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2001 Ambient Air Quality Report



State of North Carolina Michael F. Easley, Governor Department of Environment and Natural Resoures William G. Ross, Jr., Secretary Division of Air Quality B. Keith Overcash, P.E., Director Ambient Monitoring Section Hoke P. Kimball, Chief



Published June 2008





2001 Ambient Air Quality Report



STATE OF NORTH CAROLINA Michael F. Easley, Governor DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES William G. Ross, Jr., Secretary DIVISION OF AIR QUALITY B. Keith Overcash, P.E., Director AMBIENT MONITORING SECTION Hoke P. Kimball, Chief



PUBLISHED June 2008





2001 Ambient Air Quality Report Ambient Monitoring Section Report # 2008.01



Acknowledgements: Primary Author: Wayne Cornelius Additional Assistance: Lucyna Kozek



Public Sources of Data: North Carolina Division of Air Quality Forsyth County Environmental Affairs Department EPA/AIRS Air Quality Subsystem National Atmospheric Deposition Program



http://daq.state.nc.us/



http://www.co.forsyth.nc.us/EnvAffairs/weathereport.htm



http://www.epa.gov/airsweb



http://nadp.sws.uiuc.edu



Published: June 2008 Not copyrighted. Copies of this public document will be printed only by special request



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Preface This report is issued by the Division of Air Quality of the Department of Environment and Natural Resources to inform the public of air pollution levels throughout the state of North Carolina. It describes the sources and effects of the following pollutants for which the U.S. Environmental Protection Agency and the State of North Carolina have established ambient air quality standards:



Particulate Matter Carbon Monoxide Sulfur Dioxide Nitrogen Dioxide Ozone Lead



A brief discussion of the ambient air monitoring program, including a description of the monitoring network, is provided. Detailed results are presented of monitoring that was conducted in 2001 to measure the outdoor concentrations. The data are presented graphically and as statistical summaries, including comparisons to the ambient air quality standards. The report discusses the recorded data, and the seasonal variability of some pollutants. Data and areas exceeding the ambient air quality standards are identified. Factors that have contributed to those exceedances are described also. Acid rain data from the National Atmospheric Deposition Program/National Trends Network for North Carolina also are included for 2001. Data collected after 2001 will be discussed in later reports. Current air pollution information is available for the Charlotte area 24 hours a day through the use of the air quality index telephone numbers listed below: Charlotte area 704-333-SMOG Additional copies of this report and previous annual reports are available from: Division of Air Quality Department of Environment and Natural Resources 1641 Mail Service Center Raleigh, North Carolina 27699-1641 and on the Division of Air Quality's website http://daq.state.nc.us/monitor/reports/ . Comments regarding this report or suggestions for improving future reports are welcomed. Comments may be sent to Dr. Wayne L. Cornelius, at the above address. B. Keith Overcash, P.E., Director Division of Air Quality



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Executive Summary In 2001, the North Carolina Division of Air Quality (DAQ), the three local program agencies and one tribal agency (listed in Appendix A) collected 451,032 air quality samples. These samples included measurements of the U.S. Environmental Protection Agency's (EPA) criteria air pollutants: particulate matter, carbon monoxide, ozone, sulfur dioxide, nitrogen dioxide and lead. This report discusses each pollutant and presents summary tables, maps, charts and explanations of the data. The report also includes data from weekly acid rain samples collected by the National Atmospheric Deposition Program/National Trends Network (NADP) at seven North Carolina sites and one Tennessee site very close to the North Carolina border. It discusses acid rain and presents summary tables, maps, charts and explanations of the data. Three different types of particulate matter were sampled in North Carolina during 2001. Total Suspended Particulate (TSP), considered to be particles having an aerodynamic diameter of 100 micrometers or less, is regulated by North Carolina standards. Particulate matter (PM10) with a mean aerodynamic diameter less than or equal to a nominal 10 micrometers (0.00004 inches) is regulated by both EPA and N.C. standards. Fine particulate matter (PM2.5) with a mean aerodynamic diameter less than or equal to a nominal 2.5 micrometers (0.00001 inches) has been regulated by EPA since 1997. TSP was not sampled in 2001, but we report the most recent sampling within three years. In 2000 TSP was sampled at 2 sites, yielding 92 daily samples. No exceedances of the state TSP ambient air quality standard for 24-hour samples (150 g/m3) were observed in 2000. PM10 was sampled at 31 sites, yielding 2376 daily samples. There were no exceedances of the National Ambient Air Quality Standards for PM10 (150 g/m3 for 24-hour samples and 50 g/m3 for the annual arithmetic mean). Mean 24-hour concentrations have decreased about 30 percent since 1985. PM2.5 was sampled at 38 sites yielding 5375 daily samples. There was one exceedance of the ambient air quality standards for PM2.5 (65 g/m3 for 24-hour samples). The value of 93.3 was observed at the Bingham Road site in Asheville. Four of the 38 sites exceeded the annual arithmetic mean standard of 15 g/m3. Carbon monoxide (CO), the most common air pollutant, largely results from fuel combustion. The most likely areas to have excessive CO concentrations are larger cities where there are more cars and congested streets. CO was sampled at 11 sites, yielding 57,473 valid hourly averages. The National Ambient Air Quality Standards for CO are 35 ppm for the maximum one-hour average and 9 ppm for the maximum eight-hour average. There were no exceedances of the standards. The



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highest one-hour concentration of 9.3 was observed at the Tryon site in Charlotte. The highest eight hour concentration of 4.4 ppm was observed at the Oleander and College site in Wilmington and the Person Street site in Raleigh. Both the mean one-hour average and the mean eight-hour average have been decreasing by about 4 percent per year. The combined effects of newer cars in the vehicle fleet, traffic control strategies, and the Inspection and Maintenance program in Durham, Orange, Wake, Forsyth, Guilford, Cabarrus, Gaston, Mecklenburg, and Union Counties have helped reduce the number and intensity of CO exceedances from previous years. Ozone (O3) forms in the lower atmosphere when hydrocarbons (or volatile organic compounds) and nitrogen oxides chemically react in the presence of sunlight and high temperatures. The main emphases in control of ozone has been to limit hydrocarbon and nitrogen oxide emissions. O3 was sampled at 46 sites, yielding 233,160 valid hourly averages. The National Ambient Air Quality Standard for O3 is 0.08 ppm for the maximum eight-hour average and 0.12 ppm for the maximum one-hour average. In 2001, there were 6 exceedances of the one-hour standard, all of which occurred on two days in August. Eight exceedances occurred in North Carolina in 2000, and 20 occurred in 1999. Mecklenburg, Rowan and Wake Counties met or exceeded the criteria for nonattainment of the one-hour ozone standard with eleven, five and six exceedances respectively over a three-year period, however EPA had rescinded the one-hour standard during that time period. Mecklenburg County was redesignated as in attainment for ozone in July 1995. Hydrocarbon control strategies continue to be used there to help reduce ozone concentrations. In 2001, the 8-hour standard was exceeded 182 times, on 37 different days, with six counties having 10 or more exceedances at individual sites. The site at 246 West Street and Gold Hill Avenue, Rockwell in Rowan County had the highest number, 17. Sulfur dioxide (SO2) is mainly produced by combustion of fossil fuels containing sulfur compounds and the manufacture of sulfuric acid. SO2 was sampled at 17 sites, yielding 136,344 valid hourly averages. There were no exceedances of the National Ambient Air Quality Standards (365 g/m3 or 0.14 ppm for a 24-hour average, 1300 g/m3 or 0.50 ppm for a three-hour average, 80 g/m3 or 0.03 ppm for the annual arithmetic mean) at network monitoring sites. Nitrogen oxides (NOx) are produced primarily from the burning of fossil fuels such as coal, oil and gasoline, due to the oxidation of atmospheric nitrogen and nitrogen compounds in the fuel. The primary combustion product is NO, which reacts with hydrocarbons, ozone and other atmospheric compounds to form NO2. NOx compounds play an important role in the formation of ozone. Reactive nitrogen species (NOy) were monitored in Charlotte and Winston-Salem to gather data for the development of control strategies for ozone non-attainment areas.



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The criteria pollutant NO2 was sampled at two sites, yielding 16,334 valid hourly averages. There were no exceedances of the National Ambient Air Quality Standard (0.053 ppm for the annual arithmetic mean). The mean one-hour average concentration has been decreasing by about 20 percent per year. Lead (Pb) emissions result from coal combustion and the sandblasting of highway bridges, overpasses, and water tanks. In the past, the combustion of gasoline containing tetraethyl lead as an additive was a major source. Lead was not sampled in 2001. There have been no recent exceedances of the ambient air quality standard for lead (1.5 g/m3 for a quarterly arithmetic mean). Mean lead concentrations have decreased by 92 percent since 1979. The steady decline in the use of leaded gasoline is primarily responsible for this trend. Acid Rain is produced when nitrate and sulfate ions from motor vehicles, combustion and industrial sources reach the upper atmosphere, react with moisture in the air, and are deposited as acid precipitation. Monitoring of pH and other ion concentrations in precipitation will help to identify trends and demonstrate the results of efforts to reduce emissions from mobile and industrial sources. The annual mean pH in 2001 ranged from 4.43 (Rowan County) to 4.88 (Sampson County).



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CONTENTS



Introduction............................................................................................................................. 1 Description of Criteria Pollutants ........................................................................................... 2 Particulate Matter............................................................................................................ 2



2.1.1 2.1.2 2.2.1 2.2.2 2.3.1 2.3.2 2.4.1 2.4.2 2.5.1 2.5.2 2.6.1 2.6.2 Sources........................................................................................................................ 2 Effects ......................................................................................................................... 3 Carbon Monoxide ........................................................................................................... 3 Sources........................................................................................................................ 3 Effects ......................................................................................................................... 3 Ozone.............................................................................................................................. 4 Sources........................................................................................................................ 4 Effects ......................................................................................................................... 4 Sulfur Dioxide................................................................................................................. 4 Sources........................................................................................................................ 4 Effects ......................................................................................................................... 5 Nitrogen Oxides.............................................................................................................. 5 Sources........................................................................................................................ 5 Effects ......................................................................................................................... 5 Lead................................................................................................................................. 5 Sources........................................................................................................................ 5 Effects ......................................................................................................................... 6



1 2 2.1



2.2



2.3



2.4



2.5



2.6



3 4 5 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 6 7 7.1 7.2 7.3



Standards................................................................................................................................. 7 Ambient Air Quality Monitoring Program ............................................................................. 9 Pollutant Monitoring Results ................................................................................................ 18 Total Suspended Particulates........................................................................................ 18 PM10.............................................................................................................................. 20 PM2.5 ............................................................................................................................. 26 Carbon Monoxide ......................................................................................................... 32 Ozone............................................................................................................................ 36 Sulfur Dioxide............................................................................................................... 46 Nitrogen Dioxide .......................................................................................................... 50 Lead............................................................................................................................... 51 Air Quality Index .................................................................................................................. 52 Acid Rain .............................................................................................................................. 62 Sources.......................................................................................................................... 62 Effects ........................................................................................................................... 62 Monitoring .................................................................................................................... 62 References............................................................................................................................ 66 Appendix A. Air Pollution Monitoring Agencies................................................................. 67 Appendix B. Exceptional Events .......................................................................................... 70 Appendix C. Box-And-Whisker Plots .................................................................................. 71 Appendix D. Nonattainment and North Carolina ................................................................. 72 vii





