2015 Ambient Air Quality Monitoring 5 Year Network Assessment For Mecklenburg County Air Quality

Transcription

1 M E C K L E N B U R G C O U N T Y A I R Q U A L I T Y A I R Q U A L I T Y M O N I T O R I N G G R O U P 2015 Ambient Air Quality Monitoring 5 Year Network Assessment For Mecklenburg County Air Quality Mecklenburg County Land Use and Environmental Services Agency Air Quality 700 North Tryon Street Suite 205 Phone Fax July 1, 2015 Page 1 of 79

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3 CERTIFICATION By the signatures below, Mecklenburg County Air Quality (MCAQ) certifies that the information contained in the Ambient Air Quality Monitoring 5 Year Network Assessment for Mecklenburg County Air Quality is complete and accurate, to the best of MCAQ s knowledge at the time of submittal to EPA Region 4. The assessment is submitted to comply with the requirements of 40 CFR 58.10(d). Due to unforeseen circumstances or the need for adjustments to the monitoring network that may arise during the sampling year, some network information may change. Changes will be updated in the annual network plan. Print Name: Jeff Francis Signature: Date: Air Quality Monitoring Manager, MCAQ Print Name: Leslie Rhodes Signature: Date: Director, MCAQ Page 3 of 79

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5 Table of Contents Summary of Findings Introduction and Requirements of 5-Year Network Assessment Monitoring Objectives and Spatial Scales Site Types Spatial Scales Monitoring Station Types Information to Evaluate Requirements of Assessment Pollutant Specific Assessment of Network Ozone (O3) Network Monitoring Requirements and General Description Particulate Matter PM Carbon Monoxide (CO) Sulfur Dioxide (SO2) Nitrogen Dioxide (NO2) Particulate Matter PM Lead (Pb) Waiver Requests Population Summary Emission Trends in Mecklenburg County Stationary Source Emission Trends in Mecklenburg County Mobile Source Emission Data - Mecklenburg County General Meteorological Characteristics References Page 5 of 79

6 Summary of Findings Ambient Air Quality Monitoring 5 Year Network Assessment For Mecklenburg County Air Quality Ozone The MCAQ monitoring stations ( and ) meet the requirements of 40 CFR 58, Appendix D, 1.1 for monitoring objectives and 40 CFR 58 Appendix D, for monitor site types. The two stations operated by MCAQ meet the minimum requirements for ozone monitoring stations in the MSA. Additionally, The North Carolina Division of Air Quality (NCDAQ) operates 3 stations in the MSA; one each in Rowan, Lincoln and Union counties. South Carolina Department of Health and Environmental Control (SCDHEC) operates a station in York County, SC in the MSA. There are a total of 6 stations operated in the Charlotte-Concord-Gastonia, NC-SC MSA. PM2.5 - The network assessment indicates that 2 of the currently operating stations ( and should be maintained. The third station ( ) will be re-located to the near-road monitoring station ( ) to comply with the near-road monitoring requirement for PM2.5. Nearroad PM2.5 monitoring is required to begin by January 1, The PM2.5 monitoring network operated by MCAQ meets the monitoring objectives defined in 40 CFR 58 Appendix D. Carbon Monoxide - The network assessment indicates the network should be maintained in its current configuration. CO monitoring meets the requirements of 40 CFR 58 Appendix D for NCore measurements. An additional CO monitor will be installed at the near-road NO2 station in accordance with requirements. The additional site must be operational by January 1, Sulfur Dioxide The current SO2 NAAQS (June 2, 2010) requires one site in the CBSA. MCAQ operates one (1) NCore site, which meets the requirement. SCDHEC operates an additional site in York County, SC. Nitrogen Dioxide The most recent NO2 NAAQS (February 9, 2010) requires two sites in the CBSA. MCAQ operates two sites that meet current regulatory requirements, one near-road NO2 station ( ) and one area-wide site (NCore ). PM10 PM10 is a lower priority because measured concentrations in the MCAQ network have been below 80% of the NAAQS. Two to four stations are required. MCAQ is operating 3 stations. The number of PM10 monitoring sites in the MCAQ network will be evaluated for efficiencies over the next 5 years. The number of stations may be reduced. Lead One (1) population-oriented lead monitoring site is required in the CBSA. MCAQ operates a lead monitoring station at the NCore station ( ) in accordance with CFR requirements. Page 6 of 79

7 Ambient Air Monitoring Network Assessment Summary - Table CFR 58 Appendix D, 1.1Monitoring Objectives 2. Need New Monitoring Sites? 3. Need to Terminate Sites? 4. Need New Technology? 5. Air Quality Measured Near Susceptible Individuals? 6. Impact of Site Discontinuance on Data Users? 7. Change PM2.5 Siting Due to Population Changes? 8, Population Statistics in Assessment? 9. Historical Data? 10. Appropriate Spatial Scale of Representativen ess? 11. Spatial Redundancy (SR) and / or Gaps (G)? 12. Programmatic Trends or Shifts? Ozone PM2.5 CO SO2 NO2 PM10 Lead No No Analyzer No Calibrat or - Yes Complies Yesnearroad by 1/1/2017 Yesrelocate station to nearroad by 1/1/2017 FRM update Continu ous Evaluate Yesnearroad by 1/1/2017 Complies Complies Complies Complies Complies Complies No No No No No No No Evaluate No No No Yes replace NCore Yes Yes Yes Yes Yes Yes Yes None None NA NA NA NA NA NA No NA NA NA NA NA Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes SR No G - No Highest Priority SR No G - No High Priority SR No G - No NCore High Priority SR No G - No NCore High Priority SR No G No NCore High Priority No SR No G - No Low Priority No SR No G - No Low Priority Page 7 of 79

8 Ambient Air Quality Monitoring 5 Year Network Assessment for Mecklenburg County Air Quality 1.0 Introduction and Requirements of 5-Year Network Assessment The Mecklenburg County Air Quality (MCAQ) monitoring program, a division of the Mecklenburg County Land Use and Environmental Services Agency (LUESA); provides air quality monitoring services for Mecklenburg County, North Carolina. Mecklenburg County Air Quality is a state certified local air pollution program whose purpose is to improve and maintain ambient air quality and reduce exposure to unhealthy levels of air pollution. MCAQ operates an ambient air surveillance monitoring network as required by the United States Environmental Protection Agency (EPA). The ambient air surveillance monitoring network is required to operate in accordance with the United States Code of Federal Regulations (CFR). Title 40 CFR 58.10(d) requires a periodic network assessment of the air quality surveillance system. The periodic network assessment is to be conducted once every five years. The specific language follows: 40 CFR (d) The state, or where applicable local agency, shall perform and submit to the EPA Regional Administrator an assessment of the air quality surveillance system every 5 years to determine, at a minimum, if the network meets the monitoring objectives defined in appendix D to this part, whether new sites are needed, whether existing sites are no longer needed and can be terminated, and whether new technologies are appropriate for incorporation into the ambient air monitoring network. The network assessment must consider the ability of existing and proposed sites to support air quality characterization for areas with relatively high populations of susceptible individuals (e.g., children with asthma), and, for any sites that are being proposed for discontinuance, the effect on data users other than the agency itself, such as nearby states and tribes or health effects studies. The state, or where applicable local, agency must submit a copy of this 5- year assessment, along with a revised annual network plan, to the Regional Administrator. The assessments are due every five years beginning July 1, The information contained herein ( Ambient Air Quality Monitoring 5 Year Network Assessment for Mecklenburg County Air Quality ) provides pollutant specific assessments of the monitoring network as required by 40 CFR 58.10(d). 2.0 Monitoring Objectives and Spatial Scales The ambient air monitoring network is designed to meet three basic monitoring objectives. These basic objectives per 40 CFR 58 Appendix D are: a) Provide air pollution data to the general public in a timely manner. Page 8 of 79

9 b) Support compliance with national ambient air quality standards (NAAQS) and emissions strategy development. c) Support air pollution research studies. 2.1 Site Types In order to support the air quality management work indicated in the three basic air monitoring objectives, a network must be designed with a variety of types of monitoring sites. Monitoring sites must be capable of informing managers about many things including the peak air pollution levels, typical levels in populated areas, air pollution transported into and outside of a city or region, and air pollution levels near specific sources. To summarize some of these sites, here is a listing of six general site types: a) Sites located to determine the highest concentrations expected to occur in the area covered by the network. b) Sites located to measure typical concentrations in areas of high population density. c) Sites located to determine the impact of significant sources or source categories on air quality. d) Sites located to determine general background concentration levels. e) Sites located to determine the extent of regional pollutant transport among populated areas; and in support of secondary standards. f) Sites located to measure air pollution impacts on visibility, vegetation damage, or other welfare-based impacts. 2.2 Spatial Scales To clarify the nature of the link between general monitoring objectives, site types, and the physical location of a particular monitor, the concept of spatial scale of representativeness is defined. The goal in locating monitors is to correctly match the spatial scale represented by the sample of monitored air with the spatial scale most appropriate for the monitoring site type, air pollutant to be measured, and the monitoring objective. Thus, spatial scale of representativeness is described in terms of the physical dimensions of the air parcel nearest to a monitoring site throughout which actual pollutant concentrations are reasonably similar. The scales of representativeness of most interest for the monitoring site types described above are as follows: a) Micro Scale meter diameter b) Middle Scale meter diameter c) Neighborhood Scale kilometer diameter Page 9 of 79

