Division of Air Quality 

North Carolina Department of 

Environmental Quality 

1641 Mail Service Center 

Raleigh, North Carolina 27699-1641 Dear Ms. Holman: 

Thank you for submitting the state ofNorth Carolina's 2015 annual ambient air monitoring network 

plan (Network Plan), dated July 23, 2015. The Network Plan is required by 40 Code ofFederal 

Regulations (CFR) §58.1 0. The Network Plan covers the ambient air monitoring network for the North 

Carolina Division of Air Quality (NC-DAQ) and the local air quality agencies in North Carolina. 

The U.S. Environmental Protection Agency Region 4 understands that the NC-DAQ provided the public 

a 30-day review period for its draft Network Plan. Comments on the draft plan were submitted by 

several stakeholders and the final Network Plan includes the NC-DAQ responses to these comments. 

According to 40 CFR §58.1 O(a)(2), since public inspection and comment have already been solicited, 

the EPA is not required to offer another comment period. 

The EPA approves North Carolina's 2015 Network Plan. The Network Plan requested the permanent 

discontinuation of fifteen regulatory monitors: nine fine particulate monitors, five ozone monitors, and 

one carbon monoxide monitor. The EPA approves the discontinuation of all ofthe proposed monitors in 

the Network Plan. Details regarding the EPA's review of the Network Plan are provided in the enclosed 

comments. 

Thank you for working with us to monitor air pollution and promote healthy air quality in North 

Carolina and the nation. If you have any questions or concerns, please contact Gregg Worley at 

(404) 562-9141 or Ryan Brown at (404) 562-9147. 

Enclosure 

Sincerely, 

Beverly H. Baniste$ 

Director 

Air, Pesticides and Toxics Management Division 

Internet Address (URL) • http:/lwww.epa.gov 

Recycled/Recyclable • Printed with Vegetable Oil Based Inks on Recycled Paper (Minimum 30% Postconsumer) 
cc: Mr. Donnie Redmond 

Ambient Monitoring Section Chief, NC-DAQ 

Ms. Leslie Rhodes, Director 

Mecklenburg County Land Use and 

Environmental Services Agency 

Mr. WiJliam M. Barnette, Director 

Forsyth County Environmental Affairs Department 

Mr. David Brigman, Director 

Western North Carolina Regional Air Quality Agency 
matter less than 10 microns (PM10), nitrogen dioxide (N02), sulfur dioxide (SOz), carbon monoxide 

(CO), and lead (Pb). 

The minimum monitoring requirements are based on core based statistical area (CBSA) boundaries as 

defined by the U.S. Office ofManagement and Budget (OMB), July l, 2014, population estimates from 

the U.S. Census Bureau, and historical ambient air monitoring data. Minimum monitoring requirements 

for 03, PM2.s, and PMto, only apply to metropolitan statistical areas (MSAs), which are a subset of 

CBSAs. OMB currently defines 17 MSAs in the state ofNorth Carolina. On February I, 2013, OMB 

redefined the CBSA boundaries based on 2010 census data. In North Carolina, there are two recently 

defined MSA's: Myrtle Beach-Conway-North Myrtle Beach, SC-NC and New Bern, NC that were 

previously defined as micropolitan CBSAs. Additionally, the composition of some MSA populations 

changed due to the inclusion and/or exclusion of counties from OMB's February 2013 MSA 

delineations. The July 1, 2014 population estimates from the U.S. Census Bureau are shown in Table 1. 

Table 1: Metropolitan Statistical Areas and Populations 

MSAName 2014 Population 

Charlotte-Concord-Gastonia, N C-SC 2,380,314 

Virginia Beach-Norfolk-Newport News, V A-NC 1,716,624 

Raleigh, NC 1,242,974 

Greensboro-High Point. NC 746,593 

Winston-Salem, NC 655,015 

Durham-Chapel Hill, NC 542,710 

Asheville, NC 442,316 

Myrtle Beach-Conway-North Myrtle Beach, SC-NC 417,668 

Fayetteville, NC 377,939 

Hickory-Lenoir-Morganton, NC 362,896 

Wilmington, NC 272,548 

Jacksonville, NC 187,589 

Greenville, NC 175,354 

Burlington, NC 155,792 

Rocky Mount, NC 149,290 

NewBern, NC 134,760 

Goldsboro, NC 124,456 

Monitoring Network Changes Proposed by NC-DAQ 

The NC-DAQ received internal comments on the Network Plan as well as from six commenters including the Southern Environmental Law Center on behalf of the North Carolina League of 

Conservation Voters, the Sierra Club, the Southern Alliance for Clean Energy, and the Western North 
Carolina Alliance. The NC-DAQ provided a response to the comments as part of its final Network Plan. 

