Ms. Myra Reece UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 4 ATLANTA FEDERAL CENTER 61 FORSYTH STREET ATLANTA, GEORGIA 30303-8960 

# ocr s-zot4

Chief, Bureau ofAir Quality Control South Carolina Department ofHealth and

Environmental Control 2600 Bull Street Columbia, South Carolina 29201
DearMs. Reece: Thank you for submitting the state ofSouth Carolina's 2014 annual ambient airmonitoring network plan (Network Plan) dated July 3, 2014. The Network Plan is required by40 Code ofFederal (CPR) Regulations §58.10. TheU.S. Environmental ProtectionAgency Region 4 understands that the South CarolinaDepartment of Health and Environmental Control (SC DHEC) provided the public a 30-dayreview period for its draft Network Plan. Comments on the draft plan were submittedby six stakeholders and the final Network Plan includes the SC DHEC response to these comments. With this letter, the EPARegion4 is approving the Network Plan provided that the following changes are made: 1. An ozone (03) monitoring site mustbe established in the Myrtle Beach-Conway-North Myrtle Beach, SC-NC Metropolitan StatisticalArea (MSA) bythe beginning ofthe 2015 ozone monitoring season. 2. Air Quality Index reporting for the Myrtle Beach-Conway-North Myrtle Beach, SC-NC MSA must be initiated once the 03 monitoring site is established. Details regarding ourreview ofthe Network Plan are provided inthe enclosed 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 to monitor air pollution and promote healthy air quality in South Carolina. Ifyou have any questions orconcerns, please contact Gregg Worley at (404) 562-9141 or David McNeal at (404) 562-9102.

Enclosure

cc: Mr. Robert Brown Division Director, Air Planning Development and Outreach, SC DHEC 

### Mr. ScottReynolds Beverly H. Banister Director Air, Pesticides andToxics Management Division

Director, Division ofAir QualityAnalysis, SC DHEC Mr. Thomas Flyrm Manager, AirDataAnalysis and Support Section, SC DHEC The HonorableWilliam Harris Chiefofthe Catawba Indian Nation Mr. Darin Steen Director, Environmental Services, Catawba Indian Nation

### CY 2014 State ofSouth Carolina Ambient Air Monitoring Network Plan The U.S. EPA Region 4 Comments and Recommendations This document contains the U.S. EPA Region 4 comments and recommendations regarding the state of South Carolina's 2014 ambient air monitoring networkplan (Network Plan). Ambient airmonitoring rules, which address network plans, data certification, and minimum monitoring requirements, among otherrequirements, are found in 40 CFRpart 58. Minimum monitoring requirements for criteria pollutants are listed in 40 CFRpart 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 (PM10), nitrogen dioxide (N02), sulfur dioxide (S02), carbon monoxide (CO), and lead (Pb). The minimum monitoring requirements are based on core based statistical area (CBSA) boundaries as defined bythe U.S. Office ofManagement and Budget (OMB), July 1, 2013, population estimates from the U.S. Census Bureau, and historical ambient air monitoring data. Minimum monitoring requirements for 03, PM2.s, and PM10 only apply to metropolitan statistical areas (MSAs) which are a subset of CBSAs. OMB currently defines 10 MSAs in the state ofSouth Carolina. These MSAs and the respective July 1, 2013, population estimates from the U.S. Census Bureau are shown in Table 1.
Table 1: Metropolitan Statistical Areas and Populations

MSAName Charlotte-Gastonia-Concord NC-SC Greenville-Anderson-Mauldin, SC Columbia, SC Charleston-North Charleston-Summerville, SC Augusta-Richmond County, GA-SC Myrtle Beach-Conway-North Myrtle Beach, SC-NC Spartanburg, SC Florence, SC Hilton Head Island-Bluffton-Beaufort, SC Sumter, SC 

### Minimum OJMonitoringRequirements 40 CFRpart58, appendix D, table D-2 Population 2,335,358

850,965 793,779 712,220 580,270 404,951 318,999 206,261 198,467 108,123

Region4 has determined thatthe 03 monitoring network outlined in the Network Plan meets the minimumrequirements found in 40 CFRpart 58, appendix D, table D-2 for nine ofthe MSAs in South Carolina. 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 triggered the requirement for an 03 monitor inthe MSA, andthe 2014 Network Plan indicates thatthe SC DHEC has entered into discussions with North Carolina and other stakeholders to identify an appropriate location for a newmonitoring site. Since the need for an 03 monitoring site inthe Myrtle Beach-Conway-North Myrtle Beach, SC-NC MSA has been known since early 2013, Region4 believes that a reasonable deadline for beginning the required monitoring would be the beginning ofthe 2015 ozone season (April2015).

