This is the AQS (Air Quality System) Transaction Format Guide.

It contains information about how to assemble a file of transactions for loading into AQS.


This document reproduces and/or describes terms and processes defined in statute and regulation. If there are any differences between this document and other official materials, the latter should be considered authoritative. This is not a policy document. It is intended to provide information to help users assemble data for submitting to the system.

This document contains all of the information needed to create text transactions for loading data into the AQS database. Information is presented on a transaction by transaction basis. Each transaction has an explanatory section which is followed by a table listing each field in the transaction. The names of the fields in this table are links to a full description of the field if more information is desired. This includes business rules used by the AQS software to help users build error free transactions, or troubleshoot failed transactions.

This document includes the description of the formats, requirements, and business rules of various transactions used to create, update, or delete data in AQS. It is intended for those individuals assembling data for or maintaining data in the system.

There is a search function on the left, below the navigation menu.

The largest volume of data reported to AQS is the ambient pollutant concentration data. But AQS also collects descriptive information about the location of the monitoring site (e.g., address, latitude/longitude, local site name, etc.) where the ambient data are collected as well as information about the types of monitors used to collect the ambient measurements. Quality assurance information is also reported to AQS.

This document is traditionally called the “Coding Manual” since most of the data was originally submitted as codes to reduce the network bandwidth required to transmit files.