10 d) Urban Scale 4 50 kilometer diameter e) Regional s of kilometer diameter f) National or Global Nation and globe as a whole Proper siting of a monitor requires specification of the monitoring objective, the types of sites necessary to meet the objective, and then the desired spatial scale of representativeness. 2.3 Monitoring Station Types The National ambient air monitoring system includes several types of monitoring stations, each targeting a key data collection need and each varying in technical sophistication. a) Research Grade Stations platforms for scientific studies, either involved with health or welfare impacts, measurement methods development, or other atmospheric studies. b) NCore Multi-pollutant Stations sites that measure multiple pollutants in order to provide support to integrated air quality management data needs. c) State and Local Air Monitoring Stations (SLAMS) sites intended to address specific air quality management interest. d) Special Purpose Monitoring (SPM) Stations short-term monitoring station for criteria pollutants or longer-term monitoring station for non-criteria pollutants or non-federal reference method (FRM)/non-federal equivalent (FEM) methodologies. 2.4 Information to Evaluate Information to be considered in the evaluation of the ambient air surveillance monitoring network relative to the monitoring objectives and spatial scale includes: a) General monitoring requirements, design criteria for NCore sites and pollutantspecific design criteria for State and Local Air Monitoring Stations (SLAMS) monitoring for National Ambient Air Quality Standards (NAAQS) pollutants. b) Air quality summary information available for each NAAQS pollutant of interest. c) Meteorological summary information. d) 40 CFR 58 Appendix D Objectives Evaluation e) Monitoring site type evaluation. f) Population summary information. Page 10 of 79

11 g) Emissions inventory (source and mobile) summary information. 2.5 Requirements of Assessment The 5 year network assessment is required to determine at a minimum: a) If the network meets the monitoring objectives defined in 40 CFR 58 Appendix D. b) Whether new sites are needed. c) Whether existing sites are no longer needed and can be terminated. d) Whether new technologies are appropriate for incorporation into the ambient air monitoring network. e) Whether the network sufficiently supports characterization of air quality in areas with large populations of susceptible individuals. f) Whether discontinuance of a monitoring site would have an adverse impact on other data users or health studies. g) For PM2.5, the assessment must identify needed changes to population oriented sites. h) If monitoring is required near any additional Pb sources according to the most recent National Emissions Inventory. (Monitoring is required near sources with Pb emissions greater than 0.5 tons per year.) i) Any waiver of 40 CFR 50 and /or 58 regulatory requirements must be renewed during each 5-year assessment unless otherwise specified to be renewed annually during the network plan process. To include: Pb source monitoring waivers. Continuous PM2.5 FEM Comparability (NAAQS Exclusion). Siting criteria Any additional waiver of Part 50 and/or 58 Appendix E, Section 10. Page 11 of 79

12 3.0 Pollutant Specific Assessment of Network The MCAQ ambient air surveillance monitoring network as currently configured consists of six (6) monitoring stations: Figure 1. MCAQ Monitoring Stations Station Name EPA AQS ID CO NO2 O3 Pb PM2.5 PM10 SO2 PMC #11 Fire Station X County Line X Garinger X X X X X X X X Montclaire X X X Oakdale X Remount X Table 2. Site Name, Site AQS ID, Pollutant Monitored. The MCAQ network consists of one (1) National Core multi-pollutant monitoring station (NCore, Station ) and five (5) State and Local Air Monitoring Stations (SLAMS). The U.S. EPA has set National Ambient Air Quality Standards for six air pollutants. These air pollutants (also known as "criteria pollutants") are particulate matter (PM2.5 and PM10), ozone (O3), carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2) and lead (Pb). Page 12 of 79

13 National Ambient Air Quality Standards Pollutant [final rule cite] Primary/ Secondary Averaging Time Level Form Carbon Monoxide [76 FR 54294, Aug 31, 2011] primary 8-hour 1-hour 9 ppm 35 ppm Not to be exceeded more than once per year Lead [73 FR 66964, Nov 12, 2008] primary and secondary Rolling 3 month average 0.15 μg/m 3 (1) Not to be exceeded Nitrogen Dioxide [75 FR 6474, Feb 9, 2010] [61 FR 52852, Oct 8, 1996] primary primary and secondary 1-hour Annual 100 ppb 53 ppb (2) 98th percentile of 1-hour daily maximum concentrations, averaged over 3 years Annual Mean Ozone [73 FR 16436, Mar 27, 2008] primary and secondary 8-hour ppm (3) Annual fourth-highest daily maximum 8- hr concentration, averaged over 3 years primary Annual 12 μg/m 3 annual mean, averaged over 3 years Particle Pollution Dec 14, 2012 PM 2.5 secondary primary and secondary Annual 24-hour 15 μg/m 3 35 μg/m 3 annual mean, averaged over 3 years 98th percentile, averaged over 3 years PM 10 primary and secondary 24-hour 150 μg/m 3 Not to be exceeded more than once per year on average over 3 years Sulfur Dioxide [75 FR 35520, Jun 22, 2010] [38 FR 25678, Sept 14, 1973] primary secondary 1-hour 3-hour 75 ppb (4) 0.5 ppm 99th percentile of 1-hour daily maximum concentrations, averaged over 3 years Not to be exceeded more than once per year Table 3. (1) Final rule signed October 15, The 1978 lead standard (1.5 µg/m3 as a quarterly average) remains in effect until one year after an area is designated for the 2008 standard, except that in areas designated nonattainment for the 1978, the 1978 standard remains in effect until implementation plans to attain or maintain the 2008 standard are approved. (2) The official level of the annual NO2 standard is ppm, equal to 53 ppb, which is shown here for the purpose of clearer comparison to the 1-hour standard. (3) Final rule signed March 12, The 1997 ozone standard (0.08 ppm, annual fourth-highest daily maximum 8-hour concentration, averaged over 3 years) and related implementation rules remain in place. In 1997, EPA revoked the 1-hour ozone standard (0.12 ppm, not to be exceeded more than once per year) in all areas, although some areas have continued obligations under that standard ( anti-backsliding ). The 1-hour ozone standard is attained when the expected number of days per calendar year with maximum hourly average concentrations above 0.12 ppm is less than or equal to 1. (4) Final rule signed June 2, The 1971 annual and 24-hour SO2 standards were revoked in that same rulemaking. However, these standards remain in effect until one year after an area is designated for the 2010 standard, except in areas designated nonattainment for the 1971 standards, where the 1971 standards remain in effect until implementation plans to attain or maintain the 2010 standard are approved. Page 13 of 79

14 The following sections will provide an assessment of the monitoring network for each criteria pollutant that is monitored in the MCAQ network per the requirements of 40 CFR 58.10(d) and as outlined in Section 1.0 Introduction and Requirements of 5-Year Network Assessment above. 3.1 Ozone (O3) Network Monitoring Requirements and General Description The minimum monitoring requirements for ozone are listed in Table D-2 of 40 CFR 58 Appendix D, 4.1. Table D-2 is reproduced below (Table 4): Table D-2 of Appendix D to Part 58 - SLAMS Minimum O3 Monitoring Requirements MSA population 1,2 Most recent 3-year design value concentrations 85% of any O3NAAQS 3 Most recent 3-year design value concentrations <85% of any O3NAAQS 3,4 >10 million million ,000 <4 million 50,000 <350, Table 4. (D-2) The number of sites required in the network is based on MSA population and design value (NAAQS compliance value). Mecklenburg County is located in the Charlotte- Concord-Gastonia (16740) metropolitan statistical area (MSA). The MSA component counties are Cabarrus, Gaston, Iredell, Lincoln, Mecklenburg, Rowan and Union Counties in North Carolina and Chester, Lancaster and York Counties in South Carolina. The 2014 U.S. Census population estimate for the MSA is 2,380,314. The most recent design value ( ) for the MSA is ppm (8-hour design value). Eighty five percent (85%) of the 8-hour NAAQS is ppm. The design value for the MSA is 85% of the 8-hour NAAQS (0.075 ppm). Based on the 2014 U.S. Census population estimate and the most recent design value 85% of the 8-hour design value, the minimum number of required monitoring sites for the MSA is two (2). There are currently 6 ozone monitoring stations operating in the MSA. A seventh station, (Arrowood) operated through This station was discontinued on 11/01/2014 as a result of the loss of the leasing agreement with the site property owner. Page 14 of 79

15 The 7 stations and their respective 2014 design values are listed in the table that follows: Ozone monitoring stations active in the Charlotte-Concord-Gastonia MSA MCAQ sites in blue shading: AQS ID Site Name County, State 2014 Design Value Crouse Lincoln, NC ppm Garinger Mecklenburg, NC ppm * Arrowood Mecklenburg, NC ppm County Line Mecklenburg, NC ppm Rockwell Rowan, NC ppm Monroe Union, NC ppm York York, SC ppm Table 5. *-Site discontinued 11/1/2014. The six (6) active ozone monitoring station locations (indicated by ) in the Charlotte- Concord-Gastonia MSA are shown in Figure 2 below: Figure 2. Page 15 of 79

16 Mecklenburg County Air Quality (MCAQ AQS Reporting Organization ) operates 2 of the currently active monitoring sites in the MSA: Currently active ozone monitoring sites operated by MCAQ. AQS ID Site Name County, State 2014 Design Value Garinger Mecklenburg, NC ppm County Line Mecklenburg, NC ppm Table 6. Ozone forms more readily during warmer times of the year. The MCAQ ozone monitoring site locations are geographically oriented along a vector that corresponds to the direction of the seasonal prevailing southwesterly winds during the summer months (Figure 3 below). Figure 3. Summer June, July, and August NWS Station KCLT Page 16 of 79

