Border Air Quality Data - About the HAP Monitor Count Report

What Does The Report Tell Me ?

The border air quality data HAP Monitor Count Report displays the number of hazardous air pollutant (HAP) monitors in operation at a location. The report is an easy way to determine which monitoring sites are measuring the pollutants you select, or to find the total number of monitors in a county, state, or region of the U.S.-Mexico border area.

Hazardous air pollutants are substances that are known or suspected to cause serious health problems. Section 112(b) of the Clean Air Act currently identifies a list of 188 pollutants as HAPs. Some of those are further subdivided for air monitoring procedures, resulting in about 200 HAPs that may be monitored for their ambient concentrations in air.

Each row of the HAP Monitor Count Report lists the number of hazardous air pollutant monitors that were operating in a particular year, at a single site or in a single geographic area, for the pollutant(s) you select. The Grand Total rows at the bottom of each report page list the total number of monitors in the geographic scope of the report, by year.

This report has a special pollutant choice, All HAPs, which gives the total number of HAP monitors at a site or in a geographic area. You may select All HAPs alone or in combination with other pollutants. In the report, the All HAPs column always gives the total number of HAP monitors. The total count is not reduced when the report also includes counts of specific HAPs.

A monitor "counts" in a particular year if it reported hazardous air pollutant data to the AQS database for that year. As the Detail or Summary section below explains, each row of the report may give monitor counts for a site, a county, or a larger geographic area.

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 monitoring site ID, which arranges rows in order of state, county, and monitoring site.

The reporting software automatically adds year as a secondary sort key for most report columns. If a report includes data for multiple years, rows having identical values for the primary sort key, which you choose with the SORT buttons, are arranged in ascending order by year.

Detail or Summary

Omitting optional report columns can change the level of summarization in the report. The default, detail report lists the number of monitors at each monitoring site within the geographic area you select. You can produce summary reports for counties, states, or border regions by omitting all report columns that pertain to individual sites. See the table below for details. A summary report gives the total number of monitors at all monitoring sites within the geographic area being summarized (county, state, or border region).

Report Column	Including This Column Has What Effect ?
Site-related information (all columns except county, state, and border region, as listed below)	Report shows site detail -- the number of monitors for each individual monitoring site. Omit all site-related report columns to summarize at a higher level.
County (name) or County Code	Report shows county summary -- the total number of monitors at all sites in each county. Omit these columns to summarize at a higher level.
State Abbreviation	Report shows state summary -- the total number of monitors at all sites in each state. Omit this column to summarize at a higher level.
Border Region	Report shows regional summary -- the total number of monitors at all sites in each border region. This is the highest summary level available.

Report Width

This report potentially can include over 30 columns if you select all the optional columns. Viewing such a "wide" report in a browser requires a lot of horizontal scrolling, and printing the full report width probably is not possible.

What Do the Report Columns Mean ?

The HAP Monitor Count report includes the following columns:

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.

Number of Monitors

Number of air pollution monitors in operation, at a specific monitoring site or within a geographic area, during any part of the indicated calendar year. Counts are shown separately (in columns) for each hazardous air pollutant that you select.

Year

The calendar year to which the monitor counts pertain. 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.

Site ID

The AQS database identification code for an air monitoring site. An AQS site ID has the following parts:

FIPS state code (2 digits)
FIPS county code (3 digits)
FIPS is the acronym for Federal Information Processing Standards, which defines codes used in most U.S. government information systems.
AQS site code (4 characters) - an arbitrary code that identifies a particular monitoring site within a county

For example, AQS site ID 48-141-0058 is a monitoring site in El Paso, Texas (48 = Texas, 141 = El Paso County, 0058 = a monitoring site in El Paso city). In border air quality reports, this site ID is displayed as 481410058, with no hyphens separating the parts of the ID.

For compatibility with U.S. state/county coding, Mexico is assigned "state" code 80, and Mexican states are coded as "counties." For example, a monitoring site in Ciudad Juarez (Juarez city), Chihuahua State, Mexico, has AQS site ID 80-006-0007 (80 = Mexico, 006 = Chihuahua State), which is displayed as 800060007 in border air quality reports.

Site Address

Address where the monitoring site is located.

City

Name of the city, town, village or other municipality in which the site is located. Blank if the site is not located within such a jurisdiction, or if no value was provided.

