UNITEDSTATESENVIRONMENTALPROTECTIONAGENCYREGJON4Ms.SheilaC.HolmanDirectorDivisionofAirQualityNorthCarolinaDepartmentofEnvironmentalQuality1641MailServiceCenterRaleigh,NorthCarolina27699-1641DearMs.Holman:ATLANTAFEDERALCENTER61FORSYTHSTREETATLANTA,GEORGIA30303-8960NOV12015ThankyouforsubmittingthestateofNorthCarolina's2015annualambientairmonitoringnetworkplan(NetworkPlan),datedJuly23,2015.TheNetworkPlanisrequiredby40CodeofFederalRegulations(CFR)§58.10.TheNetworkPlancoverstheambientairmonitoringnetworkfortheNorthCarolinaDivisionofAirQuality(NC-DAQ)andthelocalairqualityagenciesinNorthCarolina.TheU.S.EnvironmentalProtectionAgencyRegion4understandsthattheNC-DAQprovidedthepublica30-dayreviewperiodforitsdraftNetworkPlan.CommentsonthedraftplanweresubmittedbyseveralstakeholdersandthefinalNetworkPlanincludestheNC-DAQresponsestothesecomments.Accordingto40CFR§58.1O(a)(2),sincepublicinspectionandcommenthavealreadybeensolicited,theEPAisnotrequiredtoofferanothercommentperiod.TheEPAapprovesNorthCarolina's2015NetworkPlan.TheNetworkPlanrequestedthepermanentdiscontinuationoffifteenregulatorymonitors:ninefineparticulatemonitors,fiveozonemonitors,andonecarbonmonoxidemonitor.TheEPAapprovesthediscontinuationofalloftheproposedmonitorsintheNetworkPlan.DetailsregardingtheEPA'sreviewoftheNetworkPlanareprovidedintheenclosedcomments.ThankyouforworkingwithustomonitorairpollutionandpromotehealthyairqualityinNorthCarolinaandthenation.Ifyouhaveanyquestionsorconcerns,pleasecontactGreggWorleyat(404)562-9141orRyanBrownat(404)562-9147.EnclosureSincerely,BeverlyH.Baniste$DirectorAir,PesticidesandToxicsManagementDivisionInternetAddress(URL)•http:/lwww.epa.govRecycled/Recyclable•PrintedwithVegetableOilBasedInksonRecycledPaper(Minimum30%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 Env i ronmental Affairs Department

Mr . David Brigman, Director

Western North Carolina Regional Air Quality Agency2015StateofNorthCarolinaAmbientAirMonitoringNetworkPlanTheU.S.EPARegion4CommentsandRecommendationsThisdocumentcontainstheU.S.EPAcommentsandrecommendationsonthestateofNorthCarolina's2015ambientairmonitoringnetworkplan(NetworkPlan).Ambientairmonitoringrules,whichincluderegulatoryrequirementsthataddressnetworkplans,datacertification,andminimummonitoringrequirements,amongotherrequirements,arefoundin40CFRPart58.Minimummonitoringrequirementsforcriteriapollutantsarelistedin40CFRPart58,AppendixD.Minimummonitoringrequirementsarelistedforozone(03),particulatematterlessthan2.5microns(PM2.s),particulatematterlessthan10microns(PM10),nitrogendioxide(N02),sulfurdioxide(SOz),carbonmonoxide(CO),andlead(Pb).Theminimummonitoringrequirementsarebasedoncorebasedstatisticalarea(CBSA)boundariesasdefinedbytheU.S.OfficeofManagementandBudget(OMB),Julyl,2014,populationestimatesfromtheU.S.CensusBureau,andhistoricalambientairmonitoringdata.Minimummonitoringrequirementsfor03,PM2.s,andPMto,onlyapplytometropolitanstatisticalareas(MSAs),whichareasubsetofCBSAs.OMBcurrentlydefines17MSAsinthestateofNorthCarolina.OnFebruaryI,2013,OMBredefinedtheCBSAboundariesbasedon2010censusdata.InNorthCarolina,therearetworecentlydefinedMSA's:MyrtleBeach-Conway-NorthMyrtleBeach,SC-NCandNewBern,NCthatwerepreviouslydefinedasmicropolitanCBSAs.Additionally,thecompositionofsomeMSApopulationschangedduetotheinclusionand/orexclusionofcountiesfromOMB'sFebruary2013MSAdelineations.TheJuly1,2014populationestimatesfromtheU.S.CensusBureauareshowninTable1.Table1:MetropolitanStatisticalAreasandPopulationsMSAName2014PopulationCharlotte-Concord-Gastonia,NC-SC2,380,314VirginiaBeach-Norfolk-NewportNews,VA-NC1,716,624Raleigh,NC1,242,974Greensboro-HighPoint.NC746,593Winston-Salem,NC655,015Durham-ChapelHill,NC542,710Asheville,NC442,316MyrtleBeach-Conway-NorthMyrtleBeach,SC-NC417,668Fayetteville,NC377,939Hickory-Lenoir-Morganton,NC362,896Wilmington,NC272,548Jacksonville,NC187,589Greenville,NC175,354Burlington,NC155,792RockyMount,NC149,290NewBern,NC134,760Goldsboro,NC124,456MonitoringNetworkChangesProposedbyNC-DAQTheNC-DAQreceivedinternalcommentsontheNetworkPlanaswellasfromsixcommentersincludingtheSouthernEnvironmentalLawCenteronbehalfoftheNorthCarolinaLeagueofConservationVoters,theSierraClub,theSouthernAllianceforCleanEnergy,andtheWesternNorthCaro l ina Alliance. The NC-DAQ provided a response to the comments a s p art of i ts final Networ k Plan .