17 Annual wind data (See Figure 4 below.) demonstrates an orientation similar to data collected during the summer months with an increased westerly component and secondary northerly winds. Figure NWS Station - KCLT. Within the MCAQ monitoring network, stations and are designed to record the maximum concentrations in the network. Both stations are downwind (prevailing wind from the SW) of the central business district of the city of Charlotte, NC. Station (Garinger) is 5.4 kilometers Figure 5. Active MCAQ Ozone Stations ENE of the central business district of Charlotte and monitors maximum Figure 5. concentrations in an area of high population density. The site is typical of urban areas within Mecklenburg County. The site is neighborhood scale (4 km diameter). Page 17 of 79

18 Station (County Line) is 20 kilometers NE of the central business district of Charlotte and is a maximum concentration monitoring site downwind of the urban core. The County Line station scale of representativeness is urban (4 km 50 km diameter). The County Line site design value (0.073 ppm 8-hour ozone) is the maximum design value site ( ) in the MSA. A third ozone site, (Arrowood) was discontinued at the close of the 2014 monitoring season due to eviction from the property. The site was 14.5 kilometers SW of the Charlotte central business district in the SW section of Mecklenburg County. The monitoring objectives of the Arrowood ozone instrument were to measure upwind background ambient concentrations and population exposure. During periods of northeasterly winds this site would occasionally record the daily maximum in the network. Figure 6. The last measured exceedance of the NAAQS for ozone at the Arrowood station was recorded in In 2012, 3 exceedances of the ppm ozone NAAQS were recorded at the station. None of those exceedances were site specific maximum values for their respective days. Other sites within the MCAQ network recorded higher site specific maximum values on the dates of those exceedances. No exceedances of the NAAQS were recorded at this station in 2013 or The station has not been re-sited as of the date of this assessment and is not required to be re-located to meet minimum ozone monitoring requirements Compliance with 40 CFR 58 Appendix D, Monitoring Objectives (a) Provide air pollution data to the general public in a timely manner: The MCAQ monitoring network collects data from two (2) ozone monitoring sites. Data is downloaded each 12 minutes by TCP/IP connections to the MCAQ central computer system. Hourly data is displayed on the MCAQ website after it is downloaded each hour. MCAQ ozone data is uploaded to the USEPA AirNow website ( on an hourly basis for dissemination on the national air quality website. Page 18 of 79

19 After ozone data is validated it is uploaded to the USEPA Air Quality System (AQS). AQS is the national data repository for air quality data. MCAQ uploads data to AQS on a monthly basis. Data from the monitoring sites operated by MCAQ is available to the general public in a timely manner. (b) Support compliance with national ambient air quality standards (NAAQS) and emissions strategy development: Data from the MCAQ ozone monitoring network complies with applicable siting requirements and is available for NAAQS compliance determination and may be used for emissions strategy development. Data from the two monitoring sites operated by MCAQ may be used in the development of attainment and maintenance plans. Data from the SLAMS site ( ) and the NCore site ( ) is available for use in the evaluation of regional air quality models used in developing emission strategies, and may be used to track trends in air pollution abatement control measures impact on improving air quality. (c) Support for air pollution research studies: Site (Garinger) is an NCore site and may be used to supplement data collected by researchers working on health effects assessments and atmospheric processes, or for monitoring methods development Types of Monitoring Sites (40 CFR 58 Appendix D 1.1.1): The MCAQ ozone monitoring network is designed to support the air quality management work indicated in the three basic air monitoring objectives listed above by providing information regarding peak air pollution levels, typical levels in populated areas, and air pollution transported into and outside the county. The stations in the MCAQ network are located geographically to track ozone transport over the county. The sites are also located so that measurements are conducted in areas of expected maximum concentration and in areas of high population density (Figure 7). Page 19 of 79

20 Figure Census Population Projections Need for New Monitoring Sites The MCAQ network is comprised of 2 monitoring stations. These stations ( , ) meet the minimum requirements for the entire MSA. Station is the maximum design value site for the MSA ( ). This site is designed to record maximum concentrations in the MSA (40 CFR 58 Appendix D 4.1(b). Station is an approved NCore site. The site is designed to measure maximum concentrations in an area of high population density (See Figure 7). The site may measure maximums due to transport or during periods of stagnation and recirculation. The ozone monitoring network operated by MCAQ meets the monitoring requirements of 40 CFR 58 Appendix D. Based on this analysis, no new ozone sites are proposed for Mecklenburg County, however, MCAQ will continue to evaluate the option of replacing station over the next assessment period as part of the annual network planning process Need to Terminate Existing Sites Each site operated by MCAQ serves a specific purpose is an approved NCore ozone site and is required. Page 20 of 79

21 is the maximum concentration (design value) site in the MSA. The site is oriented along the primary summer wind vector (SW to NE) which intersects the central business district of Charlotte, NC and measures air quality conditions directly downwind of a major urban area. Stations and should continue operating in the MCAQ network Appropriateness of New Technologies MCAQ is currently utilizing the newest generation of ozone monitoring instrumentation manufactured by Thermo Environmental Instruments, Inc. (Model 49i). The technology is a proven Federal Equivalent Method (FEM) that should meet the monitoring requirements for the next five (5) years. Two ozone calibration standards are previous generation Thermo Environmental Instrument, Inc. C Series devices. These two devices have been in service for thirteen (13) years. The C Series ozone calibration equipment should be replaced with newer equipment within the next year ( ) as factory support for this generation of equipment will end August 31, Page 21 of 79

22 3.1.5 Ability of Existing and Proposed Sites to Support Air Quality Characterization in Areas with High Populations of Susceptible Individuals Station is located in an area of high population density. Susceptible individuals in this assessment are defined as those < 5 years of age and > 65 years of age. The maps in Figures 8 and 9 display the location of the Garinger site in relation to the population densities of person under the age of 5 (Figure 8) and over the age of 65 (Figure 9). Station is well sited for monitoring susceptible individuals as it is located near areas with higher density populations of the very young (<5 years of age) and older adults (>65 years of age). Figure Census Population Projections - People under the age of 5. Figure Census Population Projections - People over the age of 65. Page 22 of 79

23 3.1.6 Impact of Discontinuance on Data Users or Health Studies MCAQ plans to continue operation of two ozone monitoring stations in the network. There should be minimal impact on data users or health studies resulting from the discontinuance of station (Arrowood) PM2.5 Changes to Population-Oriented Sites Not Applicable Statewide and Local Level Population Statistics See Section 5.0. Page 23 of 79

24 Concentration, ppm ppm Historical Data Design values measured at MCAQ monitoring stations in 2014 have declined by -29.8% from year 2000 levels and are % lower than 2010 levels. See figures 10 and 11 below Ozone Air Quality, Mecklenburg County 8-hour Design Value Concentration Based on Annual 4th Maximum 8-hour Average Mecklenburg Compliance Value 2008 NAAQS Figure 10. Ozone Air Quality, Mecklenburg County 8-hour Design Value Concentrations For Each Site Operated by MCAQ Based on Annual 4th Maximum 8-hour Average NAAQS Figure 11. Page 24 of 79

25 Network Suitability to Measure the Appropriate Spatial Scale of Representativeness Site is urban scale and is suitable for the measurement of maximum concentrations that may occur in the network. Urban scale measurements are used to estimate concentrations over large portions of an urban area with dimensions of a few kilometers to 50 kilometers. Station is neighborhood scale. The scale of representativeness of this site is suitable for ozone measurements in a reasonably homogeneous urban sub-region (40 CFR 58 Appendix D 4.1(c)(1) Monitoring Spatial Redundancy or Gaps The monitoring stations operated by MCAQ are relatively close geographically. Typical concentrations measured at each site may be somewhat similar during periods of low ozone concentrations. When conditions become more extreme (due to ozone transport, stagnation, recirculation, etc.), meteorological effects on ozone concentrations at individual monitoring sites may be significant. To insure that ozone concentrations are measured under various conditions; monitoring sites serve specific functions in the monitoring network (as outlined previously), and thus an acceptable level of potential geographic redundancy is tolerated to achieve the specific objective(s) of the individual site. As a result of the loss of station (due to eviction), there is less redundancy in the network. The southern portion of the county is no longer directly represented by a local monitoring station. However, the area is generally bracketed by ozone sites to the north, east and west. Historic data indicates that the existing monitoring stations located in the areas surrounding the former monitoring site should be indicative of typical concentrations in southern Mecklenburg in the near term. The area east of the former site has a relatively dense population and may warrant consideration of additional monitoring in the future. As stated previously, the option of relocating a station in this area may be reassessed in the future, during the annual network planning process Programmatic Trends or Shifts in Data Needs Monitoring indicates the MSA does not currently ( ) violate the 2008 ozone NAAQS. The design value for the MSA for the most recent period was recorded at station The design value at this station is ppm, just below the NAAQS of ppm. Monitored 8-hour ozone concentrations remain near the current NAAQS at both monitoring stations operating in the MCAQ network, therefore the highest priority for the MCAQ ambient air quality monitoring group is the on-going operation of an accurate and reliable ozone monitoring network that is in full compliance with the requirements of 40 CFR 58 Appendix D. Stations and support the needs of the program. Page 25 of 79