List of Tables Table 3.1 National and North Carolina Ambient Air Quality Standards........................................ 8 Table 4.1 Ambient Air Monitoring Sites Operated in North Carolina, 2001 ............................... 11 Table 5.1 Total Suspended Particulates in Micrograms Per Cubic Meter for 2000 ..................... 19 Table 5.2 PM10 in Micrograms Per Cubic Meter for 2001 ........................................................... 21 Table 5.3 PM2.5 in Micrograms Per Cubic Meter for 2001........................................................... 27 Table 5.4 Carbon Monoxide in Parts Per Million for 2001.......................................................... 33 Table 5.5 One-Hour Ozone in Parts Per Million for 2001............................................................ 38 Table 5.6 Eight-Hour Ozone in Parts Per Million for 2001.......................................................... 42 Table 5.7 Sulfur Dioxide in Parts Per Million from All Sites for 1999-2001 .............................. 47 Table 5.8 Nitrogen Dioxide in Parts Per Million for ................................................................... 50 Table 6.1 Air Quality Index Category Days in the Major Metropolitan Statistical Areas, 2001 . 55 Table 7.1 pH, Conductivity in Microsiemans per Centimeter and Precipitation in Inches from the National Atmospheric Deposition Program for 2001........................................................... 64 Table 7.2 Ion Concentrations in Milligrams per Liter (Precipitation-weighted Annual Means) from the National Atmospheric Deposition Program Data for 2001.................................... 65



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List of Figures Figure 4.1 Monitoring Sites Active in 2001 ................................................................................. 10 Figure 5.1 Location of PM10 Monitoring Sites............................................................................ 21 Figure 5.2 PM10: Second Highest 24-Hour Averages, 2001........................................................ 25 Figure 5.3 PM10: Maximum Annual Arithmetic Means, 2001.................................................... 25 Figure 5.4 Location of PM2.5 Monitoring Sites ............................................................................ 26 Figure 5.5 PM2.5: Second Highest 24-Hour Averages, 2001....................................................... 30 Figure 5.6 PM2.5: Maximum Annual Arithmetic Means, 2001 ................................................... 30 Figure 5.7 PM2.5: Design Values by County, 1999-2001 ............................................................ 31 Figure 5.8 Location of Carbon Monoxide Monitoring Sites ........................................................ 33 Figure 5.9 Carbon Monoxide: Second Highest 1-Hour Average, 2001 ....................................... 35 Figure 5.10 Carbon Monoxide: Second Highest Non-overlapping 8-Hour Average, 2001......... 35 Figure 5.11 Location of Ozone Monitoring Sites......................................................................... 37 Figure 5.12 Ozone: Second Highest Annual 1-Hour Average, 2001 ........................................... 45 Figure 5.13 Ozone: Mean Annual Fourth Highest 8-Hourr Average, 1999-2001....................... 45 Figure 5.14 Locations of Sulfur Dioxide Monitoring Sites in 1999,2000 and 2001 .................... 47 Figure 5.15 Sulfur Dioxide: Second Highest 3-Hour Averages in the Most recent Year of Data from 1999, 2000 and 2001............................................................................................................ 49 Figure 5.16 Sulfur Dioxide: Second Highest 24-Hour Averages in the Most Recent Year of Data from 1999, 2000 or 2001 ...................................................................................................... 49 Figure 5.17 Location of Nitrogen Dioxide Monitoring Sites ...................................................... 50 Figure 6.1 Daily Air Quality Index Values for Asheville, NC, Metropolitan Statistical Area, 2001 ............................................................................................................................................... 55 Figure 6.2 Daily Air Quality Index Summary for Asheville, NC, Metropolitan Statistical Area, 2001....................................................................................................................................... 56 Figure 6.3 Daily Air Quality Index Values for Charlotte-Gastonia, NC,-Rock Hill, SC, Metropolitan Statistical Area, 2001...................................................................................... 56 Figure 6.4 Daily Air Quality Index Summary for Charlotte-Gastonia, NC,-Rock Hill, SC, Metropolitan Statistical Area, 2001...................................................................................... 57 Figure 6.5 Daily Air Quality Index Values for Fayetteville, NC, Metropolitan Statistical Area, 2001....................................................................................................................................... 57 Figure 6.6 Daily Air Quality Index Summary for Fayetteville, NC, Metropolitan Statistical Area, 2001....................................................................................................................................... 58 Figure 6.7 Daily Air Quality Index Values Greensboro-Winston-Salem-High Point, NC, Metropolitan Statistical Area, 2001...................................................................................... 58 Figure 6.8 Daily Air Quality Index Summary Greensboro-Winston-Salem-High Point, NC, Metropolitan Statistical Area, 2001...................................................................................... 59 Figure 6.9 Daily Air Quality Index Values for Raleigh-Durham, NC, Metropolitan Statistical Area, 2001............................................................................................................................. 59 Figure 6.10 Daily Air Quality Index Summary for Raleigh-Durham, NC, Metropolitan Statistical Area, 2001............................................................................................................................. 60 Figure 6.11 Daily Air Quality Index Values for Wilmington, NC, Metropolitan Statistical Area, 2001....................................................................................................................................... 60 ix





Figure 6.12 Daily Air Quality Index Summary for Wilmington, NC, Metropolitan Statistical Area, 2001............................................................................................................................. 61 Figure 7.1 Annual Mean pH Values at North Carolina NADP Sites, 2001.................................. 63



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1 Introduction This annual report summarizes the ambient air monitoring performed in calendar year 2001 by the North Carolina Division of Air Quality (DAQ), three local air pollution agencies and one tribal agency, which are more fully described in Appendix A. There were 451,1241 air quality samples of the U.S. Environmental Protection Agency's (EPA) criteria pollutants particulate matter, carbon monoxide, ozone, sulfur dioxide, nitrogen dioxide and lead-which are discussed in this report. Chapter 2 describes the criteria pollutants and discusses their sources and effects on human health, plants and animals. Chapter 3 outlines the standards applied to criteria pollutant concentrations established by the EPA and the state of North Carolina to protect human health (primary standards) and plants, animals, and property (secondary standards). Chapter 4 describes the ambient monitoring program conducted by DAQ and three local program agencies. Chapter 5



gives detailed monitoring results for each pollutant, with a map of the monitor sites, a table of the monitor summary statistics relevant to the standards, one or more maps summarizing the important statistics for each county with monitors, and additional summaries as appropriate to each pollutant. Chapter 6 describes the EPA Air Quality Index for the criteria pollutants and charts index measurements for five Metropolitan Statistical Areas of North Carolina. Chapter 7 presents sources, effects and monitoring of acid rain data conducted in North Carolina by the National Atmospheric Deposition Program and National Trends Network (NADP). It also includes a map of the calendar year mean pH level and site statistics for the calendar year in two tables. In previous reports, we included a final chapter that provides statewide summary trends for the criteria pollutants. We intend to restore the trends report chapter in subsequent annual report to be published in 2008.



1 The number includes TSP samples collected in



2000.



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2 Description of Criteria Pollutants



2.1 Particulate Matter



Atmospheric particulate matter is defined as any airborne material, except uncombined water (liquid, mist, steam, etc.) that exists in a finely divided form as a liquid or solid at standard temperature (251C) and pressure (760 mm mercury) and has an aerodynamic diameter of less than 100 micrometers (m). In the period covered by this report, three sizes of particulate matter were monitored, total suspended particulate (TSP), PM10 and PM2.5. TSP is any particulate matter measured by the method described in EPA regulations 40 CFR 50 App. B (United States Environmental Protection Agency [US EPA] 1993, p. 715-728) and is generally considered to be particles having an aerodynamic diameter of 40 m or less (Watson and Chow 2001), although particles up to about 100 m are sometimes captured by samplers. (The probability of inhalation for 100 m particles is about 50 percent and increases with decreasing particle size [Maynard and Jensen 2001].) PM10 is particulate matter with an aerodynamic diameter less than or equal to 10 m as measured according to EPA regulations 40 CFR 50 App. J (United States Environmental Protection Agency [US EPA] 1993, p. 769-773). TSP measurements have been made in North Carolina since the early 1960s and PM10 has been sampled locally in Charlotte since 1985 and statewide since 1986 (North Carolina Department of Environment, Health, and Natural Resources 1991). The new PM2.5 standard was adopted by North Carolina on April 1, 1999. On May



14, 1999 the U.S. Court of Appeals ruled the setting or the standard by EPA was an unconstitutional use of authority and could be vacated. The Supreme Court later upheld the new standard. EPA continues to require monitoring for PM2.5. 2.1.1 Sources Particulates are emitted by many human activities, such as fuel combustion, motor vehicle operation, industrial processes, grass mowing, agricultural tilling and open burning. Natural sources include windblown dust, forest fires, volcanic eruptions, and plant pollen. Particles emitted directly from a source may be either fine (less than 2.5 m) or larger (2.5 - 60 m), but particles photochemically formed in the atmosphere will usually be fine. Generally, larger particles have very slow settling velocities and are characterized as suspended particulate matter. Typically, fine particles originate by condensation of materials produced during combustion or atmospheric reactions.



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2.1.2 Effects Particulate matter can cause health problems affecting the breathing system, including aggravation of existing lung and heart disease, limitation of lung clearance, changes in form and structure of organs, and development of cancer. Individuals most sensitive to the effects of particulate matter include those with chronic obstructive lung or heart disease, those suffering from the flu, asthmatics, the elderly, children, and mouth breathers. Health effects from inhaled particles are influenced by the depth of penetration of the particles into the respiratory system, the amount of particles deposited in the respiratory system, and by the biological reaction to the deposited particles. The risks of adverse health effects are greater when particles enter the tracheobronchial and alveolar portions of the respiratory system. Small particles can penetrate into these deeper regions of the respiratory system. Healthy respiratory systems can trap particles larger than 10 micrometers more efficiently before they move deeply into the system and can more effectively remove the particles that are not trapped before deep movement. Particulate matter also can interfere with plant photosynthesis, by forming a film on leaves reducing exposure to sunlight. Particles also can cause soiling and degradation of property, which can be costly to clean and maintain. Suspended particles can absorb and scatter light, causing reduction of visibility. This is a national concern, especially in areas such as national parks, historic sites and scenic attractions visited by sightseers.



2.2 Carbon Monoxide Carbon monoxide (CO) is the most commonly occurring air pollutant. CO is a colorless and poisonous gas produced by incomplete burning of carbon-containing fuel.



2.2.1 Sources Most atmospheric CO is produced by incomplete combustion of fuels used for vehicles, space heating, industrial processes and solid waste incineration. Transportation accounts for the majority of CO emissions. Boilers and other fuel burning heating systems are also significant sources.



