# EPA Green Book area boundaries

The EPA Green Book's mapped non-attainment and maintenance area boundaries, one shapefile per standard in force, and how much of each county and metro lies inside a non-attainment area, per pollutant. Where the county designations count a county only partly inside an area in full, these measure the part.

## Source

| Fact | Value |
| --- | --- |
| Publisher | U.S. Environmental Protection Agency |
| Product | Green Book: non-attainment and maintenance area boundaries (GIS shapefiles) |
| Source | [https://www.epa.gov/green-book/green-book-gis-download](https://www.epa.gov/green-book/green-book-gis-download) |
| Category | Hazard |
| Period | The export date of the county file (each area's status and class); each shapefile's own date is stored with it |
| Refresh cadence | Monthly |
| Geographies | County, for every state and territory, and metro. A county the Green Book designates whole is 1, one it designates in part is measured on the boundary, and a metro is its counties' shares weighted by area. |
| Availability | Available |
| Cadastre key | `epa-green-book-areas` |

## Licence and attribution

| Fact | Value |
| --- | --- |
| Licence | Public domain (U.S. federal government work) |
| Terms | [https://www.epa.gov/web-policies-and-procedures/epa-disclaimers](https://www.epa.gov/web-policies-and-procedures/epa-disclaimers) |
| Register status | Production approved; licence open |
| Allowed uses | `evaluation`, `internal`, `public_display`, `derived_analytics`, `redistribution`, `bulk_export`, `public_geometry` |

This source requires no credit line beyond naming the publisher. Cite it as **U.S. Environmental Protection Agency, Green Book: non-attainment and maintenance area boundaries (GIS shapefiles)**.

## Measures

The key is the measure's identifier in Cadastre. A measure stored for the metro itself is read as stored; **Rule from counties** is how a metro is assembled from its counties where it is not (see [Methodology](https://getcadastre.com/docs/methodology)).

| Key | Label | Unit | Rule from counties |
| --- | --- | --- | --- |
| `epa_ozone_nonattainment_area_share` | Area inside ozone non-attainment areas (share) | share of the area (0-1) inside an area in ozone non-attainment (class 2 or more); 1 for a county the Green Book designates whole; a county designated in part is measured on the boundary; a metro is its counties' shares weighted by area; area, not population; measured on EPA's mapped area boundaries, which EPA says are for mapping only and not the legal definition (40 CFR part 81) | Not assembled from counties: a metro has a value only where one is stored for the metro itself |
| `epa_pm25_nonattainment_area_share` | Area inside PM2.5 non-attainment areas (share) | share of the area (0-1) inside an area in PM2.5 non-attainment (class 2 or more); 1 for a county the Green Book designates whole; a county designated in part is measured on the boundary; a metro is its counties' shares weighted by area; area, not population; measured on EPA's mapped area boundaries, which EPA says are for mapping only and not the legal definition (40 CFR part 81) | Not assembled from counties: a metro has a value only where one is stored for the metro itself |
| `epa_pm10_nonattainment_area_share` | Area inside PM10 non-attainment areas (share) | share of the area (0-1) inside an area in PM10 non-attainment (class 2 or more); 1 for a county the Green Book designates whole; a county designated in part is measured on the boundary; a metro is its counties' shares weighted by area; area, not population; measured on EPA's mapped area boundaries, which EPA says are for mapping only and not the legal definition (40 CFR part 81) | Not assembled from counties: a metro has a value only where one is stored for the metro itself |
| `epa_so2_nonattainment_area_share` | Area inside sulfur dioxide non-attainment areas (share) | share of the area (0-1) inside an area in sulfur dioxide non-attainment (class 2 or more); 1 for a county the Green Book designates whole; a county designated in part is measured on the boundary; a metro is its counties' shares weighted by area; area, not population; measured on EPA's mapped area boundaries, which EPA says are for mapping only and not the legal definition (40 CFR part 81) | Not assembled from counties: a metro has a value only where one is stored for the metro itself |
| `epa_lead_nonattainment_area_share` | Area inside lead non-attainment areas (share) | share of the area (0-1) inside an area in lead non-attainment (class 2 or more); 1 for a county the Green Book designates whole; a county designated in part is measured on the boundary; a metro is its counties' shares weighted by area; area, not population; measured on EPA's mapped area boundaries, which EPA says are for mapping only and not the legal definition (40 CFR part 81) | Not assembled from counties: a metro has a value only where one is stored for the metro itself |
| `epa_co_nonattainment_area_share` | Area inside carbon monoxide non-attainment areas (share) | share of the area (0-1) inside an area in carbon monoxide non-attainment (class 2 or more); 1 for a county the Green Book designates whole; a county designated in part is measured on the boundary; a metro is its counties' shares weighted by area; area, not population; measured on EPA's mapped area boundaries, which EPA says are for mapping only and not the legal definition (40 CFR part 81) | Not assembled from counties: a metro has a value only where one is stored for the metro itself |
| `epa_no2_nonattainment_area_share` | Area inside nitrogen dioxide non-attainment areas (share) | share of the area (0-1) inside an area in nitrogen dioxide non-attainment (class 2 or more); 1 for a county the Green Book designates whole; a county designated in part is measured on the boundary; a metro is its counties' shares weighted by area; area, not population; measured on EPA's mapped area boundaries, which EPA says are for mapping only and not the legal definition (40 CFR part 81) | Not assembled from counties: a metro has a value only where one is stored for the metro itself |
| `epa_any_nonattainment_area_share` | Area inside any non-attainment area (share) | share of the area (0-1) inside an area in non-attainment for any criteria pollutant (class 2 or more); 1 for a county the Green Book designates whole; a county designated in part is measured on the boundary; a metro is its counties' shares weighted by area; area, not population; measured on EPA's mapped area boundaries, which EPA says are for mapping only and not the legal definition (40 CFR part 81) | Not assembled from counties: a metro has a value only where one is stored for the metro itself |

## Known gaps and caveats

- EPA publishes the shapefiles for mapping and visualization only: they are not the legal definition of the areas, which is 40 CFR part 81.
- These are shares of area (inland water included), not of population: where people live inside a partial county is not known at this grain.
- An area's status and class come from the Green Book county file, read by the same rules as the county designations; revoked standards are skipped.
- Connecticut replaced its eight counties with nine planning regions, which Census geography now uses; a planning region at least 98% inside legacy counties designated whole is 1, any other is measured against the boundaries of the legacy counties' areas it overlaps.
- A boundary is a designation, not monitored air quality, a permit outcome or a statement about a particular site.

## See also

- [All datasets](https://getcadastre.com/docs/datasets)
- [Rights and attribution](https://getcadastre.com/docs/rights)
- [Data freshness](https://getcadastre.com/docs/freshness)