UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 4

Ms. Sheila C. Holman Director Division ofAir Quality North Carolina Department of

Environment and Natural Resources 1641 Mail Service Center Raleigh, North Carolina 27699-1641
Dear Ms. Holman: ATLANTA FEDERAL CENTER 61 FORSYTH STREET ATLANTA, GEORGIA 30303-8960 

# NOV 

# 252013J

Thank you for submitting the state ofNorth Carolina's 2013 annual ambient air monitoring network plan (Network Plan), dated July 2, 2013. The Network Plan is required by40 Code ofFederal Regulations (CFR) §58.10. The Network Plan covers the ambient air monitoring network for the North Carolina Division ofAir Quality (NC-DAQ) and the local air quality agencies in North Carolina.
The U.S. Environmental Protection Agencyunderstands that the NC-DAQ provided a 30-daypublic comment period and did not receive any public comments. According to 40 CFR §58.10(a)(2), since public inspection and commenthave alreadybeen solicited, the EPA is not required to offer another comment period. The EPA approves North Carolina's 2013 Network Plan.
Thank you for working with us to monitor air pollution and promote healthy air quality inNorth Carolina and the nation. Ifyou have any questions or concerns, please contact Gregg Worley at (404) 562-9141 or Ryan Brown at (404) 562-9147.

Enclosure

cc: Mr. Donnie Redmond Ambient Monitoring Section Chief, NC-DAQ
Mr. Leslie Rhodes Director, Mecklenburg County Land Use and Environmental Services Agency Sincerely,

# ;J~hA·**~-rr anne**  M

.Gettle,

## 'A;i~g Director Air, Pesticides and Toxics

Management Division

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

### Mr. William M. Barnette, Director Forsyth County Environmental Affairs Department
Mr. David Brigman, Director , Western North Carolina Regional Air Quality Agency

### FY 2013 State ofNorth Carolina Ambient Air Monitoring Network Plan U.S. EPA Region 4 Comments and Recommendations

This document contains the U

.S. EPA comments and recommendations onthe state ofNorth Carolina's 2013 ambient airmonitoring network plan (Network Plan). Ambient air monitoring rules, which include regulatoryrequirements that address network plans, data certification, and minimum monitoring requirements, among otherrequirements, are found in 

### 40 CFR Part 58. Minimum monitoring requirements for criteria pollutants are listed in

### 40 CFR Part 58, Appendix D. Minimum monitoring requirements are listed for ozone (03), particulate matter less than 

### 2.5 microns (PM2.s), particulate matter less than 10 microns (PMw), nitrogen dioxide (N02), sulfur dioxide (S02), carbon monoxide (CO), and lead (Pb).
The minimum monitoringrequirements are based on corebased statistical area (CBSA) boundaries as defined bythe U.S. Office ofManagement and Budget, July 1, 2011, population estimates from the U.S. Census Bureau, and historical ambient air monitoring data. Minimum monitoringrequirements for 03, PM2

.5, PM 10, only apply to metropolitan statistical areas (MSAs), which are a subset ofCBSAs. OMB currently defines 17 MSAs inthe state ofNorth Carolina. On February 1, 2013, OMB redefined the CBSAboundaries based on 2010 census data. InNorth Carolina, there are two newly defined MSA's: Myrtle Beach-Conway-North Myrtle Beach, SC-NC and New Bern, NC that werepreviously defined as micropolitan CBSAs. Additionally, some MSA populations changed due to the inclusion and/or exclusion ofcounties from OMB's February 2013 MSA delineations. The 2009 and 2013 defined MSAs and the respective July 1, 2011, and 2012 population estimates from the U.S. Census Bureau are shown in Table 1.