2.2.2 Effects Breathing carbon monoxide affects the oxygen-carrying capacity of the blood. Hemoglobin in the blood binds with CO more readily than with oxygen, starving the body of vital oxygen. Individuals with anemia, lung and heart diseases are particularly sensitive to CO effects. Low concentrations affect mental function, vision and alertness. High concentrations can cause fatigue, reduced work capacity and may adversely affect fetal development. Chronic exposure to CO at concentrations as low as 70 ppm (80 mg/m3) can cause cardiac damage. Other health effects associated with exposure to CO include central nervous system effects and pulmonary function difficulties.



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Ambient CO apparently does not adversely affect vegetation or materials.



2.3 Ozone Ozone is a clear gas that forms in the troposphere (lower atmosphere) by chemical reactions involving hydrocarbons (or volatile organic compounds) and nitrogen oxides in the presence of sunlight and high temperatures. Even low concentrations of tropospheric ozone are harmful to people, animals, vegetation and materials. Ozone is the most widespread and serious criteria air pollutant in North Carolina. Ozone in the upper atmosphere (stratosphere) shields the earth from harmful effects of ultraviolet solar radiation. Stratospheric ozone can be damaged by the emission of chlorofluoro-hydrocarbons (CFCs) such as Freon.



2.3.2 Effects Ozone is a pulmonary irritant, affecting the respiratory mucous membranes, as well as other lung tissues and respiratory functions. Ozone has been shown to impair normal function of the lung causing shallow, rapid breathing and a decrease in pulmonary function. Other symptoms of exposure include chest tightness, coughing and wheezing. People with asthma, bronchitis or emphysema probably will experience breathing difficulty when exposed to shortterm concentrations between 0.15 and 0.25 ppm. Continued or repeated long-term exposure may result in permanent lung structure damage. Ozone damages vegetation by injuring leaves. Ozone also accelerates material aging, cracking rubber, fading dyes and eroding paint.



2.3.1 Sources Ozone (O3) is the major component of a complex mixture of compounds known as photochemical oxidants. Ozone is not usually emitted directly into the atmosphere, but is formed by a series of complex reactions involving hydrocarbons, nitrogen oxides and sunlight. Ozone concentrations are higher during the daytime in late spring, summer and early autumn when the temperature is above 601F and the sunlight is more intense. Two natural sources of upper atmosphere ozone are solar radiation and lightning during thunderstorms. These are not significant sources of tropospheric (ground level) ozone.



2.4 Sulfur Dioxide Sulfur dioxide (SO2) is a colorless, corrosive, harmful gas with a pungent odor. Smaller concentrations of sulfur trioxide and other sulfate compounds are also found in SO2 emissions. Sulfur oxides contribute to the formation of acid rain and the formation of particles that reduce visibility.



2.4.1 Sources The main sources of SO2 are combustion of fossil fuels containing sulfur compounds and the manufacture of sulfuric acid. Other sources include refining of petroleum and smelting of ores that contain sulfur.



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2.4.2 Effects The most obvious health effect of sulfur dioxide is irritation and inflammation of body tissues brought in contact with the gas. Sulfur dioxide can increase the severity of existing respiratory diseases such as asthma, bronchitis, and emphysema. Sulfuric acid and fine particulate sulfates, which are formed from sulfur dioxide, also may cause significant health problems. Sulfur dioxide causes injury to many plants. A bleached appearance between the veins and margins on leaves indicates damage from SO2 exposure. Commercially important plants sensitive to SO2 include cotton, sweet potatoes, cucumber, alfalfa, tulips, apple trees, and several species of pine trees.



combustion product is NO, which reacts to form NO2.



2.5 Nitrogen Oxides Several gaseous oxides of nitrogen are normally found in the atmosphere, including nitrous oxide (N2O), nitric oxide (NO) and nitrogen dioxide (NO2). Nitrous oxide is a stable gas with anesthetic characteristics and typical ambient concentrations well below the threshold concentration for a biological effect. Nitric oxide is a colorless gas with ambient concentrations generally low enough to have no significant biological effect. Nitrogen dioxide is reddish-brown but is not usually visible at typical ambient concentrations.



2.5.2 Effects At typical concentrations, nitrogen dioxide has significant health effects as a pulmonary irritant, especially upon asthmatics and children. In North Carolina a much greater health concern is the formation of ozone, which is promoted by the presence of NO2 and other nitrogen oxides. Some types of vegetation are very sensitive to NO2, including oats, alfalfa, tobacco, peas and carrots. Chronic exposure causes chlorosis (yellowing) and acute exposure usually causes irregularly shaped lesions on the leaves. Nitric oxide and nitrogen dioxide do not directly damage materials. However, NO2 can react with moisture in the air to produce nitric acid, which corrodes metal surfaces and contributes to acid rain. High concentrations of NO2 may reduce visibility. Much of the brownish coloration sometimes observed in polluted air in winter months may be due to NO2.



2.5.1 Sources The most significant nitrogen oxide emissions result from the burning of fossil fuels such as coal, oil and gasoline, due to the oxidation of atmospheric nitrogen and nitrogen compounds in the fuel. The primary



2.6 Lead Lead is a toxic heavy metal element occurring in the atmosphere as small particles.



2.6.1 Sources The major source of atmospheric lead used to be the combustion of gasoline containing



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the additive tetraethyl lead as an anti-knock agent. However, the availability of leaded fuel has declined, and the concentration of lead in such fuel has decreased, minimizing gasoline as a source. Significant remaining sources include coal combustion (lead exists in very small quantities as an impurity in coal) and sandblasting of highway structures and water tanks. Lead also is used in some batteries, paints, insecticides and newspaper inks concentrations interferes with blood production and specific enzyme systems. It is believed to cause kidney and nerve cell damage, and severe lead poisoning is known to cause brain damage in children.



2.6.2 Effects



Lead (Pb) persists and accumulates in the environment and the human body. It may be inhaled, ingested, and eventually absorbed into the bloodstream and distributed to all body tissues. Exposure to low



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3 Standards



Ambient air quality status is determined by measuring pollutant concentrations in outdoor air and comparing the measured concentrations to corresponding standards. The US EPA (Environmental Protection Agency) defines the ambient air as "that portion of the atmosphere, external to buildings, to which the general public has access." Ambient air quality standards are classified as primary and secondary. Primary standards are those established to protect public health. Secondary standards are those established to protect the public welfare from adverse pollution effects on



soils, water, crops, vegetation, manmade materials, animals, wildlife, weather, visibility, climate, property, transportation, economy, and personal comfort and wellbeing. The scientific criteria upon which the standards are based are reviewed periodically by the EPA, which may reestablish or change the standards according to its findings. A pollutant measurement that is greater than the ambient air quality standard for a specific averaging time is called an exceedance. The national primary, secondary and North Carolina ambient air quality standards that were in effect during 2001 are summarized in Table 3.1.



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Table 3.1 National and North Carolina Ambient Air Quality Standards



For new or anticipated new standards, References in the Code of Federal Regulations are given. For standards expressed in parts per million, an equivalent mass per unit volume is also shown.



Pollutant/ Ambient Measurement/ (Reference) TSP 24 hour average PM-2.5 24 hour average (40CFR50, App. N)



Averaging Period Type of Summary



Primary National (Health Related) Standard



(1) (1)



15 g/m3 65 g/m3 50 g/m3



Secondary National (Welfare Related) Standard



(1) (1)



15 g/m3 65 g/m3 50 g/m3



North Carolina Standard



PM-10 24 hour average (40CFR50, App. N)



CO 1 hour average



O3 1 hour average (40CFR50, App. I)



SO2 1 hour average



NO2 1 hour average Pb 24-hour average



1 year 1 day 1 year 1 day 1 year 1 day 8 hours 1 hour 1 hour 8 hours 1 year 1 day 3 hours (nonoverlapping) 1 year 1 quarter geometric mean 2nd maximum average2 arithmetic mean average2 98th percentile average2 arithmetic mean average2 2nd maximum3 2nd maximum 2nd maximum expected4 2nd maximum average5 arithmetic mean 4th maximum arithmetic mean 2nd maximum 2nd maximum arithmetic mean arithmetic mean



75 g/m3 150 g/m3



15 g/m3 65 g/m3 50 g/m3



(6) (6) (6)



(6)



150 g/m3 9 ppm (10 mg/m3) 35 ppm (40 mg/m3) (235 g/m3) (157 g/m3) 0.03 ppm (80 g/m3) 0.14 ppm (365 g/m3)



0.12 ppm (6)



0.08 ppm (6)



150 g/m3



0.12 ppm



(6)



150 g/m3 9 ppm (10 mg/m3) 35 ppm (40 mg/m3) 0.12 ppm (235



g/m3) (6,7)



0.08 ppm



(6)



(235 g/m3) (157 g/m3)



0.08 ppm (6)



0.053 ppm (100 g/m3) 1.5 g/m3



0.50 ppm (1,300 g/m3) 0.053 ppm (100 g/m3) 1.5 g/m3



(157 g/m3) 0.03 ppm (80 g/m3) 0.14 ppm (365 g/m3) 0.50 ppm (1,300 g/m3) 0.053 ppm (100 g/m3) 1.5 g/m3



1. In 1987, National standards for PM-10 replaced those for TSP. 2. Arithmetic mean over the 3 most current years. 3. In July 1997, a percentile-based statistic replaced the 2nd maximum, but in May 1999 the 2nd maximum standard was reinstated. That change was vacated in 2000, but we overlooked it in the 2000 Annual Air Quality Report. 4. Determined by adjusting for incomplete days and averaging over the most recent 3 consecutive, complete calendar years. 5. Arithmetic mean value over the most recent 3 consecutive, complete calendar years. 6. On April 1, 2000 North Carolina adopted the EPA PM2.5 and Ozone standards. On May 14, 2000 the US Court of Appeals ruled the new EPA PM2.5 standard vacated and the new 8-hour ozone standard as unenforceable. On appeal to the US Supreme Court the new standard was upheld. 7. On May 27, 2000, the one-hour ozone standard was rescinded by the Environmental Management Commission based on EPA guidance. The one-hour standard is being reinstated by EPA.



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4 Ambient Air Quality Monitoring Program



The North Carolina Division of Air Quality, three local air pollution control programs, and one tribal program (Appendix A) performed ambient monitoring and analyses of samples in 2001. Ambient air monitoring data are used to determine whether air quality standards are being met; to assist in enforcement actions; to determine the improvement or decline of air quality; to determine the extent of allowable industrial expansion; and to provide air pollution information to the public. A list of all monitoring sites active in 2001 is presented in Table 4.1 and shown as a map in Figure 4.1. The locations of sites for individual pollutants are shown in Figures 5.1, 5.4, 5.8, 5.11, 5.14, and 5.17. In general, ambient monitors are operated year-round, but in some cases seasonal variations in pollutant levels make it feasible to suspend sampling at certain times. Ambient carbon monoxide associated with transportation and heating tends to produce significant concentrations only in cold weather conditions, so (with the US EPA's permission) we generally operate these monitors only from October through March. Ozone concentrations, by contrast, are correlated positively with ambient temperature. US EPA regulations accordingly require monitoring in NC from April through October. Along with ozone at some locations we also monitor ozone precursor pollutants. Indeed, one of the ozone precursors is carbon monoxide. See §5.4 for more information about seasonal carbon monoxide monitoring and §5.5 for more information about seasonal ozone monitoring. Siting of monitors involves several considerations, including size of the area represented, distance from roadways and nearby sources, unrestricted air flow, safety, availability of electricity and security. Each site has a defined monitoring objective, and annual evaluations are conducted to ensure that the objectives are met. The four basic monitoring objectives are to determine: · the highest concentration expected in an area; · representative concentrations in areas of high population density; · the impact of significant sources or source categories on ambient air quality; · general background concentration levels. All monitors have known precision, accuracy, interferences and operational parameters. The monitors - as well as all measurement devices - are carefully calibrated at predetermined frequencies, varying from daily to quarterly. Measurements are traceable to National Institute of Standards and Technology (NIST), when standards are available.