The public comments expressed concern over the numerous monitor shutdown requests in the Network 

Plan and the number of monitor shutdowns in recent years. The EPA conducted its own analysis of 

North Carolina's ambient air monitoring network including historical design values (DVs), annual PMz.s 

and 03 trends, nearby monitor correlations, meteorology, and spatial coverage when evaluating the 

requests to discontinue the requested regulatory monitors. 

Since 2012, PMz.s concentrations in North Carolina have decreased. Because the PMz.s levels have 

remained lower for the last four years, the EPA is approving a significantly reduced PM2.s monitoring 

network. Many of the PM2 s monitors to be shutdown are not located in CBS As and were sited to 

measure general background or regional transport. Also, the EPA is approving the shutdown of several 

monitors located in CBSAs where the network exceeds the minimum requirements. These "over 

minimum requirement" monitors that are approved for shutdown read similarly to other nearby monitors 

or have consistently recorded concentrations lower than nearby monitors. 

Ozone levels across the state have also been lower in the last three years. The EPA is approving 

reductions in the OJ ambient air monitoring network for monitors that have consistently been below the 

standard and consistently measured lower concentrations than nearby monitors. 

Further rationale for the EPA's approval of specific network changes can be found below in the 

pollutant sections of this document. Monitors proposed for discontinuation or relocation and the EPA's 

determination are summarized in Table 2. 

Table 2: Monitors Pro£oscd for Discontinuation 

AQSID Site Name Pollutant pc Comments 

37- 11 9-1005 Arrowood OJ SLAMS Aeproved 

3 7-069-000 1 Franklinton OJ SLAMS ~mroved 

37-183-0016 Fuguax OJ SLAMS AQRroved 

37-037-0004 Pittsboro OJ SLAMS eroved 

37-067-0028 Shiloh Church OJ SLAMS Ae,eroved 

3 7-189-0003 Boone PMu SLAMS A(! roved 

37-033-0001 Che!!)!Grove PMz.s SLAMS Aeeroved 

37-191-0005 Dillard School PM2.s SLAMS A.Q_Qroved in 2014 Network Plan 

37-117-000 1 Jamesville PMz s SLAMS A[![!roved 

3 7-061-0002 Kenansville PMz..s SLAMS Aeeroved 

37-111-0004 Marion PM:u SLAMS Aeeroved 

37- 159-0021 Rockwell PMz s SLAMS Aee,roved 

37-087-0012 Waxnesville PMB SLAMS A(!eroved 

37-067-0030 Clemmons Middle PMzs SLAMS Al!eroved 

37-067-0023 Peter's Creek co SLAMS Aeeroved 

On October 23, 2015, NC-DAQ submitted a letter to the EPA to move the Pitt County Ag Center 
met for the respective if the monitors are located in after the monitors are discontinued 

or relocated. 

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 

required to report an AQI: Virginia Beach-Norfolk-Newport 

Greensboro-High Point, Durham-Chapel Hill, Winston-Salem, Asheville, Hickoryand Wilmington. NC-DAQ meets these AQI reporting requirements. 

National Core (NCore) Monitoring Network 

40 CFR Part 58, Appendix D, 3.0 

Ambient air monitoring network criteria for NCore sites are found in 40 CFR Part 58, Appendix D, 3. 

NC-DAQ lists two NCore sites in the Network Plan. The first site (AQS ID 37-183-0014) is located at 

the East Millbrook Middle School site in Raleigh, NC and is operated by NC-DAQ. The second site 

{AQS ID 37-119-0041) is located at the Garinger site in Charlotte, NC and is operated by the 

Mecklenburg County Air Quality (MCAQ) agency. The EPA approval of these sites was granted on 

October 2009. The 2015 Network Plan meets the minimum monitoring requirements for NCore 

sites. 