The pu b lic comments expres s ed concern over the numerous monitor sh u tdown req u est s in the Network

P l an and the number of monitor shutdowns in recent years . The EPA conducted its own analy s is of

North Carolina's am b ient air monitoring network including historical de s ign values (DVs) , ann u al 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. Beca u se th e PMz . s levels have

remained lower for th e last four years, the EPA is approving a significantly redu c ed PM2 . s mon it oring

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

m e asure general background or regional transport . Also, the EPA is approv i ng the sh u tdown of several

monitors located in CBSAs where the network exceeds the minimum requi r ements . These " ov e r

minimum req u irement" monitors that are approved for shutdown read si m i larly to other nearby monitors

or have consistently recorded concentrations lower than nearby monitors .

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

reductions i n the OJ ambient air monitoring network for monitors that have con s i s tently been be l ow the

standard and consi s tently measured lower concentrations than nearby mon i tors .

Further rat i ona l e fo r the EPA ' s approval of specific network changes can b e fo u nd below in t he

pollutant sectio n s of this doc u ment. Monitors proposed for discontinuation or r e l ocation and the EPA's

determination are summarized in Table 2.

Table 2: Monitors Pro £ oscd for Discontinuation

A Q SID Site Name Pollutant **pc** Comments

37- 11 9-1005 Arrowood OJ SLAMS A e proved

3 7-069-000 1 Franklinton OJ SLAMS **~m roved** 

37-183-0016 Fu g ua x OJ SLAMS A QR roved

37-037-0004 Pittsboro OJ SLAMS **eroved**

37-067-0028 Shiloh Church OJ SLAMS A e,e roved

3 7-189-0003 Boone PM u SLAMS **A(! roved** 

37-033-000 1 Che !!)! Grove PM z .s SLAMS Ae e roved

37-191-0005 Dillard School PM 2 . s SLAMS A .Q_Q roved in 2014 Network Plan

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

3 7-061-0002 Kenansville PM z..s SLAMS A ee rov e d

37- 1 11-0004 Marion PM :u SLAMS A ee roved

37- 1 59-0021 Rockwell PMz s SLAMS A e e,r oved

37-087-00 1 2 Wa x nesville PM B SLAMS A (! eroved

37-067-0030 C l emmons Middle PM zs SLAMS A l!e ro v ed

37-067-0023 Peter's Cr ee k co SLAMS Aeeroved

On October 23, 2015 , NC-DAQ submitted a letter to the EPA to move the Pitt County Ag Center

monitoring site (AQS ID 37-147-0006) a distance of 350 meters to a location on the same property . The

