WESTAR 2003 Fall Technical Conference onWESTAR 2003 Fall Technical Conference on

PSD Increment Tracking & Cumulative Effects ModelingPSD Increment Tracking & Cumulative Effects Modeling

Seattle, WashingtonSeattle, Washington

Conducting Class I Area Increment AnalysesConducting Class I Area Increment Analyses

Ken Rairigh, P.E.Ken Rairigh, P.E.

State of WyomingState of Wyoming

Department of Environmental Quality - Air Quality DivisionDepartment of Environmental Quality - Air Quality Division

September 16, 2003September 16, 2003

Requirements for Conducting a Class I Area Increment Analysis in the PSD Rule

• No specific requirements provided in PSD Rule for conducting increment analyses for New Source Review

• PSD Rule states:“An analysis of the predicted impact of emissions from the facility is required for all pollutants … which are emitted in significant amounts. Such analysis shall identify and quantify the impact on the air quality in the area of all emissions not included in the baseline concentrations including, but not limited to, those emissions resulting from the instant application and all other permits issued in the area. The purpose of this analysis is to determine the total deterioration of air quality from the baseline concentrations.”

EPA Guidance on Conducting a Class I Area Analyses

• Guideline on Air Quality Models (Revised 2003)

• New Source Review Workbook (EPA, 1990)

If proposed major source or major modification located

< 100 kilometers from a Class I area:

- Increment Analysis

- Analysis of Air Quality Related Values (AQRVs)

Notifying the FLM of the Proposed Modification or Proposed New Source

• If proposed major source or major modification located < 100 kilometers from a Class I area

• March 19, 1979 memorandum from EPA Regional offices:

“Provide notice to the Federal Land Manager of any proposed PSD

sources that would locate within 100 kilometers of a Class I area.”

Notifying the FLM of the Proposed Modification or Proposed New Source

• Not clearly defined when proposed PSD source located > 100 kilometers from Class I area

PSD Rule states, “the Administrator shall provide written notification to all Federal Class I Area Federal Land Managers of such proposed new major emitting facility or major modification whose emissions may affect the Federal Class I Area or affect visibility in such Area.”

How to Determine If Proposed PSD Source May Affect a Class I Area ?

• Use Class I Significant Impact Levels (SILs)– Brought into Proposed Rules in 1996– No prescribed distance criteria for using SILs

• < 100 km from Class I area – use Class I SILs for any PSD source

- Modeled impact > Class I SILs => Cumulative analysis

• No prescribed distance for constructing the emissions inventory for cumulative Class I increment analysis

• > 100 km – Rely on Class I SILs for large PSD sources

Proposed Class I SILs

• Two Sets of Proposed Class I SILs (EPA & FLM)

Pollutant Ave Period EPA FLM• SO2 3-hour 1.0 0.48

24-hour 0.2 0.07 Annual 0.1 0.03

• PM10 24-hour 0.3 0.27 Annual 0.2 0.08

• NOx Annual 0.1 0.03

• EPA Class I SILs are calculated as 4% of the PSD Class I increments

• FLMs have typically deferred to EPA Class I SILs

• Apply to Increment Consumption, not AQRVs

Constructing the Cumulative Class I Increment Emissions Inventory

• Based on the lack of guidance, State of Wyoming DEQ developed some concepts:

• Start with Class II increment source inventory (50 km)

» Includes major and minor sources

• Add 50 kilometers onto Class II increment source EI (100 km)

» Does not include sources near Class I areas

if distance from source to Class I area > 100 km

What About Sources Located Near the Class I Area ?

• Alternative approaches under consideration by WDEQ to better define increment inventory:

• Calculate distance (radius) from proposed major source or major modification to Class I Area(s) and include additional major sources:

1. Circle centered on location of PSD source

2. Circle centered on Class I Area(s)

Issues Associated With Acquiring Emissions Inventories for Cumulative Analyses

• Difficult to acquire baseline source/emissions data

• Model actual or allowable emission rates ?

