UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION4

Ms. Myra Reece Chief Bureau ofAir Quality Control
. ATLANTA FEDERAL CENTER 61 FORSYTH STREET ATLANTA, GEORGIA 30303-8960 

## NOV 

# 1 92015

South Carolina Department ofHealth and Environmental Control 2600 Bull Street Columbia, South Carolina 29201 Dear Ms. Reece: Thank you for submitting the state ofSouth Carolina's 2015 annual ambient air monitoring network plan (Network Plan) dated July 20, 2015. The Network Plan is required by 40 Code ofFederal Regulations (CFR) §58.1 0. The U.S. Environmental Protection Agency Region 4 understands that the South Carolina Department of Health and Environmental Control (SC DHEC) provided the public a 30-day review period for its draft Network Plan. Comments on the draft plan were submitted by three stakeholders and the final Network Plan includes the SC DHEC response to these comments. With this letter, the EPA Region 4 is approving the Network Plan with the following exceptions: 1. The EPA does not approve the proposed discontinuation ofthe ozone (OJ) monitor at the Clemson site (AQS ID 45-072-0002) in the Greenville-Anderson-Mauldin Metropolitan Statistical Area (MSA). At this time the information provided does not adequately support that the Clemson monitor is duplicative. In its Network Plan, SC DHEC indicated that additional information on it shutdown request would be provided in its monitoring network assessment document; however the assessment has not yet been submitted. When it is submitted, the EPA will reconsider its position on the request and discuss it with SC DHEC staff. The monitoring network assessment is required by 40 CFR 58.1 0(d). We look forward to receiving the additional information for further review and consideration. Please note that the EPA is willing to consider the discontinuation ofa different, lower value ozone monitoring site(s) in this MSA. 2. An 

### 03 monitoring site must be established and approved by the EPA in the Myrtle BeachConway-North Myrtle Beach, SC-NC MSA by the beginning ofthe 2016 

### 03 monitoring season. The 2015 Network Plan identifies a site name (Coastal Carolina), location, and AQS ID (45-051- 0008) for this site; however, insufficient information was provided for the EPA to approve this location. The EPA requests that SC DHEC submit a Network Plan addendum with a complete site proposal containing, at minimum, the information required by 40 CFR §58.10(b). In addition to the information on the new site, this addendum may also include a formal proposal to relocate the York (AQS ID 45-091-0006) ozone monitor. By this letter, the EPA is approving a temporary shutdown for this monitor in 2016 while SC DHEC relocates the monitoring site. As a

Internet Address (URL) • http : //

www epa.gov Recycled/Recyclable • Prinled with Vegetable Oil Based Inks on Recycled Paper (Minimum 30% Postconsumer)reminder, every addendum to the Network Plan must undergo a public inspection process before being submitted to the EPA. 3. Monitor siting criteria, as described in 40 CFR Part 58, Appendix E must be evaluated and met at each site operating a regulatory moni tor. Ideally, each site in the monitoring network should be evaluated annually for compliance with Appendix E siting criteria
. The EPA Science and Ecosystem Support Division found SC DHEC monitoring sites which were not meeting regulatory monitor siting criteria in its July 2015 technical systems audit ofthe SC DHEC air monitoring program. The EPA requests that SC DHEC submit documenta tion ofmonitor siting evaluations, determinations, and corrective actions for all ofits regulatory monitoring sites in the next annual 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 South Carolina. Ifyou have any questions or concerns, please contact Gregg Worley at (404) 562-9141 or Ryan Brown at (404) 562-9147
. Sincerely,



### 0. everly H. Banister -'1n Director
. 

# U Air, Pesticides and Toxics Management Division Enclosure

cc: Mr. Robert Brown Division Director, Air Planning Development and Outreach, SC DHEC Mr. Scott Reynolds Director, Division ofAir Quality Analysis, SC DHEC Mr. Thomas Flynn Manager, Air Data Analysis and Support Section, SC DHEC The Honorable William Harr is Chiefofthe Catawba Indian Nation Mr. Darin Steen Director, Environmental Services, Catawba Indian Nation