### Minimum PM1o Monitoring Requirements 40 

### CFRpart58, 

### appendix A, 3.3.1 40 

### CFRpart58, 

### appendix D, 

### table D-4 Region 4 has determined that the PM10 monitoring network outlined in the Network Plan meets or exceeds the minimum requirements found in 40 CFRpart 58, appendix D, table D-4 for all MSAs. Also, all manual PM10 collocationrequirements are met. 

### Minimum PM2.s Monitoring Requirements 40 

### CFRpart58, 

### appendix A, 3.2.5 40 

### CFRpart58, 

### appendix D, 

### table D-5 Region 4 has determined thatthe PM2.s monitoring network outlined in the Network Plan meets or exceeds the minimum requirements found in 40 CFRpart 58, appendix D, table D-5 for all MSAs. Also, all PM2.s collocation requirements are met. 

### PM2.s Continuous MonitoringRequirements 40 

### CFRpart58, 

### appendix D, 4.7.2 Regulatory provisions for continuous PM2

.smonitoring require that "The State, or where appropriate, local agencies must operate continuous PM2

.s analyzers equal to at least one-half(roundup) ofthe minimum required sites listed in Table D-5 ofthis appendix. At least one required continuous analyzer in each MSA mustbe collocated with one ofthe required FRMIFEM/ARM [Federal Reference Method/Federal Equivalent Method/Approved Regional Method] monitors, unless at least one ofthe required FRMIFEM/ ARM monitors is itselfa continuous FEM orARM monitor in which case no collocationrequirement applies." After review ofthe Network Plan, Region 4 has determinedthat the proposed PM2

.scontinuous monitoring network meets orexceeds the minimum requirements in all of the MSAs in the state. Also, the continuous PM2.s collocationrequirements are metin all MSAs. 

### PM2.s Background and Transport Sites 40 

### CFRpart58, 

### appendix D, 4.7.3 40 CFRpart 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 levels and at least one PM2.s site to monitor for regional transport." The 2014 Network Plan identifies Ashton (AQS ID 45-029-0002) in Colleton County as a regional background site and Chesterfield (AQS ID 45-025-0001) in Chesterfield County as a regional transport site. Therefore, the SC DHEC has satisfied the requirements of40 CFRpart 58 for regional background and transport sites. 

### PM2.s Chemical Speciation Network The EPAhas been conducting an assessment ofthe Chemical SpeciationNetwork (CSN) in an effort to optimize the network and create a networkthat is sustainable going forward. As a result ofthis assessment, EPA is recommending defunding a number ofmonitoring sites, eliminating the CSN PM2

.s mass measurement, reducing the frequency ofcarbonblanks, reducing sample frequency at monitoring sites, and reducing the number oficepacks in shipments during the coolermonths oftheyear.The EPA is currently soliciting feedback regarding their recommendations. Should these recommendations become final, the CSN monitors at the Chesterfield (AQS ID 45-025-0001) and the Greenville ESC (AQS ID 45-045-0015) sites would need to be shutdown. The CSN PM2.s mass measurement is recommended for elimination in July 2014 and all other changes are recommended to take place in January 2015. Final changes to the CSN in the state ofSouth Carolina will need to be reflected in the 2015 Network Plan. Pb Monitoring Requirements 40 CFR part 58, appendix D, 4.5 40 CFRpart 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 ormore tons per year and from each airport which emits 1.0 ormore tons per year..." Although South Carolinahas no sources that exceed the thresholds for Pb monitoring, the Johnson Control Battery Group conducts source-based ambient Pb monitoring at three sites around the Florence Recycling Center in Florence, South Carolina. The company is conducting this monitoring underterms ofa settlement agreement reached with several petitioners who commented onthe construction permit for the facility. Locations for the monitoring sites were selectedbased upon an agreement betweenthe companyandthe stakeholders. According to the 2014 Network Plan, a collocated Pb monitor has been added to one ofthe three existing sites for quality assurance purposes. 40 CFRpart 58, appendix D, 3(b) requires that "NCore sites in CBSAs with a population of500,000 people (as determined in the latest Census) or greater shall also measure Pb either as Pb-TSP orPbPMIO

