About the Facility Count Report - Criteria Air Pollutants

What does the report tell me ?

The AirData Facility Count report displays the number of point sources in a county, state, or EPA region, that emitted a criteria air pollutant (or precursor) during a year you specify. In addition, the report gives the aggregate emissions of those sources for each geographic area. It provides an easy way to compare the number of point sources in each county of a state, for example.

A point source is a stationary source of air pollutant emissions, such as an electric power plant or a factory, that can be identified by name and location. The terms "point source" and "facility" are equivalent.

Each row of the Facility Count report displays the number of facilities in a single geographic area (county, state, or region), and the sum of their estimated annual emissions. The Grand Total line at the bottom of each report page shows the total number of facilities in the report and their total emissions, by year.

What does the report look like?

In this report example, each row lists the number of facilities per county that emitted carbon monoxide or nitrogen oxides in year 1999, and the aggregate amount of their emissions. The grand total row lists sums of those quantities for the two states included in the report. The red arrow-button under Number of Facilities indicates that column determines report order, and values are in descending order.

How can I customize the report?

Sort Order

You can use the SORT buttons in each report column to change the order of rows in the report. The default sort order is descending number of sources, which puts geographic areas with the most sources at the beginning.

Detail or Summary

This is always a summary report. Omitting optional report columns can change the level of summarization. The default report summarizes source counts and emissions by county. Omitting the County and County Code columns produces a state-level summary, and omitting the State column produces an EPA region summary. (You must include at least one of the geographic columns - county, state, or EPA region - to produce a report.)

Pollutant - Single or Multiple

If you select a single pollutant, the report includes only sources emitting that pollutant, and one report column shows the emissions of that pollutant. If you select multiple pollutants, the report includes sources emitting any of them, and the report has multiple columns to show the emissions of each pollutant.

Year - Single or Multiple

The report includes a row for every combination of geographic area and year in which there were emissions. If you select a single year, the number of rows is the number of geographic areas (counties, states, EPA regions) having emissions in that year. If you select multiple years, there are (normally) multiple rows for each geographic area.

What do the report columns mean?

Row #: Sequence number of report rows (lines). Sequence numbers are not associated with particular rows; they simply enumerate the rows of a report from first to last. Thus, choosing an alternate sort order for a report would change the sequence numbers associated with particular rows.
EPA Region: EPA region number in which a source is located. There are ten EPA regions. [ Details ]
State: Postal abbreviation for the state or territory in which a source is located. [ Details ]
County: Name of the county (or equivalent jurisdiction) in which a source is located.
County Code: Code for the county (or equivalent jurisdiction) in which a source is located, consisting of 2-digit FIPS state code and 3-digit FIPS county code. FIPS is the acronym for Federal Information Processing Standards, which defines codes used in most U.S. government information systems.
Year: The calendar year in which pollutant emissions occurred. This column is displayed only when you select multiple years for the report. If you select a single year, it is shown in the report title.
Number of Facilities: Number of air pollution point sources (facilities) within the geographic entity represented by a row of the report -- a county, state, or EPA region.
Percent of Total Facilities: Fraction (percentage) of the report's Grand Total number of sources attributable to the geographic entity and year represented by a row of the report.
Pollutant Emissions: Estimated air pollutant emissions, in short tons, from all the point sources within the geographic entity and year represented by a row of the report. (A short ton is 2000 pounds.)

If you selected a particular pollutant, it is identified in the report heading. If you selected multiple pollutants, the report includes a column for each one, and pollutant names are in the column headings.

An emissions estimate is based on the normal operating schedule of each source, and includes the effects of installed pollution control equipment and regulatory restrictions on operating conditions. This is called estimated emissions with rule effectiveness.
Percent of Total Emissions: Fraction (percentage) of the report's Grand Total emissions attributable to the geographic entity and year represented by a row of the report.

If you selected multiple pollutants, the report includes a percentage column for each pollutant, corresponding to the columns for emissions. Otherwise, the report has a single percentage column.