EPA reviewed this request and approves the relocation of t he Pitt County Ag Center S i te (see Table 3).Table3:MonitorsProosedforRelocation/StartuAQSIDSiteName37-147-0006PittAg.CenterPollutantTypeSLAMSCommentsApproved-relocationofmonitoringsite-350metersfromexistingsiteTheEPAreviewedtheserequestsformonitordiscontinuationorrelocationanddeterminedthattheymeettherequirementsof40CFR§58.14(c)formonitordiscontinuationandrelocation.TheminimummonitoringrequirementsforPM2.s.and03foundin40CFRPartAppendixDwillcontinuetobemetfortherespectiveifthemonitorsarelocatedinafterthemonitorsarediscontinuedorrelocated.AirQualityIndex(AQI)Reporting40CFR§58.50AQIreportingisrequiredinMSAswithpopulationsover350,000.Thereare10MSAsinthestaterequiredtoreportanAQI:VirginiaBeach-Norfolk-NewportGreensboro-HighPoint,Durham-ChapelHill,Winston-Salem,Asheville,HickoryandWilmington.NC-DAQmeetstheseAQIreportingrequirements.NationalCore(NCore)MonitoringNetwork40CFRPart58,AppendixD,3.0AmbientairmonitoringnetworkcriteriaforNCoresitesarefoundin40CFRPart58,AppendixD,3.NC-DAQliststwoNCoresitesintheNetworkPlan.Thefirstsite(AQSID37-183-0014)islocatedattheEastMillbrookMiddleSchoolsiteinRaleigh,NCandisoperatedbyNC-DAQ.Thesecondsite{AQSID37-119-0041)islocatedattheGaringersiteinCharlotte,NCandisoperatedbytheMecklenburgCountyAirQuality(MCAQ)agency.TheEPAapprovalofthesesiteswasgrantedonOctober2009.The2015NetworkPlanmeetstheminimummonitoringrequirementsforNCoresites.MinimumOJMonitoringRequirements40CFRPart58,AppendixD,TableD-2ThestateofNorthproposedOJmonitoringnetworkmeetstheminimumrequirementsfoundin40CFRPartAppendixD,TableD-2forallMSAs,excepttheMyrtleBeach-Conway-NorthMyrtleBeachMSA(seediscussionbelow).OMBchangedthecompositionofseveralMSAboundariesinFebruaryincludingaddingBrunswickNorthCarolinatotheMyrtleBeach-Conway-NorthMyrtleBeach,SC-NCMSA.Thischangehastriggeredtherequirementtoestablishan03monitorinthisMSA.NC-DAQprovidedamemorandumofagreementwithSouthCarolinaDepartmentofHealthandEnvironmentalControl(SCDHEC)tocollectivelymeettheOJmonitoringrequirementsforthisMSA.TheSCDHEC2015AnnualMonitoringNetworkPlanidentifiesalocationforanewOJmonitortomeetthisrequirement.However,SCDHECdidnotprovideadequateandsufficientinformationfortheEPAtoapproveitsproposedlocation.TheEPAhasrequestedthatSCDHEQprovideanaddendwntoitsNetworkPlanwithadditionalinformationontheproposedOJmonitoringlocationintheMyrtleBeach-Conway-NorthMyrtleSC-NCMSA.3The 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) (l i sted in Table 2 above).

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

Durham areas of North Carolina . The EPA looked at h i storical comparisons of03 concentrations,

meteorology, and the spat i al distribution of 03 monitors in the Durham-Chapel Hill and Raleigh MSAs

to make t h is determinatio n . 03 levels have been below the new standard of 70 ppb for the last three

years (2013, 2014, and 20 1 5) 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 co n centrations at the Franklinton

monitor have consistently been s i milar or l ower than the 03 c oncentrations 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 Rale i gh MSAs will still meet the

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

The EPA also appro v es the shutdown ofthe Arrowood 0 3 monitor, operat e d by the MCAQ . In 2014, the

property for the Arrowood site was sold and the MCAQ' s l ease was not ren e wed. The EPA previously

approved the temporary shutdown of the Arrowood 03 monitor for the 2 015 03 season, while the MCAQ

eval u ated whether t o replace / relocate the Arrowood 03 mo nit or. The MCAQ ultimate l y decided not to

rep l ace 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 i n the

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

lower 03 va l ues than the other 03 mon i tors in the area . Without the Arrowood O J monitor operating, the

C h arlotte-Concord-Gastonia MSA still meets the minimum 03 moni t oring requirements found in 40

CFR Part 58 , Append i x D.