26 NOx and VOC Emission Point Sources in Mecklenburg County (Synthetic Minor and Title V) Figures 12 and 13 depict the location of the MCAQ ozone monitoring stations relative to point source emissions of oxides of nitrogen (NOx) and volatile organic compounds (VOCs). NOx and VOCs are important precursor compounds in the formation of ozone. Point sources plotted on these maps represent synthetic minor and Title V sources. Title V point sources are defined as sources with a potential to emit >100 tons per year (tpy) of a regulated NAAQS pollutant, >10 tpy of at least one hazardous air pollutant (HAP) or >25 tpy of all HAPs combined. Synthetic minor point sources are sources whose potential would normally classify them as a Title V facility except that their potential emissions are reduced below the threshold by a limitation on the capacity of the facility to emit an air pollutant. Figure 12. NOx Emission Point Sources (Synthetic Minor and Title V). Page 26 of 79

27 Figure 13. VOC Emission Point Sources (Synthetic Minor and Title V) Summary of Assessment for Ozone The MCAQ monitoring stations ( and ) as discussed above meet the requirements of 40 CFR 58, Appendix D, 1.1 for monitoring objectives and 40 CFR 58 Appendix D, for monitor site types. The two monitoring stations operated by MCAQ are located to determine expected maximum concentrations and to provide air quality concentration data in an area of high population density at the appropriate spatial scales. These two stations meet the minimum requirements for ozone monitoring stations in the MSA. Additionally, three monitoring stations operated by North Carolina Division of Air Quality (NCDAQ) and one station operated by South Carolina Department of Health and Environmental Control (SCDHEC) provide stations in areas adjacent to Mecklenburg County and within the MSA. The combination of stations operated throughout the MSA by multiple agencies should enhance the network and provide a minimum and adequate network of ozone monitoring stations. Page 27 of 79

28 3.2 Particulate Matter PM2.5 The minimum monitoring requirements for PM2.5 are listed in Table D-5 of 40 CFR 58 Appendix D, Table D-5 is reproduced below (Figure 11): MSA population 1,2 Most recent 3-year design value concentrations 85% of any PM2.5 NAAQS 3 Most recent 3-year design value concentrations <85% of any PM2.5 NAAQS 3,4 >1,000, ,000-1,000,000 50,000- <500,000 5 Table The number of stations required in the network is based on population and design value. Mecklenburg County is located in the Charlotte-Gastonia-Concord (16740) metropolitan statistical area (MSA). The MSA component counties are Cabarrus, Gaston, Iredell, Lincoln, Mecklenburg, Rowan and Union Counties in North Carolina and Chester, Lancaster and York Counties in South Carolina. The 2014 U.S. Census population estimate for the MSA is 2,380,314. The 2014 design values for the MSA are 9.2 g/m 3 (annual design value, 77% of NAAQS) and 20 g/m 3 (24-hour design value, 57% of NAAQS). The controlling design value is the annual standard. The design value for the MSA is 85% of any PM2.5 NAAQS, therefore based on population and design value the number of required monitoring sites for the MSA is 2. There are currently five (5) PM2.5 Federal Reference Method (FRM) monitoring sites operating in the MSA: 2014 Annual Hour AQS ID Site Name County DV DV * Grier Middle Gaston, NC 8.5 g/m 3 * 19 g/m 3 * Garinger Mecklenburg, NC 9.0 g/m 3 18 g/m Montclaire Mecklenburg, NC 9.2 g/m 3 20 g/m Oakdale Mecklenburg, NC 8.6 g/m 3 17 g/m Rockwell Rowan, NC 9.1 g/m 3 19 g/m 3 *-Station discontinued by NCDAQ in Page 28 of 79

29 The monitoring site locations are shown in Figure 14 below: Figure 14. Mecklenburg County Air Quality (MCAQ AQS Reporting Organization ) operates 3 of the monitoring sites (Figure 14.) in the MSA: 2014 Annual Hour AQS ID Site Name County DV DV Garinger Mecklenburg, NC 9.0 g/m 3 18 g/m Montclaire Mecklenburg, NC 9.2 g/m 3 20 g/m Oakdale Mecklenburg, NC 8.6 g/m 3 17 g/m 3 Page 29 of 79

30 Figure 15. According to 40 CFR 58 Appendix D 4.7.1(b): The required monitoring stations or sites must be sited to represent area-wide air quality... The MCAQ PM2.5 monitoring stations are sited to represent area-wide air quality. Section continues with 3 basic requirements: 40 CFR 58 Appendix D 4.7.1(b)(1): At least one monitoring station is to be sited at neighborhood or larger scale in an area of expected maximum concentration 40 CFR 58 Appendix D 4.7.1(b)(2): For CBSAs with a population of 1,000,000 or more persons, at least one PM2.5 monitor is to be collocated at a nearroad NO2 station required in section 4.3.2(a) of this appendix 40 CFR 58 Appendix D 4.7.1(b)(3): For areas with additional required SLAMS, a monitoring station is to be sited in an area of poor air quality. Additionally 40 CFR 58 Appendix D states: Requirement for Continuous PM2.5 Monitoring. The State, or where appropriate, local agencies must operate continuous PM2.5 analyzers equal to at least one-half (round up) the minimum required sites listed in Table D-5 of this appendix Page 30 of 79

31 This section would require 2 PM2.5 stations and at least one continuous PM2.5 analyzer of any kind. MCAQ currently operates 3 PM2.5 stations equipped with federal reference method (FRM) samplers. Two (2) of these PM2.5 stations are equipped with continuous PM2.5 monitoring instruments. MCAQ operates continuous PM2.5 monitors at and The section (40 CFR ) also requires a PM2.5 analyzer to be located at the nearroad NO2 monitoring station. The regulation requires implementation of near-road PM2.5 monitoring by January 1, MCAQ plans to relocate to the near-road site on a timeline that would comply with the near-road requirement. The annual wind rose in Figure 16 indicates prevailing winds from the southwest ( 40% in the quadrant) with both a northerly and southerly component. Figure NWS Station KCLT Page 31 of 79

32 Station (Garinger, Figure 17) is located 5.4 kilometer ENE of the central business district of Charlotte, NC and monitors maximum concentrations in an area of high population density. The site is typical of urban areas within Mecklenburg County. The site is designed to measure particulate emissions originating from a wide variety of mobile, commercial, and industrial sources. Figure 17. Garinger ( ) with 4km diameter circle. Page 32 of 79

33 Station (Montclaire, Figure 18) is located 8.8 kilometers SSW of the central business district of uptown Charlotte, NC. The site is designed to monitor population exposure and maximum concentration in an area of high population density. Figure 18. Montclaire ( ) with 4 km diameter circle. Page 33 of 79

34 Station (Oakdale, Figure 19) is located 9.5 kilometers NW of the central business district of uptown Charlotte, NC. The site is designed to monitor population exposure and maximum concentrations in an area downwind of industrial and commercial emission sources west of Charlotte s central business district. Figure 19. Oakdale ( ) with 4 km diameter circle Compliance with 40 CFR 58 Appendix D, 1.1 Monitoring Objectives (a) Provide air pollution data to the general public in a timely manner: The MCAQ monitoring network collects data from three (3) PM2.5 monitoring sites. In order to comply with the requirement to provide data to the public in a timely manner, MCAQ operates continuous PM2.5 monitors at two sites. Continuous PM2.5 instruments are operated at and Data from these instruments is downloaded each 12 minutes by TCP/IP connections to the MCAQ central computer system. Hourly data is displayed on the MCAQ website after it is downloaded each hour. MCAQ continuous PM2.5 data is uploaded to the USEPA AirNow website on an hourly basis for dissemination on the national air quality website. After PM2.5 FRM and PM2.5 continuous data is validated, it is uploaded to the USEPA Air Quality System (AQS). AQS is the national data repository for air quality data. MCAQ uploads data to AQS on a monthly basis. Page 34 of 79

35 (b) Support compliance with national ambient air quality standards (NAAQS) and emissions strategy development: Data from the MCAQ PM2.5 monitoring network complies with applicable siting requirements and is available for NAAQS compliance determination and may be used for emissions strategy development. Data from the three monitoring sites operated by MCAQ may be used in the development of attainment and maintenance plans. Data from the two (2) SLAMS sites ( and ) and the NCore site ( ) is available for use in the evaluation of regional air quality models used in developing emission strategies, and may be used to track trends in air pollution abatement control measures impact on improving air quality. (c) Support for air pollution research studies: Site (Garinger) is an NCore site and may be used to supplement data collected by researchers working on health effects assessments and atmospheric processes, or for monitoring methods development. Additionally, a PM2.5 speciation sampler is operated at the Garinger ( ) site as part of the speciation trends network (STN). Discussion of 40 CFR 58 Appendix D Types of Monitoring Sites: The MCAQ PM2.5 monitoring network is designed to support the air quality management work indicated in the three basic air monitoring objectives listed above by providing measurements at sites in areas that represent area-wide air quality. The three sites in the MCAQ network are located to measure area-wide PM2.5 concentrations in three geographically distinct areas of the county. The sites are located to measure population exposure (Figure 20) to expected maximum concentrations under a variety of meteorological conditions in areas of poor air quality. The monitoring sites measure emissions from a wide variety of emission source types, including industrial, commercial, and mobile sources. Page 35 of 79

