This page contains pre-generated files of data. All the files on this page have been exported in Integrated FED format, a normalized relational schema specifically optimized for bulk-import into a data analysis application or database. The files are formatted as pipe ("|") delimited ASCII text files which are then compressed ("zipped", *.zip) to reduce their size. The files are organized by dataset, and at the top of each submenu of files below is a summary of the frequency, scope, and schema of the associated dataset.

NOTE: The data in these files can also be obtained from the Database Query Wizard (), which provides additional flexibility in customizing the scope and format of the output files and allows you to filter your data based on monitoring sites, parameters, and date range, and also allows you to choose and customize the names of the output columns.

CAUTION: Clicking on a file link will immediately cause your browser to download the associated file unless you have configured your browser otherwise.