----- Forwarded by RobertJ Wayland/RTP/USEPA/US on 05/27/2011 11:12 PM

----- |------------> | From: | |------------> >--------------------------------------------------------------------------- ---------------------------------------------------------------| |"Wehrum, William L." <wwehrum@hunton.com> | >--------------------------------------------------------------------------- ---------------------------------------------------------------| |------------> | To: | |------------> >--------------------------------------------------------------------------- ---------------------------------------------------------------| |RobertJ Wayland/RTP/USEPA/US@EPA | >--------------------------------------------------------------------------- ---------------------------------------------------------------| |------------> | Cc: | |------------> >--------------------------------------------------------------------------- ---------------------------------------------------------------| |"Admire, John D" <JDAdmire@dcpmidstream.com>, "Grygar, Bill" <Bill.Grygar@anadarko.com>, "Adams, Jeffrey A" <jeffrey.adams@bp.com>, "Matt | |Todd" <ToddM@api.org>, "Lisa Beal" <lbeal@ingaa.org> | >--------------------------------------------------------------------------- ---------------------------------------------------------------| |------------> | Date: | |------------> >--------------------------------------------------------------------------- ---------------------------------------------------------------| |05/27/2011 03:12 PM | >--------------------------------------------------------------------------- ---------------------------------------------------------------| |------------> | Subject: | |------------> >--------------------------------------------------------------------------- ---------------------------------------------------------------| |Additional RICE MACT Information

Bob -- in preparation for our meeting with you next week on the RICE MACT, I'm forwarding additional information on the DOT pipeline classification system. We had thought that DOT/PHMSA had readily available and useful overview materials on the system that you could use to better understand how it works. On further review, we have not found anything suitable from DOT/PHMSA. So, we are instead providing the two attached documents. The first is a summary and overview of the relevant rules. The second is a set of diagrams that illustrate how the rules should be applied. In addition, you have asked for an estimate of how many large area source RICE would be in Class 1 versus Classes 2, 3, and 4. To get a sense of this, we polled companies belonging to the various petitioners' groups. Although this is not a scientific survey, we believe that the results should be representative for the sectors we represent. Here are the results: Total companies reporting: 17.Total number of > 500 hp area source RICE reported: 4140. Number of engines in Class 1: 3572 (86% of total). Number of engines in other classes: 568 (14% of total). We hope that you find this information useful. Please don't hesitate to call if you have questions or need more information.

Bill Wehrum Partner wwehrum@hunton.com Hunton & Williams LLP 1900 K Street, N.W. Washington, DC 20006 Phone: (202) 955-1637 Fax: (202) 778-7417 www.hunton.com