36 Figure Census Population Projections. The MCAQ network as summarized above meets the monitoring objectives of 40 CFR 58, Appendix D, Need for New Monitoring Sites The MCAQ network is comprised of 3 monitoring sites. A minimum of two PM2.5 sites are required for the MSA. MCAQ operates 3 of 5 sites in the MSA. Station is an approved NCore site. The site is population-oriented and is designed to measure expected maximum concentrations in an area of high population density. The site is located 5.4 km downwind of the central business district of Charlotte, NC. Station is population-oriented and is designed to measure expected maximum concentrations is an area of poor air quality and high population density. The site is the maximum annual NAAQS DV for the MCAQ network and the MSA ( : Annual DV=9.2 g/m 3 and 24-hour DV=20 g/m 3 ). The site is located along a commercial corridor near South Boulevard (Hwy. 521), south of the central business district of uptown Charlotte, NC. Secondary winds are from the north. The site measures emissions from both the primary west/southwesterly flow from the commercial corridor and from the secondary wind vector north of the station. Page 36 of 79

37 Station is a population-oriented site in an area of poor air quality. The site measures concentrations in an area downwind of industrial and commercial emission sources west of Charlotte s central business district. Based on this analysis, a new PM2.5 monitoring site is required to be sited at the near-road monitoring station ( ). A new near-road monitoring station must be in operation by January 1, The existing station will be discontinued and relocated to the near-road station to meet the near-road requirement. Relocation will be complete by January 1, Currently, the PM2.5 monitoring network operated by MCAQ meets and exceeds the minimum monitoring requirements of 40 CFR 58 Appendix D Need to Terminate Existing Sites To insure that PM2.5 concentrations are fully characterized geographically, three PM2.5 monitoring sites in the MCAQ network should continue operation. Station will be discontinued and relocated at the near-road monitoring station Operation of the PM2.5 near-road monitor will begin January 1, Appropriateness of New Technologies MCAQ is currently using the Thermoenvironmental Model 2025 Sequential PM2.5 sampler (formerly R-P) for filter based sampling. The technology is a proven Federal Reference Method (FRM) that meets monitoring requirements. However, several of the instruments in the network are at least fifteen (15) years old and need to be replaced or significantly refurbished. Replacement will take place as resource availability allows. MCAQ is using the R-P TEOM analyzer for continuous PM2.5 monitoring. In Mecklenburg County the R-P TEOM performs well. However, it is not a Federal Equivalent Method (FEM) or an approved regional method (ARM) and therefore cannot be used for NAAQS compliance determination. The R-P TEOM continuous analyzer is used to provide near real time information regarding PM2.5 concentrations and for public information purposes. Data from these continuous analyzers is used to report the air quality index (AQI). The R-P TEOM analyzers are over 10 years old and minimally supported by Thermoenvironmental Instruments. MCAQ operates a Met One Beta Attenuation Monitor (BAM - Model 1020) at the NCore monitoring station ( ) with the intent to eventually replace the R-P TEOM with the BAM. The BAM is being operated in a non-fem mode. During the next five (5) years it is expected that as technologies for continuous PM2.5 monitoring are improved MCAQ may transition to them if resources are available. PM2.5 speciation sampling is required at the NCore monitoring site ( ). Monitoring is conducted with the Met One SuperSASS sampler (inorganic compounds and ions) and the URG 3000n sampler (carbon parameters). Both the Met One and URG instruments should be suitable for PM2.5 speciation monitoring for the next 5 years. Page 37 of 79

38 3.2.5 Ability of Existing and Proposed Sites to Support Air Quality Characterization in Areas with High Populations of Susceptible Individuals Susceptible individuals in this assessment are defined as those individuals less than (<) 5 years of age and greater than (>) 65 years of age. Site is located in an area of high population density of individuals under 5 years of age and over 65 years of age. Site is also located in an area with a high density of susceptible individuals (over age 65). The maps in Figures 21 and 22 display the location of the sites in relation to the population densities of person under the age of 5 (Figure 21) and over the age of 65 (Figure 22). Figure Census Population Projections - People under the age of 5. Figure Census Population Projections - People over the age of 65. Page 38 of 79

39 3.2.6 Impact of Discontinuance on Data Users or Health Studies MCAQ plans to continue operation of the three PM2.5 monitoring sites in the network. There should be no impact on data users or health studies resulting from the discontinuance of any of the MCAQ operated PM2.5 monitoring sites PM2.5 Changes to Population-Oriented Sites The MCAQ PM2.5 monitoring sites are sited for population-oriented monitoring. The population of Mecklenburg County has increased by 10.1% from 2010 (919,628) to 2014 (1,012,539). Population increases have occurred in almost all areas of Mecklenburg County Statewide and Local Level Population Statistics See Section 5.0. Page 39 of 79

40 Historical Data 24-hour design values (compliance value) measured at MCAQ monitoring stations in 2014 have declined by -16.7% from year 2010 levels (Figure 23). Annual design values have declined by -22.7% from 2010 levels (Figure 24). g/m Particulate Matter - PM2.5, Mecklenburg County NAAQS 24-Hour Average Comparison Mecklenburg 24 - Hour Compliance Value 2006 NAAQS Figure 23. g/m Particulate Matter - PM2.5, Mecklenburg County NAAQS Annual Average Comparison Mecklenburg Annual Compliance Value 2012 NAAQS Figure Network Suitability to Measure the Appropriate Spatial Scale of Representativeness 40 CFR 58 Appendix D 4.7.1(b): The required monitoring stations or sites must be sited to represent area-wide air quality. These sites can include sites collocated at PAMS. These monitoring stations will typically be at neighborhood or urban-scale; however, Page 40 of 79

41 micro-or middle-scale PM2.5 monitoring sites that represent many such locations throughout a metropolitan area are considered to represent area-wide air quality Station represents area-wide air quality. It is a population-oriented neighborhood scale site. The site is also suitable for the measurement of expected maximum concentrations that may occur in the network. Stations and are also area-wide stations. The stations are neighborhood scale. They are also population-oriented sites. These sites are located to measure population exposure in areas of potentially poor air quality Monitoring Spatial Redundancy or Gaps Each site operated in the MCAQ network is sited to provide information regarding concentrations in distinct geographical regions of the county and to provide data under a variety of the most common meteorological conditions. All three sites are sited to measure area-wide air quality. The MCAQ PM2.5 monitoring sites provide data that represent conditions in areas where people commonly live and work for periods comparable to those specified in the NAAQS (40 CFR 58 Appendix D 4.7.1(c)(3). Each site provides data from areas that are somewhat unique, but are representative of several basic area types within the county. Site is an urban residential area with institutional, commercial, and light industrial development. Site is urban, commercial, and industrial. Site is suburban with commercial and heavy industrial sources upwind. The network provides spatial uniformity (Figure 14) with an acceptable level of redundancy, while minimizing gaps in coverage of the area served Programmatic Trends or Shifts in Data Needs In the past 5 years Mecklenburg County has monitored levels of PM2.5 close to the annual NAAQS of 12.0 g/m 3. Operation of a representative, accurate, and reliable PM2.5 monitoring network should remain a high priority. Implementation of continuous methods to reduce costs and improve data completeness should be adopted when and if suitable methods become available and are cost effective. Page 41 of 79

42 PM2.5 Emission Point Sources in Mecklenburg County (Synthetic Minor and Title V) Figure 25 depicts the location of the MCAQ PM2.5 monitoring stations relative to point source emissions of PM2.5. Point sources plotted on these maps represent synthetic minor and Title V sources. Title V point sources are defined as sources with a potential to emit >100 tons per year (tpy) of a regulated NAAQS pollutant, >10 tpy of at least one hazardous air pollutant (HAP) or >25 tpy of all HAPs combined. Synthetic minor point sources are sources whose potential would normally classify them as a Title V facility except that their potential emissions are reduced below the threshold by a limitation on the capacity of the facility to emit an air pollutant. The MCAQ PM2.5 monitoring stations are located so that they should capture the influence of upwind sources. Figure 25. PM2.5 Emission Point Sources (Synthetic Minor and Title V) Summary of Assessment for PM2.5 The MCAQ monitoring stations ( , and ) as discussed above meet the requirements of 40 CFR 58, Appendix D, 1.1 for monitoring objectives and 40 CFR 58 Appendix D, for monitor site types. The stations are sited in accordance with 40 CFR 58, Appendix D, 4.7. They are sited to represent areawide air quality at the neighborhood scale of representativeness in areas of expected maximum concentration. One station, will be relocated by January 1, 2017 Page 42 of 79

43 to comply with 40 CFR 58 Appendix D, (b)(2) to comply with the requirement to locate a PM2.5 station at the near-road NO2 station. 3.3 Carbon Monoxide (CO) 40 CFR 58 Appendix D, 3(b) and 40 CFR 58 Appendix D, 4.2 provide the design criteria for CO monitoring. CO monitoring is required at NCore stations and at the nearroad NO2 monitoring station. The near-road CO requirement must be implemented by January 1, 2017 in the MCAQ network. MCAQ operates one (1) neighborhood scale CO monitoring station ( , Garinger) at the Garinger NCore station (Figure 26). Figure 26. Garinger ( ) NCore station with 4 km diameter circle Compliance with 40 CFR 58 Appendix D, 1.1 Monitoring Objectives (a) Provide air pollution data to the general public in a timely manner: The MCAQ monitoring network collects data from one (1) CO monitoring site. Data is downloaded each 12 minutes by TCP/IP connections to the MCAQ central computer system. Hourly data is displayed on the MCAQ website after it is downloaded each hour. After CO data is validated it is uploaded to the USEPA Air Quality System (AQS). AQS is the national data repository for air quality data. Data uploads are performed on a monthly basis. Page 43 of 79

