the complexities of new source review air permitting – a case study ddix 020116

3/2/2016 The Complexities of New Source Review Air

Permitting – A Case Study

The Complexities of New Source Review

Air Permitting – A Case StudyDan Dix

Technical Manager

610.422.1118

[email protected]

Kristin Gordon, P.E.

Houston Office Director

281.937.7553 x301

[email protected]

mailto:[email protected]




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



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



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)



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



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




• 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




• 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)



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)




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




Solutions for PM2.5 NAAQS air quality modeling demonstration – (Continued)

18

8

PM

2.5

An

nu

al C

on

cen

trat

ion

(m

g/m

3)

80

NAAQS Level

Monitored Background

Value

0.4 mg/m3 available for modeling

12

11.6




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)




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




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)




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




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



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



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



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



Dan Dix

Technical Manager

610.422.1118

[email protected]

Kristin Gordon P.E.

Houston Office Director

(281) 937-7553 x301

[email protected]

Philadelphia | Atlanta | Houston | Washington DC



the complexities of new source review air permitting – a case study ddix 020116

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