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

Forsyth County Office of Env i ronmental Assistance and Protect i on (OEAP) . This monitor has

consistently measured the lowest concentrations in the W i nston-Salem MSA . When this monitor is

s h utdown , 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

Am bi ent air monitoring netw o rk desig n 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

near-road N02 s i te. For both the Raleigh CBSA and the Charlotte CBSA , CO monitors are req u ired to

operate by January 1, 2017 as indicated in 40 CFR §58.13( e )(2). This req u irement will apply to the

Triple Oak near-road site (AQS ID 37-183-0021) in the Raleigh CBSA and the Re m ount Road near · road

site (AQS ID 37 -1 19-0045) in the C h arlotte CBSA .

The F orsyth County OEAP requested i n an append i x to the Networ k Plan to shutdown the Peter ' s Creek

CO moni t oring site (AQS ID 37-067 - 0023). This monitor has been requ i red to operate as part of a CO

maintenance plan , which expired November 7, 201 5 . The highest DV measured a t the Peter's Creek site

4inthelastfiveyearwas26%oftheNAAQS.Thismonitormeetstherequirementsof40CFR§58.14(c)(1)forshutdowneligibilityandtheCOmonitoringrequirementsfoundin40CFRPart58,AppendixDwillcontinuetobemetintheWinston-SalemCBSA.EPAapprovestheshutdownofthePeter'sCreekCOmonitor,onceitisnolongerrequiredbythemaintenanceplan.N02MonitoringRequirements40CFRPart58,AppendixD,4.4AmbientairmonitoringnetworkdesigncriteriaforN02arefoundin40CFRPart58,AppendixD,4.3.TherearethreetypesofrequiredN02monitoring:near-road,area-wide,andRegionalAdministratorrequired.ThesetypesofN02monitoringaredescribedinSections4.3.2,4.3.3,and4.3.4,respectively.TheEPApreviouslyapprovedtheTripleOaksite(AQSID37-183-0021)andtheRemountRoadsite(AQSID37-119-0045)infulfillmentofthenear-roadN02requirementsfortheRaleighCBSAandtheCharlotte-Concord-GastoniaCBSA.TheGreensboro-HighPoint,NC;Winston-Salem,NC;andDurham-ChapelHill,NCCBSAsarerequiredtohavenear-roadN02monitoringbyJanuary1,2017.AnewN01monitoringruleisexpectedtobepromulgatedin2016.ThenewrulemaychangetheN01near-roadmonitoringrequirementsforCBSAswithpopulationsbetween500,000and1,000,000people,suchastheGreensboro-HighPoint;Winston-Salem;andDurham-ChapelHillCBSAs.TheEPApreviouslyapprovedtheselectionoftheGaringer(AQSID37-119-0041)andMillbrook(AQSID37-183-0014)sitesinfulfillmentofthearea-wideN01monitoringrequirementfortheCharlotteConcord-GastoniaandRaleighCBSAs.TheEPAalsopreviouslyselectedtheHattieAvenuesite(AQSID37-067-0022)operatedbyForsythCountyOEAPasalocationforaRegionalAdministratorrequiredN01monitortohelpprotectsusceptibleandvulnerablepopulations.ThefulllistofN01monitorsidentifiedbytheEPA'sRegionalAdministratorscanbefoundontheEPA'swebsiteathttp://www.theEPA.gov/ttnamtil/svpop.html.S02MonitoringRequirements40CFRPart58,AppendixD,4.4AmbientairmonitoringnetworkdesigncriteriaforS01arefoundin40CFRPart58,AppendixD,4.4.Thissectionrequiresthat"Thepopulationweightedemissionsindex(PWEI)shallbecalculatedbystatesforeachcorebasedstatisticalarea(CBSA)."Asaresult,theS01monitoringsite(s)requiredineachCBSAwillsatisfyminimummonitoringrequirementsifthemonitor(s)issitedwithintheboundariesoftheparentCBSAandisoneofthefollowingsitetypes:populationexposure,maximumconcentration,source-oriented,generalbackground,orregionaltransport.AnS01monitoratanNCorestationmaysatisfyminimummonitoringrequirementsifthatmonitorislocatedwithinaCBSAwithminimallyrequiredmonitorsconsistentwithAppendixD,4.4.Table4showsthelocationonrequiredS02monitorsbasedonthe2012PWEI.ExistingS01monitoringsitesdescribedintheNetworkPlanmeettheminimumrequirementsof40CFRPart58.TheNC-DAQoperatesregulatory802monitorsintheCharlotte-Gastonia-Concord,NC-SC;Durham,NC;andWilmington,NCCBSAstomeetthePWEIrequirements.TheVirginiaDepartmentofEnvironmentalQualityoperatesaregulatory802monitorintheVirginiaBeach-Norfolk-NewportNews,VA-NC5CBS A. The EPA recommends that North Carolina update its MSA agreement with Virginia to include