Minimum OJ Monitoring Requirements 40 CFR Part 58, Appendix D, Table D-2 

The state ofNorth proposed OJ monitoring network meets the minimum requirements found 

in 40 CFR Part Appendix D, Table D-2 for all MSAs, except the Myrtle Beach-Conway-North 

Myrtle Beach MSA (see discussion below). 

OMB changed the composition of several MSA boundaries in February including adding 

Brunswick North Carolina to the Myrtle Beach-Conway-North Myrtle Beach, SC-NC MSA. 

This change has triggered the requirement to establish an 03 monitor in this MSA. NC-DAQ provided a 

memorandum of agreement with South Carolina Department of Health and Environmental Control (SC 

DHEC) to collectively meet the OJ monitoring requirements for this MSA. The SC DHEC 2015 Annual 

Monitoring Network Plan identifies a location for a new OJ monitor to meet this requirement. However, 

SC DHEC did not provide adequate and sufficient information for the EPA to approve its proposed 

location. The EPA has requested that SC DHEQ provide an addendwn to its Network Plan with 

additional information on the proposed OJ monitoring location in the Myrtle Beach-Conway-North 

Myrtle SC-NC MSA. 

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The Network Plan also proposes to shutdown five 03 monitors: Franklinton (AQS ID 37-069-0001), 

Pittsboro (AQS ID 37-037-0004), Fuquay (AQS ID 37-183-0016), Arrowood (AQS ID 37-119-1005), 

and Shiloh Church (AQS ID 37-067-0028) (listed in Table 2 above). 

The EPA approves the shutdown of the Pittsboro, Franklinton, and Fuquay monitors in the Raleigh and 

Durham areas of North Carolina. The EPA looked at historical comparisons of03 concentrations, 

meteorology, and the spatial distribution of 03 monitors in the Durham-Chapel Hill and Raleigh MSAs 

to make this determination. 03 levels have been below the new standard of 70 ppb for the last three 

years (2013, 2014, and 2015) for this entire region. The Pittsboro monitor is upwind of the Durham 

MSA and has read consistently lower than the other 03 monitors in the MSA. The Franklinton 03 

monitor is located downwind of the Raleigh urban core, however concentrations at the Franklinton 

monitor have consistently been similar or lower than the 03 concentrations measured at the Millbrook 

monitor in Raleigh. The Fuquay monitor is the upwind monitor for the Raleigh MSA. This monitor has 

consistently measured 03 concentrations similar to and slightly lower than the Millbrook 03 monitor. 

When these monitors are shutdown, the Durham-Chapel Hill and the Raleigh MSAs will still meet the 

minimum 03 monitoring requirements found in 40 CFR Part 58, Appendix D. 

The EPA also approves the shutdown ofthe Arrowood 0 3 monitor, operated by the MCAQ. In 2014, the 

property for the Arrowood site was sold and the MCAQ's lease was not renewed. The EPA previously 

approved the temporary shutdown of the Arrowood 03 monitor for the 2015 03 season, while the MCAQ 

evaluated whether to replace/relocate the Arrowood 03 monitor. The MCAQ ultimately decided not to 

replace this monitor and proposed the pennanent shutdown of Arrowood instead of relocating the 

monitor to a nearby area. The EPA reviewed meteorology and historical 03 concentrations in the 

Charlotte area. The Arrowood site is typically upwind of the Charlotte urban area and has recorded 

lower 03 values than the other 03 monitors in the area. Without the Arrowood OJ monitor operating, the 

Charlotte-Concord-Gastonia MSA still meets the minimum 03 monitoring requirements found in 40 

CFR Part 58, Appendix D. 

The EPA also approves the permanent shutdown of the Shiloh Church 03 monitor, operated by the 

Forsyth County Office of Environmental Assistance and Protection (OEAP). This monitor has 

consistently measured the lowest concentrations in the Winston-Salem MSA. When this monitor is 

shutdown, the Winston-Salem MSA will still meet the minimum 03 monitoring requirements found in 

40 CFR Part 58, Appendix D. 

CO Monitoring Requirements 

40 CFR Part 58, Appendix D, 4.2 

Ambient air monitoring network design criteria for CO are found in 40 CFR Part 58, Appendix D, 4.2. 

