Pollutant Standard Index (PSI)
Note: EPA no longer updates this information, but it may be useful as a reference or resource.
Files identified as "ZIP" files must be de-archived using 'PKUNZIP.' Downloading instructions, archivers, and de-archivers are available through "File Compression Utilities" under the TTN Top Menu.
From the listing below, find the file you would like to download. The available file formats are represented by icons on the right side of the listing. Click on the icon that represents the file format you wish to receive. For an explanation of file formats and their icons, see our TTNWeb File Types.