9





Monitoring and analyses are performed according to a set of standard operating procedures. Field personnel visit manual sampling sites once every six days to replace sample media and check the operation and calibration of monitors. Personnel check continuous monitors at least twice monthly for correct instrument operation. Monitoring agencies carry out quality assurance activities to determine the quality of the collected ambient data, improve the quality of the data and evaluate how well the monitoring system operates. The goal of quality assurance activities is to produce high quality air pollution data with defined completeness, precision, accuracy, representativeness and comparability. Microprocessors are used at most sites to collect the data. A computerized telemetry system aids in assembly of the data for submission to the US EPA. This enhances data validity, minimizes travel costs, and allows real-time data to be available by computer polling when needed. Numerous checks are performed to ensure that only valid data are reported.



Figure 4.1 Monitoring Sites Active in 2001



10





Table 4.1 Ambient Air Monitoring Sites Operated in North Carolina, 2001



SITE COUNTY 37-001-0002 ALAMANCE 37-003-0003 ALEXANDER 37-011-0002 AVERY 37-013-0006 BEAUFORT 37-021-0003 BUNCOMBE 37-021-0030 BUNCOMBE 37-021-0034 BUNCOMBE 37-025-0004 CABARRUS 37-027-0003 CALDWELL 37-029-0099 CAMDEN 37-033-0001 CASWELL 37-035-0004 CATAWBA 37-035-0005 CATAWBA 37-037-0004 CHATHAM



ADDRESS POLLUTANTS



827 S GRAHAM & HOPEDALE RD BURLINGTON 324 MINNIGAN LANE TAYLORSVILLE 7510 BLUE RIDGE PARKWAY SPUR



PM2.5



O3



O3



NC 306 @ PCS ENTRANCE SO2



HEALTH & SOCIAL SERVICES BLDG WOODFIN ST ASHEVILLE ROUT 191 SOUTH BREVARD RD ASHEVILLE 175 BINGHAM ROAD ASHEVILLE 933 FLOYD STREET KANNAPOLIS HWY 321 NORTH LENOIR COUNTY ROAD 1136 & 1134



PM10



O3



PM2.5



PM10 PM2.5



O3



O3



7074 CHERRY GROVE RD REIDSVILLE 1650 1ST STREET HICKORY 7075 WEST NC HWY 10 HICKORY ROUTE 4 BOX 62 PITTSBORO



O3 PM2.5



PM10 PM2.5



PM2.5



SO2 PM2.5 O3



11





SITE COUNTY 37-051-0007 CUMBERLAND 37-051-0008 CUMBERLAND 37-051-0009 CUMBERLAND 37-051-1003 CUMBERLAND 37-057-0002 DAVIDSON 37-059-0002 DAVIE 37-061-0002 DUPLIN 37-063-0001 DURHAM 37-063-0013 DURHAM 37-065-0003 EDGECOME 37-065-0099 EDGECOME 37-067-0022 FORSYTH 37-067-0023 FORSYTH 37-067-0024 FORSYTH 37-067-0025 FORSYTH



ADDRESS POLLUTANTS



CUMBERLAND CO ABC BOARD, 1705 OWEN DR FAYETTEVILLE 1/4 MILE SR1857/US301/1857



CO



O3



4533 RAEFORD RD FAYETTEVILLE 3625 GOLFVIEW RD HOPE MILLS SOUTH SALISBURY STREET LEXINGTON 246 MAIN STREET COOLEEMEE HIGHWAY 50 KENANSVILLE HEALTH DEPT 300 E MAIN STREET DURHAM 2700 NORTH DUKE STREET DURHAM TALBERT PARK AT SPRUCE & CAROLINA ROCKY MOUNT 7589 NC HIGHWAY 33 NW TARBORO 1300 BLK HATTIE AVENUE WINSTON-SALEM 1401 CORPORATION PARKWAY WINSTON-SALEM NORTH FORSYTH HIGH SCHOOL WINSTON-SALEM 100 SW STRATFORD RD WINSTON-SALEM



PM10 PM2.5



O3



PM10 PM2.5



O3



O3 PM2.5



PM10 PM2.5



CO O3



PM10 PM2.5



O3



CO CO SO2 PM10 NO2 PM2.5 PM10



PM2.5



CO



12





SITE COUNTY 37-067-0027 FORSYTH 37-067-0028 FORSYTH 37-067-0029 FORSYTH 37-067-1008 FORSYTH 37-069-0001 FRANKLIN 37-071-0016 GASTON 37-077-0001 GRANVILLE 37-081-0009 GULIFORD 37-081-0011 GULIFORD 37-081-0013 GULIFORD 37-081-1005 GULIFORD 37-081-1011 GULIFORD 37-087-0002 HAYWOOD 37-087-0004 HAYWOOD 37-087-0010 HAYWOOD



ADDRESS POLLUTANTS



7635 HOLLYBERRY LANE WINSTON-SALEM 6496 BAUX MOUNTAIN ROAD WINSTON-SALEM 1985 GRIFFITH ROAD WINSTON-SALEM 3656 PIEDMONT MEMORIAL DRIVE WINSTON-SALEM 431 S. HILLSBOROUGH STREET FRANKLINTON 1622 EAST GARRISON BLVD GASOTNIA



O3



O3



CO



O3



O3



PM10 PM2.5



WATER TREATMENT PLANT JOHN UMSTEAD HOSP CO BUTNER



EDGEWORTH & BELLEMEADE ST'S GREENSBORO KELLY PARK , KELLY RD MC CLEANSVILLE 205 WILOUGHBY BLVD GREENSBORO E. GREEN & S CENTENNIAL STREET HIGH POINT 401 WEST WENDOVER GREENSBORO CANTON FIRE DEPARTMENT CANTON 2177 ASHEVILLE ROAD WAYNESVILLE 9 MAIN STREET WAYNESVILLE



PM10



O3



PM2.5



O3



PM2.5



PM10 PM2.5



CO



PM10



O3



PM2.5



13





SITE COUNTY 37-087-0011 HAYWOOD 37-087-0035 HAYWOOD 37-087-0036 HAYWOOD 37-089-1006 HANDERSON 37-099-0005 JACKSON 37-099-0006 JACKSON 37-101-0002 JOHNSTON 37-107-0004 LENIOR 37-109-0004 LINCOLN 37-111-0004 MC DOWELL 37-117-0001 MARTIN 37-119-0001



ADDRESS POLLUTANTS



PROSPECT AND NORTHSIDE STREETS CANTON TOWER BLUE RIDGE PARKWAY MILE MARKER 410 GREAT SMOKY MOUNTAINS NATIONAL PARK CORNER OF ALLEN & WASHINGTON ST'S HENDERSONVILLE BARNET KNOB FIRE TOWER RD



PM10



O3



O3



PM10



O3



US ROUTE 19 NORTH CHEROKEE RESERVATION 1338 JACK ROAD CLAYTON HIGHWAY 70 EAST AND HIGHWAY 58 SOUTH KINSTON 1487 RIVERVIEW ROAD LINCOLNTON



PM2.5



O3



O3 PM2.5



O3



BALWIN AVENUE (EAST MARION JR. HIGH SCHOOL PM10 MARION



1210 HAYES STREET JAMESVILLE 600 EAST TRADE STREET



SO2



PM2.5



O3



PM10



MECKLENBURG CHARLOTTE 37-119-0003 FIRE STATION # 11, 620 WEST 28TH STREET MECKLENBURG CHARLOTTE 37-119-0010 FIRE STATION # 10, 2136 FREMOUNT ROAD MECKLENBURG CHARLOTTE 37-119-0038 301 NORTH TRYON STREET MECKLENBURG CHARLOTTE



PM10



PM10 PM2.5



CO



14





SITE COUNTY 37-119-0041



ADDRESS



POLLUTANTS PM2.5 SO2 NO2



1130 EASTWAY DRIVE CO O3



MECKLENBURG CHARLOTTE 37-119-0042 1935 EMERYWOOD DRIVE MECKLENBURG CHARLOTTE 37-119-1001 FILTER PLANT MECKLENBURG DAVIDSON 37-119-1005 400 WESTINGHOUSE BLVD. MECKLENBURG CHARLOTTE 37-119-1009 29 N @ MECKLENBURG CAB CO. MECKLENBURG CHARLOTTE



37-121-0001 MITCHELL 37-123-0001 CITY HALL, SUMMIT STREET SPRUCE PINE 112 PERRY DRIVE



PM2.5



PM10



O3 PM10



CO O3



PM10 PM2.5



PM2.5



MONTGOMERY CANDOR 37-129-0002 6028 HOLLY SHELTER ROAD NEW HANOVER CASTLE HAYNE 37-129-0006 HIGHWAY 421 NORTH NEW HANOVER WILMINGTON 37-129-0008 CORNER OF OLEANDER & COLLEGE RD NEW HANOVER WILMINGTON 37-129-0009 2710 MARKET STREET NEW HANOVER WILMINGTON 37-131-0002 ROUTE 46 NORTHAMPTON GASTON



37-133-0005 ONSLOW 37-135-0007 ORANGE 37-139-0002 PASQUOTANK 617 HENDERSON DR JACKSONVILLE MASON FARM ROAD CHAPEL HILL 600 WESTOVER STREET ELIZABETH CITY



O3



SO2



CO



PM10 PM2.5



O3



PM10 PM2.5



PM2.5



PM10 PM2.5



15





SITE COUNTY 37-145-0003 PERSON 37-147-0005 PITT 37-147-0099 PITT 37-151-0004 RANDOLPH 37-155-0005 ROBESON 37-157-0099 ROCKINGHAM 37-159-0021 ROWAN 37-159-0022 ROWAN 37-173-0002 SWAIN 37-179-0003 UNION 37-183-0011 WAKE 37-183-0014 WAKE 37-183-0015 WAKE 37-183-0016 WAKE 37-183-0017 WAKE



ADDRESS POLLUTANTS



STATE ROAD 1102 & NC 49 SO2 O3



851 HOWELL STREET GREENVILLE US 264 NEAR WATER TOWER FARMVILLE 4507 BRANSON DAVIS ROAD SOPHIA 1170 LINKHAW ROAD LUMBERTON 6371 NC 65 @ BETHANY SCHOOL BETHANY 301 WEST ST & GOLD HILL AVENUE ROCKWELL 925 NORTH ENOCHVILLE AVENUE CHINA GROVE CENTER ST/PARKS & RECREATION FACILITY