CBSAs with populations over one million are required to operate one CO monitor collocated with a 
Ambient air monitoring network design criteria for N02 are found in 40 CFR Part 58, Appendix D, 4.3. 

There are three types of required N02 monitoring: near-road, area-wide, and Regional Administrator 

required. These types ofN02 monitoring are described in Sections 4.3.2, 4.3.3, and 4.3.4, respectively. 

The EPA previously approved the Triple Oak site (AQS ID 37-183-0021) and the Remount Road site 

(AQS ID 37-119-0045) in fulfillment of the near-road N02 requirements for the Raleigh CBSA and the 

Charlotte-Concord-Gastonia CBSA. 

The Greensboro-High Point, NC; Winston-Salem, NC; and Durham-Chapel Hill, NC CBSAs are 

required to have near-road N02 monitoring by January 1, 2017. A new N01 monitoring rule is expected 

to be promulgated in 2016. The new rule may change the N01 near-road monitoring requirements for 

CBSAs with populations between 500,000 and 1,000,000 people, such as the Greensboro-High Point; 

Winston-Salem; and Durham-Chapel Hill CBSAs. 

The EPA previously approved the selection of the Garinger (AQS ID 37-119-0041) and Millbrook (AQS 

ID 3 7-183-0014) sites in fulfillment of the area-wide N01 monitoring requirement for the CharlotteConcord-Gastonia and Raleigh CBSAs. 

The EPA also previously selected the Hattie Avenue site (AQS ID 37-067-0022) operated by Forsyth 

County OEAP as a location for a Regional Administrator required N01 monitor to help protect 

susceptible and vulnerable populations. The full list ofN01 monitors identified by the EPA's Regional 

Administrators can be found on the EPA's website at http://www.the EPA.gov/ttnamtil/svpop.html. 

S02 Monitoring Requirements 

40 CFR Part 58, Appendix D, 4.4 

Ambient air monitoring network design criteria for S01 are found in 40 CFR Part 58, Appendix D, 4.4. 

This section requires that "The population weighted emissions index (PWEI) shall be calculated by 

states for each core based statistical area (CBSA)." As a result, the S01 monitoring site(s) required in 

each CBSA will satisfy minimum monitoring requirements if the monitor(s) is sited within the 

boundaries of the parent CBSA and is one of the following site types: population exposure, maximum 

concentration, source-oriented, general background, or regional transport. An S01 monitor at an NCore 

station may satisfy minimum monitoring requirements if that monitor is located within a CBSA with 

minimally required monitors consistent with Appendix D, 4.4. 

Table 4 shows the location on required S02 monitors based on the 2012 PWEI. Existing S01 monitoring 

sites described in the Network Plan meet the minimum requirements of 40 CFR Part 58. The NC-DAQ 

operates regulatory 802 monitors in the Charlotte-Gastonia-Concord, NC-SC; Durham, NC; and 

Wilmington, NC CBSAs to meet the PWEI requirements. The Virginia Department of Environmental 

Quality operates a regulatory 802 monitor in the Virginia Beach-Norfolk-Newport News, VA-NC 

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CBS A. The EPA recommends that North Carolina update its MSA agreement with Virginia to include 

sharing the S02 minimum monitoring requirements for the Virginia Beach-Norfolk CBSA and include 

this update in its 2016 Network Plan. 

