UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 4



### Ms. MayaRao Chief Mississippi Department of

Environmental Quality P.O. Box 2249 Jackson, Mississippi 39225-2261 Dear Ms. Rao: ATLANTA FEDERAL CENTER 61 FORSYTH STREET ATLANTA, GEORGIA 30303-8960 

### November 22, 2013

Thank you for submitting the annual ambient air-monitoring network plan (Network Plan) for the state ofMississippi, dated June 26, 2013, and the Addendum to the Network Plan, dated August 27, 2013. TheNetwork Plan is required by 40 Code ofFederal Regulations (CFR) §58.10. The Network Plan covers ambient air monitoring networks operated bythe Mississippi Department ofEnvironmental Quality. The cover letter submitted with the MDEQ Network Plan indicated that the public was provided a comment period and that MDEQ did not receive public comments regarding the plan. While the letter did not indicate that the comment period was 30-days in length, it is our understanding from subsequent conversations with your staffthat the commentperiod was 30-days inlength as required. Afterreview oftheplan, the EPA approves the MDEQ'sNetwork Plan with the exception ofthe proposal to discontinue the Meridian ozonemonitoring site. The EPA believes that the Meridian site is important to preserve the spatial representation ofthe ozone-monitoring network inthe southern Mississippi and southern Alabama area. The EPA approves the Pascagoula (Jackson Co. 28-059-0006) site to be among the Regional Administrator required nitrogen dioxide (N02) monitors intended to help protect susceptible and vulnerable populations. The full list ofN02 monitors identified bythe Regional Administrators canbe found on the EPA's website at http://www.epa.gov/ttnamtil/svpop.html. Enclosed is a summary ofour analysis and comments that maybeuseful in understanding the EPA's decisions and in developing next year'splan. Please contact us ifyou have any questions related to our 

### comments.

Internet Address (URL) • http://www.epa.gov Recycled/Recyclable • Printed with Vegetable Oil Based Inks on Recycled Paper (Minimum 30% Postconsumer)

### Thank you for working with us regarding air quality and monitoring air pollution in Mississippi. Ifyou have questions or concerns, please contact Gregg Worley at (404) 562-9141 or Phyllis Warrilow at (404) 562-9198.

Enclosure
cc: Mr. Jerry Beasley, MDEQ, Air Standards and Planning Mr. Michael Jordan, Sincerely,

# -{)~**~---J**eaneanne M. Gettle Acting Director Air, Pesticides and Toxics Management Division

Mississippi Department ofEnvironmental Quality

### CY 2013 State ofMississippi Ambient Air Monitoring Network Plan U.S. EPA Region 4 Comments and Recommendations The EPA reviewed the Mississippi Department ofEnvironmental Quality annual air monitoring network plan (Network Plan)
. Ambient air monitoring rules are found in 40 CFR Part 58, which include regulatory requirements regarding network plans, data certification, and minimum monitoring requirements. Minimum monitoring requirements for critical pollutants are listed in 40 CFR Part 58, Appendix D. New national ambient air quality standards (NAAQS) for carbon monoxide (CO) with minimum monitoring requirements are effective January 1, 2015, and January 1, 2017. Minimum monitoring requirements are listed for ozone (03), particulate matter less than 2.5 microns (PM2.5), particulate matter less than 10 microns (PM10), nitrogen dioxide (NOz) sulfur dioxide (SOz), and lead (Pb). The minimum monitoring requirements arebased on core based statistical area (CBSA) boundaries as defined bythe U.S. Office ofManagement and Budget July 1, 2012 population estimates from the U
.S. Census Bureau and historical ambient air monitoring data. Minimum monitoring requirements for 

### 0 3, PM2.5, and PM 10 only apply to metropolitan statistical areas (MSAs), which are a subset ofCBSAs. The state's four MSAs and respective population estimates from the U.S. Census Bureau are shown in Table 1
. Table 1: Metropolitan Statistical Areas and July 1, 2012 Population Estimates Name Population
Hattiesburg, MS 146,766
Memphis, TN-MS-AR 1,341,690 After review ofMDEQ's Network Plan with respect to the applicable requirements, the EPA makes the following comments and recommendations: 