PM10 PM2.5



O3



O3



PM2.5



O3



CO CO O3 O3



SO2 PM2.5 PM10 O3



701 CHARLES STREET MONROE 420 S PERSON STREET RALEIGH 3801 SPRING FOREST ROAD RALEIGH 808 NORTH STATE STREET RALEIGH 201 NORTH BROAD STREET FUQUAY-VARINA 5033 TV TOWER ROAD GARNER



O3



CO



O3 PM2.5 PM10



CO PM2.5 O3



O3



O3



16





SITE COUNTY 37-183-0018 WAKE 37-189-0003 WATAUGA 37-191-0005 WAYNE 37-199-0003 YANCEY Sites operated in 2001



ADDRESS POLLUTANTS



US HIGHWAY 70 WEST & NC HIGHWAY 50 NOR RALEIGH 361 JEFFERSON ROAD BOONE DILLARD MIDDLE SHOOL, DEVEREAU STREET GOLDSBORO STATE HIGHWAY 128 BURNSVILLE 93



CO



PM2.5



PM10 PM2.5



O3



17





5 Pollutant Monitoring Results Air quality in a given area is affected by many factors, including meteorological conditions, the location of pollutant sources, and the amount of pollutants emitted from them. The speed and direction of air movement determine whether pollutant emissions cause exceedances of the ambient air quality standards and where those exceedances will occur. Atmospheric stability, precipitation, solar radiation and temperature also affect pollutant concentrations. Geographic factors that affect concentrations include variables such as whether an area is urban or rural, and whether the area has mountains, valleys or plains. Important economic factors affecting air quality include concentration of industries, conditions of the economy, and the day of the week. Air quality also may be influenced by "exceptional events" in the short term. Exceptional events may be either natural (e.g., forest fire) or manmade (e.g., construction or demolition). Unusual data that can be attributed to an exceptional event are considered biased and may be omitted from data summaries when they are not representative of normal conditions. In



the tabular listings in this report, data affected by exceptional events are excluded, and are omitted from summaries in charts. However they are addressed in the text of the report. A list of typical exceptional events is given in Appendix B. Data for the 2001 ambient air quality report were collected at 153 air pollutant monitors operated by state and local agencies in North Carolina (listed in Appendix A). To minimize operating expenses, some sulfur dioxide monitors are operated only every third year. Twelve of the 153 monitors used for this report operated most recently in 1999 or 2000.



5.1 Total Suspended Particulates Total Suspended Particulate matter (TSP) is collected on filters using a "high volume" sampler (an EPA Reference Method). The sampler motor is set and calibrated to an air flow rate of 40±4 cubic feet per minute. Gravimetric analysis is performed by comparing the exposed filter weight to the unexposed filter weight. Weights are measured to the nearest 0.1 milligram. The difference between the exposed and



18





unexposed weights is the amount of particulate collected from a known volume of air. The state and local program agencies discontinued routine ambient TSP sampling at the end of 2000, but will resume a limited sampling program again in 2003. In 2000, two sites in Mecklenburg County were used to monitor TSP and 92 samples were collected. A detailed summary of the data from each site is given in Table 5.1. No sample exceeded the N.C. TSP ambient air quality standards in 2000. The highest 24-hour average was 116, which was 77 percent of the standard. This value occurred at the Fire Station # 10 site in Charlotte. Attainment status is based on the second highest 24-hour concentration and on the geometric mean of all the 24-hour concentrations at a given site. The largest geometric mean TSP average was 45 g/m3, which is 59 percent of the level of the air quality standard. This value occurred at the East Trade Street site in Charlotte. During early November 2000, especially November 2, 3, 4, and 8 there were several sites on which particulate matter samplers were affected by smoke from forest fires in North Carolina and neighboring states. A reading of 152 g/m3, which is above the standard of 150 g/m3, was recorded at the East Trade Street site in Charlotte. The geometric mean increased to 49 g/m3 as well.



Table 5.1 Total Suspended Particulates in Micrograms Per Cubic Meter for 2000



SITE NUMBER COUNTY 37-119-0001 MECKLENBURG NUM OBS 40 24-HOUR MAX



1st 90 2nd 82 3rd 75



ARITH GEOM GEOM



MEAN MEAN 47 45 SD 1.4



37-119-0010 MECKLENBURG Total Samples Total Sites Sampled



ADDRESS 600 EAST TRADE STREET CHARLOTTE FIRE STA #10 2136 REMOUNT ROAD CHARLOTTE



4th 70



52 116 75 73 71 44 41 1.5



92 2



19





5.2 PM10



State and local program agencies in North Carolina use high volume samplers and size selective inlets to collect PM10 samples. A gravimetric analysis procedure (EPA Reference Method) is used to analyze the samples. In 2001, 2376 ordinary 24-hour samples of PM10 were collected from monitors located at 31 sites. A map of the PM10 sampling sites is shown in Figure 5.1, and a detailed summary of the data from each site is given in Table 5.2. There was one exceedance of the PM10 ambient air quality standards in 2001. During the forest fires in November, the monitor in Bryson City recorded 203 g/m3 on 15 November and 79 g/m3 on 22 November. During the same fire episode on 15 November the Asheville monitor recorded 115 g/m3. For about a week, from 30 October through 5 November, peat fires were burning in the vicinity of the monitor



near Elizabeth City. DAQ scheduled daily sampling that was successful on five of the seven days. Here, on 30 October the monitor recorded 84 g/m3, and on the other days several concentrations between 10 and 20 g/m3. Excluding these samples affected by fires, the highest 24-hour maximum concentration was 75 g/m3, or about 50 percent of the standard (150 g/m3). The highest annual arithmetic mean was 29.6 g/m3, which is about 60 percent of the standard (50 g/m3). NAAQS attainment is based on the level of the second highest 24-hour concentration (Table 3.1), the second highest 24-hour concentrations are shown by county in Figure 5.2 and the annual arithmetic means are shown in Figure 5.3. (In counties with more than one PM10 monitoring site, the concentration reported in Figure 5.2 is the county-wide second maximum 24-hour concentration, and the mean reported in Figure 5.3 is the maximum arithmetic mean for the county.)



20





Figure 5.1 Location of PM10 Monitoring Sites



Table 5.2 PM10 in Micrograms Per Cubic Meter for 2001



SITE NUMBER COUNTY 37-021-0003 BUNCOMBE



ADDRESS



NUM OBS 24-HOUR MAXIMA ARITH MEAN



HEALTH & SOCIAL SERVICES BLDG WOODFIN ST ASHEVILLE 53



1st 43 2nd 34 3rd 32 4th



17.5



37-025-0004 CABARRUS FLOYD STREET KANNAPOLIS 61 53 46 40 35 20.1



37-035-0004 CATAWBA 1650 1ST. ST. HICKORY 48 47 39 35 33 21.0



37-051-0009 CUMBERLAND 4533 RAEFORD ROAD FAYETTEVILLE 57 44 39 35 33 21.5



37-057-0002 DAVIDSON S. SALISBURY ST. LEXINGTON, NC 52 47 46 35 35 21.3



21





SITE NUMBER COUNTY 37-063-0001 DURHAM



ADDRESS



NUM OBS 24-HOUR MAXIMA ARITH MEAN



HEALTH DEPT 300 E MAIN ST DURHAM 61



1st 48 2nd 46 3rd 39 4th 39



23.6



38-065-0003 EDGECOMBE TALBERT PARK at SPRUCE ST ROCKY MOUNT 18 34 30 29 29 18.8



37-067-0022 FORSYTH 1300 BLK. HATTIE AVE WINSTON-SALEM 365 71 58 53 51 21.5



37-067-0023 1401 CORPORATION PARKWAY 346 75 67 57 57 24.1



FORSYTH WINSTON-SALEM



37-071-0016 GASTON 1622 E. GARRISON BLVD GASTONIA 58 49 37 34 30 19.4



37-081-0009 GUILFORD EDGEWORTH & BELLEMEADE STS GREENSBORO 60 46 43 41 40 21.3



37-081-0013 GUILFORD 205 WILOUGHBY BLVD GREENSBORO 3 19 10 2 0 10.3



37-081-1005 GUILFORD E GREEN & S CENTENNIAL ST HIGH POINT 24 57 42 35 32 22.6



37-087-0002 HAYWOOD ROOF, CANTON FIRE DEPT. CANTON 34 63 53 52 47 29.6



37-08-70011



PROSPECT AND NORTHSIDE STREETS 22 54 36 32 30 23.7



HAYWOOD



37-089-1006



CORNER OF ALLEN & WASHINGTON STS 60 53 46 46 40 21.5



22





SITE NUMBER COUNTY HENDERSON



ADDRESS



NUM OBS 24-HOUR MAXIMA ARITH MEAN



1st 2nd 3rd 4th



HENDERSON-VILLE



37-111-0004



BALWIN AVENUE (EAST MARION JR. HIGH SCHOOL) 60 46 43 37 33 20.7



MC DOWELL MARION



37-119-0001 MECKLENBURG 600 EAST TRADE STREET CHARLOTTE 40 59 41 37 36 25.5



37-119-0003 MECKLENBURG FIRE STA #11 620 MORETZ STREET CHARLOTTE 57 71 58 52 47 28.0



37-119-0010



MECKLENBURG



FIRE STA #10 2136 REMOUNT RD CHARLOTTE 60 62 58 41 39 24.9



37-119-1001 MECKLENBURG FILTER PLANT DAVIDSON 61 55 53 37 36 20.6



37-119-1005 400 WESTINGHOUSE BLVD. 60 74 65 56 51 29.2



MECKLENBURG CHARLOTTE



37-121-0001 MITCHELL CITY HALL SUMMIT ST SPRUCE PINE 60 44 42 40 39 23.3



37-129-0009 NEW HANOVER 2710 MARKET STREET WILMINGTON 58 32 31 26 26 16.0



37-133-0005 ONSLOW 617 HENDERSON DRIVE JACKSONVILLE 59 34 28 27 26 15.6



23





SITE NUMBER COUNTY 37-139-0002



ADDRESS



NUM OBS 24-HOUR MAXIMA ARITH MEAN



600 WESTOVER STREET 54



1st 38 2nd 34 3rd 30 4th 29



17.6



PASQUOTANK ELIZABETH CITY



37-147-0005 PITT 851 HOWELL STREET GREENVILLE 57 41 38 33 31 18.7



37-173-0002 SWAIN CENTER ST/PARKS 7 REC FACILITY 51 46 37 32 29 19.3



37-183-0014 WAKE 3801 SPRING FOREST RD. RALEIGH 265 56 52 42 42 19.5



37-183-0014 WAKE 3801 SPRING FOREST RD. RALEIGH 56 47 43 42 41 21.9



37-191-0005



WAYNE



DILLARD MIDDLE SCHOOL DEVEREAU ST GOLDSBORO 56 38 35 33 33 20.8



Total Samples Total Sites Sampled 2,376 31



24





Figure 5.2 PM10: Second Highest 24-Hour Averages, 2001



Figure 5.3 PM10: Maximum Annual Arithmetic Means, 2001



25





5.3 PM2.5 In 2001, 38 sites were used to monitor PM2.5 and 5375 samples were collected. A map of the PM2.5 sampling sites is shown in Figure 5.4 and a detailed summary of the data from each site is given in Table 5.3. There was one exceedance of the PM2.5 24-hour ambient air quality standards in 2001 at the Asheville site in Buncombe County. This highest 24-hour maximum concentration was 93.3 g/m3, or about 145 percent of the standard (65 g/m3) (See Table 5.3). The highest annual arithmetic mean was 16.5 g/m3, which is about 10 percent over the level of the standard (15 g/m3) at the Lexington in Davidson County. Three other monitors exceeded the annual arithmetic mean standard in 2001: Hickory in Catawba County, Winston-Salem in Forsyth County and Charlotte in Mecklenburg County (See Table 5.3). NAAQS attainment is based on the level of the 98th percentile concentration (Table 3.1). The 98th percentile concentrations are shown by county in Figure 5.5, and the annual arithmetic means are shown in Figure 5.6. (In counties with more than one monitoring site, the concentration reported in Figure 5.5 is the maximum 98th percentile and the mean reported in Figure 5.6 is the maximum arithmetic mean for the county.) Figure 5.7 is a map of "design values" for PM2.5, computed from the highest 3year average arithmetic mean in each county for 1999 through 2001, using the federal reference method monitors. Twenty-five counties have enough reported data to compute this metric correctly, and fourteen of them appear to be violating the ambient standard that is due to be implemented. Attainment decisions for PM2.5 will be based on the design values observed during 2001 through 2003, which may or may not resemble the values illustrated here.