Table 1: Metropolitan Statistical Areas and Populations

MSAName Charlotte-Concord-Gastonia, NC-SC VirginiaBeach-Norfolk-NewportNews, VA-NC Raleigh, NC Greensboro-High Point, NC Winston-Salem, NC Durham-Chapel Hill, NC Asheville, NC Myrtle Beach-Conway-NorthMyrtle Beach, SC-NC Fayetteville, NC Hickory-Lenoir-Morganton, NC Wilmington, NC Jacksonville, NC Greenville, NC Burlington, NC Rocky Mount, NC NewBem,NC Goldsboro, NC

*previously micropolitan CBSA 2011 Population 2009MSA definition 1,795,472 1,679,894 1,163,515 730,966 482,025 512,979 429,017

NA* 374,157 369,685 364,567 192,690 179,719 153,291 152,157

NA* 123,697 2012 Population 2013MSA definition 2,296,569 1,699,925 1,188,564 736,065 647,697 522,826 432,406 394,542 374,585 363,627 263,429 183,263 172,554 153,920 151,662 128,119 124,246

### Minimum 0 3 

### Monitoring Requirements 40 

### CFRPart 58, 

### Appendix D, 

### Table D-2
The state ofNorth Carolina's proposed 

### 0 3 monitoring network meets the minimum requirements found in 40 CFR Part 58, Appendix D, Table D-2 for all MSAs, except the Myrtle Beach-Conway-North Myrtle Beach MSA.
Due to changes
·that OMB made to MSA boundaries in February of2013, Brunswick County, North Carolinahas been added to the Myrtle Beach-Conway-North Myrtle Beach, SC-NC MSA. This change has triggered the requirement for an 

### 03 monitor in' this MSA. The 2013 Network Plan indicates that NCDAQ has entered into discussions with the SC Department ofHealth and Environmental Control (SC DHEC) and other stakeholders to identify an appropriate location for a new monitoring site. Once a suitable monitoring location is identified, information regarding the site canbeprovided either as an amendment to the current Network Plan orinnext year's Network Plan.
TheNetwork Plan also proposes to shutdown the 

### 03 monitor at the Enochville site (AQS ID 37-159- 0022). EPA approves the shutdown ofthis monitor. The EPA reviewed historical data and other information to make this determination. The 0 3 monitor at the Rockwell site (AQS ID 37-159-0021) is in the same county and has recorded similar values compared to the Enochville monitorover the last five years. After the Enochville monitor is shutdown, the Charlotte-Concord-Gastonia, NC-SC MSA would still meet the minimum monitoringrequirements found in 40 CFR Part 58, Appendix D. Additionally, the Network Plan proposes to relocate two 

### 03 monitoring sites: Waggin Trail (AQS ID 37- 003-0004) and Bent Creek (AQS ID 37-021-0030). The EPA approved the relocation ofthe Bent Creek
ozone site in a letter to the Western North Carolina Regional Air QualityAgency dated April29, 2013. The new Bent Creek location is less than a mile from the previous site and has the same AQS ID.
The EPA also approves the relocation ofthe Waggin Trail site to a new location that will be named Taylorsville 2013 with an AQS ID of37-003-0005. The EPA has reviewed theNorth Carolina Division ofAir Quality's (NC-DAQ) request to relocate the Waggin Trail 

### 03 site and determined that this monitor meets the relocation requirements of40 CFR 

### § 58.14(c)(6). The Taylorsville 2013 site is nearby the Waggin Trail site and should berepresentative ofthe same spatial scale as the Waggin Trail site.


### Minimum PM10 MonitoringRequirements 40 

### CFRPart 58, 

### Appendix A, 3.3.1 40 

### CFR Part58, 

### Appendix D, 

### Table D-4
The state ofNorth Carolina's current PM10 primarymonitoring network meets theminimum requirements for all areas. All PM10 collocation requirements for manual methods found in 40 CFR Part 58, Appendix A, 3.3.1 are currentlybeing met. These include the requirement that fifteen percent of each network ofmanual PM10 methods (at least one site) must be collocated.


