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Frequently Asked Questions

This page provides answers to frequently asked questions about the information contained in the Green Book. The questions are divided into Data, GIS/Map, and Other categories. Click on a question below to view answers relating to your selection. Links throughout the answers will guide you to further information on our website. Should you have any further questions or comments, please click on the "Contact Us" link near the top of this page.


~ Data Questions ~
 
1. Does EPA provide exports of the type of area and/or county data in the Green Book reports?
 
2. Is there a unique ID field for the nonattainment areas in the data exports?
 
3. Is there a file export that shows the nonattainment status of all counties over a period of years in the past? Ideally, it would be a spreadsheet that shows each year that a county was in nonattainment. So if 100 counties were in non-attainment each year, it would have 2,000 rows (100 counties x 20 years).
 
4. Is it possible to obtain the information contained in the "Nonattainment Status for Each County by Year" report in a spreadsheet or database format, preferably with county and state FIPS codes?
 
5. Is there a way to get the information published in the "Currently Designated Nonattainment Areas for All Criteria Pollutants" report in spreadsheet or database format?
 
6. What do the asterisks on the classifications mean on the "Previous Maintenance Areas No Longer Subject to the 1-hour Ozone Standard" report?
 
~ GIS / Map Questions ~
 
7. Are GIS shapefiles available for all pollutant nonattainment areas?
 
8. Is there a way to get copies of all of the maps in the Green Book?
 
~ Other Questions ~
 
9. A Green Book link to a Federal Register Notice on the GPO website results in a "No Documents Found" message.
 
10. Is the information in the Green Book kept up-to-date as areas are redesignated or reclassified?
 


 
~ Data Answers ~
 
1. Does EPA provide exports of the type of area and/or county data in the Green Book reports?
 
The Green Book includes a Data Downloads web page that provides various types of area and county-level exported data in xbase (dbf) and spreadsheet (xls) formats. When a data export relates to the data displayed in an existing Green Book report, links to example reports are provided. A data dictionary in PDF format is also available for download that contains additional details about all of the downloadable data files. Each file contains an export date (exportdt) field, which is duplicated on all rows.

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2. Is there a unique ID field for the nonattainment areas in the data exports?
 
The area-level data exports contain a composID field containing a unique identifier developed by EPA for designated nonattainment areas for all National Ambient Air Quality Standards (NAAQS). A complete list of the area composID values are included in the AREADATA file export available on the Data Downloads web page. This identifier was developed specifically for use across GIS applications, but it is also available for use as an area ID for other purposes. The composID is clearly recognizable, defining the pollutant, the pollutant standard, and a general name for the area, e.g.,
Ozone_8-hr.1997.Chicago.

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3. Is there a file export that shows the nonattainment status of all counties over a period of years in the past? Ideally, it would be a spreadsheet that shows each year that a county was in nonattainment. So if 100 counties were in non-attainment each year, it would have 2,000 rows (100 counties x 20 years).
 
This information is available in xbase (dbf) and spreadsheet (xls) exports downloadable from the Green Book Data Downloads web page.

The PHISTORY file export contains the annual nonattainment status of each county since 1978 to the present. Each row lists the years a county was in a pollutant nonattainment area, and whether the whole county or part of the county was in the area. The "W" and "P" distinction refers to whether the county is wholly (W) or partially (P) in a pollutant nonattainment area. If a county is in a pollutant nonattainment area that is redesignated at any time during a calendar year, the W or P indicator is omitted for that year.

Please note that the example of 100 counties x 20 years is simpler than the reality. A county may be in a nonattainment area for more than one criteria pollutant, with the same, similar, or different boundaries for each area. This will result in multiple rows in PHISTORY for a single county.

The Whole or Part County Nonattainment Status by Year Since 1978 for All Criteria Pollutants report displays by state the same data as contained in the PHISTORY file. Please refer to this report's Important Notes for additional information about the creation of the historical data in the report and the PHISTORY file.

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4. Is it possible to obtain the information contained in the "Nonattainment/Maintenance Status for Each County by Year for All Criteria Pollutants" report in a spreadsheet or database format, preferably with county and state FIPS codes?
 
This information is available in xbase (dbf) and spreadsheet (xls) exports downloadable from the Green Book Data Downloads web page.

The NAYRO export file contains the information in this report, with the annual nonattainment status of each county. A separate row is listed for each area that the county is in from 1992 to the present. This export has similar year-by-year nonattainment status information to that contained in PHISTORY with the additional rows for each nonattainment area the county falls within. Each row lists the years a county was in a pollutant nonattainment area, along with the area status, classification, and redesignation dates (where applicable).

