Changes to Data Download Files

The Download Files page has been updated with new data and many other changes.

Please note that we have made several changes to the data files. These changes include changing the formats of several files. We understand that this may be a nuisance to existing programs that ingest the data, but all changes were made based on requests from the users over the last year and we are committed to constantly improving our products.

To accommodate the changes, all files have been recreated. That is, not just files that include data that changed since the last update are new, they are all newly generated.

The changes are:

Hourly Data files: Correction to method detection limit (MDL) values. It was recently discovered that the MDL value in the hourly data files may have been listed in a unit of measure that does not match the unit of measure listed in the record. This happened when the sample had an alternate MDL that was reported in units other than the standard units.

Hourly Data files: Added Method Code column. In addition to the method name, these files now include the AQS method code (number).

Daily Data files: Added Method Code column. In addition to the method name, these files now include the AQS method code (number).

Annual Summary Data files: Added Completeness Indicator column. A column indicating whether the data meets the regulatory requirements for completeness for the year has been added. Different parameters have different completeness requirements and it is not always straight-forward to determine if an annual value is complete.

Added files for NO, NOx, and NOy. Many people have requested that our measurements of NO, NOx, and NOy be made available. They have always been in the annual files, but we have added daily and hourly files of this data.

Added files for 8-hour averages of ozone and CO. The form of the NAAQS average for ozone and CO includes an 8-hour average. We are providing these files as a convenience for users who need this data.