." The Network Plan indicates that a Pb sampleris located at the Parklane NCore site (AQS ID 45- 079-0007). The Pb monitoring network described in the Network Plan meets all ofthe design criteriaof40 CFR part 58. SulfurDioxide (S02) Monitoring Requirements 40 CFRpart 58, appendix D, 4.4 Ambient air monitoring network design criteria for S02 are found in section 4.4 of40 CFRpart 58, appendix D. This sectionrequires that "Thepopulation weighted emissions index (PWEI) shall be calculatedby states for each core-based statistical area (CBSA)

..." As a result, the S02monitoring site(s) required in each CBSAwill satisfy minimum monitoring requirements ifthe monitor(s) is sited within the boundaries ofthe parent CBSAand is ofthe following site types: population exposure, maximum concentration, source-oriented, general background, orregional transport. An S02monitor at anNCore station may satisfy minimum monitoring requirements ifthat monitor is located within a CBSAwith minimally required monitors consistent with appendix D, section 4.4. Basedupon PWEis calculated using the latestpopulation estimates and emission inventory data, the minimum number of monitors required for the CBSAs in South Carolina is summarized in Table 2.

3

### Table 2: S02 Monitoring System Status

CBSAName Augusta-Richmond County, GA-SC Charleston-North Charleston-Summerville, SC Charlotte-Gastonia-Concord NC-SC Columbia, SC Greenville-Anderson-Mauldin, SC 

### SLAMS required 1 1 1 1 1 

### SLAMS present 1 1 1 1 1 Based upon the information summarized in Table 

### 2, the S02 monitoring network outlined in the Network Plan meets the design criteria specified in section 4.4 ofappendix D to 40 CFRpart 58. 

### N02Monitoring Requirements 40 

### CFRpart58, appendix D, 4.3 Ambient air monitoring network design criteria for N02 are found in Section4.3 ofappendix D to 40 CFRpart 58. Three types ofN02monitoring are required: near-road, area-wide, and Regional Administrator. These types ofN02monitoring are described in sections 4.3.2, 4.3.3 and 4.3.4, respectively. Ambient air monitoring design criteria for near-road N02monitoring sites are found in section 4.3.2 of appendix D to 40 CFRpart 58. The requirement for near-road monitoring inthe Charlotte-GastoniaConcordNC-SC CBSAwill be met using the Remount site (AQS ID 3 7-119-0045) operated by Mecklenburg County's Land Use and Environmental ServicesAgency (MCLUESA) in Charlotte, North Carolina. No other CBSAin South Carolina is currently required to have near-road N02 monitoring. By January, 1 2017, South Carolina CBSAs with populations over 500,000 will be required to operate nearroad N02 monitoring. Ambient air monitoring network design criteriafor area-wide N02sites are found in section 4.3.3 of appendix D to 40 CFRpart 58. The Garinger High School site (AQS ID 37-119-0041) currently operated by MCLUESAwill be used for fulfilling the area-wide N02 monitoring requirement for the Charlotte-Gastonia-ConcordNC-SC CBSA. No other CBSAin South Carolina is required to have an area-wide N02 monitor. Ambient air monitoring network design criteria for RegionalAdministratorrequired N02monitoring, often referred to as RA-40 monitoring, are found in section4.3.4 ofappendix D to 40 CFRpart 58. Underthese provisions RegionalAdministrators mustrequire a minimum of40 additional N02 monitoring stations nationwide, with a primary focus on siting these monitors inlocations to protect susceptible and vulnerable populations. As part oflastyear's Network Planreview, Region 4 selected the Greenville ESC site (AQS ID 450-045-0015) as a RA-40 N02monitoring site.

