  SEQ CHAPTER \h \r 1 

July 28, 2008

MEMORANDUM

SUBJECT:  NONROAD2005d Emissions Inventory Model Documentation for the
Small		          Nonroad and Marine Spark-Ignition Engine Final
Rulemaking	

FROM:        Richard S. Wilcox

	                     Assessment and Standards Division

	                     Office of Transportation and Air Quality			

TO:		    Docket EPA-HQ-OAR-2004-0008

	The purpose of this memorandum is to docket EPA’s NONROAD2005d
emission inventory model that was used to generate the baseline and
control case emission inventories for the Small Nonroad and Marine
Spark-Ignition Engine final rulemaking.  This documentation consists of
a compact disk that contains the computer model, input files, supporting
technical documents,  and user’s guide.  It also contains a read me
file that explains how our NONROAD2005a model was modified to develop
NONROAD2005d and how the model was used to generate the emission
inventories for the final rulemaking.  The NONROAD2005a model is also
available in the docket referenced above and on our website: 
www.epa.gov/otaq/nonrdmdl.htm.

	Please note that this version of the nonroad model (i.e., NONROAD2005d)
is not considered by EPA to be a replacement of the existing public
NONROAD2005a model that has been approved for use in State
Implementation Plans, conformity determinations, or other official
submissions.  It is intended only to support the Small Nonroad and
Marine Spark-Ignition Engine final rulemaking.

Attachment

Source Selection Information – See FAR 2.101 and 3.104	Page   PAGE  2 
of   NUMPAGES  1 