Table 4: PWEI and S01 Required Monitors in North Carolina 

CBSAName July 2012 PWEI Values 

Virginia Beach-Norfolk-Newport News, V A-NC 78,540 

Charlotte-Gastonia~Concord, NC-SC 34,426 

Durham, NC 16,885 

Wilmington, NC 10,045 

July 2012 PWEI Required 

Monitors 

The EPA finalized the S02 Data Requirements Rule (ORR) on August 10, 2015. This rule will require 

characterization of the air quality near sources with SOz emissions greater than 2,000 tons per year (tpy) 

by conducting ambient air monitoring or modeling. We encourage your agency to begin having 

conversations with affected sources in the state ofNorth Carolina to determine an agreed upon approach 

for meeting the ORR requirements. By January 15, 2016, NC-DAQ must submit a final list of sources to 

the EPA Region 4 identifying the sources in the state around which S02 air quality must be 

characterized. For sources that NC-DAQ decides to evaluate using ambient air monitoring, new site 

proposals must be included in the 2016 Network Plan. The location of these monitoring sites should be 

selected using the process outlined in the SOz NAAQS Designations Source-Oriented Monitoring 

Technical Assistance Document1• 

The Network Plan requests a waiver of the requirement for a PWEI S02 monitor in the Asheville CBSA, 

due to an increase in Asheville's population. The PWEI calculated by NC-DAQ is 5,074. Forty CFR 

Part 58, Appendix D, 4.4 states that "For any CBSA with a calculated PWEI value equal to or greater 

than 5,000, but less than I 00,000, a minimum of one S02 monitor is required within that CBSA." The 

EPA's previous calculations show the Asheville PWEI to be below the PWEI threshold for requiring an 

S02 monitor. NC-DAQ may elect to conduct S02 monitoring in the Ashville CBSA beginning in 2017 

under the ORR. The EPA will work with NC-DAQ to determine the appropriate requirements for this 

CBSA. The EPA grants a waiver of this S02 monitoring requirement for 2016, so that the NC-DAQ, the 

Western North Carolina Regional Air Quality Agency (WNCRAQA), and the EPA can determine the 

appropriate requirements for this CBSA. NC-DAQ should address S02 monitoring requirements for the 

Asheville CBSA in the 2016 Network Plan 

Pb Monitoring Requirements 

40 CFR Part 58, Appendix D, 4.5 

40 CFR Part 58, Appendix D, 4.5 requires that "At a minimum, there must be one source-oriented 

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In its approval of the state's 2011 Network Plan, pursuant the provisions ofthe above section, the EPA 

granted waivers of the source-oriented ambient air monitoring requirements at two sources: Blue Ridge 

Paper Products, Inc. in Canton, NC and Saint Gobain Containers in Wilson, NC. The waivers must be 

renewed every five years as part of the network assessment required under 40 CFR §58.1 0( d). 

The Saint Gobain Containers facility is the only facility in North Carolina with 2011 NEI Pb emissions 

over 0.5 tpy. This facility is estimated to emit 0.53 tpy. The 2011 modeling ofthis facility used Pb 

emissions of 1.3 tpy. The EPA believes that the previously submitted modeling is sufficiently 

conservative and is approving the renewal of the source-oriented ambient air Pb monitoring 

requirements at Saint Gobain Containers in Wilson, NC for five years, until 2020. 

Based on the 2011 NEI, Blue Ridge Paper Products, Inc. in Canton, NC emitted less than 0.5 tpy ofPb. 

Thus, Blue Ridge Paper Products is not subject to the Pb monitoring requirements. A waiver of the 

source-oriented ambient air Pb monitoring requirements is no longer required for this facility. If in the 

future this facility is estimated to emit more than 0.5 tpy, then NC-DAQ will need to submit a new 

waiver request or monitor for Pb near the facility. At this time, no other facilities in North Carolina emit 

more than 0.5 tpy ofPb and are subject to required Pb source-oriented monitoring. 

Forty CFR Part 58, Appendix D, 3(b) requires that "NCore sites in CBS As with a population of 500,000 

people (as determined in the latest census) or greater shall also measure Pb either as Pb-TSP or PbPMJO." This monitoring was required to begin December 27, 2011. The Network Plan indicates that PbPMIO sampling is ongoing at the Charlotte NCore site (AQS ID 37-119-0041) and the Raleigh NCore 

site (AQS ID 37-183-0014). As a result, the Pb monitoring network described in the Network Plan meets 

the design criteria of 40 CFR Part 58. 