sharing the S02 minimum monitoring requirements for the V i rginia 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 Document 1 •

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 w o rk 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

SLAMS [state and local air monitoring station] site located to measure the maximum Pb concentration

in ambient air resulting from each non-airport Pb source which emits 0.50 or more tons per year and

1 S02 NAAQS Designations Source-Oriented Monitoring Technical Assistance Document. U.S. EPA Office of Air Quality

Planning and Standards Air Quality Assessment Div i sion, Draft December 2013.

h ttp : // www3.e pa.g ov / air g uali ty / sulfurdiox j d el p df s/ S02Monitorin g T AO. Qd f

6fromeachairportwhichemits1.0ormoretonsperyear..."Section4.5(a)(ii)providesthefollowingprovisionsforawaiverofthePbmonitoringrequirements:"(ii)TheRegionalAdministratormaywaivetherequirementinparagraph4.5(a)formonitoringnearPbsourcesiftheStateor,whereappropriate,localagencycandemonstratethePbsourcewillnotcontributetoamaximumPbconcentrationinambientairinexcessof50%oftheNAAQS(basedonhistoricalmonitoringdata,modeling,orothermeans).Thewaivermustberenewedonceevery5yearsaspartofthenetworkassessmentrequiredunder58.10(d)."Initsapprovalofthestate's2011NetworkPlan,pursuanttheprovisionsoftheabovesection,theEPAgrantedwaiversofthesource-orientedambientairmonitoringrequirementsattwosources:BlueRidgePaperProducts,Inc.inCanton,NCandSaintGobainContainersinWilson,NC.Thewaiversmustberenewedeveryfiveyearsaspartofthenetworkassessmentrequiredunder40CFR§58.10(d).TheSaintGobainContainersfacilityistheonlyfacilityinNorthCarolinawith2011NEIPbemissionsover0.5tpy.Thisfacilityisestimatedtoemit0.53tpy.The2011modelingofthisfacilityusedPbemissionsof1.3tpy.TheEPAbelievesthatthepreviously submittedmodelingissufficientlyconservativeandisapprovingtherenewalofthesource-orientedambientairPbmonitoringrequirementsatSaintGobainContainersinWilson,NCforfiveyears,until2020.Basedonthe2011NEI,BlueRidgePaperProducts,Inc.inCanton,NCemittedlessthan0.5tpyofPb.Thus,BlueRidgePaperProductsisnotsubjecttothePbmonitoringrequirements.Awaiverofthesource-orientedambientairPbmonitoringrequirementsisnolongerrequiredforthisfacility.Ifinthefuturethisfacilityisestimatedtoemitmorethan0.5tpy,thenNC-DAQwillneedtosubmitanewwaiverrequestormonitorforPbnearthefacility.Atthistime,nootherfacilitiesinNorthCarolinaemitmorethan0.5tpyofPbandaresubjecttorequiredPbsource-orientedmonitoring.FortyCFRPart58,AppendixD,3(b)requiresthat"NCoresitesinCBSAswithapopulationof500,000people(asdeterminedinthelatestcensus)orgreatershallalsomeasurePbeitherasPb-TSPorPbPMJO."ThismonitoringwasrequiredtobeginDecember27,2011.TheNetworkPlanindicatesthatPbPMIOsamplingisongoingattheCharlotteNCoresite(AQSID37-119-0041)andtheRaleighNCoresite(AQSID37-183-0014).Asaresult,thePbmonitoringnetworkdescribedintheNetworkPlanmeetsthedesigncriteriaof40CFRPart58.MinimumPM10MonitoringRequirements40CFRPart58,AppendixA,3.3.140CFRPart58,AppendixD,TableD-4ThestateofNorthCarolina'scurrentPM1oprimarymonitoringnetworkmeetstheminimumrequirementsforallareas.AllPM10collocationrequirementsformanualmethodsfoundin40CFRPart58,AppendixA,3.3.1arebeingmet.Theseincludetherequirementthat15percentofeachnetworkofmanualPM10methods(atleastonesite)mustbecollocated.TheNetworkPlanrequestedawaiveroftherequirementstooperateasecondPMwmonitorinRaleigh.SincePM10levelshavebeensignificantlylowerthantheNAAQSforthelastdecade,theEPAgrantsawaiveroftherequirementforasecondPM10monitorintheRaleighMSA.7Minimum 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 Pro p osed for Discontinuation