### MinimumPM2.s MonitoringRequirements 40 

### CFRPart 58, 

### Appendix A, 3.2.5 40 

### CFRPart58, 

### Appendix D, 

### Table D-5
The state ofNorth Carolina's current PM2

.smonitoring network meets the minimum requirements found in 40 CFR Part 58, Appendix D, Table D-5 for all MSAs. Manual PM2.s collocation requirements arefound in 40 CFR Part 58, Appendix A, 3.2.5. These include the requirement that fifteen percent ofeach network ofmanual PM2.s methods (at least one site) mustbe collocated. The manual collocation requirements for PM2.s are currentlybeing met in the Network Plan.
TheNetwork Plan proposes to shut down three PM2.5monitors at the end of2013: FinelyFarm (AQS ID 37-183-0020), Springfield Rd (AQS ID 37-065-0004), and Lenoir Community College (AQS ID 37- 107-0004). The design values for all three PM2

.s monitors havebeen trending down inrecent years and
are all well below the NAAQS. Themostrecent design values (2009-2012) for these monitors are 9.3, 8.9, and 9.0 micrograms per cubic meter, respectively. After the shutdown ofthese PM2.s monitors, the state's network would still meet the minimum monitoring requirements found in40 CFR Part 58, Appendix D. Therefore, the EPA approves the shutdown ofthe Finley Farm, Springfield Rd, and Lenoir CommunityCollege PM2.s monitors.
After submission ofthe Network Plan, NC-DAQ sent a formal request, dated October 1, 2013 to relocate the Spruce Pine (AQS ID 37-121-0001) PM2.s monitor. The EPAhas reviewed ND-DAQ's request to relocate the Spruce Pine PM2.s monitor and determined that this monitor meets the relocation requirements of40 CFR 

### § 58.14(c)(6). Theproposed BRR Hospital site is nearby the existing Spruce Pine site and shouldberepresentative ofthe same spatial scale as the Spruce Pine site. The EPA approves the relocation ofthe Spruce Pine PM2

.smonitor to the proposed BRR Hospital site, which will have the AQS ID of37-121-0004.


### PM2.s Continuous Monitoring Requirements 40 

### CFR Part58, Appendix D, 4.7.2 Regulatory requirements for continuous PM2.s monitoringrequire that "

...State, orwhere appropriate, local agencies must operate continuous PM2.s analyzers equal to atleast one-half(round up) the minimumrequired sites listed inTable D-5 ofthis appendix. At least onerequired 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 is itselfa continuous FEM orARMmonitor in which case no collocation requirement applies." These minimum continuous PM2.s monitoringrequirements are currentlymet inthe all MSAs in the state. Also, the continuous PM2.s collocation requirements are currently metin all MSAs. Therefore, the continuous PM2.s monitoring network described in the 2013 Network Planmeets all ofthe design criteria of40 CFR Part 58.


### PM2.s Background andTransportSites 40 

### CFRPart58, Appendix D, 4.7.3
40 CFR Part 58, Appendix D, 4.7.3 requires that "each State shall install and operate at least one PM2

.5 site to monitor for regional background and at least one PM2.s site to monitor for regional transport." TheNetwork Plan identifies six PM2.s sites as general background sites that include: Mendenhall (AQS ID: 37-081-0013), Cherry Grove (AQS ID: 37-033-0001, Kenansville (AQS ID: 37-061-0002), Boone (AQS ID: 37-189-0003), Candor (AQS ID: 37-123-0001), and Jamesville (AQS ID: 37-117-0001). The Network Planidentifies three regional transport sites for PM2

.s identified as: Cherry Grove (AQS ID: 37-033-0001), Jamesville (AQS ID: 37-117-0001), and Bryson City (AQS ID: 37-173-0002). Therefore, NC-DAQ has satisfied therequirements of40 CFR Part 58 for background and transport sites.



### 3

### Pb MonitoringRequirements 40 CFR Part58, Appendix D, 4.5
40 CFR Part 58, Appendix D, 4.5 requires that "At a minimum, there must be one source-oriented SLAMS [state and local air monitoring station] site located to measure the maximum Pb concentration in ambient airresulting from each non-airport Pb source which emits 0.50 ormore tons per year and from each airp_ort which emits 1.0 ormore tons per year
..."
Section 4.5(a)(ii) ofAppendix D to 40 CFR Part 58 provides the following provisions for a waiver

### ofthe Pb monitoring requirements: "(ii) The Regional Administrator may waive the requirement inparagraph 4.5(a) for monitoring near Pb sources ifthe State or, where appropriate, local agency can demonstrate the Pb source will not contribute to a maximum Pb concentration in ambient air in excess of50% ofthe NAAQS (based on historical monitoring data, modeling, orother means). The waivermust be renewed once every 

