The Union of Concerned Scientists made a FOIA request to the EPA and then got a release of responsive documents. The EPA also released the documents on its public FOIA portal for anyone to view. A few days later the EPA decided to pull those documents claiming it was for privacy reasons (note- whenever there is a controversy about publicly released documents, its always a standby position for agency officials to say the word privacy in their reason to block public dissemination of documents). However, the requester kept a copy of the documents and have them posted online. The documents show that the EPA decided to adopt a position of a Texas Representative (Lamar Smith - R) who is a noted climate change denier and wants to steer government polices towards his position.
The documents and other information can be found here.