A Q SID Site Name County MSA

37-033-0001 C h e ny Grove Caswell Not in a MSA

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

37-087-0012 Wa y n e sville Haywood Ash e vill e , NC

37-111-0004 Mar i on McDowell Not in a MSA

37- 1 17-000 1 Jamesvil l e Martin Not i n a MSA

37-159 - 002 1 Rockwell Rowan Ch a rlotte-Concord-Gastoni a , NC-SC

37-189-0003 Boone Watau g a Boone , NC

37 - 1 9 1 · 0005 Dillard School Wa y ne Goldsboro, NC

37 - 067-0030 Clemmons Fors y! 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, Jamesvill e , and Boone PM2 s sites meet

EPA's guidance f or determini n g shutdown eligibility and the r equirements of 40 CFR 58 . 14(c)(1) . Thus,

EPA approv e s the discontinua t ion of these four monitors.

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

concentrations t han the other monitors in the Charlo tt e-Concord-Gaston i a MSA. Additionally, th e

Rockwell m onitor has measur e d PM 2.S annual average concentrations about 9 **~g/m 3**  since 2012. This is

3 **~glm 3**  below the annual standard . With the shutdown of the Rockwell monitor, the Char l otte CBSA

will continue to meet the minimum monitoring requirements in 40 CFR Part 5 8 , Appendix D. The EPA

approves the di s continuat i on of the Rockwell PM2 . s monitor .

The Marion PM 2 . s monitor is not in a MSA w i th m i nimum monitoring req u irements and has measured

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

the discontinuation of PM 1 . s measurement at the Marion site. Because the EPA previously approved th e

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 i n the

Asheville MSA . The WNCRAQA operates PM2 . s mon i tors at the Board of Education site (AQS ID 37 -

087-0012) in Buncombe County , NC, also in the Asheville MSA. The Waynesville monitor h as

cons i stently measured both higher annual average PM2 . s concentrations and daily av e rage concentrations

than the Board of Education site . The daily ave r age measurements at each s i te do not correlate well ,

indicating that they measure different airsheds, and different local a i r pollut i on sources and e v ents . This

might be expected since the Wayne s ville and Board of Education sites are located in separate valleys of