### CY 2015 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 2015 ambient air monitoring network plan (Network Plan). Ambient air monitoring rules, which include regulatory requirements that address network plans, data certification, and minimum monitoring requirements, among other requirements, 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 (PM1 o ), 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 by the U.S. Office ofManagement and Budget (OMB), July 1, 2014, population estimates from the U.S
. Census Bureau, and historical ambient air monitoring data
. Minimum monitoring requirements for OJ, PM2
.s, and PM1o 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, 2014, population estimates from the U
.S
. Census Bureau are shown in Table 

### 1. Table I: Metropolitan Statistical Areas and Populations

MSAName Population

u Charlotte-Gastonia-Concord NC-SC 2,380,314 Greenville-Anderson-Mauldin, SC 850,965 Columbia, SC 800,495 Charleston-North Charleston-Summerville, SC 727,689 Augusta-Richmond County. GA

-SC
. 583,632 Myrtle Beach-Conwa y-North Myrtle Beach, SC-NC 417,668 Spartanburg, SC 321,418 Florence, SC 207,030 Hilton Head Island-Bluffton-Beaufort, SC 203,022 Sumter, SC 107,919 

### Proposed Monitoring Network Changes The EPA's rationale for approval or disapproval of specific network changes can be found below in the pollutant sections ofthis document. Monitors proposed for discontinuation and the EPA's determination are summarized in Table 

### 2. Table 2: Monitors Proposed for Discontinuation AQSID Site Name Pollutant Tipe Comments 45-072-0002 Clemson 

## o, SLAMS Not AJ!Eroved Temporary shutdown 45-091-0006 YorkCMS OJ SLAMS approved for 20 16,will be relocated in 2017 45-045-0015 Greenville ESC PM1.' speciation SPM Shutdown. No longer funded b the EPAThe Network Plan also mentioned relocation or possible relocation ofthe monitors summarized in Tabte 3. For EPA to approve any ofthese relocations, SC DHEC must submit these requests in a future Network Plan or as part ofa Network Plan addendum with all the requisite information requir ed by 40 CFR §58.10(b)
. Table 3: Monitors Proposed for Relocation or Possible Relocation AQSID Site Name 45-091-0006 York

45-015-0002 Bushy Park Pump Station 45-063-0008 

### Operating Schedules 40 CFR 

### § 58
. 12 lrmo Pollutant 

## o,

PM:u /other Type SLAMS Comments Will be relocated in 2017. SC DEHC must submit a site relocation request as part ofthe next Network Plan or a Network Plan addendum. SLAMS Possible relocation

- tree encroachment SLAMS/other Possible relocation

- possible changes in property use by land owner

The monitoring network proposed in the Network Plan meets the required operating schedules for all continuous analyzers and all manual Pb, PM10, PMH. and PM2.s Speciation Trends Network (STN) monitors. SC DHEC has not proposed any changes to its operating schedules in the Network Plan. 

### Air Quality Index (AQI) Reporting 40 CFR §58.50 AQI reporting is required in MSAs with populations over 350,000
. There are four MSAs in the state of South Carolina required to report an AQI : Greenville-Anderson-Mauldin, Columbia, Charleston-North Charleston, and Myrtle Beach-Conway-North Myrtle Beach, SC-NC MSAs. The Network Plan indicates that the daily AQI for all ofthese areas except the Myrtle Beach-Conway-North Myrtle Beach, SC-NC MSA is available on the EPA' s AIRNow web site. Once an OJ monitoring site is approved and operating in this MSA in order to satisfy the minimum requirements in 40 CFR Part 58, AQI reporting should also be provided for the Myrtle Beach-Conway-North Myrtle Beach, SC-NC MSA. 

### National Core {NCore) Monitodng Network 40 CFR Part 58, Appendix D, 3 A requirement that each state operate at least one NCore site is found in 40 CFR Part 58, Appendix D, 3
. The state's approved NCore site is located in Columbia at the Parklane site (AQS ID 45-079-00047) and the SC DHEC has not proposed any changes for the site in its Network Plan. 