• Short-term emissions data not available

» Defer to allowable emissions on a short-term basis

• Acquiring emissions data from multiple states

» Need a regional database that states can access

» AIRS is gone, NEI is successor

» NEI format is widely used in regional scale analyses

Model Selection for Class I Area Analyses

• Distances < 50 km:

– ISC, AERMOD*, CTDMPLUS, CALPUFF

• Approved models under Appendix A of the

Guideline on Air Quality Models

• (* AERMOD expected to be added to Appendix A)

– September 8, 2003 Notice in Federal Register

Model Selection for Class I Area Analyses

• Distances > 50 km:

– CALPUFF, CMAQ, UAM-V, CAM-X

– CALPUFF is the least resource intensive

– Established guidance from EPA and FLMs

already being implemented for CALPUFF by some states

» (IWAQM Phase II Report)

– CALPUFF has been recommended by EPA for assessing

PSD increment consumption - April 15, 2003 Revisions to

Guideline on Air Quality Models

CMAQ, UAM-V, CAM-X

• Photochemical grid models are very resource intensive

• Model run times may preclude the use of more than

one year of meteorological data

• Much better treatment of chemistry than CALPUFF

• Could use at larger distances than CALPUFF

IWAQM Phase IIPrescribed Methodologies for CALPUFF

• CALPUFF “Lite” methodology– Simplistic, single station met data

– Intended as a screening-level option for CALPUFF

– Typically limited to single source analyses

• CALPUFF refined methodology

– More complex, 3-D wind field, prognostic data)

– Required for cumulative source increment analyses

– Requires a lot more resources and time to QA/QC

meteorological inputs than CALPUFF “Lite analysis

Case Study: Conducting Class I Analyses“The WYGEN 2 Experience”

• WYGEN 2 - Proposed Coal-Fired 500 MW Power Plant• Located in Campbell County, WY

• Nearest Class I Areas to proposed WYGEN 2 location:

– Wind Cave NP (SD) = 168 km– Badlands NP (SD) = 213 km– N. Cheyenne Indian Res. (MT) = 172 km

• Permit Review Period => April 2001 – September 2002

Class I Modeling Protocol

• WDEQ required applicant to submit a Class I modeling

protocol to WDEQ and FLM

 • Follow-up meeting to be held after the FLM (NPS) reviews Class I modeling protocol

• Class I area modeling protocol submitted to WDEQ

and the National Park Service (NPS)

• Conference call with NSR applicant, DEQ, and FLM (NPS)

• April 25, 2001 – May 24, 2001

Class I Modeling Protocol Cont’d.

• Proposed CALPUFF “Lite” for screening level analysis and also CALPUFF refined analyses, if required

• Compare impacts from new source to proposed Class I SILs

• Class I protocol did not specifically commit to or identify

additional analyses if source's impact was greater than Class I SILs

(OUR BAD !!)

• The NPS did not comment on the Class I modeling protocol

Initial Proposed Emission Rates Used in Class I Area Significance Analysis

• SO2• Annual emission rate = 3,381 TPY• Short-term rates for boiler = 0.15 lb/MMBtu (30-day average) • 0.17 lb/MMBtu (2-hour

average)• NOx• Annual emission rate = 2,028 TPY (0.09 lb/MMBtu)

• PM10

• Annual emission rate = 421 TPY (0.018 lb/MMBtu)

CALPUFF Screening Level Analysis

• Predicted PM10 and NOx impacts from the proposed

new source were at least 1-2 orders of magnitude below the proposed Class I SILs for these two pollutants

• WDEQ did not require applicant to conduct

cumulative Class I NOx and PM10 increment

consumption analyses

CALPUFF Screening Level Analysis

• July 2001 – November 2001

• Permit application received

• Modeled SO2 impact from the proposed new source greater

than 3-hour & 24-hour Class I SILs

• WDEQ required the applicant to conduct a cumulative

SO2 Class I increment consumption analysis for three (3)

designated Class I areas

• Cumulative analyses required going to refined CALPUFF

analysis (IWAQM Phase II)

CALPUFF Refined Increment Analysis

• November 2001 – March 2002

• CALMET wind field and SO2 emissions inventory

provided to applicant by WDEQ

• Cumulative source emissions inventory based on SO2 sources

located within 100 km of the proposed WYGEN 2 site

• Applicant submits cumulative PSD Class I increment

consumption analysis for SO2

» SO2 emission rates based on WDEQ’s BACT determination

BACT Emission Rates Used in CALPUFF Refined Increment Analyses

• SO2• Annual emission rate = 2,254 TPY• Short-term rates for boiler = 0.10 lb/MMBtu (30-day average) • 0.15 lb/MMBtu (3-hour

average)• NOx• Annual emission rate = 1,578 TPY (0.07 lb/MMBtu)

• PM10

• Annual emission rate = 270 TPY (0.012 lb/MMBtu)

Permit Out to Public Notice

• May 2, 2002 - Permit analysis out on public notice• May 9, 2002 - FLM requested CALMET & CALPUFF files

» First time we have heard from FLM in a year» FLM had concerns that no upper air stations were used in

CALMET simulation

• May 31, 2002 - Comments received from EPA, FLM, and Environmental Defense organization

Now, All He## Breaks Loose !!