### Minimum 03 

### Monitoring Requirements 40 CFRPart58, Appendix D, Table D-2 Based onpopulation figures and current design values, MDEQ is required to have two 0 3monitors 

### in each ofthe Gulfport-Biloxi-Pascagoula and Jackson MSAs. The Gulfport-Biloxi-Pascagoula MSA currently has two 0 3monitor(s) and Jackson MSAhas two 03 monitors. The Memphis MSA is also required to have two 

### 0 3 monitors; however, MDEQ's memorandum of agreement (MOA) with Arkansas, Tennessee, and the Shelby County Health Department allows Mississippi to meet the 03 requirement for the Memphis MSA with the single 03 monitorin DeSoto County. The 

### 0 3 network described inthe 2013 Network Plan meets the minimum monitoring requirements specified by40 CFRPart 58, Appendix D, Table D-2 in all areas.

### S02 

### Monitoring Requirements 40 CFR Part58, Appendix D, 4.4 Ambient air monitoring network design criteria for S02 are found in Section 4.4 ofAppendix D of40 CFR Part 58. This section requires that "Thepopulation weighted emissions index (PWEI) shall be calculated by States for each corebased statistical area (CBSA),
..." S02 monitors should be sited within CBSAboundaries and be ofthe following site types: population exposure, maximum concentration, source-oriented, general background, orregional transport. An S02monitor at an NCore station may satisfy minimum monitoringrequirements ifthat monitor is located within a CBSA that is required to have a monitorunder Appendix D, 4.4. MDEQ's S02 monitors are at the Jackson NCore (28-049-0020) station and at the Pascagoula (Jackson Co. 28-059- 0006) monitoring site. The S02 monitoring network design proposed in the Network Plan meets the minimum requirements of40 CFR Part 58
. NOz 

### MonitoringRequirements 40 CFR Part58, Appendix D, 4.4 Ambient air monitoring network design criteria for N02 are found in Section 4.3 ofAppendix D to 40 CFRPart 58. There are three types ofrequired N02 monitoring: near-road, area-wide, and Regional Administrator. These types ofN02 monitoring are described in sections 4.3.2, 4
.3.3, and 4.3.4, respectively. Any CBSA with a population of500,000 ormore persons is required to have a near-road N02 station that monitors expected maximum hourly concentrations near a majorroad. Any CBSA with a population of2,500,000 ormore persons orthat has one ormore roadway segments with a 250,000 or greater annual average daily traffic (AADT) count is required to have an additional near-road N02 monitoring station. The near-road N02 Monitoring Technical Assistance Document provides guidance to state and local agencies in selecting an appropriate near-road N02monitoring location. This document can be found onthe internet at http://www
.epa.gov/ttnamtil/files/nearroad!NearRoadTAD.pdf. Ambient air monitoring network design**riteria** 

### for area-wide N02 sites are found in Section 4.3.3 of Appendix D to 40 CFR Part 58. Any CBSA with a population of 1,000,000 ormore persons is required to monitor a location ofexpected highest N02 concentrations representing the neighborhood or larger spatial scales. Ambient air monitoring network design criteria for Regional Administrator required N02 monitoring, often referred to as RA-40 monitoring, are found in Section 4.3.4 ofAppendix D to 40 CFR Part 58. This section states, "the Regional Administrators, in collaboration with States, must require a minimum offorty additional N02 monitoring stations nationwide in any area, inside oroutside ofCBSAs, above the minimum monitoring requirements, with a primary focus on siting these monitors in locations to protect susceptible and vulnerable populations. The Regional Administrators, working with States, may also consider additional factors
... to require monitors beyond theminimum network requirement." For the Memphis CBSA, the requirement for near-road N02 monitoring will bemetby a near-road site operated by Memphis/Shelby County Health Department, Air Pollution Control Program, in Memphis, TN. Additionally, the Marion (Crittenden Co. 05-035-0005) site 

### in Arkansas fulfills the area-wide N02 monitoring requirement for the Memphis CBSA. No other CBSA 

### in Mississippi is currentlyrequired tohave area-wide 

### NOz monitoring or near-road 

### NOz monitoring. The Jackson, MS CBSA will be required to have one near-road

### NOz monitor operating byJanuary 1, 2017. The EPA approves the**Pascagou~a** (Jackson Co. 28-059-0006) site to be among the Regional Administrator required 

### NOz monitors intended to help protect susceptible and vulnerablepopulations. The full list ofN02 monitors identified by the Regional Administrators can be found on the EPA's website at http://www.epa
.gov/ttnamtillsypop.html
. 