44 (b) Support compliance with national ambient air quality standards (NAAQS) and emissions strategy development: Data from the MCAQ CO monitoring network complies with applicable siting requirements and is available for NAAQS compliance determination and may be used for emissions strategy development. Data from the monitoring site operated by MCAQ may be used in the development of attainment and maintenance plans. Data from the SLAMS and NCore site ( ) is available for use in the evaluation of regional air quality models used in developing emission strategies, and may be used to track trends in air pollution abatement control measures impact on improving air quality. (c) Support for air pollution research studies: Site (Garinger) is an NCore site and may be used to supplement data collected by researchers working on health effects assessments and atmospheric processes, or for monitoring methods development. Discussion of 40 CFR 58 Appendix D Types of Monitoring Sites: The MCAQ CO monitoring network is designed to support the air quality management work indicated in the three basic air monitoring objectives listed above by providing measurements as required at the approved NCore monitoring site ( , Garinger). The CO station the MCAQ network is located to measure CO concentrations in an area of high population density (Figure 27, Garinger High School). Page 44 of 79

45 Figure Need for New Monitoring Sites 40 CFR 58 Appendix D, requires the installation of a CO analyzer at the near-road NO2 monitoring station. The near-road CO analyzer must be operational by January 1, 2017 (40 CFR 58.13(e)(2) Need to Terminate Existing Sites Currently, MCAQ operates a CO analyzer at the Garinger ( ) NCore site. The NCore CO instrument will remain in operation. The NCore site is required and will continue operation. A CO analyzer will be established at the near-road NO2 monitoring station ( ) by January 1, No CO sites will be terminated Appropriateness of New Technologies MCAQ is currently operating up to date technology for the measurement to CO. Page 45 of 79

46 3.3.5 Ability of Existing and Proposed Sites to Support Air Quality Characterization in Areas with High Populations of Susceptible Individuals Susceptible individuals in this assessment are defined as those individuals less than (<) 5 years of age and greater than (>) 65 years of age. Site is located in an area of high population density of individuals under 5 years of age and over 65 years of age. (See Figures 28 and 29). Figure Census Population Projections - People under the age of 5. Figure Census Population Projections - People over the age of Impact of Discontinuance on Data Users or Health Studies MCAQ plans to continue operation of the CO monitoring site in the network. There should be no impact on data users or health studies resulting from site discontinuance. Page 46 of 79

47 ppm PM2.5 Changes to Population-Oriented Sites Not Applicable Statewide and Local Level Population Statistics See Section Historical Data 8-hour design values (compliance value) measured at the MCAQ monitoring station in 2014 have declined by -48.4% from year 2005 levels (Figure 30) and have remained about the same over the past five years ( ) Carbon Monoxide Air Quality, Mecklenburg County Based on Annual 2nd Maximum 8-hour Average Mecklenburg Compliance Value NAAQS Figure Network Suitability to Measure the Appropriate Spatial Scale of Representativeness The MCAQ CO monitoring site is an NCore site and has been approve by the USEPA Office of Air Quality Planning and Standards (OAQPS) and has been determined to be suitable to measure CO concentrations at the appropriate spatial scale of representativeness for NCore measurements Monitoring Spatial Redundancy or Gaps CO monitoring in MCAQ meets the requirements of 40 CFR 58 Appendix D for NCore measurements Programmatic Trends or Shifts in Data Needs Operation of the CO monitor at the NCore site ( ) is required. The MCAQ program uses the most advanced technology appropriate for ambient air monitoring of CO concentrations that is currently available. MCAQ is operates the Thermoenvironmental 48i-tle CO analyzer at station (Garinger NCore). Page 47 of 79

48 Carbon Monoxide Emission Point Sources in Mecklenburg County (Synthetic Minor and Title V) Figure 31 depicts the location of the MCAQ CO monitoring station relative to point source emissions of CO. Point sources plotted on the map represent synthetic minor and Title V sources. Title V point sources are defined as sources with a potential to emit >100 tons per year (tpy) of a regulated NAAQS pollutant, >10 tpy of at least one hazardous air pollutant (HAP) or >25 tpy of all HAPs combined. Synthetic minor point sources are sources whose potential would normally classify them as a Title V facility except that their potential emissions are reduced below the threshold by a limitation on the capacity of the facility to emit an air pollutant. Figure 31. CO Emission Point Sources (Synthetic Minor and Title V) Summary of Assessment for CO The MCAQ CO monitoring station ( ) as discussed above meets the requirements of 40 CFR 58, Appendix D, 1.1 for monitoring objectives and 40 CFR 58 Appendix D, for monitor site types. The station is sited in accordance with 40 CFR 58, Appendix D, 3 for NCore. It is sited to represent typical concentrations in areas of high population density. The station is neighborhood scale of representativeness. An additional CO monitor will be installed at the near-road NO2 station, by January 1, 2017 to comply with 40 CFR 58 Appendix D, to comply with the requirement to locate a CO monitor at the near-road NO2 station. Page 48 of 79

49 3.4 Sulfur Dioxide (SO2) The required number of monitoring sites in the SO2 network is determined by the population weighted emissions index (PWEI) for the core based statistical area (CBSA). The formula for determining the PWEI for a CBSA is found in 40 CFR 58 Appendix D PWEI is determined by multiplying the most recent CBSA (Charlotte-Concord-Gastonia, NC-SC) population estimate (2014 estimate = 2,380,314) by the total amount of SO2 in tons per year emitted within the CBSA (2011 National Emissions Inventory = 17229) and dividing the product by 1,000,000. The calculate PWEI for the Charlotte-Concord- Gastonia, NC-SC CBSA is CFR 58 Appendix D states For any CBSA with a calculated PWEI value equal to or greater than 1,000,000, a minimum of three SO2 monitors are required within that CBSA. For any CBSA with a calculated PWEI value equal to or greater than 100,000, but less than 1,000,000, a minimum of two SO2 monitors are required within that CBSA. For any CBSA with a calculated PWEI value equal to or greater than 5,000, but less than 100,000, a minimum of one SO 2 monitor is required within that CBSA This is followed by 40 CFR 58 Appendix D 4.4.2(1), The SO2 monitoring site(s) required as a result of the calculated PWEI in each CBSA shall satisfy minimum monitoring requirements if the monitor is sited within the boundaries of the parent CBSA and is one of the following site types (as defined in section of this appendix): population exposure, highest concentration, source impacts, general background, or regional transport. SO2 monitors at NCore stations may satisfy minimum monitoring requirements if that monitor is located within a CBSA with minimally required monitors under this part MCAQ is currently operating one SO2 monitoring site in the CBSA at (Garinger, Figures 32, 33 and 34). The Garinger site is an NCore station that meets the requirements of the regulation in terms of number of stations and station type. An additional station is operated in the MSA in York County, SC as part of the South Carolina Department of Health and Environmental Control s monitoring network ( ). Page 49 of 79

50 Figure 32. SO2 Monitoring Stations operational in 2015 in the CBSA. Station operated by MCAQ. Figure 33. MCAQ SO2 Station Page 50 of 79

51 Figure 34. (4km diameter circle) Compliance with 40 CFR 58 Appendix D, 1.1 Monitoring Objectives (a) Provide air pollution data to the general public in a timely manner: The MCAQ monitoring network collects data from one (1) SO2 monitoring site (neighborhood). Data is downloaded each 12 minutes by TCP/IP connections to the MCAQ central computer system. Hourly data is displayed on the MCAQ website after it is downloaded each hour. After SO2 data is validated it is uploaded to the USEPA Air Quality System (AQS). AQS is the national data repository for air quality data. Data uploads are performed on a monthly basis. (b) Support compliance with national ambient air quality standards (NAAQS) and emissions strategy development: Data from the MCAQ SO2 monitoring network complies with applicable siting requirements for existing sites and is available for NAAQS compliance determination and may be used for emissions strategy development. Data from the monitoring site operated by MCAQ may be used in the development of attainment and maintenance plans. Data from the SLAMS and NCore site ( ) is available for use in the evaluation of regional air quality models used in developing emission strategies, and may be used to track trends in air pollution abatement control measures impact on improving air quality. (c) Support for air pollution research studies: Site (Garinger) is an NCore site and may be used to supplement data collected by researchers working on health effects assessments and atmospheric processes, or for monitoring methods development. Page 51 of 79

52 Discussion of 40 CFR 58 Appendix D Types of Monitoring Sites: One SO2 monitoring station is required in the MSA. The site currently in operation at the NCore location ( , Garinger) meets siting requirements Need for New Monitoring Sites No new monitoring stations are required as of the date of this assessment Need to Terminate Existing Sites The existing monitoring station in the MCAQ network should continue in operation Appropriateness of New Technologies MCAQ is currently operating the Thermoenvironmental Model 43i-tle SO2 analyzer at the NCore monitoring site ( , Garinger). The technology is current and appropriate for ambient monitoring at the NCore station type Ability of Existing and Proposed Sites to Support Air Quality Characterization in Areas with High Populations of Susceptible Individuals Susceptible individuals in this assessment are defined as those individuals less than (<) 5 years of age and greater than (>) 65 years of age. Site is located in an area of high population density of individuals under 5 years of age and over 65 years of age. (See Figures 35 and 36). Figure Census Population Projections - People under the age of 5. Page 52 of 79