Comments From EPA

• Inclusion of additional major sources in Class I increment consumption analyses:

– Colstrip power plant (MT)

– Ben French power plant (SD)

– South Dakota cement plant (SD)

• Include baseline facilities near the proposed WYGEN 2 site

if there have been emission increases since the minor source

baseline date was triggered

Comments From FLM

• FLM did not receive a technical report describing Class I increment analysis and assumptions used

• FLM claims application is incomplete

» Based on lack of cumulative AQRV analyses

• Concerns regarding the impacts of emissions to visibility

and other AQRVs at Wind Cave and Badlands National Parks

• No formal adverse impact determination to AQRVs

Comments From Environmental Defense

• WDEQ unlawfully relied upon significant impact levels (SILs) for Class I areas to exempt WYGEN 2 from a cumulative modeling analysis for the NO2

and PM10 increments at the nearby Class I areas

• WDEQ did not require the applicant to conduct

cumulative visibility and AQRV analyses

Remember what the PSD Rule requires:

» An analysis of the impairment to visibility, …

that would occur as a result of the facility or modification …

WDEQ Ran Additional Analyses To Evaluate Impact From Colstrip

• Colstrip power plant (Unit #3 & Unit #4) included in Class I increment analysis

• Ben French power plant and South Dakota cement plant were also pre-baseline sources and were not included in our analyses

» Unit #1 & Unit #2 are pre-baseline sources

» Not included in Class I increment analysis

Cumulative Class I Increment Analysis Results

• Badlands National Park Class I Increments– HSH 3-hr = 1.8 g/m3 3-hr = 25 g/m3

– HSH 24-hr = 0.5 g/m3 24-hr = 5 g/m3

• Wind Cave National Park– HSH 3-hr = 2.1 g/m3

– HSH 24-hr = 0.7 g/m3

• Northern Cheyenne Indian Reservation– HSH 3-hr = 27.3 g/m3 => Single modeled exceedance– HSH 24-hr = 3.5 g/m3

» Colstrip power plant (MT) contribution = 99.9%

Use Class I SILs To Demonstrate Insignificant Impact From WYGEN 2

• Modeled exceedance was due to Colstrip power plant

located 24 km south of Northern Cheyenne Indian Reservation

» Near-field impact – CALPUFF may not be the right tool

• WDEQ compared new source’s contribution to Class I SIL:

» Contribution from WYGEN2 at NCIR was 0.07 g/m3

(7% of Class I SO2 3-hr SIL)

• Proposed new source does not significantly impact the location

of the modeled exceedance

Final Decision

• September 26, 2002

• WDEQ demonstrated that the proposed source does not

exceed the Class I increments, or contribute significantly to

any existing Class I increment exceedances

• WDEQ issued final decision to approve NSR permit for

WYGEN 2 after having reviewed all comments received

• NPS has appealed WDEQ's final issuance of permit

• NPS appeal based on visibility impacts, not increment issues

FLM Involvement in the Permit Review Process

• WDEQ involved FLM in the application review process as required by the PSD Rule:

– Early involvement with FLM

– Consultant sent Class I modeling protocol to FLM

and requested approval

– Submitted permit application to FLM within 30 days of receipt

– Submitted permit analysis review, permit conditions, and

proposed decision on public notice

FLM Responsibility in the Permit Review Process

• FLMs are part of the PSD review process

• WDEQ expects the FLM to review permit application

in a timely fashion

• WDEQ expects some kind of response from FLM

if a protocol has been submitted to FLM

• FLM needs to understand and work within our

review process and required time lines as well

Changes in FLM Notification Based on this Experience

• Improve on communications with FLM

• Upon determining completeness of application:

- Notify FLM that application is complete

- Submit all information to FLM that has been

received since initial permit application

Questions ??Questions ??