In response to the good word for the Adobe Acrobat PDF format put in by John Word, I'd like to put in another bad word for it. :-)
It is in fact not possible to *reliably* convert a PDF document into Word, ASCII or anything else. When you copy and paste from PDF, you are forced to copy entire horizontal lines of the text, and the copy operation doesn't preserve columns. That means that in a document with more than one column of text or a multicolumn table (i.e. almost all EPA documents) you get the two columns mixed together in an unreadable fashion. As a result, PDF is the black hole of file formats; you can convert anything to PDF, but once it's in PDF you'll never get it back out.
And although PDF files may be searchable within Acrobat Reader, or as one of a collection of files on a hard drive (under certain circumstances), they are certainly not searchable by Web search engines.
Aren't most EPA and other governmental documents now written in MS Word? That now has a function for automatic conversion to HTML, and the Word file could be attached. Those few documents that are so graphics-heavy that they must be prepared using a desktop publishing program could still be provided in PDF.