### Minimum PM 1

### oMonitoring Requirements 40 

### CFRPart58, 

### Appendix D, 3.3.1 40 

### CFR Part58, 

### Appendix D, 

### Table D-4 The state ofMississippi's current 

### PMw monitoring network meets the minimum requirements found in 40 CFR Part 58, Appendix D, Table D-4 for all MSA' s. All 

### PMw collocation requirements for manual methods found in 40 CFR Part 58, Appendix A, Section 3.3.1 are also currently being met. Fifteen percent ofeach network ofmanual 

### PMw methods (at least one site) must be collocated. MDEQ will meet this requirementbyhavingbothregular and collocated federal reference method (FRM) PM 10 samplers at the relocated NCore site in the Jackson MSA. The new Air Quality System (AQS) identification number is Hinds Co. 28-049-0020. 

### Minimum PM2.s MonitoringRequirements 4il 

### CFRPart 58, 

### Appendix A, 3.2.5 40 

### CFRPart 58, 

### Appendix D, 

### Table D-5 The state ofMississippi's 

### PMz
.smonitoring network meets the minimum requirements found in40 CFR Part 58, Appendix D, Table D-5 for all MSAs. The following MSA's are required to have one PM2.5 monitor: Gulfport-Biloxi-Pascagoula; Hattiesburg, and Jackson. The Memphis MSA is required to have two 

### PMz
.smonitors. MDEQ's MOA with Arkansas and Memphis-Shelby County, TN allows Mississippi to meet the 

### PMz
.srequirements for the Memphis MSA with the single PM2.5 monitor in DeSoto County. MDEQ's primary

### PMz
.smonitoring network as described inthe Network Plan meets the minimum requirements found in 40 CFR Part 58, Appendix D, table D-5 for all MSAs. 

### PM2
.s Continuous Monitoring Requirements 40 

### CFR Part 58, 

### Appendix D, 4.7.2 Regulatory requirements for continuous 

### PMz.s monitoring require that "
...State, orwhere appropriate, local agencies must operate continuous 

### PMz
.s analyzers equal to at least one-half(roundup) the minimum required sites listed inTable D-5 ofthis appendix. At least one required continuous analyzer in each MSA mustbe collocated with one ofthe required FRM/FEM/ARM [federal reference method/federal equivalent method/approved regional method] monitors, unless at least one ofthe required FRMIFEM/ ARM monitors isitselfa continuous FRM orARM monitor in which case no collocation requirements applies." Theseminimum continuous 

### PMz
.smonitoring requirements are being met in all MSAs. Therefore, the continuous PM2.5 monitoring network described in the 2013 Network Plan meets all design criteria of40 CFR Part 58.

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### PM2.5 

### Continuous Federal EquivalentMethods 40 CFR 

### § 58.10(e) As part ofthe recent revisions to the PM2.s NAAQS, the EPA created new procedures for handling data collected using continuous PM2 .5 FEMs. These procedures are found at 40 CFR 

### § 58.10(e). Ifan agency can demonstrate that the FEM data are not ofsufficient comparability to a collocated FRM, then the monitoring agency mayrequest that the FEM data not be used in comparison to the NAAQS. In the Network Plan addendum submitted on August 27,2013, MDEQ has demonstrated that the PM2
.s continuous FEM at the new Jackson NCore site (Hinds Co. 28-049-0020) is not ofsufficient comparability to a collocated FRM. The EPA approves Mississippi's request that this monitor not be considered comparable to the PM2
.s NAAQS. MDEQ is requested to report the data from this monitor to the AQS parameter code 88502. This approval also includes the historical data collected at this monitor, so the historical data canbe reassigned to parameter code 88502 as well. Also, the minimum PM2.s monitoring requirements will continue to bemet for the Jackson MSA without counting this monitor. 

