EPA publishes roughly 2,000 documents in the Federal Register (FR) each year. Of the documents published each year, the majority are Notices. The Office of Policy (OP) has identified a subset of these as "Administrator-Signed Rules". EPA's Administrator-Signed rules are only those published actions which are signed by the Administrator and which modify or propose to modify the Code of Federal Regulations (CFR) and therefore, contain rule text. The data compiled and presented on this site primarily draws on this subset of rules signed by the EPA Administrator.
A key feature of the site is a set of graphs and charts to document how many rules are being signed, how long it takes to get through the various steps of each regulatory action, and the number of rules published in the Federal Register. There is also a link called "Regulatory Gateway" in which the public can see what EPA rulemaking, especially the priority rules, is currently in progress.
The EPA Reg Stat site can be viewed here.