Figure 5.4 Location of PM2.5 Monitoring Sites



26





Table 5.3 PM2.5 in Micrograms Per Cubic Meter for 2001



SITE NUMBER COUNTY 37-001-0002 ALAMANCE 37-021-0034 BUNCOMBE 37-025-0004 CABARRUS 37-033-0001 CASWELL 37-035-0004 CATAWBA 37-035-0005 CATAWBA 37-037-0004 CHATHAM 37-051-0009 CUMBERLAND 37-057-0002



ADDRESS



NUM OBS 122



24-HOUR MAXIMA



2nd 38.0 3rd 36.5



DAVIDSON 37-061-0002 DUPLIN 37-063-0001 DURHAM 38-065-0003 EDGECOMBE 37-067-0022 FORSYTH 37-067-0024 FORSYTH 37-071-0016 GASTON 37-081-0009



827 SOUTH GRAHAM & HOPE BURLINGTON 175 BINGHAM ROAD ASHEVILLE 933 FLOYD STR KANNAPOLIS 7074 CHERRY GROVE REIDSVILLE 1650 1ST. ST. HICKORY 7075 WEST HWY 10 HICKORY RT4 BOX62 PITTSBORO 4533 RAEFORD ROAD FAYETTEVILLE SOUTH SALISBURY STREET LEXINGTON HWY 50 KENANANSVILLE HEALTH DEPT 300 E MAIN ST DURHAM TALBERT PARK at SPRUCE ST ROCKY MOUNT 1300 BLOCK, HATTIE AVENUE WINSTON-SALEM NORTH FORSYTH HIGH SCHOOL WINSTON-SALEM 1622 EAST GARRISON BLVD GASTONIA EDGEWORTH &



1st 44.5 4th 35.1



PERCENTILE 98TH 36.5 ARITH MEAN 14.0



84 93.3 45.2 31.1 29.4 45.2 14.1



118 44.7 34.1 31.4 30.3 31.4 14.4



119 50.2 41.5 40.3 35.6 40.3 13.6



103 40.0 32.8 32.0 30.4 32.0 16.0



119 38.9 30.5 30.0 28.6 30.0 13.3



118 39.5 32.2 30.0 27.5 30.0 12.9



119 39.6 38.5 27.0 26.2 27.0 14.3



106 41.6 39.2 37.7 29.0 37.7 16.5



119 31.4 30.1 25.6 25.5 25.6 12.4



335 45.4 35.9 34.5 34.0 33.0 14.6



38 24.5 22.7 22.5 20.2 24.5 11.2



337 49.4 46.4 44.6 42.3 35.4 15.7



113 43.2 42.7 41.2 32.5 41.2 14.3



118 39.5 28.8 28.1 26.9 28.1 14.0



341 49.8



27



47.2 40.3 35.0 32.7 14.9





SITE NUMBER COUNTY GUILFORD 37-081-0013 GUILFORD 37-081-1005 GUILFORD 37-087-0010 HAYWOOD 37-099-0006 JACKSON 37-107-0004 LENOIR 37-111-0004 MC DOWELL 37-119-0010 MECKLENBURG



ADDRESS



NUM OBS



24-HOUR MAXIMA 2nd 3rd



1st 4th



PERCENTILE 98TH ARITH MEAN



37-119-1041 MECKLENBURG 37-119-1042



MECKLENBURG 37-121-0001 MITCHELL 37-123-0001 MONTGOMERY



BELLEMEADE GREENSBORO 205 WILOUGHBY BLVD GREENSBORO E GREEN & S CENTENNIAL ST HIGH POINT 9 MAIN STREET WAYNESVILLE US RT 19 NORTH CHEROKEE RES CORNER HWY 70 EAST KINSTON BALDWIN AVE MARION FIRE STA #10 2136 REMOUNT ROAD CHARLOTTE 1130 EASTWAY DRIVE CHARLOTTE 1935 EMERYWOOD DRIVE CHARLOTTE CITY HALL SUMMIT ST SPRUCE PINE 112 PERRY DRIVE



13 16.2 12.9 12.7 12.3 16.2 10.4



50 24.6 23.7 23.6 22.5 24.6 14.1



118 40.7 37.6 35.9 32.2 35.9 14.9



81 60.4 36.5 34.0 33.4 36.5 13.7



122 27.5 27.3 27.1 24.2 27.1 12.0



122 40.7 37.1 35.7 30.6 35.7 15.0



360 40.9 40.5 35.3 35.0 31.9 15.5



320 40.3 39.6 33.6 33.4 31.8 14.8



116 39.8 28.4 27.9 27.2 27.9 14.6



120 37.2 34.7 32.7 30.8 32.7 14.2



117 31.5 25.9 25.9 25.7 25.9 12.7



37-129-0009 NEW HANOVER 37-133-0005 ONSLOW 37-135-0007 ORANGE 2710 MARKET STREET WILMINGTON 617 HENDERSON DRIVE JACKSONVILLE MASON FARM ROAD CHAPEL HILL



109 29.3 26.3 25.4 25.1 25.4 11.5



114 38.3 26.2 26.0 25.7 26.0 11.5



119 38.0 30.2 30.1 30.0 30.1 13.6



37-139-0002 PASQUOTANK 600 WESTOVER STREET ELIZABETH CITY 128 37.2 36.4 32.3 30.6 32.3 12.3



28





SITE NUMBER COUNTY 37-147-0005 PITT 37-155-0005 ROBESON 37-173-0002 SWAIN 37-183-0014 WAKE 37-183-0015 WAKE 37-189-0003 WATAUGA 37-191-0005 WAYNE



ADDRESS



NUM OBS 24-HOUR MAXIMA



2nd 30.0 3rd 27.8



851 HOWELL STREET GREENVILLE 1170 LINKHAM ROAD LUMBERTON CENTER ST/PARKS 7 REC FACILITY EAST MILLBROOK JR HI RALEIGH 808 NORTH STATE STREET RALEIGH 361JEFFERSON HWY BOONE DILLARD MIDDLE SCHOOL GOLDSBORO



107



1st 30.3 4th 26.4



PERCENTILE 98TH 27.8



ARITH MEAN



12.5



115 28.7 25.9 25.7 24.2 25.7 13.2



114 64.4 57.1 36.2 32.3 36.2 13.8



361 48.7 36.9 32.5 32.5 31.1 14.2



120 43.9 35.9 29.3 28.8 29.3 14.1



18 27.1 26.6 19.1 13.6 27.1 9.8



122 32.7 30.3 29.2 29.1 29.2 14.7



Total Samples Total Sites Sampled 5,375 38



29





Figure 5.5 PM2.5: Maximum 98th percentile, 2001



Figure 5.6 PM2.5: Maximum Annual Arithmetic Means, 2001



30





Figure 5.7 PM2.5: Design Values by County, 1999-2001



31





5.4 Carbon Monoxide Carbon monoxide (CO) data were collected for two purposes in 2001: to determine attainment status of the ambient air quality standard and to gather data on CO as an ozone precursor. The carbon monoxide associated with ozone formation consists of very low concentrations (not greater than 2 ppm) collected at special sites considered optimal for input to a large photochemical grid model. This report will not further discuss the role of CO as an ozone precursor, but these data and more information are available on request from the Division of Air Quality (see the Preface for a mailing address). To assess CO attainment status, the Division of Air Quality collected data from monitors in Fayetteville, Chapel Hill, Wilmington, Durham, Greensboro and Raleigh, and local program agencies collected data from three monitors in Winston-Salem and Charlotte using EPA Reference or equivalent methods to measure the concentrations. In 2001, 11 sites were used to monitor CO and 57,473 valid hourly averages were collected. To keep operating costs minimal, some sites are operated only in the colder months. A map of the CO sampling sites is shown in Figure 5.8, and a detailed summary of the data from each site is presented in Table 5.4. There were no exceedances of the CO ambient air quality standards in 2001. The highest 1-hour average was 9.3 parts per million (ppm), or about 25 percent of the standard (35 ppm). This value occurred at the Tryon Street site in



Charlotte. The highest 8-hour average was 4.4 ppm, at the same site, which is about 50 percent of the standard. The second highest 1-hour concentrations in each county are shown in Figure 5.9 and the second highest 8hour concentrations are shown in Figure 5.10. Historical data have demonstrated that high concentrations of CO occur more frequently in autumn and winter than during the warmer months of the year. There are three main reasons for this seasonal variation: (1) North Carolina experiences more atmospheric inversions in colder months, trapping air pollutants at low heights; (2) motor vehicles emit more CO due to inefficient combustion during cold starts and warm up; and (3) during colder temperatures, more fuel is burned for comfort heating. All areas monitored are attaining the ambient air quality standards for carbon monoxide. Several factors have reduced CO concentrations, with the most significant being that older vehicles are gradually being replaced with newer, more efficient vehicles. The motor vehicle Inspection and Maintenance program (in effect in Mecklenburg, Wake, Durham, Forsyth, Guilford, Gaston, Cabarrus, Orange and Union counties) is an intentional control strategy that helps assure cleanerrunning cars. Other factors include increased news media interest and public awareness, and the reporting of the Air Quality Index ( see Chapter 6 of this report ). As a result of greater public awareness, more cars are kept in better running condition, thus operating more cleanly. Traffic flow improvements such as new roads and better coordinated traffic signals also help reduce CO.