53 Figure Census Population Projections - People over the age of Impact of Discontinuance on Data Users or Health Studies MCAQ plans to continue operation of the SO2 monitoring site located at (Garinger). There should be no impact on data users or health studies resulting from site discontinuance PM2.5 Changes to Population-Oriented Sites Not applicable Statewide and Local Level Population Statistics See Section Historical Data 1-hour design values (compliance value) measured at the MCAQ monitoring station in 2014 have declined by -82.5% from year 2010 levels (Figure 37). Page 53 of 79

54 ppm Sulfur Dioxide Air Quality Mecklenburg County 3-Year Average 1 - Hour Daily Max 99th Percentile Year Average 1-hour Daily Max 99th Percentile Hour NAAQS Figure Network Suitability to Measure the Appropriate Spatial Scale of Representativeness Site (Garinger) is neighborhood scale and meets the requirements of 40 CFR 58 Appendix D 4.4.2(1) for SO Monitoring Spatial Redundancy or Gaps One site is required in the network. There is no spatial redundancy in the SO2 monitoring network. MCAQ operates the NCore station ( ) and SCDHEC operates an additional site in York, SC ( ). There are no monitoring gaps per the current requirements of 40 CFR 58 Appendix D Programmatic Trends or Shifts in Data Needs The SO2 monitoring stations operating in the MSA meet the programmatic and data needs in the MSA at this time Sulfur Dioxide Emission Point Sources in Mecklenburg County (Synthetic Minor and Title V) Figure 38 depicts the location of the MCAQ SO2 monitoring station relative to point source emissions of SO2. Point sources plotted on the map represent synthetic minor and Title V sources. Title V point sources are defined as sources with a potential to emit >100 tons per year (tpy) of a regulated NAAQS pollutant, >10 tpy of at least one hazardous air pollutant (HAP) or >25 tpy of all HAPs combined. Synthetic minor point sources are sources whose potential would normally classify them as a Title V facility except that their potential emissions are reduced below the threshold by a limitation on the capacity of the facility to emit an air pollutant. Page 54 of 79

55 Figure 38. SO2 Emission Point Sources (Synthetic Minor and Title V) Summary of Assessment for SO2 The MCAQ SO2 monitoring station ( ) as discussed above meets the requirements of 40 CFR 58, Appendix D, 1.1 for monitoring objectives and 40 CFR 58 Appendix D, for monitor site types. The station is sited in accordance with 40 CFR 58, Appendix D, 3 for NCore. It is sited to represent typical concentrations in areas of high population density. The station is neighborhood in scale of representativeness and satisfies the requirements of 40 CFR 58 Appendix D Nitrogen Dioxide (NO2) Within the NO2 network, there must be one micro-scale near-road NO2 monitoring station in each CBSA with a population of 500,000 or more persons to monitor a location of expected maximum hourly concentrations sited near a major road with high AADT counts as specified in paragraph 4.3.2(a)(1) of this appendix (40 CFR 58 Appendix D 4.3.2(a). In an area with a population 2,500,000 or 500,000 and with a roadway segment 250,000 annual average daily traffic (AADT) a second monitor is required. Additionally, there is a requirement for area-wide monitoring. Within the NO2 network, there must be one monitoring station in each CBSA with a population of 1,000,000 or more persons to monitor a location of expected highest NO2 concentrations representing the neighborhood or larger spatial scales (40 CFR 58 Appendix D 4.3.3(a). Page 55 of 79

56 The 2014 U.S. Census population estimate for the CBSA is 2,380,314. The maximum AADT measured in the CBSA by the North Carolina Department of Transportation (NCDOT) is 179,000 AADT. Based on the population information and the maximum AADT, the requirements of 40 CFR 58 Appendix D specify a monitoring network consisting of one (1) near-road NO2 monitoring station (Figure 39) and one (1) area-wide monitoring station. Figure 39. Most heavily trafficked roadway segments in CBSA in heavy red. The population of the CBSA is approaching 2.5 million. When the 2.5 million threshold is crossed, a second near-road NO2 monitoring station will be required by 40 CFR 58 Appendix D. The next CBSA population estimate is scheduled to be released by the U.S. Census in March 2016 ( ). At that time MCAQ will evaluate the population data and in consultation with NCDAQ and U.S. EPA determine the appropriate course of action. Currently, MCAQ operates one (1) near-road NO2 monitoring station ( , Remount) and one (1) area-wide monitoring station ( , Garinger-NCore). The MCAQ network (Figure 40-41) meets the requirements of 40 CFR 58 Appendix D at this time. Page 56 of 79

57 Figure 40. NO2 stations. Figure 41. NO2 Monitoring Stations and PY2016 Population Density Compliance with 40 CFR 58 Appendix D, 1.1 Monitoring Objectives (a) Provide air pollution data to the general public in a timely manner: The MCAQ monitoring network collects data from one (1) NO2 monitoring site (neighborhood). Data is downloaded each 12 minutes by TCP/IP connections to the Page 57 of 79

58 MCAQ central computer system. Hourly data is displayed on the MCAQ website after it is downloaded each hour. After NO2 data is validated it is uploaded to the USEPA Air Quality System (AQS). AQS is the national data repository for air quality data. Data uploads are performed on a monthly basis. (b) Support compliance with national ambient air quality standards (NAAQS) and emissions strategy development: Data from the MCAQ NO2 monitoring network complies with applicable siting requirements for existing sites and is available for NAAQS compliance determination and may be used for emissions strategy development. Data from the monitoring stations operated by MCAQ may be used in the development of attainment and maintenance plans. Data from the near-road station ( ) and the NCore station ( ) are available for use in the evaluation of regional air quality models used in developing emission strategies, and may be used to track trends in air pollution abatement control measures impact on improving air quality. (c) Support for air pollution research studies: Site (Garinger) is an NCore site and may be used to supplement data collected by researchers working on health effects assessments and atmospheric processes, or for monitoring methods development. Discussion of 40 CFR 58 Appendix D Types of Monitoring Sites: Two monitoring stations are required in the CBSA. The NCore location ( , Garinger) meets the requirement for an area-wide monitoring site. 40 CFR 58 Appendix D 4.3.2(a)(1) states the requirement for one near-road monitoring site. The near-road station ( ) meets the requirements for the additional station Need for New Monitoring Sites No new NO2 stations are required at this time. The CBSA population is approaching 2.5 million. 40 CFR 58 Appendix D requirements state that a second near-road monitoring station is required when this threshold is reached. The need for a second station will be evaluated at that time Need to Terminate Existing Sites MCAQ does not plan to terminate any of the currently operating NO2 monitoring stations Appropriateness of New Technologies MCAQ is currently operating the Thermo Environmental Model 42c NO2 analyzer at the area-wide monitoring site ( , Garinger). The instrument was purchased in November This instrument is one generation older than the most recently designated instrumentation and should be replaced prior to August 30, 2015, as factory support for this generation of instrumentation will no longer be available. Page 58 of 79

59 The near-road monitoring station is equipped with a Teledyne Advanced Pollution Instrumentation Model T200UP analyzer. This instrument is current generation technology and is adequate for the next five years at this station. NO2 instrumentation is rapidly evolving. Newer technologies have recently been developed that allow direct measurement of NO2. These technologies should be investigated and implemented as necessary Ability of Existing and Proposed Sites to Support Air Quality Characterization in Areas with High Populations of Susceptible Individuals Susceptible individuals in this assessment are defined as those individuals less than (<) 5 years of age and greater than (>) 65 years of age. Site is located in an area of high population density of individuals under 5 years of age and over 65 years of age. (See Figures 42 and 43). Figure Census Population Projections - People under the age of 5. Page 59 of 79

60 Figure Census Population Projections - People over the age of Impact of Discontinuance on Data Users or Health Studies MCAQ plans to continue operation of the NO2 monitoring stations located at (Garinger) and (Remount). There should be no impact on data users or health studies resulting from site discontinuance PM2.5 Changes to Population-Oriented Sites Not applicable Statewide and Local Level Population Statistics See Section 5.0. Page 60 of 79

61 ppm ppm Historical Data Historical values in the graphics of this section are reported from the area-wide monitoring station ( ). Monitoring began at the near-road NO2 station, , on July 17, 2014; therefore trend data from the near-road station is limited. Annual design values (Figure 44) have declined -25.0% from 2010 to hour design values (Figure 45) measured at the MCAQ monitoring station ( , Garinger) in 2014 have declined by -14.6% from year 2010 levels Nitrogen Dioxide Air Quality Mecklenburg County Annual Average Mecklenburg Compliance Value NAAQS Figure Nitrogen Dioxide Air Quality Area-Wide Monitor, Mecklenburg County 3-Year Average 98th Percentile hour Mecklenburg Compliance Value NAAQS Figure 45. Page 61 of 79

