NOx and sulfur dioxide (SO2)

5. 3/2/2016 Page 5
The Complexities of New Source Review Air
Permitting – A Case Study
Identifying the Major Applicable Air
Permitting Regulations
• New Source Review (NSR) air permitting regulations determined the
following pollutants were major based on applicable significant
emissions rate (SER) increases due to block 2
• Nonattainment New Source Review (NNSR)
• NOX, VOC, PM2.5
• Prevention of Significant Deterioration (PSD)
• Nitrogen Dioxide (NO2), Particulate Matter less than 10 microns (PM10), Carbon
Monoxide (CO), & PM2.5
• PM2.5 evaluated under both NNSR and PSD due to uncertainty with attainment
redesignation timeline and issuance of final permit

6. 3/2/2016 Page 6
The Complexities of New Source Review Air
Permitting – A Case Study
NNSR Air Permitting Process
• Lowest Achievable Emissions Rate (LAER) determinations
• Purchase of Emissions Reduction Credits (ERCs)
• Well established marketplace for VOC and NOx ERCs due to OTR
• Ability to purchase VOC and NOx ERCs anywhere within OTR with reciprocity
agreements
• Although current demand for VOC and NOx ERCs increasing in area driving
prices up
• Major issue in TX area and further exacerbated by recent reduction of 8-
hour ozone NAAQS from 75 ppb to 70 ppb effective December 28, 2015

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The Complexities of New Source Review Air
Permitting – A Case Study
NNSR Air Permitting Process
• PM2.5 ERCs very limited
• Purchasing PM2.5 ERCs outside of Air Quality Control Region (AQCR)
requires an air quality modeling study to show that the location from
which PM2.5 ERCs are purchased is contributing to the nonattainment
status of area where ERCs are required
• U.S. EPA preferred air dispersion model for < 50 km AERMOD and for
>50 km long range transport air dispersion model
• Potentially ERCs identified 70 km from project site

8. 3/2/2016 Page 8
The Complexities of New Source Review Air
Permitting – A Case Study
NNSR Air Permitting Process
• Long range transport air quality modeling analysis used the CALPUFF
air dispersion model, pre 40 CFR Part 51 Appendix W proposed
revisions
• Use of existing meteorological dataset from Regional Haze Best
Available Retrofit Technology (BART) permitting process utilized to cut
cost of long range transport air quality modeling analysis and to
decrease air permitting timeline
• Ambient air quality monitoring guidance utilized to justify level of
modeled concentrations required to demonstrate “significant impact”
0.01 micrograms per meter cubed (mg/m3)

9. 3/2/2016 Page 9
The Complexities of New Source Review Air
Permitting – A Case Study
PSD Air Permitting Process
• Best Available Control Technology (BACT) analysis
• Air quality modeling analysis
• U.S. EPA preferred nearfield air dispersion model (AERMOD) utilized
• Local meteorological data utilized from existing nuclear power plant 100 m tall
multi-level meteorological monitoring system located 4 km away (purchased
for $500)
• Major hurdles with air quality modeling analysis
• 1-Hour NO2 NAAQS (100 ppb) and combustion turbine startup emissions
• PM2.5 NAAQS and low headroom with current PM2.5 ambient monitoring
concentrations (required to be added to modeled impacts)

10. 3/2/2016 Page 10
The Complexities of New Source Review Air
Permitting – A Case Study
PSD Air Permitting Process
Solutions for PM2.5 NAAQS air quality modeling demonstration
• Air quality modeling analysis is a two step process
• Model project-related emissions for comparison to the Significant Impact
Levels (SILs) and if predicted concentrations are less than the SILs no
further analysis is required
• If predicted concentrations are greater than the SILs then NAAQS and
PSD increment evaluations required
• Strategy was to remain below PM2.5 SILs for the annual average due to
existing NAAQS levels and utilize U.S. EPA guidance for using SILs

11. 3/2/2016 Page 11
The Complexities of New Source Review Air
Permitting – A Case Study
PSD Air Permitting Process
Solutions for PM2.5 NAAQS air quality modeling demonstration – (Continued)
18
8
PM2.5AnnualConcentration
(mg/m3)
80
NAAQS
Level
Monitored
Background
Value
0.4 mg/m3 available for modeling
12
11.6

12. 3/2/2016 Page 12
The Complexities of New Source Review Air
Permitting – A Case Study
PSD Air Permitting Process
Solutions for PM2.5 NAAQS air quality modeling demonstration – (Continued)
• Remaining below the PM2.5 Annual SIL critical because NAAQS analysis would
require the addition of local sources to the analysis and inclusion of background
concentration from representative ambient monitoring station
• Since area was currently going through PM2.5 redesignation process existing
monitoring levels where 11.6 mg/m3 which left 0.4 mg/m3 of headroom for
permitted facility and local sources
• To remain below PM2.5 annual SIL, air quality modeling iterations were performed
to determine the maximum amount of hours per year ULSD could be utilized and
still provide flexibility to the facility (~500 hours)

