The policy and guidance documents provided at http://cfpub.epa.gov/compliance/resources/policies/civil/seps/ relate to EPA's Supplemental Environmental Projects Policy. These are documents that are in current use.
You will need Adobe Acrobat Reader, available as a free download, to view some of the files on this page. See EPA's PDF page to learn more about PDF, and for a link to the free Acrobat Reader.
Please note - Currently the Supplementary Environmental Projects themselves are not available on-line. These documents are currently being updated for public access in the Enforcement and Compliance History Online (ECHO). A short description of the SEP is available by conducting a search at the following ECHO site: http://www.epa.gov/echo/compliance_report_sep.html