### 5 years as part ofthe network assessment required under 58.10(d)."
In its approval ofthe state's 2011 Network Plan, pursuant the provisions ofthe above section, The EPA granted the waivers ofthe source-oriented ambient air monitoringrequirements at two sources: Blue Ridge Paper Products, Inc. in Canton, North Carolina and Saint Gobain Containers in Wilson, North Carolina. The waivers mustberenewed every five years as part ofthe network assessment required under40 CFR §58.10(d).
40 CFR Part 58, Appendix D, 3(b) requires that "NCore sites in CBSA with a population of500,000 people (as determined in the latest Census) orgreater shall also measure Pb either as Pb-TSP orPbPMw

." This monitoring was required to begin December 27, 2011. The Network Plan indicates that PbPMw sampling is ongoing at the CharlotteNCore site (AQS ID: 37-119-0041) and the Raleigh NCore site (AQS ID: 37-183-0014). As a result, the Pb monitoring network described inthe Network Plan meets all ofthe design criteria of40 CFRPart 58.


### 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 to 40 CFR Part 58. This section requires that "Thepopulation weighted emissions index (PWEI) shall be calculated by States for each core based statistical area (CBSA)." As a result, the S02monitoring site(s) required in each CBSA will satisfy minimum monitoring requirements ifthe monitor(s) is sited within theboundaries ofthe parent CBSA and is one ofthe following site types: population exposure, maximum concentration, source-oriented, general background, orregional transport. An S02monitor at a NCore station may satisfy minimum monitoring requirements ifthat monitor is located within a CBSA with minimallyrequired monitors consistent with Appendix D, 4.4.



### 4Table 2 shows the required S02 monitors based onthe 2012 PWEI. Existing S02 monitoring sites described in the Network Plan meet the minimum requirements of40 CFR Part 58.

Table 2: PWEI and S02 Required Monitors in North Carolina
CBSAName Virginia Beach-Norfolk-NewportNews, V A-NC Charlotte-Gastonia-Concord, NC-SC Durham,NC Wilmington, NC


### N02 MonitoringRequirements 40 CFR Part58, Appendix D, 4.4 July 2012 PWEI Values 78,540 34,426 16,885 10,045 July 2012 PWEI Required Monitors

1

Ambient air monitoring network design criteria forNOz are found in Section 4.3 ofAppendix D to 40 CFR Part 58. There are three types ofrequired N02monitoring: near-road, area-wide, and Regional Administratorrequired. 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 monitoring station that monitors expected maximumhourly concentrations near a major road. 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. TheNear-roadNOzMonitoring TechnicalAssistanceDocument (TAD) provides guidance to state and local agencies in selecting an appropriate near-road N02 monitoring location. This document can be found on the internet at http://www.epa.gov/ttnamtil/files/nearroad/NearRoadTAD.pdf.
Ambient air monitoring network design criteria for area-wide N02sites 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 N02concentrations representing the neighborhood orlarger spatial scales.
Ambient air monitoring network design criteria for Regional Administratorrequired N02monitoring, oftenreferred to as RA-40 monitoring, are found in Section 4.3.4 ofAppendix D to 40 CFR Part 58. This section states that ''the Regional Administrators, in collaboration with States, must require a minimum offorty additional N02monitoring stations nationwide in any area, inside or outside of CBSAs, 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 the minimum network requirement."
The EPA Region 4 approves the selection oftheTriple Oak (AQS ID 37-183-0021) site in fulfillment of the near-road N02 requirement for the Raleigh, NC CBSA. 

### In the Network Plan, Mecklenburg County Air Quality (MCAQ) proposed two potential sites to meet the requirement for the near-road N02 requirement in the Charlotte-Concord-Gastonia, NC-SC. 