32





Figure 5.8 Location of Carbon Monoxide Monitoring Sites



Table 5.4 Carbon Monoxide in Parts Per Million for 2001



SITE NUMBER COUNTY ADDRESS NUM OBS



ONE-HOUR MAXIMA 1st



2nd



EIGHT-HOUR MAXIMA 1st



2nd



37-051-0007 CUMBERLAND 37-063-0013 DURHAM 37-067-0023 FORSYTH 37-067-0025 FORSYTH 37-067-0029 ABC BOARD, 1705 OWEN DR FAYETTEVILLE 2700 NORTH DUKE STREET DURHAM 1401 CORPORATION PKY WINSTON-SALEM 100 SW STRATFORD RD WINSTON-SALEM 1985 GRIFFITH ROAD



4,132 5.2 5.2 4.0 3.9



2,890 1.7 1.6 1.3 1.1



8,708 4.8 4.6 3.5 3.5



4,211 3.0 3.0 2.0 1.6



8,712 6.3 6.1 4.2 4.0



33





SITE NUMBER COUNTY ADDRESS NUM OBS



ONE-HOUR MAXIMA 1st



2nd



EIGHT-HOUR MAXIMA 1st



2nd



FORSYTH 37-081-1011 GUILFORD 37-119-0038 MECKLENBURG 37-119-0041 MECKLENBURG 37-129-0008 NEW HANOVER 37-183-0011 WAKE 37-183-0018 WAKE Total Samples Total Sites Sampled WINSTON-SALEM 401 WEST WENDOVER GREENSBORO 301 N TRYON ST CHARLOTTE 1130 EASTWAY DRIVE CHARLOTTE OLEANDER & COLLEGE WILMINGTON 420 S PERSON ST RALEIGH US HWY 70 WEST AND NC HWY 50 NORTH RALEIGH



4,340 4.4 4.4 3.3 3.0



8,522 9.3 8.8 4.3 4.3



8,137 4.8 4.6 3.7 2.9



4,319 7.5 5.8 4.4 3.4



2,147 6.2 5.4 3.7 3.5



1,355 4.7 4.5 3.1 3.0



57,473 11



34





Figure 5.9 Carbon Monoxide: Second Highest 1-Hour Average, 2001



Figure 5.10 Carbon Monoxide: Second Highest Non-overlapping 8-Hour Average, 2001



35





5.5 Ozone



Ozone (O3) concentrations are measured using EPA reference or equivalent continuous monitors. Ozone is a seasonal pollutant formed in the atmosphere as a result of many chemical reactions that occur in sunlight, mainly during the warmer months. Thus, most ozone monitors only operate from April through October. The state and local program agencies operated 46 monitoring sites in 2001 during the ozone season, April through October. A map of the O3 sampling sites is presented in Figure 5.11, and a detailed summary of the one-hour data from each site is given in Table 5.5, and the 8-hour data in Table 5.6. These 46 monitoring sites provided 9715 site-days of valid data (a success rate of 98.5 percent for the days that sampling is required). There were 6 exceedances of the 1-hour ozone standard in North Carolina in 2001, one each in Franklinton and Butner, one in Cooleemee, two at Enochville (Rowan County) and one in Mecklenburg County. The one-hour standard is exceeded when one valid one-hour average exceeds 0.124 ppm at a site and the expected number of exceedances is greater than 1. (To exceed the standard, the largest average must be larger than 0.12 ppm when rounded to two significant digits.



The "expected number" of exceedances is determined from a 3-year average of exceedance day counts for an area. Moreover, when any ozone sampling day does not have a valid maximum ozone measurement for any reason, the missing day can be counted as an estimated exceedance day under certain circumstances [40 CFR 50 App. J, US EPA 1993, p. 767-768]. Table 5.5 gives both the actually measured and the estimated number of exceedance days at each site.) The 8-hour standard was exceeded a total of 182 times at the 46 sites that monitored for O3. Thirty-two monitors had at least one exceedance. The largest number at one monitor was 17 in Rockwell (Rowan County). These exceedances were distributed over 34 days during the ozone season where at least one site within the state recorded values greater than 0.085 ppm. The second highest 1-hour concentrations in each county are shown in Figure 5.12 for areas with one or more monitors active in 2001. Monitors whose second highest 1-hour concentration exceeds 0.124 ppm potentially violate the EPA one-hour standard (although it is no longer in effect in North Carolina). Historical average fourth-highest 8-hour concentrations of O3 in counties where monitors were operated in 2001 are shown in Figure 5.13. Monitors whose fourth-highest 8-hour ozone concentration (averaged over three



36





years) exceeds 0.084 ppm are deemed in violation of the EPA 8-hour standard.



Figure 5.11 Location of Ozone Monitoring Sites



37





Table 5.5 One-Hour Ozone in Parts Per Million for 2001



SITE NUMBER COUNTY 37-003-0003 ALEXANDER



ADDRESS



NUM OBS



DAILY 1-HR MAXIMA



2nd 0.099 3rd 0.096



NO. VALUES > 0.125



4th MEAS 0.093 EST



324 MINNIGAN LANE TAYLORSVILLE 5136



1st 0.105



0 0.00



37-011-0002 AVERY 7510 BLUE RIDGE 5136 0.087 0.084 0.083 0.081 0 0.00



37-021-0030 BUNCOMBE ROUTE 191 SOUTH BREVARD RD ASHEVILLE 5040 0.097 0.091 0.087 0.086 0 0.00



37-027-0003 CALDWELL HWY 321 NORTH LENOIR 5088 0.104 0.096 0.094 0.094 0 0.00



37-029-0099 CAMDEN COUNTY ROAD 1136 & 1134 5112 0.090 0.090 0.086 0.086 0 0.00



37-033-0001 CASWELL 7074 CHERRY GROVE REIDSVILLE 5112 0.113 0.108 0.105 0.103 0 0.00



37-037-0004 CHATHAM RT 4 BOX 64 PITTSBORO NC 27312 5112 0.091 0.091 0.089 0.089 0 0.00



37-051-0008 CUMBERLAND 1/4MI SR1857/US301/1857 WADE 5136 0.115 0.108 0.097 0.096 0 0.00



37-051-1003 CUMBERLAND 3625 GOLFVIEW ROAD HOPE MILLS 5136 0.097 0.095 0.094 0.093 0 0.00



37-059-0002 DAVIE 246 MAIN STREET COOLEEMEE 5088 0.128 0.122 0.119 0.102 1 1.00



37-061-0002 DUPLIN HWY 50 KENANSVILLE 5112 0.087 0.086 0.085 0.085 0 0.00



37-063-0013 DURHAM 2700 NORTH DUKE STREET DURHAM 5136 0.116 0.105 0.105 0.103 0 0.00



38





SITE NUMBER COUNTY ADDRESS NUM OBS DAILY 1-HR MAXIMA 2nd 3rd NO. VALUES > 0.125 4th MEAS EST



1st



37-065-0099 EDGECOMBE 7589 NC HWY 33-NW LEGGETT 5064 0.105 0.099 0.098 0.092 0 0.00



37-067-0022 FORSYTH 1300 BLK. HATTIE AVENUE WINSTON-SALEM 5088 0.109 0.106 0.105 0.104 0 0.00



37-067-0027 FORSYTH 7635 HOLLYBERRY LANE WINSTON-SALEM 5136 0.107 0.103 0.096 0.095 0 0.00



37-067-0028 FORSYTH 6496 BAUX MOUNTAIN RD WINSTON-SALEM 5136 0.115 0.113 0.108 0.108 0 0.00



37-067-1008 FORSYTH 3656 PIEDMONT MEMORIAL DRIVE WINSTON-SALEM 5136 0.109 0.108 0.104 0.101 0 0.00



37-069-0001 FRANKLIN 431 S. HILLBOROUGH ST FRANKLINTON 5112 0.128 0.107 0.094 0.093 1 1.00



37-077-0001 GRANVILLE WATER TREATMENT PLANT, JOHN UMSTEAD HOSPITAL BUTNER 5112 0.127 0.108 0.105 0.097 1 1.00



37-081-0011 GUILFORD KEELY PARK, KEELY RD, GREENSBORO 5136 0.120 0.111 0.107 0.104 0 0.00



37-087-0004 HAYWOOD 2177 SCHEVILLS ROAD WAYNESVILLE 5136 0.087 0.084 0.083 0.081 0 0.00



37-087-0035 HAYWOOD TOWER BLUE RIDGE PARKWAY MILE MARKER 410 4752 0.095 0.092 0.091 0.090 0 0.00



37-087-0036 HAYWOOD GREAT SMOKY MOUNTAIN NATIONAL PARK 4896 0.093 0.092 0.092 0.088 0 0.00



37-099-0005 JACKSON BARNET KNOB FIRE TOWER 4776 0.101 0.097 0.089 0.086 0 0.00



37-101-0002 JOHNSTON 1338 JACK ROAD CLAYTON 5112 0.098 0.090 0.089 0.088 0 0.00



37-107-0004 LENOIR CORNER HWY EAST KINSTON 5088 0.099 0.085 0.083 0.083 0 0.00



39





SITE NUMBER COUNTY 37-109-0004 LINCOLN



ADDRESS



NUM OBS



DAILY 1-HR MAXIMA



2nd 0.106 3rd 0.105



NO. VALUES > 0.125



4th MEAS 0.104 EST



1487 RIVERVIEW ROAD LINCOLNTON 5136



1st 0.121



0 0.00



37-117-0001 MARTIN 1210 HAYES STREET JAMESVILLE 5064 0.091 0.088 0.087 0.086 0 0.00



37-119-0041 1130 EASTWAY DRIVE 4752 0.121 0.119 0.115 0.111 0 0.00



MECKLENBURG CHARLOTTE



37-119-1005 400 WESTINGHOUSE BLVD. 5064 0.121 0.116 0.101 0.095 0 0.00



MECKLENBURG CHARLOTTE



37-119-1009 29 N@ MECKLENBURG CAB CO 5112 0.128 0.120 0.119 0.109 1 1.00



MECKLENBURG CHARLOTTE



37-129-0002 NEW HANOVER 6028 HOLLY SHELTER RD 5136 0.101 0.089 0.088 0.084 0 0.00



37-131-0002 ROUTE 46 5136 0.095 0.090 0.090 0.087 0 0.00



NORTHAMPTON GASTON



37-145-0003 PERSON SR49 5136 0.117 0.111 0.101 0.095 0 0.00



37-147-0099 PITT US 264 NEAR WATTER TOWER FARMVILLE 5136 0.097 0.091 0.090 0.086 0 0.00



37-151-0004 RANDOLPH 4507 BRANSON DAVIS ROAD SOPHIA 5136 0.109 0.102 0.101 0.100 0 0.00



37-157-0099 ROCKINGHAM 6371 NC 65 @ BETHANY SCHOOL 5136 0.107 0.105 0.105 0.103 0 0.00



37-159-0021 ROWAN 301 WEST ST & GOLD HILL AVENUE ROCKWELL 5136 0.121 0.118 0.118 0.114 0 0.00



37-159-0022 ROWAN 925 N ENOCHVILLE AVE 4944 0.145 0.142 0.123 0.115 2 2.10



37-173-0002 SWAIN CENTER STREET 5112 0.084 0.081 0.078 0.078 0 0.00



40





SITE NUMBER COUNTY 37-179-0003 UNION



ADDRESS



NUM OBS



DAILY 1-HR MAXIMA



2nd 0.094 3rd 0.090



NO. VALUES > 0.125



4th MEAS 0.089 EST



701 CHARLES STREET MONROE 4944



1st 0.124



0 0.00



37-183-0014 WAKE 3801 SPRING FOREST ROAD RALEIGH 5112 0.113 0.113 0.113 0.102 0 0.00



37-183-0015 WAKE 808 NORTH STATE STREET RALEIGH 5136 0.108 0.104 0.104 0.099 0 0.00



37-183-0016 WAKE 201 NORTH BROAD STREET FUQUAY-VARINA 5088 0.093 0.091 0.090 0.089 0 0.00



37-183-0017 WAKE 5033 TV TOWER ROAD GARNER 5112 0.101 0.093 0.091 0.089 0 0.00



37-199-0003 YANCY BLUE RIDGE PARKWAY 4608 0.094 0.093 0.090 0.089 0 0.00



Total Samples Total Sites Sampled 233,160 46 6 6.10



41





Table 5.6 Eight-Hour Ozone in Parts Per Million for 2001



SITE NUMBER COUNTY 37-003-0003 ALEXANDER 37-001-0002 AVERY 37-021-0030 BUNCOMBE 37-027-0003 CALDWELL 37-029-0099 CAMDEN 37-033-0001 CASWELL 37-037-0004 CHATHAM 37-051-0008 CUMBERLAND 37-051-1003 CUMBERLAND 37-059-0002 DAVIE 37-061-0002 DUPLIN 37-063-0013 DURHAM 37-065-0099 EDGECOMBE 37-067-0022 FORSYTH 37-067-0027 FORSYTH 37-067-0028 FORSYTH 37-067-1008 FORSYTH