Minimum PM10 Monitoring Requirements 40 CFR Part 58, Appendix A, 3.3.1 

40 CFR Part 58, Appendix D, Table D-4 

The state ofNorth Carolina's current PM1o primary monitoring network meets the minimum 

requirements for all areas. All PM10 collocation requirements for manual methods found in 40 CFR Part 

58, Appendix A, 3.3.1 are being met. These include the requirement that 15 percent of each network of 

manual PM10 methods (at least one site) must be collocated. The Network Plan requested a waiver of the 

requirements to operate a second PMw monitor in Raleigh. Since PM10 levels have been significantly 

lower than the NAAQS for the last decade, the EPA grants a waiver ofthe requirement for a second 

PM10 monitor in the Raleigh MSA. 

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Minimum PM2.s Monitoring Requirements 

40 CFR Part 58, Appendix A, 3.2.5 

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

The state proposed to shutdown nine PM2.s monitors. These monitors are listed in the Table 5 below. 

Table 5: PM1.s Monitors Proposed for Discontinuation 

AQSID Site Name County MSA 

37-033-0001 Cheny Grove Caswell Not in a MSA 

3 7-061-0002 Kenansville Duplin Not in a MSA 

37-087-0012 Waynesville Haywood Asheville, NC 

37-111-0004 Marion McDowell Not in a MSA 

37-117-0001 Jamesville Martin Not in a MSA 

37-159-002 1 Rockwell Rowan Charlotte-Concord-Gastonia, NC-SC 

37-189-0003 Boone Watauga Boone, NC 

37- 1 9 1·0005 Dillard School Wayne Goldsboro, NC 

37-067-0030 Clemmons Forsy!h Winston-Salem, NC 

The EPA reviewed historical DVs, annual PM2.s trends, nearby monitor correlations, meteorology, and 

spatial coverage when evaluating the requests to shutdown these monitors. The PM2.s levels have 

continued to remain low for the last four years, thus allowing the EPA to approve a reduced PM2 s 

monitoring network in North Carolina. 

The Network Plan demonstrates that Cherry Grove, Kenansville, Jamesville, and Boone PM2 s sites meet 

EPA's guidance for determining shutdown eligibility and the requirements of 40 CFR 58.14(c)(1). Thus, 

EPA approves the discontinuation of these four monitors. 

The Rockwell monitor is downwind of Charlotte, however it has consistently recorded lower PM2.s 

concentrations than the other monitors in the Charlotte-Concord-Gastonia MSA. Additionally, the 

Rockwell monitor has measured PM2.S annual average concentrations about 9 ~g/m3 since 2012. This is 

3 ~glm3 below the annual standard. With the shutdown of the Rockwell monitor, the Charlotte CBSA 

will continue to meet the minimum monitoring requirements in 40 CFR Part 58, Appendix D. The EPA 

approves the discontinuation of the Rockwell PM2.s monitor. 

The Marion PM2.s monitor is not in a MSA with minimum monitoring requirements and has measured 

annual average PM2.s values well below the annual standard for the last five years. The EPA approves 

the discontinuation of PM1.s measurement at the Marion site. Because the EPA previously approved the 

shutdown of the Dillard PM2.s monitor, no additional approval is needed. 

The Waynesville PM2.s monitor operated by the NC-DAQ is located in Haywood County in the 

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The EPA compared PM2.s concentrations at the Clemmons site operated by the Forsyth County OEAP, 

with the nearby Hattie Avenue PM2.5 site, also operated by the Forsyth County OEAP. The 

measurements at the two sites correlate well, indicating that they measure very similar airsheds. Also, 

the Clemmons PM2.s site has typically measured slightly lower PM2.s daily average concentrations than 

the Hattie A venue PM2.s monitor measured. Thus, the EPA approves shutting down the PM2.s 

monitoring at the Clemmons site. 

Forty CFR Part 58, Appendix D, Table D-5 requires MSAs with over one million people, like Raleigh, 

to operate three PM2.s monitors, if the most recent DV is greater than or equal to 85% of the NAAQS. 

The 2012-2014 PM2.s DV at the Millbrook site is 86% of the NAAQS. There are currently two PM2.s 

monitoring sites operating in the Raleigh MSA: Millbrook (AQS ID 37-183-0014) and West Johnson 

Co. (AQS ID 37-101-0002). By 2017, the NC-DAQ is required to operate a PM2.s monitor at the Triple 

Oak (AQS ID 37-183-0021) near-road site (see the next section). Once operating, the PM2.s monitor at 

the Triple Oak site will be the third PM2.s site in the Raleigh MSA and the MSA will meet the minimum 

monitoring requirements found in 40 CFR Part 58, Appendix D. 

