Executive Director 

Mississippi Department of Environmental Quality P.O. Box 2261 

Jackson, Mississippi 39225-2261 Dear Ms. Fisher: 

Thank you for submitting the annual ambient air monitoring network plan (Network 

Plan) for the State of Mississippi dated July 8,2010, and revised per an email from Mike 

Norcom of your staff on November 15,2010. The Network Plan is required by 40 Code of 

Federal Regulations (CFR) $58.10. The Environmental Protection Agency (EPA) understands 

that the Mississippi Department of Environmental Quality (MDEQ) provided the public a 30-day 

comment period on the Network Plan as required. While the Network Plan did not indicate 

whether comments were received from the public, it is our understanding from subsequent 

conversations with your staff that no comments were received. 

The EPA Region 4 air monitoring staff has reviewed your Network Plan and found it to 

meet all requirements. As a result, Mississippi's Network Plan is approved. Enclosed is a 

summary of our analysis and comments that may be useful in development of next year's plan. 

Please let us know if you have any questions related to the EPA comments. 

Thank you for your cooperation and continued efforts to monitor air pollution and 

promote healthy air quality in Mississippi and the nation. If you have any questions or concerns, 

please have a member of your staff contact Doug Neeley at (404) 562-9097 or Phyllis Warrilow 

at (404) 562-9 198. 

C Gwendolyn Keyes Fleming Regional Administrator 

Enclosure 

Internet Address (URL) http://www.epa.gov 

Recycled/Recyclable .Printed wilh Vegetable Oii Based Inks on Recyded Paper (Mlnimum 30% Postconsumer) 
requirements for criteria pollutants are listed in 40 CFR Part 58, Appendix D. Minimum 

monitoring requirements do not exist for carbon monoxide (CO) unless required by the 

establishment of a National Core (NCore) multi-pollutant monitoring station andlor a state 

implementation plan. However, new national ambient air quality standards (NAAQSs) were 

promulgated this year for nitrogen dioxide (NO2) and sulfur dioxide (SO2) with minimum 

monitoring requirements effective January 1,20 13. Minimum monitoring requirements are 

listed for ozone (03), particulate matter less than 2.5 microns (Ph&), particulate matter less than 

10 microns (PMlo), and lead (Pb). 

The minimum monitoring requirements are based on metropolitan statistical area (MSA) 

boundaries as defined by the U.S. Office of Management and Budget (OMB) on July 1,2008, 

population estimates from the U.S. Census Bureau, and historical ambient air monitoring data. 

OMB currently defines five MSAs in the State of Mississippi. These MSAs and the respective 

July 1,2009, population estimates from the U.S. Census Bureau are shown in Table 1. 

Table 1: Metropolitan Statistical Areas and Populations 

MSA Name Population 

Memphis-TN-MS- AR 1,304,926 Jackson, MS 540,866 

Gulhort-Biloxi. MS 238.772 

Pascagoula, MS 155,603 

After review of MDEQ's Network Plan with respect to the applicable requirements, EPA 

offers the following comments and recommendations. 

Minimum Ozone Monitoring Requirements 

40 CFR Part 58, Appendix D, Table D-2 

MDEQ is required to have one O3 monitor in the following MSAs: Gulfport/Biloxi [Air 

Quality System # (AQS) 28-047-00081, Jackson (AQS 28-049-0010), and Pascagoula (AQS 28- 

059-0006). The Memphis MSA is required to have two O3 monitors. However, because the 

State has a memorandum of agreement (MOA) with Arkansas and Memphis-Shelby County, TN, 

MDEQ's one O3 monitor (28-033-0002) meets the requirement. The Jackson O3 monitor is to be 

relocated to the Jackson NCore site (AQS 28-049-0019) as required by January 1,201 1. 

At this time, the O3 network described in the 2010 Network Plan meets the minimum O3 

monitoring requirements specified by 40 CFR Part 58, Appendix D, Table D-2 in all areas. 
The Memphis MSA is required to have two PMlo monitors. However, MDEQ does not 

have to operate PMlo monitors at this time because the State has an MOA with Arkansas and 

Memphis-Shelby County, TN to operate the monitors. 

All PMlo collocation requirements for manual methods found in 40 CFR Part 58, 

Appendix A, 3.3.1 are being met. 