### OJ Monitoring Requirements 40 CFR Part 58, Appendix D, Table D-2 The Network Plan includes a proposal to discontinue OJ monitoring at the Clemson site (AQS ID 45- 072-0002). The EPA does not approve this proposal at this time. The Network Plan stated that the Clemson site is duplicative, but no informationjustifying that position was included. The SC DI-IEC indicated in the Network Plan that additional rationale for discontinuing this site would be contained in the SC DHEC monitoring network assessment document. However , the SC DHEC has not yet submittedthe assessment to the EPA. Thus, the infonnation provided to EPA does not adequately support the position that the Clemson monitor is duplicative. The available data show that peak and average 

### 03 concentrations are consistently higher at the Clemson site than they are at other sites in the Greenville area. Forty CFR Part 58, Appendix D, 4.l(b) requires that "Within an OJ network, at least one 

### 03 site for each MSA, or CSA ifmultiple MSAs are involved, must be designed to record the maximum concentration for that particular metropolitan area." Based on EPA's analysis ofthe data, the Clemson site is required as the maximum concentration site in the MSA. Also, the Clemson site is representative ofa more densely populated area than other sites in the Greenville area. We look forward to receiving the additional infonnation for further review and consideration. Please note that, the SC DHEC is currently operating five Q3 monitors in this MSA where two are required at a minimum. The EPA is willing to consider a request to shut down other site(s) in the MSAthat are oflower value than the Clemson site. Due to changes that OMB made to MSA boundaries in February of2013, Brunswick County, North Carolina has been added to the Myrtle Beach-Conway-North Myrtle Beach, SC-NC MSA. This change triggered the requirement for an 

### 03 monitor in the MSA based on the population in the new MSA. The 2015 Network Plan identifies a site name (Coastal Carolina), location, and AQS ID (45-051-0008) for this monitor, however insufficient infonnation was provided for the EPA to approve this location. The EPA requests that SC DHEC submit a Network Plan addendum with a complete site proposal with all the requisite infonnation required by 40 CFR §58.1 O(b). This addendum must undergo a public inspection process before being submitted to the EPA. The Network Plan also includes a proposal to temporarily discontinue 

### 03 monitoring at the York CMS site (AQS ID 45-091-0006) for the 2016 

### 03 season and that this site will be relocated to a nearby location. The York monitor is an upwind site for the Charlotte-Concord-Gastonia NC-SC MSA and typically reads lower than the other 

### 03 monitors in the MSA. The EPA approves the temporary shutdown ofthe York monitor for 2016. Once SC DHEC has identified a suitable replacement site for the York monitor, the EPA requests that SC DHEC submit a Network Plan addendum with a complete site proposal including all the requisite infonnation required by 40 CFR §58.10(b). This addendum must undergo a public inspection process before being submitted to the EPA. With the exception ofthe Myrtle Beach-Conway-North Myrtle Beach, SC-NC MSA, the EPA has detennined that the 

### 03 monitoring network outlined in the Network Plan meets the minimum requirements found in 40 CFR Part 58, Appendix D, Table D-2 for the other MSAs in South Carolina. 

### S02 Monitoring Requirements 

### 40 CFR Part 58, Appendix D, 

### 4.4 Ambient air monitoring network design criteria for S02 are found in Section 4.4 of40 CFR Part 58, Appendix D. 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 

### SOz monitoring site(s) required in each CBSA will satisfy minimum monitoring requirements ifthe monitor(s) is sited within the boundaries ofthe parent CBSA and is ofthe following site types: population exposure, maximum concentration, source-oriented, general background, or regional transport. An 

### SOz monitor at an NCore station may satisfy minimum monitoring requirements ifthat monitor is located within a CBSA with minimally required monitors consistent with Appendix D, Section 4.4. Based upon PWEis


### 3calculated using the latest population estimates and emission inventory data, the minimum number of monitors required for the CBSAs in South Carolina is summarized in Table 4. Table 4: SO: Monitoring System Status

CBSAName Augusta-Richmond Counry, GA-SC Charleston-North Cha rleston

-Summerville, SC Charlotte-Gastonia-Concord NC

-SC Columbia, SC Greenville-Anderson -Mauldin, SC SLAMS Required SLAMS Present

Based upon the information summarized in Table 4, the S02monitoring network outlined in the Network Plan meets the S02 PWEI requirements specified in 40 CFR Part 58, Appendix D, Section 4.4. The EPA finalized the S02 Data Requirements Rule (ORR) (see 80 F ederal Register, No. 162) on August 21 , 2015. This rule will require characterization ofthe air quality near sources with S02 emissions greater than 2,000 tons per year by conducting ambient air monitoring or modeling. We encourage SC DHEC to begin having conversations with affected sources in the state to determine an agreed upon approach for meeting the ORR requirements. By January 15 , 2016, SC DHEC must submit a final list to the EPA Region 4 identifying the sources around which 