The state ofNorth Carolina's current PM2.s monitoring network meets the minimum requirements found in 40 CFR Part 58, Appendix D, Table D-5 for all MSAs, except the Raleigh MSA. Manual PM2.s 

collocation requirements are found in 40 CFR Part 58, Appendix A, 3.2.5. These include the 

requirement that 15 percent of each network of manual PM2.s methods (at least one site) must be 

collocated. The manual collocation requirements for PM2.s are currently being met in the Network Plan. 

PM2.s Near-road Monitoring Requirements 40 CFR Part 58, Appendix D, 4.7.1(b)(2) 

Regulatory requirements in 40 CFR Part 58, Appendix D, Section 4.7.1(b)!2) require that "CBSAs with 

a population of 1 ,000,000 or more persons, at least one PMB monitor is to be collocated at a near-road 

N02 station." PM2.s near-road monitoring is required in the Charlotte-Concord-Gastonia, NC-SC and 

Raleigh, NC CBSAs, by January 1, 2017. 

PMl.5 Continuous Monitoring Requirements 

40 CFR Part 58, Appendix D, 4. 7.2 

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

local agencies must operate continuous PM2.s 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 ofthe required FRMIFEMIARM [federal reference 

method/federal equivalent method/approved regional method) monitors, unless at least one of the 

required FRMIFEM/ ARM monitors is itself a continuous FEM or ARM monitor in which case no 

collocation requirement applies." These minimum continuous PM2.s monitoring requirements· are met in 

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all MSAs in the state. Also, the continuous PM2.s collocation requirements are met in all MSAs. 

Therefore, the continuous PM2.s monitoring network described in the 2015 Network Plan meets all of 

the design criteria of 40 CFR Part 58. 

PM2.s Continuous Federal Equivalent Methods 

40 CFR § 58.10(e) 

EPA regulations contain provisions for handling data collected using continuous PM2.s FEMs. These 

procedures are found at 40 CFR § 58.IO(e). If an agency can demonstrate that the FEM data are not of 

sufficient comparability to a collocated FRM, then the monitoring agency may request that the FEM 

data not be used in comparison to the NAAQS. 

In response to the 2014 Network Plan, the EPA approved five FEM monitors which are not considered 

comparable to the PM2s NAAQS at the following sites: Kenansville (AQS ID 37-061-0002); Jamesville 

(AQS ID 37-117-0001); Castle Hayne (AQS ID 37-129-0002); Dillard School {AQS ID 37-191-0005); 

and Blackstone (AQS ID 37-105-0002). NC-DAQ currently reports the data from these monitors to the 

AQS parameter code 88502. 

PM2.s Background and Transport Sites 

40 CFR Part 58, Appendix D, 4. 7.3 

Forty CFR Part 58, Appendix D, 4.7.3 requires 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 Network Plan identifies two PM2.s sites as general background sites: Mendenhall (AQS 

ID 37-081-0013), and Candor{AQS ID 37-123-0001). The Network Plan identifies the Bryson City site 

(AQS ID 37-173-0002) as a regional transport site for PM2.s. Therefore, the NC-DAQ has satisfied the 

requirements of 40 CFR Part 58 for background and transport sites. 

PM2.s Chemical Speciation Network (CSN) 

40 CFR Part 58, Appendix D, 4.7.4 

The EPA conducted an assessment of the PM2 s CSN in an effort to optimize the network and to create a 

network that is sustainable going forward . As a result of this assessment, the EPA has defunded a 

number of monitoring sites, eliminated the CSN PM2.s mass measurement, reduced the frequency of 

carbon blanks, reduced sample frequency at some monitoring sites, and reduced the number of the packs 

in shipment during the cooler months of the year. 

The EPA defunded four CSN monitors at sites in North Carolina: Rockwell (AQS ID 37-159-0021); 

Lexington Water Tower (AQS ID 37-057-0002); Asheville's Board of Education (AQS ID 37-021-

d