13. 3/2/2016 Page 13
The Complexities of New Source Review Air
Permitting – A Case Study
PSD Air Permitting Process
Solutions for NO2 NAAQS air quality modeling demonstration
• Required to evaluate periods of start-up NOx emissions due to 1-Hour averaging
period of NAAQS
• Virtually impossible to remain below NO2 1-Hour SIL (7.5mg/m3)
• Utilized non-default option in AERMOD that modifies the equilibrium ratio for the
atmospheric chemical reaction between NO2 and ozone
• Currently non-default options require U.S. EPA regional approval
• Currently proposed amendments to 40 CFR Part 51 Appendix W – Guideline on
Air Quality Models would remove regional approval requirement

14. 3/2/2016 Page 14
The Complexities of New Source Review Air
Permitting – A Case Study
PSD Air Permitting Process
Solutions for NO2 NAAQS air quality modeling demonstration – (Continued)
• U.S. EPA places high level of scrutiny on selected in-stack NOX/NO2 ratio which
is a key input to AERMOD Tier III options
• Ozone Limiting Method (OLM) – Utilized for this project
• Plume Volume Molar Ratio Method (PVMRM) – Evaluated for this project
• Ultimately U.S. EPA region required one (1) of three (3) options for justifying in-
stack NOX/NO2 ratio
• Stack test results from similar unit under similar operating loads
• Vendor guarantee from turbine provider
• Use of U.S. EPA default in-stack NOX/NO2 ratio (0.5)

15. 3/2/2016 Page 15
The Complexities of New Source Review Air
Permitting – A Case Study
PSD Air Permitting Process
Solutions for NO2 NAAQS air quality modeling demonstration –
(Continued)
• No test data available since this was a newly designed combustion
turbine
• Vendor did not have enough data to justify in-stack NOX/NO2 ratio less
than U.S. EPA default
• Ultimately U.S. EPA in-stack NOX/NO2 default utilized

16. 3/2/2016 Page 16
The Complexities of New Source Review Air
Permitting – A Case Study
PSD Air Permitting Process
Solutions for NO2 NAAQS air quality modeling demonstration – (Continued)
• 1-Hour NO2 NAAQS air quality modeling identified a local source that when
combined with facility showed an exceedance
• Two key factors led to demonstrating compliance with 1-Hour NO2 NAAQS
• Detailed review of local source uncovered that there was an existing Federal Energy
Regulatory Commission (FERC) permit to convert two gas fired compressors to electric
fired compressors (no air permit required to install electric engine)
• U.S. EPA guidance memorandum outlined recommendation for setting in-stack NOX/NO2
ratios for local sources greater than 4 km from permitted source at 0.2

17. 3/2/2016 Page 17
The Complexities of New Source Review Air
Permitting – A Case Study
Air Permitting Process Timeline
• Development of air quality modeling protocol – 2 Months from project
start
• Agency review of air quality modeling protocol – 3 Months
• Development of NSR Air Permit Application – 6 Months
• Agency Review of NSR Air Permit Application – 1 Year
• Time from development of air quality modeling protocol to receipt of final
air permit – 18 Months

18. 3/2/2016 Page 18
The Complexities of New Source Review Air
Permitting – A Case Study
Lessons Learned Throughout Air Permitting
Process
• Plan ahead
• Develop air quality modeling protocol and gain acceptance on
meteorological dataset as early as possible
• Meteorological representativeness analysis required for all off-site data and if
representativeness cannot be demonstrated the collection of 1-year of onsite
data could be required
• Identify ERCs early in the process
• Have a competent consultant that knows the ins and outs of air
permitting and air quality modeling and how they overlap

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The Complexities of New Source Review Air
Permitting – A Case Study
Additional Lessons Learned on Other
Similar Air Permitting Projects
• Plan ahead (even more)
• Utilize variable emissions rate option in AERMOD to present realistic
start-up scenario for 1-Hour NO2 NAAQS
• Be prepared for potential appeals from NIMBYs and EnviroGroups
• Support state reviewing authority for developing responses to
comments from third parties (general public, Federal Land Managers,
and regional U.S. EPA) for complex air permitting projects

20. 3/2/2016 Page 20
The Complexities of New Source Review Air
Permitting – A Case Study
Dan Dix
Technical Manager
610.422.1118
ddix@all4inc.com
Kristin Gordon P.E.
Houston Office Director
(281) 937-7553 x301
kgordon@all4inc.com
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