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AQS Codes and Descriptions
Links go to HTML pages that are refreshed nightly. The pages can be downloaded as comma separated values (CSV) files. File format information here.
Parameters - Allowed combinations of parameter + sampling methodology (collection and analysis) + reported unit + duration (sometimes called "Protocols"). If you do not see the combination here, it is not allowed into AQS. If you believe that we are missing a valid combination, please contact the AQSTeam. This list also includes other information, such as the standard unit, the summary scale and the minimum sample value that is allowed into AQS. Parameters are not just pollutants but anything that is measurable, including meteorology measurements, i.e., wind speed. To make the files smaller, we also broke out selected groups of parameters and show the valid combinations for just those.
UATMP - Urban Air Toxics Monitoring Program
Qualifiers all - Qualifiers are used when reporting data to AQS. Qualifiers further explain the data
- "Null" qualifiers - required when submitting a null (i.e., nothing was collected) sample measurement; All Null qualifiers are available for every parameter
- "QA" qualifiers - optional - quality assurance qualifiers are used when data is valid but you want to note something. i.e. measurement was "Below lowest calibration level"
- "Inform" qualifiers - optional - informational qualifiers are used in place of a REQuest EXClusion qualifier; use only when an exclusion of the data will not be requested
- "ReqExc" qualifiers - required when submitting data that is affected by an Exceptional Event and for which an exclusion will be requested
Parameters + Qualifiers all - List of parameters and the qualifiers that are open for each. ** Null open for all parameters. QA, Informand ReqExc open for some parameters
Collection frequencies - the amount of time between sample observations
Durations - required when reporting a measurement; the length of time used to acquire a sample measurement (can sometimes called the interval) E.g., measurements for ozone monitors that run continuously are reported as hourly average concentrations with AQS Duration Code = 1
Units - Units of measurement. Apply to both Reported and Standard Sample Values
Monitor types - Indicates the purpose of a monitor. Each monitor is required to have at least one monitor type
Pollutant Standards - Every NAAQS has a unique Pollutant Standard in AQS, i.e. "2008 8-hour ozone NAAQS"
AQI breakpoints - For select pollutants, the AQI transforms ambient concentrations to a scale from 0 to 500. Since AQS generates the AQI values, we also store the breakpoints for the AQI ranges ("Good", "Moderate", "Unhealthy" for sensitive groups" or "Unhealthy", "Very unhealthy", "Hazardous".)
Agencies - Air pollution control agencies and other organizations reporting data to AQS. If an agency you need already exists, but is not shown for your state within AQS, contact the AQSTeam to have your state added to the list of states that can use that agency code.
State and County - FIPS codes for all the states and the counties contained therein
Cities - FIPS codes for cities
CBSAs - Core-Based Statistical Areas (CBSAs) - defined by OMB in June 2003; areas based around an urban center of > 10,000 people and adjacent areas; designations are made using US Census numbers
CSAs - Combined Statistical Areas (CSAs) - defined by OMB in June 2003; areas based on adjacent CBSAs; designations are made using US Census numbers
MSAs - Metropolitan Statistical Areas (MSAs) - here for informational purposes only. MSAs were replaced by CBSAs.
CMSAs - Combined Metropolitan Statistical Areas (CMSAs) - here for information purposes only. CMSAs were replaced by CSAs
Legacy Null data codes - Mapping of the old mainframe codes to the newer Null qualifier codes. *** Informational purposes only
Information on the format of the files:
- You can download the full CSV (Comma Separated Values) file from any page that
you are on
- The CSV files have been designed to import into MS Excel with minimal effort
- Each column is sortable
- "<" - Sorts the column in Descending order
- ">" - Sorts the column in Ascending order
- Clicking the Title will reset the sort order using the default sort criteria