Appendix C to Appendix W of Part 51 - Example Air Quality Analysis Checklist  

This checklist recommends a standardized set of data and a standard basic level of analysis needed for PSD applications and SIP revisions. The checklist implies a level of detail required to assess both PSD increments and the NAAQS. Individual cases may require more or less information and the Regional Meteorologist should be consulted at an early stage in the development of a data base for a modeling analysis.

At pre-application meetings between source owner and reviewing authority, this checklist should prove useful in developing a consensus on the data base, modeling techniques and overall technical approach prior to the actual analyses. Such agreement will help avoid misunderstandings concerning the final results and may reduce the later need for additional analyses.

1. Source location map(s) showing location with respect to:

• Urban areas 2

• PSD Class I areas

• Nonattainment areas 2

• Topographic features (terrain, lakes, river valleys, etc.) 2

• Other major existing sources 2

• Other major sources subject to PSD requirements

• NWS meteorological observations (surface and upper air)

• On-site/local meteorological observations (surface and upper air)

• State/local/on-site air quality monitoring locations 2

• Plant layout on a topographic map covering a 1km radius of the source with information sufficient to determine GEP stack heights

2. Information on urban/rural characteristics:

• Land use within 3km of source classified according to Auer (1978): Correlation of land use and cover with meteorological anomalies. Journal of Applied Meteorology, 17: 636-643.

• Population

−> total

−> density

• Based on current guidance determination of whether the area should be addressed using urban or rural modeling methodology

3. Emission inventory and operating/design parameters for major sources within region of significant impact of proposed site (same as required for applicant)

• Actual and allowable annual emission rates (g/s) and operating rates 3

• Maximum design load short-term emission rate (g/s) 3

• Associated emissions/stack characteristics as a function of load for maximum, average, and nominal operating conditions if stack height is less than GEP or located in complex terrain. Screening analyses as footnoted above or detailed analyses, if necessary, must be employed to determine the constraining load condition (e.g., 50%, 75%, or 100% load) to be relied upon in the short-term modeling analysis.

—location (UTM's)

—height of stack (m) and grade level above MSL

—stack exit diameter (m)

—exit velocity (m/s)

—exit temperature (°K)

• Area source emissions (rates, size of area, height of area source)3

• Location and dimensions of buildings (plant layout drawing)

—to determine GEP stack height

—to determine potential building downwash considerations for stack heights less than GEP

• Associated parameters

—boiler size (megawatts, pounds/hr. steam, fuel consumption, etc.)

—boiler parameters (% excess air, boiler type, type of firing, etc.)

—operating conditions (pollutant content in fuel, hours of operation, capacity factor, % load for winter, summer, etc.)

—pollutant control equipment parameters (design efficiency, operation record, e.g., can it be bypassed?, etc.)

• Anticipated growth changes

4. Air quality monitoring data:

• Summary of existing observations for latest five years (including any additional quality assured measured data which can be obtained from any State or local agency or company) 4

• Comparison with standards

• Discussion of background due to uninventoried sources and contributions from outside the inventoried area and description of the method used for determination of background (should be consistent with the Guideline)

5. Meteorological data:

• Five consecutive years of the most recent representative sequential hourly National Weather Service (NWS) data, or one or more years of hourly sequential on-site data

• Discussion of meteorological conditions observed (as applied or modified for the site-specific area, i.e., identify possible variations due to difference between the monitoring site and the specific site of the source)

• Discussion of topographic/land use influences

6. Air quality modeling analyses:

• Model each individual year for which data are available with a recommended model or model demonstrated to be acceptable on a case-by-case basis

—urban dispersion coefficients for urban areas

—rural dispersion coefficients for rural areas

• Evaluate downwash if stack height is less than GEP

• Define worst case meteorology

• Determine background and document method

—long-term

—short-term

• Provide topographic map(s) of receptor network with respect to location of all sources

• Follow current guidance on selection of receptor sites for refined analyses

• Include receptor terrain heights (if applicable) used in analyses

• Compare model estimates with measurements considering the upper ends of the frequency distribution

• Determine extent of significant impact; provide maps

• Define areas of maximum and highest, second-highest impacts due to applicant source (refer to format suggested in Air Quality Summary Tables)

−> long-term

−> short-term

7. Comparison with acceptable air quality levels:

• NAAQS

• PSD increments

• Emission offset impacts if nonattainment

8. Documentation and guidelines for modeling methodology:

• Follow guidance documents

−> appendix W to 40 CFR part 51

−> “Screening Procedures for Estimating the Air Quality Impact of Stationary Sources, Revised” (EPA-450/R-92-019), 1992

−> “Guideline for Determination of Good Engineering Practice Stack Height (Technical Support Document for the Stack Height Regulations)” (EPA-450/4-80-023R), 1985

−> “Ambient Monitoring Guidelines for PSD” (EPA-450/4-87-007), 1987

−> Applicable sections of 40 CFR parts 51 and 52.