### SOz air pollution must be characterized. For sources that SC DHEC decides to evaluate using ambient air monitoring, new site proposals must be included in the 2016 Network Plan. The location ofthese monitoring sites should be selected using the process out lined in the S02 NAAQS Designations Source-Oriented Monitoring Technical Assistance Document1• N02 

### Monitoring Requirements 40 CFR Part 58, Appendix D, 4.3 Ambient air monitoring network design criteria for 

### NOz are found in 40 CFR Part 58, Appendix D, 4.3. There are three types ofrequired N02 monitoring: near-road, area-wide, and Regional Administrator required
. 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 N02 monitoring sites are found in 40 CFR Part 58, Appendix D, 4
.3
.2
. The requirement for near-road monitoring in the Charlotte-Gastonia-Concord NCSC CBSA will be met using the Remount site (AQS ID 37-119-0045) operated by Mecklenburg County's Land Use and Environmental Services Agency (MCLUESA) in Charlotte, North Carolina
. No other CBSA in South Carolina is currently required to have near-road N02 monitoring. By January 

### J, 2017, South Carolina CBSA's with populations over 500,000 will be required to operate near-road N02 monitoring
. South Carolina has four CBSAs in this range: Greenville-Anderson-Mauldin, SC; Columbia, SC; Charleston-North Charleston-Summerville, SC, and Augusta-Richmond County, GA-SC. As a result ofthe 5-year NAAQS review cycle, the N02monitoring requirements may be modified in 2016
. The N02 near -road monitoring requirements may change for CBS As with populations between 500,000 and 1,000,000 people, such as the South Carolina CBSAs listed above
.

1 S02NAAQS Designations Sour ce-Oriented Monitoring Technical A ssistance Document. U
.S. EPA Office ofAir Quality Planning and Standards Air Qu ality Assessmen t Di vision, Draft December 20 13
. btm: //

www3.epa.g.ov /airguali ty

/sulfurdjoxide!pdfs/S02Monitoring. TAD.pdf 

### 4Ambient air monitoring network design criteria for area-wide N02 sites are found in Section 4.3.3 of Appendix D to 40 CFR Part 58. The Garinger High School (AQS ID 37-119-0041) currently operated by MCLUESA will be used for fulfilling the area-wide NOz monitoring requirement for the CharlotteGastonia-Concord NC-SC CBSA. No other CBSA in South Carolina is required to have area-wide N02 monitoring. Ambient air monitoring network design criteria for Regional Administrator required N02 monitoring, often referred to as RA-40 monitoring, are found in 40 CFR Part 58, Appendix D, 4.3.4. Under these provisions, Regional Administrators must require a minimum offorty additional N02 monitoring stations nationwide, with a primary focus on siting these monitors in locations to protect susceptible and vulnerable populations. Previously, Region 4 selected the Greenville ESC site (AQS ID 450-045-0015) as a location for an RA-40 NOz monitoring site. The full list ofNOz monitors identified by EPA's Regional Administrators can be found on EPA's website at httt>://www.epa.gov/ttnamtillsvoop.html. 

### 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 from each airport which emits 1.0 or more tons per year..." Although SC DEC has 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 under terms ofa settlement agreement reached with several petitioners who commented on the construction permit for the facility. Locations for the monitoring sites were selected based upon an agreement between the company and the stakeholders. Forty CFR Part 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 Ph either as Ph-TSP or PbPM!o
." The Network Plan indicates that a Pb sampler is located at the Parklane NCore site (AQS ID 45- 079-0007). The Pb monitoring network described in the Network Plan meets all ofthe design criteria of 40 CFR Part 58. 

