### UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 7 901 NORTH 5TH STREET KANSAS CITY, KANSAS 66101 

### AUG 17 2012 MEMORANDUM SUBJECT:

FROM:
THRU:
TO: Technical Support Document (TSD) for Missouri State Implementation Plan (SIP) revision to Missouri Rules 10 CSR 10-6.010AmbientAir Quality Standards, 10 CSR 10-6.040ReferenceMethods, and 10 CSR 10-6.130 ControllingEmissions During Episodes of High AirPollution Potential Amy Bhesania**~** Community

### Partn**~** Programs Section Michael Jay, Section Chief Atmospheric Programs Section M0-297; EPA-R07-0AR-2012-0596


### INTRODUCTION This State Implementation Plan (SIP) revision is for Missouri Rules 10 CSR 10-6.010AmbientAir Quality Standards, 10 CSR 10-6.040ReferenceMethods, and 10 CSR 10-6.130 ControllingEmissions During Episodes of High AirPollution Potential. This revision will amend the ambient air quality standards table
.to reflect revised National Ambient Air Quality Standards (NAAQS), update reference methods associated with the revised NAAQS, and update the breakpoint values for the Air Quality Index. The Missouri Department ofNatural Resources' (MDNR) 

### Air Pollution Control Program sent this revision request to the EPA on September 21, 2010, and it was received byEPA on September.28, 2010. The effective date ofthese state regulations was May 30, 2010. 

### DESCRIPTION OF REVISIONS The revisions to 10 CSR 10-6.010AmbientAir Quality Standards update the standards to reflect changes promulgatedby EPA through December 21, 2008 for theNational Ambient Air Quality Standards (NAAQS) for particulate matter 10 microns or less, particulate matter 2.5 microns or less, ozone and lead. This amendment also corrects the 1971 nitrogen dioxide standard in Missouri. 1. The 1987 annual standard for particular matter 10 microns or less (PM10) of50 micrograms per cubic meter was removed from the table. 2. The 24-hour standard for particulate matter 2.5 (PM2.5) was revised from 65 micrograms percubic meterto the 2006 24-hour standard of35 micrograms per cubic meter, and the appropriate reference methods associated withthis NAAQS were added to the table.

### ,._;''~ I l \r L " IU J'

### 2 3
. The appropriate reference methods associated with sulfur dioxide and carbonmonoxide were added to the table. 4. The one (I)-hour ozone standard of0.12 parts permillion (ppm) was removed and the 2008 eight (8)-hour ozone standard of0.075 ppmwas added. The appropriate reference methods and form ofthe standard were added to the table. 5. The words 'photo-chemical oxidants' were removedfrom the 1997 8-hour ozone pollutant reference in the table, but the standard of.08 ppm was retained. 6. The nitrogen dioxide standard was corrected from 0.05 ppmto 0.053 ppm. 7. The applicable reference methods associated withhydrogen sulfide and sulfuric acid were added to the table. 8. The 2008lead standard of0.15 micrograms per cubic meter was added to the table. The appropriate reference methods and form ofthe standard were added to the table. The revisions to 10 CSR 10-6.040ReferenceMethods update the reference methods for measuring ambient air concentrations to determine whether areas are attaining the 2008 ozone and lead NAAQS. Additionally, the amendment incorporates byreference all reference methods found in 40 CFRPart 50 Appendices A-R as well as equivalent methods found in 40 CFR Part 53 into this rule. These appendices describe. the methods for measuring ambient concentrations ofvarious pollutants for which NAAQS have been established, and describe how attainment ofvarious NAAQS is determined. Section (4) ofthe rule was amended as follows: 1. 40 CFRPart 50 Appendices A-Rand 40 CFRpart 53 promulgated as ofJune 30, 2008, and Federal RegisterNotice 73 FR 67051-67062 promulgated November 12, 2008 were incorporated by reference in to the rule. 2. Reference to 40 CFRPart 50 Appendix Q- Reference Method for the Determination ofLead and Particulate Matter as PM10 Collected from Ambient Air was added to sub section (4)(G) ofthe rule. 3. Sub section (4)(N) was added to the rule which references that compliance with the 8-hour ozone standards is determined as specified in 40 CFRpart 50, Appendix P -Interpretation of the Primary andSecondaryNationalAmbientAir Quality Standards for Ozone 4. Sub section (4)(0) was added to the rule which references that compliance with the lead standard shall be determined as specified in 40 CFRpart 50, Appendix R- Interpretation of the National AmbientAir Quality Standards forLead. 5. Section (9) ofthe rule was removed. This amendment moves the incorporationbyreference ofthese reference methods from 10 CSR 10-6.070 (Missouri's incorporationbyreference ofthe federal NSPS requirements in40 CFR Part 60) to this rule. 10 CSR 10-6.070 was revised to reflect this change. The revisions to 10 CSR 10-6.130 ControllingEmissions DuringEpisodes of High AirPollution Potential update the breakpoint values in Table A ofthe Air Quality Index (AQI) for eight-hour ozone. The breakpoint values are used to determine whether contingency measures should be implemented during periods of excessive air pollutant concentrations. Table A was amended as follows: 

