Air Quality Impacts Analysis
Sponsored Links
This presentation is the property of its rightful owner.
1 / 45

Air Quality Impacts Analysis PowerPoint PPT Presentation


  • 94 Views
  • Uploaded on
  • Presentation posted in: General

Air Quality Impacts Analysis. Presented to: American Public Power Association APPA New Generation Meeting: Anticipating new permitting issues, IGCC Technology Options, Atmospheric Modeling, and Anticipating the Public’s Reaction Presented by: William B. Jones Project Manager

Download Presentation

Air Quality Impacts Analysis

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Air Quality Impacts Analysis

Presented to:

American Public Power Association

APPA New Generation Meeting: Anticipating new permitting issues,

IGCC Technology Options, Atmospheric Modeling,

and Anticipating the Public’s Reaction

Presented by:

William B. JonesProject Manager

Zephyr Environmental Corporation

June 28, 2006


Outline of Presentation

What is modeling and why do it?

Types of models

Typical modelinganalyses

Recent modeling activity


What is Modeling?

Running computer programs to predict air pollutant levels

Dates back to 1930’s, looked at smoke from chimneys

Different applications

Complex terrain

Long-range transport

Photochemical


Why do Modeling?

Relative to monitoring, it is

Cheaper

Faster

More extensive

Useful regulatory tool

Developing control strategies

Permitting of new/modified industrial facilities


Types of Models

Screening

SCREEN3

AERSCREEN (any day now)

Refined

ISC3

AERMOD

CALPUFF


Features of Screening Models

Quick and dirty

Required inputs are limited

Meteorological data

Source data

Terrain data

Cursory structure downwash analysis

Conservative (high) results


Features of Refined Models

Required inputs can be substantial

Preprocessed meteorological data

Preprocessed terrain data

Detailed structure downwash analysis


AERMOD

Will become EPA’s official preferred model for most near-field industrial applications on December 9, 2006

Improvements over ISC3

Dispersion within Planetary Boundary Layer

Characterization of meteorological conditions

Terrain depiction


AERMOD is a steady-state model

Straight line trajectory for plume

Spatially constant meteorological conditions

No “memory” of previous hour’s emissions


When should you use AERMOD?

Most industrial applications

When your situation involves

Pollutant concentrations within tens of km of source

Flat or complex terrain (but maybe not “complicated” terrain)

Most NAAQS/PSD Increment analyses


Issues with AERMOD

The input/output files may look the same as ISC…

But it is much more labor-intensive than ISC

AERMET

AERMAP

Computer runtimescan measure in days


CALPUFF

Non-Steady-State model (Puff model)


CALPUFF

ISC vs. CALPUFF animation here


CALPUFF

Non-Steady-State model (Puff model)

Source input requirements are more detailed than AERMOD

Terrain input requirements are more detailed than AERMOD

Meteorological data input requirements are quite substantial

MM5 can be run for anywhere in the world


When should you use CALPUFF?

Most long-range transport applications (i.e., greater than 50 km)

Class I impact/visibility assessments

Nearfield analyses involving significant terrain variations


Typical Modeling Analyses

Class II

Significance

NAAQS

PSD Increment

Class I


Class II Analyses:Significance Modeling

Consider only project in question (emissions increases and decreases)

Compare against U.S. EPA significance levels

If below, analysis is finished

If above, proceed with more comprehensive NAAQS/PSD Increment analysis


Class II Analyses:NAAQS Modeling

Comprehensive assessment of overall air quality

Include all sources at your facility

Include offsite sources

Include representative ambient background pollutant concentrations


Class II Analyses:PSD Increment Modeling

Include PSD Increment consuming and expanding sources at your facility

Include PSD Increment consuming and expanding offsite sources

No ambient background pollutant concentrations are included


Class I Areas


Areas within 300 km of Class I Area


Class I Analysis

Class I PSD Increments

Air Quality Related Values (AQRV’s)

Visibility

Acid deposition (sulfate and nitrate)


History of Class I Analyses

1993: Interagency Workgroup on Air Quality Modeling (IWAQM) formed, recommended CALPUFF

2000: Federal Land Manager’s Air Quality Related Values Workgroup (FLAG) was written to develop a more consistent approach for the FLMs to evaluate air pollution effects on their resources


History of Class I Analyses

History has shown it’s easier to define what is not a problem vs. what is a problem

Each case is different—for each facility, and each FLM


Current (typical) approach to assessment of visibility impairment

Run CALPUFF with 3 years of met data

Calculate 24-hr bext (visibility index)

Compare bext against natural conditions

If < 5%, FLM doesn’t object

If between 5% and 10%, FLM may object

If > 10%, FLM likely to object


But FLAG guidancemay be changing!