A blank year can mean that after a county has been in a nonattainment area, the area was redesignated back to attainment and has a maintenance plan in place. However, a county may also show up as no longer being in a nonattainment area (blank in a row rather than "P" or "W"), but not be in a maintenance area. Counties in areas where the standard has been revoked are displayed this way (e.g., 1-hr Ozone). Also, a multi-state nonattainment area is not counted as a maintenance area until all states in the area are redesignated.

The "Whole" and "Part" distinction refers to whether the county is wholly or partially in a pollutant nonattainment area. If parts of a single county are within more than one nonattainment area for a single pollutant, these are listed with a separate row for each nonattainment area.

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5. Is there a way to get the information published in the "Criteria Pollutant Nonattainment Summary Report" in spreadsheet or database format?
 
This information is available in xbase (dbf) and spreadsheet (xls) exports downloadable from the Green Book Data Downloads web page.

The ALLPOLLS_NAA export contains the information in this report, with an area-level listing of all criteria polutant areas currently in nonattainment. Different pollutant areas that have similar boundaries are grouped together under a common area name. This export includes a identifying code for the common area names (Common_CD), area classifications, county counts and 2010 census populations.

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6. What do the asterisks on the classifications mean on the "Previous Maintenance Areas No Longer Subject to the 1-hour Ozone Standard" report?
 
The footnote for the "Previous Maintenance Areas No Longer Subject to the 1-hour Ozone Standard" report is: * 5% Classification Change. This relates to the situation where the state had a period of time after the original 1-hour Ozone designation to get the classification changed based on what it would have been if their design value had been within 5% of the classification threshold.

For example, the previous Moderate 1-hour Ozone Huntington-Ashland, WV-KY area had a listed design value of 0.164 with 5.5 exceedences in 1989. You can review the 1-hour Ozone classification design value ranges. For a classification of "Moderate" for 1-hour Ozone, an area has a design value of 0.138 up to 0.160 ppm. In the case of the Huntington-Ashland area, the states of West Virginia and Kentucky could request bumping down to "Moderate" instead of retaining the "Serious" classification.

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~ GIS Answers ~
 
7. Are GIS shapefiles available for all pollutant nonattainment areas?
 
EPA began using ESRI shapefiles in the 2004 Ozone designation process. Shapefiles are now available for download in the Green Book for both those developed for the designation process in addition to pre-2004 shapefiles that were developed outside of the nonattainment designation process. For these pre-2004 nonattainment area designations, the boundaries in the shapefiles were based on the Part 81 table description.Both sets of shapefiles, containing boundary information for the originally designated areas for these pollutants, are available for download in the Green Book on the GIS Downloads web page. Also available for download on this web page are external data files in both xbase (dbf) and spreadsheet (xls) formats. These files contain information about the current status of the designated areas. The external data files can be linked to the shapefiles with the composID field in each file.

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8. Is there a way to get copies of all of the maps in the Green Book?
 
The Green Book now includes a Map Downloads web page containing sets of maps available in the Green Book. Maps are updated as needed each time a new version of the Green Book is posted. Each map has a month/year date listed indicating the Green Book posting date. Links for new sets of maps will be added to the download page as the first nonattainment areas are redesignated to maintenance for newer standards, and as new standards are promulgated.

The maps are downloadable as sets of zipped PDF files. The individual state maps have been generated with ESRI shapefiles for areas designated since 2004. These maps are zipped into a file of nonattainment state maps for a pollutant, maintenance state maps for a pollutant, and national maps. Since shapefiles are not available for pollutants other than those designated since 2004, maps for older pollutant standards are national maps based on whole county boundaries.

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~ Other Answers ~
 
9. A Green Book link to a Federal Register Notice on the GPO website results in a "No Documents Found" message.
 
As of September 16, 2010, the Green Book Federal Register Notice (FRN) citations are linked directly to Government Printing Office (GPO) notices. The GPO stores electronic copies of FRNs (in PDF format) from 1995 to the present. The Green Book contains HTML versions of FRNs published prior to 1995.

Occasionally, an FRN is not available on the GPO site, and the "No Documents Found" message will be displayed on the GPO search page. When a Green Book FRN citation is discovered to not have a FRN available on the GPO website, an HTML or PDF version of the FRN is added to the Green Book and the GPO link is removed. If you experience the "No Documents Found" for a Green Book citation, please click on the Green Book "Contact Us" link and specify the FRN citation that was not found so that it can be added to the Green Book.

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10. Is the information in the Green Book kept up-to-date as areas are redesignated or reclassified?
 
The complete Green Book reports and maps are updated approximately every quarter, reflecting any changes in an area's status. If interested, you can regularly check the report that lists Federal Register Notices published or effective since the last Green Book posting. A link to this report is on the Green Book home page in a blue box near the top of the page. The FRN citations on the report are linked to electronic copies of the notices on the GPO website.

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