City Code

The 5-digit FIPS code for the city, town, village or other municipality (a "named populated place") in which the monitoring site is located. Blank or zero if the site is not located within such a jurisdiction, or if no value was provided.

County

Name of the county (or equivalent jurisdiction) in which a site is located.

County Code

Code for the county (or equivalent jurisdiction) in which a site 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.

State

Postal abbreviation for the U.S. state in which a site is located. The nation of Mexico has the "state" abbreviation MX. [ Details ]

Border Region

Name of a section of the U.S.-Mexico border area in which the site is located. A border region is usually encompasses adjacent U.S. and Mexican urban areas. A border region is the smallest geographic area that you may select for border air quality reports.

Land Use

The prevalent land use within 1/4 mile of the site. Values are:

Agricultural
Blighted Area
Commercial
Desert
Forest
Industrial
Military Reservation
Mobile
Residential
Unknown

Location Type

A general characterization of the setting where the site is located. Values are:

Rural
Suburban
Urban and Center City
Unknown

Latitude/Longitude

Coordinates of the site location, in degrees. Negative values of longitude indicate locations west of the prime meridian. Blank if no value was provided.

Locational Accuracy

The estimated accuracy (uncertainty) of the site location, in meters, as specified by latitude-longitude coordinates. Blank if no value was provided.

Locational Method

The method used to determine the site location, as specified by latitude-longitude coordinates. Blank if no value was provided.

Distance to City Center

Distance in miles to the city central business district. Direction may be given also, as a compass point: N for north, NE for northeast, etc. Blank if the site is not located in a city, or if no value is available.

City Population

Population (in year 2000) of the city, town, village or other municipality in which the site is located. Blank if the site is not located within such a jurisdiction, or if no value is available.

Urbanized Area

Name of the urbanized area in which the site is located. Blank if the site is not located within such a jurisdiction, or if no value was provided. The U.S. Census Bureau defines an urbanized area as a place (city) and the adjacent densely-settled surrounding territory that together have a minimum population of 50,000 people.

UA Code

The 4-digit Census Bureau code for the 1990 urbanized area in which the site is located. Blank or zero if the site is not located within such an urbanized area, or if no value was provided.

MSA (Metropolitan Statistical Area)

Name of the MSA in which the site is located. Blank if the site is not located within an MSA, or if no value was provided.

A metropolitan statistical area consists of one or more counties having a combined population of at least 100,000 people, containing a city or urbanized area with a population of at least 50,000 people. (In New England states, the population threshold is 75,000 and MSAs comprise cities and towns rather than counties.) An MSA may contain more than one city larger than 50,000 population, and it may include counties in multiple States.

MSA Code

The 4-digit FIPS code for the metropolitan statistical area (MSA) in which the site is located. Blank or zero if the site is not located within a metropolitan statistical area, or if no value was provided.

CMSA (Consolidated Metropolitan Statistical Area)

Name of the CMSA in which the site is located. Blank if the site is not located within a CMSA, or if no value was provided.

A consolidated metropolitan statistical area consists of one or more MSAs that have a combined population of at least one million people. The constituent MSAs are called primary MSAs (PMSA).

CMSA Code

The 4-digit FIPS code for the consolidated metropolitan statistical area (CMSA) in which the site is located. Blank if the site is not located within a consolidated metropolitan statistical area, or if no value was provided.

AQCR (Air Quality Control Region)

Name of the AQCR in which the site is located. Blank if no value was provided.

An air quality control region is a group of counties within a state (or multiple adjacent states) that share common geographical or pollutant concentration characteristics based on a common pollutant source.

AQCR Code

The 3-digit AQS code for the air quality control region (AQCR) in which the site is located. Blank if no value was provided.

Site Established

The date (day, month, year) when the monitoring site began measuring air pollutant concentrations. This date pertains to the entire site, and not necessarily to a specific pollutant (monitor).

Site Terminated

The date (day, month, year) when the monitoring site stopped operating. No value is displayed if the site is still operating.

Site Detail

You can view a complete listing of all hazardous air pollutants reported by a monitoring site by clicking on the "See All HAPs" link in each row. A Site Detail report is displayed in response to your click. It shows annual summary values of every HAP reported by the site for the year associated with the row of the main report in which you clicked. The Site Detail column is included in reports whose rows pertain to distinct monitoring sites. It is not available if report rows represent larger aggregations, such as a county or a state.