Fw: Interagency Review of EPA SOx /NOx Secondary Standard

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 09:14 AM -----

From: "Laity, Jim" <James_A._Laity@omb.eop.gov>

To: Lydia Wegman/RTP/USEPA/US@EPA

Cc: Karen Martin/RTP/USEPA/US@EPA, John Hannon/DC/USEPA/US@EPA, Jan 

King/RTP/USEPA/US@EPA

Date: 07/07/2011 06:47 PM

Subject: RE: Interagency Review of EPA SOx/NOx Secondary Standard

Thx Lydia/karen. Just to clarify, when you say some areas will receive 

directionally more protection, you mean this hypothetically, based on the 

results of applying the proposed secondary standard relative to the existing 

secondary standard. In actual practice there will be no effect, since areas 

are already required to meet the primary standard and there are no new 

implementation requirements associated with meeting the secondary standard. 

This was my previous understanding. -- jim

-----Original Message-----

From: Lydia Wegman [mailto:Wegman.Lydia@epamail.epa.gov] 

Sent: Thursday, July 07, 2011 6:07 PM

To: Laity, Jim

Cc: Karen Martin; John Hannon; Jan King

Subject: Fw: Interagency Review of EPA SOx/NOx Secondary Standard

Jim,

Karen wrote a quick response to your questions. I hope these are

helpful.

The proposed 1-hr secondary standard of 75 ppb would generally be more

stringent than the current 3-hr, 500 ppb secondary standard, although

the relative degree of stringency would vary due to differences in

temporal air quality patterns in different areas. The proposal notice

proposes to keep the current 3-hr standard and to add the 1-hr standard.

The current secondary standard for NO2 is an annual standard of 53 ppb,

which is the same as the annual NO2 primary standard. The proposal

notice proposes to keep the current annual standard and to add the 1-hr

standard of 100 ppb, which is identical to the 1-hr NO2 primary standard

set in 2010.

The effect of setting secondary standards identical to the new 1-hr

primary standard would be to recognize the ecological benefit of the

reductions in oxides of nitrogen and sulfur that will result from
strategies to meet the new 1-hr standards. It would not result in any

areas receiving less protection, while some areas will receive

directionally more protection than that afforded by only the current

secondary standards.

 

 From: "Laity, Jim" <James_A._Laity@omb.eop.gov> 

 To: Karen Martin/RTP/USEPA/US@EPA, Lydia Wegman/RTP/USEPA/US@EPA 

 Date: 07/07/2011 05:17 PM 

 Subject: FW: Interagency Review of EPA SOx/NOx Secondary Standard 

Lydia, Karen, Could you give me a quick answer to the questions below:

For Sox, Is the proposed secondary NAAQS of 75 ppb over 1 hour more

stringent than the current .5 ppm (500 ppb) over 3 hours? Are you

also keeping the current secondary standard? What is the practical

effect of setting the secondary NAAQs for NOx and SOx at the same level

as the primary? i.e. Are there areas that will receive less protection

or more protection?

What is the current NAAQS for NOx? According to EPA’s website (

http://www.epa.gov/air/criteria.html), it appears that the secondary

NAAQS for NOx is already the same as the primary? So, what is the

effect of the revised proposal?

Thanks, jim