### In July of2013, the EPA Region 4 staffvisited MCAQ's proposed location on Remount Road. MCAQ communicated that due to site access and siting issues the proposed site near Remount Road wouldbepreferable to the proposed site locate

_ d onToomey 5Avenue. The EPA approves the selection ofthe near-road site on Remount Road (AQS ID 37-119-0045) in fulfillment ofthe near-road N02 requirement. As discussed in the Network Plan, the Greensboro-High Point, NC; Winston-Salem, NC; and Durham-Chapel Hill, NC CBSAs will berequired to have nearroad N02monitoringbyJanuary 1, 2017.
The EPA approves the selection ofthe Garinger (AQS ID: 37-119-0041) and Millbrook (AQS ID: 37- 183-0014) sites in fulfillment ofthe area-wide N02monitoring requirement for the Charlotte-GastoniaRock Hill and Raleigh-Cary CBSAs.
The EPA selects the Hattie Avenue site (AQS ID 450-045-0015) operated by Forsyth County Office of Environmental Assistance and Protection as a location for a Regional Administratorrequired N02 monitor to help protect susceptible and vulnerable populations. The full list ofN02monitors identified bythe EPA's Regional Administrators canbe found on the EPA's website at http://www.epa.gov/ttnamtil/svpop.html.


### Air Quality Index (AQI) Reporting 40 CFR §58.50 AQI reporting is required in MSAs with populations over 350,000. There are 10 MSAs in the state of North Carolinarequired to report an AQI: Charlotte-Gastonia-Concord, Virginia Beach-NorfolkNewport News, Raleigh-Cary, Greensboro-High Point, Durham-Chapel Hill, Winston-Salem, Asheville, Hickory-Lenoir-Morganton, Fayetteville, and Wilmington. NC-DAQ meets these AQI reporting requirements. 

### MonitoringNetwork Changes Proposed by 

### NC-DAQ NC-DAQ has proposed several monitoring network changes in its 2013 Network Plan. Monitors proposed for discontinuation orrelocation are summarized inTable 3.

Table 3: Monitors Proposed for Discontinuation/Relocation AQS ID Site Name PoUutant 37-159-0022 Enochville 0 3

37-003-0004 Waggin Trail

37-183-0020 FinleyFarm PM2

.s
37-065-0004 Springfield Rd PM2.s
37-107-0004 Lenoir Community PM25 College 37-121-0001 Spruce Pine PM2.s



### 6 Type SLAMS

SLAMS

SLAMS
SLAMS
SLAMS
SLAMS Comments Approved: Monitor will be shutdown at the end ofthe 20 13 0 3 season Approved: Monitor will shutdown at the end ofthe 2013 0 3 season and will be replaced with a nearby0 3 monitor

- Taylorsville 2013 (AQS ID 37-003-0005) Approved: Monitor will shut down 12/31/2013 Approved: Monitor will shut down 12/31/2013 Approved: Monitor will shut down 12/31/2013 Approved: Monitor will be relocated less than a mile from the existing site and will have a new AQS ID 37-121- 0004The EPA reviewed these requests for monitor discontinuation orrelocation and detennined that they all meet the requirements of40 CFR §58.14(c) for monitor discontinuation and relocation. The minimum monitoring requirements for PM2

.s and 

### 03 found in Appendix D to 40 CFRPart 58 will continue to be met for therespective MSAs after these monitors are discontinued or relocated.
The EPA also has reviewed and approves the location for the startup ofthe all monitors listed in Table 4.

Table 4: Monitors Proeosed for Startue AQSID Site Name Pollutant Tiee Comments 37-183-0021 Triple Oak N02 SLAMS

- near-road Approved: site establishment for near-road N02monitoring 37-119-0045 Remount Road N02 SLAMS

- near-road Approved: site establishment for near-road N02 monitoring 37-003-0005 Taylorsville 2013 Ozone SLAMS Approved: will replace WagginTrail site 37-121-0004 BRRHospital PM2

.s SLAMS Approved: will replace the SEruce Pine site


### National Core (NCore) MonitoringNetwork
Ambient air monitoring network criteria for NCore sites are found in Section 3 ofAppendix D to 40 CFR Part 58. NC-DAQ designated two NCore sites in the 2013 Network Plan. The first site (AQS ID 37-183-0014) is located at the East Millbrook Middle School site in Raleigh, NC. The second site (AQS ID 37-119-0041) is located at the Garinger site in Charlotte, NC and is operated byMCAQ. Official The EPA approval was granted for these sites on October 30, 2009. The 2013 Network Plan meets the minimum monitoring requirements for NCore sites.



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