Fw: SOx/NOx NAAQS: would you send a copy of ISA ?--for the docket Jan King to: Sherry Russell 07/12/2011 09:14 AM

Jan King Regulatory Development and Policy Analysis Group phone: (919) 541-5665 fax: (919) 541-2664 Mailcode: C404-05

----- Forwarded by Jan King/RTP/USEPA/US on 07/12/2011 09:09 AM -----

From: Lydia Wegman/RTP/USEPA/US To: Jan King/RTP/USEPA/US@EPA Date: 07/11/2011 02:52 PM Subject: Fw: SOx/NOx NAAQS: would you send a copy of ISA?--for the docket

----- Forwarded by Lydia Wegman/RTP/USEPA/US on 07/11/2011 02:52 PM -----

From: Rich Scheffe/RTP/USEPA/US To: "Lee, Amanda I." <Amanda

_ I.

_ Lee@omb.eop.gov> Cc: Ginger Tennant/RTP/USEPA/US@EPA, "Laity, Jim" <James

_ A.

_ Laity@omb.eop.gov>, Karen Martin/RTP/USEPA/US@EPA, Lydia Wegman/RTP/USEPA/US@EPA, Mary Ross/RTP/USEPA/US@EPA, Randy Waite /RTP/USEPA/US@EPA, Tara Greaver/RTP/USEPA/US@EPA Date: 07/11/2011 02:03 PM Subject: RE: SOx/NOx NAAQS: would you send a copy of ISA?

Amanda,

You hit on some semantics that are in play. In some ways the framework is an overall model; but in includes multiple models and other components. It's probably best to consider the AAI equation as the result of an overarching framework that links ecosystem and atmospheric modeling together, maintaining scientific integrity, but applicable to regulatory application. In a sense, the terms "framework" and "model" are interchangeable. However, a specific ecosystem model and atmospheric model are used to calculate F1, and a specific atmospheric model is used to calculate F2, F3 and F4. A combination of models is a model, and it also can be referred to as a framework.

On linearity - clearly the AAI expression appears linear; however, there are several nonlinearities imbedded in the individual terms. So, it is not incorrect to call the framework linear, but the terms linear and nonlinear are better thought of as relating to specific models, and perhaps even limited to describing the relationship of a single dependent variable on one independent variable.

Again, it boils down to semantics. Hope this useful.

Rich

. Richard Scheffe (919) 541-4650 (919) 541-4511 (Fax) scheffe.rich@epa.gov

"Lee, Amanda I." 07/11/2011 10:12:27 AM Rich, thanks for sending the link. You're right. I...From: "Lee, Amanda I." <Amanda

_ I.

_ Lee@omb.eop.gov> To: Rich Scheffe/RTP/USEPA/US@EPA, Lydia Wegman/RTP/USEPA/US@EPA Cc: "Laity, Jim" <James

_ A.

_ Laity@omb.eop.gov>, Randy Waite/RTP/USEPA/US@EPA, Mary Ross/RTP/USEPA/US@EPA, Tara Greaver/RTP/USEPA/US@EPA, Karen Martin/RTP/USEPA/US@EPA, Ginger Tennant/RTP/USEPA/US@EPA Date: 07/11/2011 10:12 AM Subject: RE: SOx/NOx NAAQS: would you send a copy of ISA?

Rich, thanks for sending the link. You’re right. I could not find the answer, and I think you nailed the
issue at hand (what is framework vs. what is modeling).

I’m confused about what is considered “framework” vs what is considered “modeling” in the AAI equation given on p. 13 of the briefing: AAI=F1

‐ F2

‐ F3(NOy)

‐ F4(SOx).

Are the parameters to be estimated (F1, F2, F3, F4) and the linearity of the equation considered “framework” or “model?”

Thank you very much for your help!

All the best,

Amanda
From: Rich Scheffe [mailto:Scheffe.Rich@epamail.epa.gov] Sent: Friday, July 08, 2011 7:22 PM To: Lydia Wegman Cc: Lee, A manda I.; Laity, Jim; Randy Waite; Mary Ross; greaver.tara@epa.gov; Karen Martin; tennant.ginger@epa.gov Subject: Re: SOx / NOx NAAQS: would you send a copy of ISA?

Amanda,

use this link (below) to download the ISA. You will not easily find an answer to your question. I gave the briefing. The framework is not uncertain. There are relatively higher uncertainties with regard to data (and modeling) that is used to apply the framework.

Rich

http :// epa

. gov / ncea / isa / soxnox

. htm

Richard Scheffe (919) 541-4650 (919) 541-4511 (Fax) scheffe

. rich @ epa

. gov

-----Lydia Wegman / RTP / USEPA / US wrote: ----- To: "Lee, Amanda I." <Amanda_I._Lee@omb.eop.gov> From: Lydia Wegman / RTP / USEPA / US Date: 07 / 08 / 2011 07:09PM cc: "James_A ._Laity" <James_A._Laity@omb.eop.gov>, "Randy Waite" <waite.randy@epa.gov>, "Rich Scheffe" < Scheffe.Rich@epamail.epa.gov>, "Mary Ross"<ross.mary@epa.gov>, greave r .tara@epa.gov, "Karen Martin" <martin.karen@epa.gov>, tennant.ginger@epa.gov Subject: Re: SOx / NOx NAAQS: would you send a copy of ISA?

I don't have a copy of the ISA Amanda at the ready but I'm forwarding your message to a couple of folks via this response. The other possibility is to go to EPA's website, then to ORD, then to NCEA, which produced the document. We often also use Google to find EPA documents--whatever works. Hopefully someone can point you to where to find it if these approaches don't work.

From: "Lee, Amanda I." [Amanda_I._Lee@omb.eop.gov] Sent: 07 / 08 / 2011 06:44 PM AST To: Lydia Wegman Cc: "Laity, Jim" <James_A._Laity@omb.eop.gov> Subject: SOx / NOx NAAQS: would you send a copy of ISA?



### Hi Lydia,

I’m confused about a sentence in the preamble about the structure of the multi- p ollutant standard. Your very helpful briefing on the rule seem to suggest that while the concept of multi- p ollutant standard is sound, the current framework is uncertain. I’m hoping that the 2008 ISA would clarify my confusion. Would you mind sending a copy of the ISA? Better yet, if it is
p ublicly available, would you send a link?

Thanks and have a good weekend.

Amanda