### PMto 

### Monitoring Requirements 40 CFR Part 58, Appendix A, 3.3.1 40 CFR Part 58, Appendix D, Table D-4 Region 4 has determined that the PM1 omonitoring network outlined in the Network Plan meets or exceeds the minimum requirements found in 40 CFR Part 58 , Appendix D, Table D-4 for all MSAs. Also, all manual PM10 collocation requirements are met.



### 5

### PMz.s Monitoring Requirements 40 CFR Part 58, 

### Appendix A, 3.2.5 

### 40 CFR Part 58, 

### Appendix D, Table D-5 The EPA has determined that the PM2
.s monitoring network outlined in the Network Plan meets or exceeds the minimum requirements found in 40 CFR Part 58, Appendix D, Table D-5 for all MSAs. Also, all PM2 

### s collocation requirements are met. 

### PMz.s Continuous Monitoring Requirements 40 

### CFR Part 58, 

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

### s monitoring r equire that "The State, or where appropriate, local agencies must operate continuous PM2
.s analyzers equal to at least one-half(round up) ofthe minimum required sites listed in Table D-5 ofthis Appendix
. At least one required continuous analyzer in each MSA must be collocated with one ofthe required FRM/FEM/AR.¥ [Federal Reference Method/Federal Equivalent Method/Approved Regional Method] monitors, unless at least one ofthe required FRM/FEM/ ARM monitors is itselfa continuous FEM or ARM monitor in which case no collocation requirement applies." After review ofthe Network Plan, the EPA has determined that the proposed PM2
.s continuous monitoring network meets or exceeds the minimum requirements in all of the MSAs in the state. Also, the continuous PM2
.s collocation requirements are met in all MSAs. 

### PMz.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 levels and at least one PM2
.s site to monitor for regional transport. " The Network Plan identifies Ashton (AQS ID 45-029

-0002) in Colleton County as a regiona l background site and Chesterfield (AQS ID 45-025

-000 1) in Chesterfield County as a regional transport site. Therefore, the SC DHEC has satisfied the requirements of40 CFR Part 58 for regional background and transport sites
. 

### PM2
.s Chemical Speciation Network (CSN) 40 CFR Part 58, Appendix D, 4
.7
.4 The EPA conducted an assessment ofthe CSN in an effort to optimize the network and create a network that is sustainable going forward. As a result ofthis assessment, the EPA defunded a number of monitoring sites, eliminated the CSN PM2 

### s mass measurement, reduced the frequency ofcarbon blanks, reduced sample frequency at monitoring sites, and reduced the number oficepacks in shipments during the cooler months ofthe year. The EPA defunded two CSN monitors at sites in South Carolina: Chesterfield (AQS ID 45-025-0001) and Greenville ESC (AQS ID 45-045-0015). The Network Plan indicates that the Chesterfield CSN monitor has been discontinued due to lack ofEPA funding and the Greenville ESC speciation monitor will continue to operate with state funding.



### 6

### Photochemical Assessment Monitoring Station (PAMS) 40 CFR Part 58, Appendix D, 5.0 With the recent passage ofa new ozone NAAQS on October 1, 2015, the EPA also finalized changes to PAMS. By June 1, 2019, the NCore site in Columbia will be required to implement PAMS monitoring. The EPA realizes there are several implementation challenges to work through and is committed to working closely with SC DHEC to identify efficiencies and minimize the burden ofimplementing this new monitoring program. However, at this time the PAMS requirement is being met by the state. 

### Monitoring Siting Criteria 40 CFR Part 58, Appendix E Monitor siting criteria, as described in 40 CFR Part 58, Appendix E, must be met and continually evaluated at each site operating a regulatory monitor. Ideally, each site in the monitoring network should be evaluated annually for compliance with regulatory siting criteria. The EPA Science and Ecosystem Support Division (SESD) found many ofthe SC DHEC monitoring sites were not meeting regulatory monitor siting criteria in the July 2015 technical systems audit (TSA) ofthe SC DHEC air monitoring program. The final TSA report, dated November 17, 2015, describes this audit finding in greater detail. The SC DHEC was provided an opportunity to comment on the draft TSA report. The EPA requests that the SC DHEC submit documentation ofmonitor siting evaluations, determinations, and corrective actions for all ofits regulatory monitoring sites in the next annual Network Plan.

7