November 3, 2014														CERTIFIED

Karl Brooks
Regional Administrator
U.S. Environmental Protection Agency Region VII
11201 Renner Blvd
Lenexa, KS 66219

Dear Regional Administrator Brooks:

The Iowa Department of Natural Resources (DNR) requests that the U.S. Environmental Protection Agency (EPA) approve the attached amendment to the state implementation plan (SIP) revision submitted to EPA on February 19, 2014, to prevent future violations of the 2006 24-hour fine particulate matter (PM2.5) National Ambient Air Quality Standards (NAAQS) in Muscatine, Iowa.  This amendment request includes modified construction permits for two facilities that are part of the PM2.5 control strategy in Muscatine, and a revised air dispersion modeling analysis that demonstrates continued attainment with the PM2.5 NAAQS in Muscatine.

Twelve construction permits were modified to reflect current operating conditions and stack configurations at the Union Tank Car (UTLX) facility.  Permits for four emission points at UTLX were modified to change PM2.5 emission limits resulting from the removal of control requirements while permits for four other emission points at the facility were modified to add control requirements and establish new PM2.5 limits.  The permits for four other emission points at UTLX were modified to incorporate changes in stack configuration and allow for revised dates for installation of controls.  Conditions pertaining to compliance demonstrations and operating condition monitoring, recordkeeping, and reporting are included in each UTLX permit.

Two construction permits were modified at Muscatine Power & Water (MPW) to include updated PM2.5 emission limits associated with the rail unloading system. Conditions pertaining to compliance demonstrations and operating condition monitoring, recordkeeping, and reporting are included in each MPW permit.

The modified construction permits for both facilities included in this amendment submittal replace the construction permits for the applicable units that were included in the February 19, 2014, submittal. 

An updated modeling analysis demonstrating that the permitted equipment modifications will allow for modeled attainment of the PM2.5 NAAQS is available in the modeling folder of the DNR's ftp server.  Instructions for accessing the ftp server can be provided upon request. 

Notice to the public of the opportunity to review and comment on drafts of the UTLX permit modifications was published in the Muscatine Journal on July 30, 2014.  A public comment period was completed from July 30, 2014 to August 28, 2014.  Notice to the public of the opportunity to review and comment on drafts of the MPW permit modifications was published in the Muscatine Journal on August 1, 2014.  A public comment period was completed from August 1, 2014 to September 4, 2014.  The proofs of publication for both comment periods is attached.  
 
If you have any questions regarding this submittal, please contact Jim McGraw at (515) 725-9543.

Sincerely,

Catharine Fitzsimmons, Chief 
Air Quality Bureau

c: Jim McGraw- AQB (w/o enclosures)

Enclosures:
Modified UTLX permits
Modified MPW permits
Proofs of Publication
