From: Melanie King/RTP/USEPA/US To: "Higgins

cc: Peter Tsirigotis/RTP/USEPA/US@EPA, RobertJ Wayland/RTP/USEPA/US@EPA

Date: Wednesday, February 17, 2010 02:39PM Subject: Re: RICE -- edits

Hi Cortney, We reviewed the suggested edits to the RIA. Attached are the edits that we are comfortable making. We do not feel comfortable making any changes beyond these. I am also adding this statement to the impacts memo: " For estimating the number engines located at major and area sources, we used our best engineering judgment, and we recognize that it may lead to an overestimate or underestimate of costs and benefits for certain sectors. " (See attached file: RIA edits.pdf)

Thanks, Melanie King Energy Strategies Group Sector Policies and Programs Division Office of Air Quality Planning and Standards U.S. Environmental Protection Agency

Mail Code D243-01 RTP, NC 27711
Phone: (919) 541-2469 Fax: (919) 541-5450 king.melanie@epa.gov

"Higgins, Cortney" ---02/17/2010 01:00:17 PM---Hi Melanie, I've attached a pdf of suggested changes to the RIA -- the first is to

Hi Melanie,

I've attached a pdf of suggested changes to the RIA -- the first is to try to address concerns about ground level transport and the characertization, the second clarifies some of the hazardous constituent language. Please let me know if you have concerns about either of these or if you can work them into the RIA. From: "Higgins, Cortney" <Cortn ey_Higgins@omb.eop.gov> To: Melanie King/RTP/USEPA/US@EPA Cc: RobertJ Wayland/RTP/USEPA/US@EPA, Peter Tsirigotis/RTP/USEPA/US@EPA Date: 02/17/2010 01:00 PM Subject: RICE -- edits 

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2/17/2010 htt p s://rtairmail1.rt p .e p a. g ov/mail/mkin g .nsf/ ( $Sent ) /98707E4F63EC643F852576CD006B

...Additionally, could you also consider the following: USDA still questions the assumption about the distribution of irrigation engines among major and area sources. Given the signature deadline, can you add some language to the source estimates memo, and possibly to the RIA, that states "For estimating the number engines located at major and area sources, we used our best engineering judgment, and we recognize that it may lead to an overestimate or underestimate of costs and benefits for certain sectors." Another suggestion is the following: " Given that few farms are known to be current major sources, less than 40% of the farms with RICE engines may be located at major sources, but EPA did not have available data to quantify an alternative estimate."

Finally, is the limited use category for area sources supposed to be for engines greater than 500 or 300? The regulatory language and preamble uses a 500 threshold, but retrofits are required for area source engines greater than 300, and, the costs of retrofits for 300 HP engines running less than 100 hours a year does not exceed the low end of the benefits
range.
Please give me a call if you have questions.

Regards, Cortney

[attachment "CI RICE NESHAP RIA 2-17-10_p133.pdf" deleted by Melanie King/RTP/USEPA/US] [attachment "CI RICE NESHAP RIA 2-17-10_p119.pdf" deleted by Melanie King/RTP/USEPA/US]

Attachments:

RIA edits.pdf 

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2/17/2010 htt p s://rtairmail1.rt p .e p a. g ov/mail/mkin g .nsf/ ( $Sent ) /98707E4F63EC643F852576CD006B

...The underlying emissions modeling and air quality modeling account for the current distribution of emissions sources, including both urban and rural sources. In addition, the air quality modeling included 14 vertical layers to simulate the differences between ground

- level emissions and higher stack emissions (U.S. EPA, 2006 a ). The distance that particles travel primarily depends on the size of the particle , the amount and release height of emissions, terrain, and meteorological conditions, such as wind speed and precipitation. Fine particles can have an a tmospheric half

- life of days to weeks and travel hundreds to thousands of kilometers, whereas ultrafine and coarse particles travel less than ten kilometers (U.S. EPA, 2009 c ). Because we have not undertaken a study specific to emissions at ground level fro m RICE, with regard to transport issues and to size fraction of PM 2.5 emissions (e.g., ultrafines and near ultrafines), there is uncertainty as to how far such emissions will travel and thus with regard to populations affected. Evidence from recent air qu ality modeling for mobile source rules with similar engines (U.S. EPA, 1999; U.S. EPA, 2000; U.S. EPA, 2004; U.S. EPA, 2008e; U.S. EPA, 2010c) shows that some fine particles can travel long distances in the atmosphere, but the proportion of such emissions
from RICE that travel more than short distances under typical ground level meteorological conditions is not yet definitively definitively known , thus introducing a potentially important source of uncertainty

.
The distance that these HAPs travel away from the emission source depends on several factors.
HAPs such as formaldehyde, acetaldehyde, PAHs, and acrolein are emitted as gases

. Regional photochemical model simulations , examining particular scenarios, have shown that gaseous HAPs like formaldehyde and acetaldehyd e can be transported hundreds of kilometers from their emissions source in distinct plumes (U.S. EPA, 2010b). Further, these emissions can contribute to regional airmasses with elevated concentrations of gaseous HAPs. These polluted airmasses , under the scenarios examined, can be transported thousands of kilometers and affect locations well distant from the original emissions

source. Some gaseous HAPs with higher molecular weight, such as toluene, can transform into particles in the atmosphere

. For engines examined in this rule, EPA does not have enough information to
determine how far each of the HAPs will travel the extent of transport specific to these HAPs

. For In general, for HAPs emitted as particles, such as metals, the travel distance primarily depends on the size of the particle and meteorological conditions, such as wind speed and precipitation. Fine particles can have an atmospheric half

- life of days to weeks and travel hundreds to thousands of kilometers, whereas ultrafine and coarse particles travel less than ten kilometers (U.S. EPA, 2009c). The level at which the emissions occur can also play a role in determining transport distances. For instance, ground level emissions are less likely to travel long distances when compared to particles emitted substantially above ground leve l.