the regional mountainous terrain . 8ThemostrecentDVfortheWaynesvillesiteis8.7!J.g/m3.Previously,theAshevilleMSAhadbeenrequiredtooperateonePM2.smonitor(per40CFRPart58,AppendixD,TableD-5),butnowitdoesnothaveaminimummonitoringrequirementsincethemostrecentDVislessthan85%oftheNAAQSandtheMSA'spopulationisunder500,000people.TheWaynesvillePM2.sDVhasbeenlessthan85%ofthe2012PM2.sNAAQS(12!J.g/m3)since2011.TheEPAapprovestheshutdownoftheWaynesvillemonitor.However,theEPArecommendsthatNC-DAQconsideroperatingaPM2.smonitorinWaynesville,evenifitisnon-regulatory.TheEPAcomparedPM2.sconcentrationsattheClemmonssiteoperatedbytheForsythCountyOEAP,withthenearbyHattieAvenuePM2.5site,alsooperatedbytheForsythCountyOEAP.Themeasurementsatthetwositescorrelatewell,indicatingthattheymeasureverysimilarairsheds.Also,theClemmonsPM2.ssitehastypicallymeasuredslightlylowerPM2.sdailyaverageconcentrationsthantheHattieAvenuePM2.smonitormeasured.Thus,theEPAapprovesshuttingdownthePM2.smonitoringattheClemmonssite.FortyCFRPart58,AppendixD,TableD-5requiresMSAswithoveronemillionpeople,likeRaleigh,tooperatethreePM2.smonitors,ifthemostrecentDVisgreaterthanorequalto85%oftheNAAQS.The2012-2014PM2.sDVattheMillbrooksiteis86%oftheNAAQS.TherearecurrentlytwoPM2.smonitoringsitesoperatingintheRaleighMSA:Millbrook(AQSID37-183-0014)andWestJohnsonCo.(AQSID37-101-0002).By2017,theNC-DAQisrequiredtooperateaPM2.smonitorattheTripleOak(AQSID37-183-0021)near-roadsite(seethenextsection).Onceoperating,thePM2.smonitorattheTripleOaksitewillbethethirdPM2.ssiteintheRaleighMSAandtheMSAwillmeettheminimummonitoringrequirementsfoundin40CFRPart58,AppendixD.ThestateofNorthCarolina'scurrentPM2.smonitoringnetworkmeetstheminimumrequirementsfoundin40CFRPart58,AppendixD,TableD-5forallMSAs,excepttheRaleighMSA.ManualPM2.scollocationrequirementsarefoundin40CFRPart58,AppendixA,3.2.5.Theseincludetherequirementthat15percentofeachnetworkofmanualPM2.smethods(atleastonesite)mustbecollocated.ThemanualcollocationrequirementsforPM2.sarecurrentlybeingmetintheNetworkPlan.PM2.sNear-roadMonitoringRequirements40CFRPart58,AppendixD,4.7.1(b)(2)Regulatoryrequirementsin40CFRPart58,AppendixD,Section4.7.1(b)!2)requirethat"CBSAswithapopulationof1,000,000ormorepersons,atleastonePMBmonitoristobecollocatedatanear-roadN02station."PM2.snear-roadmonitoringisrequiredintheCharlotte-Concord-Gastonia,NC-SCandRaleigh,NCCBSAs,byJanuary1,2017.PMl.5ContinuousMonitoringRequirements40CFRPart58,AppendixD,4.7.2RegulatoryrequirementsforcontinuousPM2smonitoringrequirethat"...State,orwhereappropriate,localagenciesmustoperatecontinuousPM2.sanalyzersequaltoatleastone-half(roundup)theminimumrequiredsiteslistedinTableD-5ofthisappendix.AtleastonerequiredcontinuousanalyzerineachMSAmustbecollocatedwithoneoftherequiredFRMIFEMIARM[federalreferencemethod/federalequivalentmethod/approvedregionalmethod)monitors,unlessatleastoneoftherequiredFRMIFEM/ARMmonitorsisitselfacontinuousFEMorARMmonitorinwhichcasenocollocationrequirementapplies."TheseminimumcontinuousPM2.smonitoringrequirements·aremetin9all MSAs i n 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 reg u lations 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 reques t 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 requir e s that "each State shall install and op e rate at least one

PM 2 ..s site to monitor for regional background and at least one PM 2 . 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 PM 2 s CSN in an effort to optimize the ne t work 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 s i tes 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-

0034) ; and Hickory Water Tower (AQS ID 37-035-0004) . CSN monitors at these sites were shutdown

on December 31, 2014. EPA continues to fund three CSN monitors in North Carolina: Garinger (AQS

ID 37-119-0041) , operated by MCAQ ; Hattie Avenue (AQS ID 37-067-0022), operated by Forsyth

County OEAP ; and Millbrook (AQS ID 37-183-0014), operated by NC-DAQ.

10Photochemical

Assessment

Monitoring

Station

(P AMS) 40 CFR

Part

58, Appendix

D,

5.0 With

the recent passage

of

a new ozone NAAQS

on October

1, 2015,

the EPA

also finalized

changes

to the PAMS program.

By June

1, 2019,

the NCore

sites

in Raleigh

and Charlotte

will

be required

to implement

P AMS monitoring.

The EPA recognizes

there

are several implementation

challenges

to work through

and

we commit

to working

closely

with NC-DAQ

and MCAQ

to minimize

the burden

of implementing

this

new monitoring

program.

At this time, however,

the PAMS requirement

is being

met in the state ofNorth

Carolina.