### I. The breakpoint value for the 8-hour ozone standard in the AQI range of0-50 was revised from 0

- 0.064 ppm to 0- 0.059 ppm. 2. Thebreakpoint value for the 8-hour ozone standard in the AQI range of51-100 was revised from 0.065

- 0.084 ppm to 0.060- 0.075 ppm. 3. The breakpoint value for the 8-hour ozone standard in the AQI range of 101

- 150 was revised from 0.085-0.104 ppm to 0.076-0.095 ppm. 4. The breakpoint value for the 8-hour ozone standard in the AQI range of 151-200 was revised from 0.105-0.124 ppm to 0.096-0.115 ppm. 5. The breakpoint value for the 8-hour ozone standard in the AQI range of201-300 was revised from 0.125

- 0.374 ppm to 0.116

- 0.374 ppm.

### 3 EPAnotes that Missouri retained the 1-hour ozone standard breakpoint values and these trigger levels are consistent withEPA's significant harm levels (SHL). EPA is approving the 8-hour breakpoint levels because they are more stringent thanthe existing 8-hour breakpoint values inMissouri's current SIP, and because EPA does not have a SHL based on an 8-hour average. CONCLUSION The revisions inthis SIP submittal are largely administrative and consistent with current Federal regulations. The revisions will update Missouri' s rule and will improve the clarity ofthe rule
. States are not required to adopt ambient air quality standards, but are required to implement the standards adopted byEPApursuant to section 110 ofthe CAA. Missouri has adopted standards which are consistent withthe EPA standards, and, therefore, this revision to update the state standards is approvable. The revisions do not have an adverse affect on air quality and improve the stringency ofthe SIP. I approve these revisions. SOURCES USED 40 CFR Part 51, Requirements for Preparation, Adoption, and Submittal ofImplementation Plans http://www.epa.gov/epacfr40/chapt-l.info/chi-toc.htm Appendix V to Part 51, Criteria for Determining the Completeness ofPlan Submissions 40 CFRPart 52, Approval and Promulgation ofImplementation Plans http://www.epa.gov/epac:fr40/chapt-l.info/chi-toc.htm Subpart AA, Missouri FederalRegisterNotice 71 FR 61144-61233, promulgated October 17, 2006 FederalRegisterNotice 73 FR 16436-16514, promulgated March 27, 2008 FederalRegisterNotice 73 FR 66964-67062, promulgatedNovember 2, 2008 

### ************************************************************************ Record ofRule Making Missouri Department ofNatural Resources
Public Hearing December 3, 2009 Adopted by Missouri Air Conservation Commission (MACC) January 28,2010 Effective Date ofRe2ulation May30, 2010 SIP Submittal sent to EPA Region 7 by MDNR September 21,2010 Rule Package received by EPA Re2ion 7 September 28,2010 Completeness letter sent to MDNR April6, 2011