4

### Air Quality Index (AQI) Reporting 40 CFR §58.50 AQI reporting is required in MSAs with populations over 350,000. FourMSAs in the state ofSouth Carolina are required to report an AQI: Greenville-Anderson-Mauldin, Columbia, Charleston-North Charleston, and Myrtle Beach-Conway-North Myrtle Beach, SC-NC. The Network Plan onPage 3 indicates that the daily AQI for all ofthese areas except the Myrtle Beach-Conway-North Myrtle Beach, SC-NC MSA is available onEPA's AIRNow web site. Once an 

### 03 monitoring site is added to the Myrtle Beach-Conway-North Myrtle Beach, SC-NC MSA in order to satisfy the minimum requirements in40 CFR part 58, AQI reporting should also be initiated. 

### ProposedMonitoringNetwork Changes SC DHEC has proposed nine monitoring network**change~** which are summarized in Table 3.
Table 3:**Pro~osed** Monitorin; Network Chan;es

AQSID Site Name Pollutant Type Comments 45-019-0003 Jenkins Ave Fire Station so2 SLAMS Editorial correction 45-091-0006 York so2 SPM Change designation 45-063-0008 lrmo SVOCs Non-regulatory Change objective 45-063-0008 Irmo Carbonyls Non-regulatory Change objective 45-045-0015 Greenville ESC N02 SLAMS Change designation 45-045-0015 Greenville ESC so2 SLAMS Change designation 45-077-0002 Clemson 03 SLAMS Add monitor 45-025-0001 Chesterfield PM2.5 speciation Supplemental Discontinue monitoring 45-073-0001 Long Creek PM2.5 SPM Change designation The designation for the SOz monitor at the Jenkins Avenue Fire Station site (AQS ID 45-019-0003) was changed from SPMto SLAMS in order to correct an error in theprevious NetworkPlan. The NetworkPlanproposes to change the designation for the SOz monitor at the York site (AQS ID 45- 091-0006) from SLAMS to SPM. Thebasis for this change is thatthere are currently two operational SOz SLAMS in the Charlotte-Gastonia-Concord CBSA, but only one is required due to substantial decreases in emissions thathave lowered the PWEI inthe CBSA. The other SOz SLAMS in the CBSA is located at the Garinger High School NCore site (AQS ID 37-119-0041) in Mecklenburg County, North Carolina. The York site has beenin operation sinceJanuary of2012, and SOzconcentrations at the site are consistently lowerthan at the Garinger High School site. Therefore, the proposal to change the SOz monitor designation at the York site to SPM is acceptable. The objective for the semi-volatile organic compound (SVOC) and carbonyl monitors at the Irmo site (AQ ID 45-063-0008) was changed to non-regulatory in orderto be consistent with the objective for the black carbon monitor located at the site. The designation for the NOz monitor at the Greenville ESC site (AQS ID 45-045-0015) was changed from SPMto SLAMS to reflect its selection as anRA-40 NOz monitoring site.



### 5The designation for the S02 monitor at Greenville ESC site (AQS ID 45-045-0015) was changed from SPM to SLAMS since the latest PWEIcalculations indicate that an S02SLAMS is required in the Greenville-Anderson-Mauldin MSA. Inits 2013 NetworkPlan, SC DHEC proposed to discontinue 03 monitoring at the Clemson site (AQS ID 45-077-0002). Becausethis proposal was not approved, information regarding Clemson site was included in the 2014 Network Plan. The Network Planproposes to discontinue PM2.s speciation monitoring at the Chesterfield site (AQS ID 45-025-0001) iffunding for this activity is discontinued byEPA. The designation for the PM2.s monitor at the Long Creek site (AQS ID 45-073-0001) was changed from SLAMS to SPM due to the inadequate performance ofthe monitor. The Long Creek site is located in a county (Oconee) that is notpart ofa MSA for which minimum monitoring requirements are specified under40 CFR part 58, appendix D. Basedupon ourreview, all ofthe proposed changes in the 2014 Network Plan are acceptable. National Core (NCore) Monitoring Network 40 CFR part 58,appendix D, 3 A requirement that each state operate at least one NCore site is found in section 3 of40 CFR part 58, appendix D. The state's approved NCore site is located at the Parklane site (AQS ID 45-079-00047) and the SC DHEC has notproposed any changes for the site in its 2014 NetworkPlan.



### 6