62 Network Suitability to Measure the Appropriate Spatial Scale of Representativeness Site (Garinger) is neighborhood scale and meets the requirements for an area-wide monitoring site for NO2. The near-road monitoring station is micro-scale in accordance with 40 CFR 58 requirements Monitoring Spatial Redundancy or Gaps Two sites are required in the network. There is no spatial redundancy in the NO2 monitoring network. There are no gaps in the network Programmatic Trends or Shifts in Data Needs The near-road NO2 station ( ) began operation in July The station supports the near-road requirements of the program. The Garinger NCore station ( ) meets the needs of the program. Direct measurement techniques for NO2 measurement are rapidly developing. New techniques should be evaluated for suitability in the network Nitrogen Dioxide Emission Point Sources in Mecklenburg County (Synthetic Minor and Title V) Figure 46 depicts the location of the MCAQ NO2 monitoring stations relative to point source emissions of NOX. Point sources plotted on the map represent synthetic minor and Title V sources. Title V point sources are defined as sources with a potential to emit >100 tons per year (tpy) of a regulated NAAQS pollutant, >10 tpy of at least one hazardous air pollutant (HAP) or >25 tpy of all HAPs combined. Synthetic minor point sources are sources whose potential would normally classify them as a Title V facility except that their potential emissions are reduced below the threshold by a limitation on the capacity of the facility to emit an air pollutant. Page 62 of 79

63 Figure 46. NOX Emission Point Sources (Synthetic Minor and Title V) Summary of Assessment for NO2 The MCAQ NO2 monitoring stations ( & ) as discussed above meets the requirements of 40 CFR 58, Appendix D, 1.1 for monitoring objectives and 40 CFR 58 Appendix D, for monitor site types. The stations are sited in accordance with 40 CFR 58, Appendix D, for near-road monitoring and area-wide monitoring. They are sited to represent typical concentrations in the near-road environment ( ) and in areas of high population density ( ). The stations are micro-scale ( ) and neighborhood scale ( ) in scale of representativeness and satisfy the requirements of 40 CFR 58 Appendix D Page 63 of 79

64 3.6 Particulate Matter PM10 Table D-4 of 40 CFR 58 Appendix D 4.6 indicates the approximate number of permanent stations required in MSA s to characterize national and regional PM10 air quality trends and geographical patterns. Table D 4 of Appendix D to Part 58 PM10 Minimum Monitoring Requirements (Approximate Number of Stations Per MSA) 1 Population category High concentration 2 Medium concentration 3 Low concentration 4,5 >1,000, ,000 1,000, , , , , Selection of urban areas and actual numbers of stations per area will be jointly determined by EPA and the State agency. 2 High concentration areas are those for which ambient PM10 data show ambient concentrations exceeding the PM 10NAAQS by 20 percent or more. 3 Medium concentration areas are those for which ambient PM10 data show ambient concentrations exceeding 80 percent of the PM 10NAAQS. 4 Low concentration areas are those for which ambient PM10 data show ambient concentrations less than 80 percent of the PM 10NAAQS. 5 These minimum monitoring requirements apply in the absence of a design value. Table 8. (D-4.) The current PM10 NAAQS is 150 g/m 3 24-hour average (not to be exceeded more than once per year on average over 3 years). The population of the MSA is 2,380,314 (Charlotte-Gastonia-Concord, NC-SC, July 1, 2014 estimate). Eighty (80%) percent of the NAAQS = 120 g/m 3. The maximum value measured in Mecklenburg County during the past 3 years is less than 60 g/m 3 (See Table 9). Year g/m 3 35 g/m 3 32 g/m 3 49 g/m 3 46 g/m g/m 3 55 g/m 3 30 g/m 3 50 g/m 3 52 g/m g/m 3 43 g/m 3 30 g/m 3 59 g/m 3 35 g/m 3 Table 9. Based on this information, the required number of monitoring stations is 2-4 (See Table 8 above). MCAQ is currently operating 1 high-volume PM10 station and 2 lo-volume PM10 stations (lo-volume for PM coarse determination) for a total of three (3) PM10 monitoring sites. Please see Figures 47 and 48. Site Monitoring Method Sampling Frequency Lo-volume 1/ Lo-volume with collocation 1/3 and 1/6 collocated High-volume with collocation 1/6 and 1/6 collocated Table 10. Page 64 of 79

65 Figure 47. Page 65 of 79

66 Figure Compliance with 40 CFR 58 Appendix D, 1.1 Monitoring Objectives (a) Provide air pollution data to the general public in a timely manner: The MCAQ monitoring network collects data from three (3) PM10 monitoring sites. PM10 monitoring is conducted using manual methods in the MCAQ network. PM10 concentrations are calculated as soon as possible after samples are collected. After PM10 data is validated, it is uploaded to the USEPA Air Quality System (AQS). AQS is the national data repository for air quality data. Data uploads are performed on a monthly basis. (b) Support compliance with national ambient air quality standards (NAAQS) and emissions strategy development: Data from the MCAQ PM10 monitoring network complies with applicable siting requirements and is available for NAAQS compliance determination and may be used for emissions strategy development. Data from the three monitoring sites operated by MCAQ may be used in the development of attainment and maintenance plans. Data from the sites is available for use in the evaluation of regional air quality models used in developing emission strategies, and may be used to track trends in air pollution abatement control measures impact on improving air quality. Page 66 of 79

67 (c) Support for air pollution research studies: Data from the MCAQ PM10 monitoring network may be used to supplement data collected by researchers working on health effects assessments and atmospheric processes, or for monitoring methods development. Discussion of 40 CFR 58 Appendix D Types of Monitoring Sites: PM10 monitoring is conducted at three sites in Mecklenburg County. All sites are neighborhood scale. The highest concentration site, , is also located in an area of above average population density. Sites and are population oriented. Site Measurement Scale Site Type Neighborhood Highest Concentration, Population Exposure Neighborhood Population Exposure Neighborhood Population Exposure Table 11. PM10 Annual Average Concentration (not a compliance value) Year g/m g/m g/m g/m g/m g/m g/m g/m g/m g/m g/m g/m g/m g/m g/m 3 Table Need for New Monitoring Sites PM10 concentrations are well characterized by the existing network. Concentrations have been well below 80% of the NAAQS for many years. No new monitoring sites are planned Need to Terminate Existing Sites MCAQ is operating 3 PM10 sites. MCAQ will continue to operate these stations in However, concentrations monitored at these sites are well below the NAAQS. In an ongoing evaluation of the network, MCAQ may reduce the network to 2 sites within the next 5 years Appropriateness of New Technologies Continuous PM10 monitoring is a logical next step to improve the time resolution of PM10 data collected in the network and to reduce costs. Continuous PM10 monitoring is being evaluated Ability of Existing and Proposed Sites to Support Air Quality Characterization in Areas with High Populations of Susceptible Individuals Susceptible individuals in this assessment are defined as those individuals less than (<) 5 years of age and greater than (>) 65 years of age. Site is located in an area of high population density of individuals under 5 years of age and over 65 years of age. Site is also located in an area with a high density of susceptible individuals Page 67 of 79

68 (over age 65). The maps in Figures 48 and 49 display the location of these sites in relation to the population densities of person under the age of 5 (Figure 49) and over the age of 65 (Figure 50). Figure Census Population Projections - People under the age of 5. Figure Census Population Projections - People over the age of Impact of Discontinuance on Data Users or Health Studies The three stations will remain in operation during There should be no impact of data users or health studies PM2.5 Changes to Population-Oriented Sites Not applicable. Page 68 of 79

69 Statewide and Local Level Population Statistics See Section Historical Data Data are well below the NAAQS compliance level of 150 g/m 3. There have been no concentrations measured that were > 70 g/m 3 in the past 14 years. See Figure 51. g/m Particulate Matter - PM10 Air Quality Mecklenburg County Maximum Measured Concentration Maximum Value - All Sites 2006 NAAQS Figure Network Suitability to Measure the Appropriate Spatial Scale of Representativeness 40 CFR 58 Appendix D 4.6 (b) states the most important spatial scales to effectively characterize the emissions of PM10 from both mobile and stationary sources are the middle scales and neighborhood scales. 40 CFR 58 Appendix D 4.6 (b) (3) continues Neighborhood scale PM10 sites provide information about trends and compliance with standards because they often represent conditions in areas where people commonly live and work for extended periods The MCAQ monitoring sites are neighborhood scale and are located in a variety of settings that are representative of areas typically found within Mecklenburg County Monitoring Spatial Redundancy or Gaps There are three (3) monitoring stations operating in the MSA. The stations are located in Mecklenburg County. Two stations ( and ) are relatively close (3.8 km) geographically. However, the types of sources in their respective scales of representativeness (neighborhood - 4 km diameter) differ. They are not spatially redundant. Page 69 of 79

70 The three stations represent three distinct locations whose source types differ to some degree. There are no gaps in coverage in the network Programmatic Trends or Shifts in Data Needs Monitored concentrations of PM10 are less than 50% of the level of the NAAQS. PM10 monitoring should be conducted at the minimally required level, indicating that the network may be reduced by one station within the next five years PM10 and PM2.5 Emission Point Sources in Mecklenburg County (Synthetic Minor and Title V) Figure 52. PM2.5 and PM10 Emission Point Sources (Synthetic Minor and Title V). Figure 52 depicts the location of the MCAQ PM10 monitoring stations relative to point source emissions of PM2.5 and PM10. Point sources plotted on the map represent synthetic minor and Title V sources. Title V point sources are defined as sources with a potential to emit >100 tons per year (tpy) of a regulated NAAQS pollutant, >10 tpy of at least one hazardous air pollutant (HAP) or >25 tpy of all HAPs combined. Synthetic minor point sources are sources whose potential would normally classify them as a Title Page 70 of 79