John Vimont (NPS) spoke at Guideline on Air Quality Models Conference in Denver this past April

Outlined proposed changes to visibility analysis methodology

Different way of accounting for relative humidity

Different way of comparing bext (98th percentile, or 8th high per year)


Examples of analyses required ofrecent coal-fired facilities

Plum Point Energy Station: Osceola, Arkansas

Comanche Generating Station: Pueblo, Colorado

Duke Energy: Cliffside, NC

Sandy Creek: McClennan County, TX

City Public Service: San Antonio, TX


Plum Point Energy Station, Osceola, ARPermit issued August 20, 2003


Plum Point Energy Station, Osceola, ARClass I Visibility Analysis

Ran CALPUFF, initially found light extinctions > 5%

Developed water content adjustment to modify natural light extinction calculation

  • Re-ran CALPUFF, did not find light extinctions > 5%


Comanche Generating Station, Pueblo, COPermit issued July 5, 2005


Intermission

Quick Class I Area Tour


Weminuche Wilderness, 1999


Weminuche Wilderness, 1999(Continental Divide)


Weminuche Wilderness, 1999(Neighbor near campsite)


Great Sand Dunes NP, 2002“The Summit”


Black Canyon of the Gunnison River NP(2002)


Comanche Generating Station, Pueblo, COClass I Analyses Performed

Visibility

Found change in light extinction to be less than 5% at all Class I areas, so acceptable

Acid Deposition

Sulfur deposition less than 0.005 kg/ha/yr (Deposition Analysis Threshold, or DAT) (western US value), so acceptable

Class I PSD Increment

PM10 impacts less than Class I significance level of 0.3 ug/m3


Comanche Generating Station, Pueblo, COAdditional Analysis: Acid Neutralizing Change

U.S. Forest Service has established threshold of concern for acid deposition in Class I areas

Considered three high altitude lakes in Class II areas

Change in ANC resulting from PM10 and H2SO4 emissions evaluated

Percent change found to be below threshold of 10%


Duke Energy, Cliffside, NCPermit Application submitted December 16, 2005


Duke Energy, Cliffside, NCPermit Application submitted December 16, 2005

Visibility

NPS required speciation of PM10 emissions by light scattering properties (soils, elemental carbon, and organic aerosols)

Acid Deposition

Used DAT of 0.01 kg/ha/yr (eastern US value)

Class I PSD Increment

PM10 and NOx impacts less than Class I Significance Levels


Sandy Creek, McClennan County, TXUpdated application submitted March 10, 2005

Closest Class I area is Wichita Mountains Wilderness (Oklahoma), ~ 370 km away

Did not have to examine any impacts on Class I areas


City Public Service, San Antonio, TXPermit issued January 2006

Closest Class I area is Big Bend National Park (Texas), ~ 440 km away

TCEQ did not require any Class I analysis

CPS assessed visibility and acid deposition at Big Bend and six other Class I areas (out to 870 km)

Results

Light extinction found to be < 5% at all Class I areas

Sulfur and Nitrogen deposition found to be < DAT at all Class I areas


Summary

Model selected based on

Type of analysis being conducted

Characteristics of region being modeled

Class II (NAAQS and PSD Increment) analyses will typically use AERMOD

More complicated than ISC was

Class I analyses will typically use CALPUFF

Reach of FLM is increasing

Requirements of analysis are very fluid


Useful Modeling Links

EPA’s SCRAM Website: www.epa.gov/scram001

IWAQM: www.epa.gov/scram001/7thconf/calpuff/phase2.pdf

FLAG: www2.nature.nps.gov/air/Permits/flag/index.cfm

CALPUFF:src.com/calpuff/calpuff1.htm

PM2.5:www.epa.gov/ttn/caaa/t1/memoranda/pm25.pdf (John Seitz (OAQPS) 10/23/97 memo on using PM10 as surrogate for PM2.5 in PSD analyses)


Hopefully you’ve found this a “model” presentation

Bill Jones

410.312.7910

[email protected]


  • Login