### PM2• 5 

### Background and Transport Sites 40 CFR Part58, Appendix D, 4.7.3 Regulatory requirements in 40 CFRPart 58, Appendix D, 4.7.3 require that "each state shall install and operate at least one PM2
.s site to monitor for regional background and at least one PM2.s site to monitor for regional transport." The Grenada (Grenada Co
. 28-043-0001) PM2.s monitoris identified as a background monitor and the PM2 . 5monitor in Hernando (DeSoto Co. 28-033-0002) is identified as the transport monitor. Therefore, MDEQ has satisfied the requirements of40 CFR Part 58 for background and transport sites. 

### Pb Monitoring Requirements 40 CFR Part58, Appendix D, 4.7.3 40 CFR Part58, Appendix D, 3(b) Ph monitoring requirements are found in 40 CFR Part 58, Appendix D, 4.5. This states "At a minimum, there must be one source-oriented SLAMS [State and Local AirMonitoring Station] site located to measure the maximum Ph concentration 

### in ambient airresulting from each non-airport Ph source which emits 0.50 ormore tons per year and from each airport which emits 1.0 ormore tons per year..." There are currently no stationary Ph sources requiring ambient air lead monitoring. Furthermore, 40 CFR Part 58, Appendix D, 3(b) requires that "NCore sites in CBSAs with populations of500,000 people (as determined in the latest census) orgreater shall measure Ph either as Ph-TSP or Pb-PMw." This monitoring was required to begin December 27, 2011. MDEQ has chosen to monitor lead at the NCore site in Jackson (Hinds Co. 28-049-0019). The EPA has determined that the Ph monitoring network described in theNetwork Plan meets all design criteria of40 CFR Part 58.

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### Air Quality Index (AQI) Reporting 40 CFR Part58.50 Air Quality Index (AQI) reporting is required in MSAs with populations over 350,000. The GulfportBiloxi-Pascagoula, MS, Jackson, MS, and Memphis, TN-MS-AR MSAs are required to report an AQI. The Network Plan includes a link on Page 3 directing users to the MDEQ web site where AQI information is available. This satisfies the AQI reporting requirements. 

### Monitoring Requirements for Multi-State CBSAs 40 CFRPart 58 Appendix D, 2(e) As mentioned previously, MDEQ has a MOA with the state ofArkansas and Tennessee and with the Shelby County Health Department for sharing responsibility to meet the minimum monitoring requirements in the Memphis CBSA. The EPA's review ofthe Network Plan found that the monitoring required in the Memphis CBSA meets the minimum requirements found in 40 CFRPart 58, Appendix D 2(e). 

### National Core (NCore) MonitoringNetwork The EPA approved the move ofMDEQ's NCore site to 232 E. Woodrow Wilson Drive, Jackson, MS. This location is approximately one mile from the former location near the University ofMississippi Medical Center. Due to the sitebeing almost one mile away (0.9 mile) and being out ofservice for almost a year, a new site number was agreed upon for the NCore site (Hinds Co. 28-049-0020). 

### Additional MonitoringNetworkChanges MDEQ has proposed several monitoring changes inthe Network Plan. MDEQ is proposing to discontinue its 

### 0 3 monitor at the Meridian site. Themonitor is reading concentrations less than 85% of theNAAQS with a 2010-2012 design value of63 parts perbillion. The EPA believes, however, that this 

### 0 3 site has significant value in preserving the spatial representativeness ofthe ozone monitoring network in the southern Mississippi and southern Alabama area. Currently, there are no other 

### 03 monitoring sites located near the Meridian site. The closest sites are 80

- 130 miles away, depending on the direction. Forthis reason, the EPA is not approving this monitor for discontinuation and requires MDEQ to continue its operation. MDEQ has requested approval to relocate the Jackson, Mississippi Metro site (Hinds Co. 28-049-0010) to Hinds Community College property due to security concerns at the current site. Members ofthe EPA Science and Ecosystem Support Division have visited theproposed site and determined that the new site meets siting criteria. The EPA approves the relocation ofthis site.

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