Minimum PMzs Primary Monitoring Requirements 

40 CFR Part 58, Appendix D, Table D-5 

The MDEQ's current primary PM2.5 monitoring network as described in the Network 

Plan meets the minimum requirements found in 40 CFR Part 58, Appendix D, Table D-5 for all 

MSAs. 

Minimum PM2J Collocated Monitoring Requirements 

40 CFR Part 58, Appendix A, 3.2.5 

The PM2.5 collocation requirement is currently being met. To meet the minimum 

requirements for the number of PM2.5 collocated monitors, the State has placed monitors at two 

locations: Tupelo (AQS 28-081-0005) and Laurel (AQS 28-067-0002). Data for these monitors 

will be reported to AQS starting January 1,201 1, which will meet the monitoring requirements. 

PMZs Continuous Monitoring Requirements 

40 CFR Part 58, Appendix D, 4.7.2 

Regulatory requirements for continuous PM2.5 monitoring require that "...State, or where 

appropriate, local agencies must operate continuous PM2.5 analyzers equal to at least one-half 

(round up) the minimum required sites listed in Table D-5 of this Appendix. At least one 

required continuous analyzer in each MSA must be collocated with one of the required [Federal 

Reference Method (FRM)/Federal Equivalent Method (FEM)/Approved Regional Method 

(ARM)] monitors, unless at least one of the required FRMFEMIARM monitors is itself a 

continuous FEM or ARM monitor in which case no collocation requirement applies." The 

MDEQ Network Plan states that a continuous PM2.5 analyzer will be added at the Hattiesburg 

site (AQS 28-035-0004). By adding the monitor the State will meet the requirements of 40 CFR 

Part 58, Appendix D, 4.7.2 in this and all other MSAs. Also, the continuous PM2.5 collocation 

requirements are currently met in all MSAs. Therefore, the continuous PM25 monitoring 

network described in the 2010 Network Plan meets all design criteria of 40 CFR Part 58. 
and operate at least one PM2.5 site to monitor for regional background and at least one PM2.5 site 

to monitor for regional transport." The Network Plan identifies the PM2.5 site in Hernando (AQS 

28-033-0002) is designated a transport sampler and the PM2.5 site in Grenada (AQS 28-043- 

0001) as a background monitor for PM2.5. Therefore MDEQ has satisfied the requirements of 40 

CF'R Part 58 for background and transport sites. 

Lead (Pb) Monitoring Requirements 

40 CFR Part 58, Appendix D, 4.5 

Pb monitoring is required at the NCore site in Jackson (AQS 28-049-0019). This 

monitoring will begin by January 1,201 1. There are currently no stationary Pb sources requiring 

ambient air lead monitoring at this time. Therefore MDEQ has satisfied the Pb monitoring requirements. 

Air Quality Index (AQI) Reporting 40 CFR $58.50 

AQI reporting is required in MSAs with populations over 350,000. The Jackson, MS and 

Memphis, TN-MS-AR MSA's are required to report an AQI. The Network Plan includes a link 

on Page Two to the MDEQ Web site under AQI where this information is readily available for 

these areas. MDEQ is satisfying the AQI reporting requirements. We also understand that 

MDEQ reports an AQI for the Biloxi/Gulfport, MS MSA even though it is not required. 

Cross - State MSA 

40 CFR $58.50, Appendix D, 2(e) 

In the Network Plan, MDEQ referenced and attached the monitoring MOA that it has 

with the States of Arkansas and Tennessee for the Memphis MSA. This MOA, which is 

referenced previously in the letter, discusses how the minimum monitoring requirements are met 

in the Memphis MSA, including the number and location of all monitors. 

Additional Monitoring Network Changes Proposed by MDEQ 

MDEQ has proposed four PM2.5 site closures and the relocation of one PM2.5 speciation 

site. The four proposed closures are: Meridian (AQS 28-075-0003), Tupelo (AQS 28-081-0005), 

Cleveland (AQS 28-01 1-0001) and Natchez (AQS 28-001-0004). EPA agrees with shutting 

down the Cleveland (AQS 28-0 1 1-000 1) and Natchez (AQS 28-00 1-0004) sites. 
National Core (NCore) Monitoring Network 

As discussed earlier, MDEQ has established its NCore station in the Jackson MSA. The 

station is at the University of Mississippi Medical Center (AQS 28-049-0019). EPA's Office of 

Air Quality Planning and Standards approved this site on October 30,2009.