Another regional administrator of the U.S. Environmental Protection Agency has been found using a private email account to conduct official business.

Region Nine administrator Jared Blumenfeld's Nov. 19, 2011, message to then-EPA Administrator Lisa Jackson concerning the resignation of Sierra Club Chairman Carl Pope was sent using his private Comcast email account and was addressed to her fake "Richard Windsor" government email account.

The agency's Region Nine is among its most politically sensitive, as it covers Arizona, California, Hawaii, Nevada, the U.S. Pacific Islands possessions, and 140 Indian Tribal Nations.

Federal officials are required to use only official email accounts and their real names to conduct government business, but are allowed to use private accounts so long as all such communications are made available to agency officials responsible for fulfilling Freedom of Information Act (FOIA) requests.

Jackson announced her resignation last December after it was revealed in September 2012 by Competitive Enterprise Institute scholar Christopher Horner in his book "The Liberal War On Transparency" that top EPA officials had been using fake names on government email accounts for years in order to avoid having their communications with each other and with supportive environmental activist groups outside the agency from becoming public via the FOIA.

Blumenfeld's message to Jackson was discovered in a tranche of thousands of emails to and from Jackson's "Richard Windsor" account, according to Washington Free Beacon reporter C. J. Ciaramella.

James Martin, EPA's Region Eight administrator, resigned last week in the wake of revelations from the same tranche of his use of a private email account to conduct official business. Martin's Denver, Colorado-based region included the Mountain and Plains states.

Bob Persciasepe, EPA's acting head, has also been found to have used a private email account, a revelation that could prevent him from being appointed by President Obama to succeed Jackson.

The Washington Examiner reported last October that CEI had filed the FOIA suit against EPA that led to the December 2012 order by the U.S. District Court for the District of Columbia that the agency turn over to the think tank copies of all of Jackson's "Richard Windsor" emails. The agency agreed to do so in a series of four releases, or "tranches," each of which was expected to include about 3,000 messages for a total of about 12,000.