ADDRESS VALID DAILY 8-HR MAXIMUM



1st 0.093 2nd 0.09 3rd 0.089 4th 0.88



STATE ROAD 1177 TAYLORSVILLE 7510 BLUE RIDGE



VALID DAYS 208 N0. VALUES .>.085 MEAS 5



204 0.082 0.078 0.075 0.074 0



ROUT 191 SOUTH BREVARD RD ASHEVILLE HWY 321 NORTH LENOIR COUNTY ROAD 1136 & 1134



209 0.085 0.083 0.077 0.076 1



204 0.087 0.086 0.084 0.082 2



209 0.082 0.081 0.080 0.080 0



37-069-0001 FRANKLIN 37-077-0001 GRANVILLE



7074 CHERRY GROVE RD REIDSVILLE RT 4 BOX 64 PITTSBORO NC 27312 1/4MI SR1857/US301/1857 WADE 3625 GOLFVIEW ROAD HOPE MILLS 246 MAIN STREET COOLEEMEE HWY 50 KENANSVILLE 2700 NORTH DUKE STREET DURHAM 7589 NC HWY 33-NW LEGGETT 1300 BLK. HATTIE AVENUE WINSTON-SALEM 7635 HOLLYBERRY LANE WINSTON-SALEM 6496 BAUX MOUNTAIN RD WINSTON-SALEM 3656 PIEDMONT MEMORIAL DRIVE WINSTON-SALEM 431 S. HILLBOROUGH ST FRANKLINTON WATER TREATMENT PLANT JOHN UMSTEAD HOSPITAL BUTNER



213 0.095 0.092 0.089 0.087 6



206 0.081 0.081 0.078 0.077 0



209 0.091 0.088 0.083 0.080 2



212 0.087 0.085 0.085 0.084 3



208 0.104 0.102 0.098 0.094 11



196 0.080 0.080 0.079 0.077 0



205 0.098 0.090 0.089 0.084 3



203 0.092 0.087 0.085 0.085 4



210 0.099 0.098 0.098 0.094 10



214 0.091 0.088 0.082 0.082 2



214 0.103 0.100 0.099 0.096 10



213 0.097 0.096 0.096 0.094 8



203 0.099 0.090 0.086 0.085 4



209 0.108 0.097 0.094 0.094 5



42





SITE NUMBER COUNTY 37-081-0011 GUILFORD 37-087-0004 HAYWOOD 37-087-0035 HAYWOOD 37-087-0036 HAYWOOD 37-099-0005 JACKSON 37-101-0002 JOHNSTON 37-107-0004 LENOIR 37-109-0004 LINCOLN 37-117-0001 MARTIN 37-119-0041 MECKLENBURG 37-119-1005 MECKLENBURG 37-119-1009 MECKLENBURG 37-129-0002 NEW HANOVER 37-131-0002 NORTHAMPTON 37-145-0003 PERSON 37-147-0099 PITT 37-151-0004 RANDOLPH 37-157-0099 ROCKINGHAM 37-159-0021 ROWAN 37-159-0022 ROWAN 37-173-0002 SWAIN



ADDRESS



KEELY PARK, KEELY RD, GREENSBORO 2177 SHEVILLE ROAD WAYNESVILLE TOWER BLUE RIDGE PARKWAY MILE MARKER 410 GREAT SMOKY MOUNTAIN NATIONAL PARK BARNET KNOB FIRE TOWER



VALID DAYS 212



VALID DAILY 8-HR MAXIMUM



1st 0.099 2nd 0.091



3rd 4th



0.087 0.086



N0. VALUES .>.085 MEAS 4



207 0.082 0.076 0.076 0.075 0



192 0.085 0.083 0.081 0.081 1



202 0.083 0.082 0.082 0.082 0



198 0.093 0.090 0.084 0.084 2



1338 JACK ROAD CLAYTON CORNER HWY 70 EAST KINSTON 1487 RIVERVIEW ROAD LINCOLNTON 1210 HAYES STREET JAMESVILLE 1130 EASTWAY DRIVE CHARLOTTE 400 WESTINGHOUSE BLVD. CHARLOTTE 29 N@ MECKLENBURG CAB CO CHARLOTTE 6028 HOLLY SHELTER RD



207 0.084 0.080 0.078 0.078 0



200 0.088 0.078 0.078 0.077 1



206 0.095 0.094 0.094 0.094 9



197 0.079 0.077 0.077 0.074 0



198 0.106 0.103 0.100 0.099 9



208 0.103 0.099 0.086 0.086 5



211 0.103 0.103 0.100 0.099 10



196 0.080 0.080 0.080 0.078 0



ROUTE 46 GASTON SR NC 49



205 0.084 0.084 0.080 0.078 0



211 0.099 0.089 0.089 0.088 5



US 264 NEAR WATER TOWER FARMVILLE 4507 BRANSON DAVIS RD SOPHIA 6371 NC 65 @ BETHANY SCHOOL BETHANY 301 WEST ST & GOLD HILL AVE ROCKWELL 925 N ENOCHVILLE AVE ENOCHVILLE CENTER STREET PARKS 7 REC FACILITY



208 0.078 0.078 0.078 0.077 0



213 0.097 0.093 0.091 0.085 7



210 0.098 0.096 0.094 0.094 9



206 0.104 0.102 0.101 0.097 17



198 0.122 0.104 0.103 0.103 15



210 0.075 0.072 0.071 0.069 0



43





SITE NUMBER COUNTY ADDRESS VALID DAYS VALID DAILY 8-HR MAXIMUM 1st 2nd 3rd 4th N0. VALUES .>.085 MEAS



37-179-0003 UNION 37-183-0014 WAKE



37-183-0015 WAKE 37-183-0016 WAKE 37-183-0017 WAKE 37-199-0003 YANCY Total Samples Total Sites Sampled



701 CHARLES STREET MONROE E. MILLBROOK JR HI 3801 SPRING FOREST ROAD RALEIGH 808 NORTH STATE STREET RALEIGH 201 NORTH BROAD STREET FUQUAY-VARINA 5033 TV TOWER ROAD GARNER BLUE RIDGE PARKWAY



194 0.096 0.085 0.085 0.081 3



208 0.093 0.093 0.089 0.089 4



206 0.093 0.091 0.088 0.088 4



199 0.084 0.083 0.083 0.082 0



204 0.084 0.081 0.077 0.077 0



183 0.086 0.084 0.084 0.084 1



9,438 46 182



44





Figure 5.12 Ozone: Second Highest Annual 1-Hour Average, 2001



Figure 5.13 Ozone: Mean Annual Fourth Highest 8-Hour Average, 1999-2001



45





5.6



Sulfur Dioxide Sulfur dioxide (SO2) concentrations were measured by the State and two local program agencies using EPA reference or equivalent methods. Eight SO2 monitors were active in North Carolina in 2001. Some SO2 sites are operated only every third year. We supplemented this report with 4 monitors that operated last in 2000, (and will next be operated in 2003), and 5 monitors that operated last in 1999 (and will next be operated in 2002). From the 17 sites with SO2 data obtained between 1999 and 2001, 136,344 valid hourly averages were collected. A map of the active SO2 sampling sites is presented in Figure 5.14 and a detailed summary of the data from each site is given in Table 5.7. There were no exceedances of the SO2 ambient air quality standards in 2001. The highest annual arithmetic mean was 0.006 ppm, or about 20 percent of the standard



(0.03 ppm). The highest maximum 24hour average was 0.050 ppm, about 30 percent of the standard (0.14 ppm), and the highest maximum 3-hour average was 0.12 ppm, about 25 percent of the welfare-related (secondary) standard (0.50 ppm). Apparently, the size of an urban area has little effect on the ambient concentrations of SO2 in North Carolina. Seasonal variations, such as those with CO and O3, do not appear to exist for SO2. Major source characteristics such as type, size, distribution, control devices, operating conditions and dispersion situations significantly affect the amount of SO2 in ambient air. The second highest three-hour concentrations in each county are shown in Figure 5.15. The second highest 24hour concentrations in each county are shown in Figure 5.16.



46





Figure 5.14 Locations of Sulfur Dioxide Monitoring Sites in 1999, 2000 and 2001.



Table 5.7 Sulfur Dioxide in Parts Per Million from All Sites for 1999-2001



SITE NUMBER COUNTY 2001 DATA ADDRESS NUM OBS ONE-HOUR MAXIMA 1st 2nd THREE-HOUR MAXIMA 1st 2nd 24-HOUR MAXIMA 1st 2nd ARITH MEAN



37-013-0006 BEAUFORT 37-037-0004 CHATHAM 37-067-0022 FORSYTH 37-117-0001 MARTIN 37-119-0041 MECKLENBURG 37-129-0006 NEW HANOVER



NC 306 @ PCS ENTRANCE AURORA RT4 BOX62 PITTSBORO 1300 BLK. HATTIE AVENUE WINSTON-SALEM 1210 HAYES STREET



7,940 0.107 0.099 0.075 0.072 0.034 0.026 0.003



8,287 0.062 0.043 0.037 0.020 0.008 0.008 0.002



8,558 0.101 0.077 0.050 0.046 0.016 0.016 0.005



8,200 0.035 0.023 0.021 0.016 0.012 0.008 0.002



1130 EASTWAY DRIVE CHARLOTTE HWY 421 NORTH



8,010 0.146 0.122 0.062 0.055 0.024 0.018 0.004



8,166 0.162 0.154 0.120 0.093 0.050 0.039 0.006



47





SITE NUMBER COUNTY 37-14-5-0003 PERSON 37-173-0002 SWAIN



ADDRESS



NUM OBS



ONE-HOUR MAXIMA



1st 0.088 2nd 0.085



THREE-HOUR MAXIMA



1st 0.069 2nd 0.057



24-HOUR MAXIMA



1st 0.016 2nd 0.015



ARITH MEAN



SR49 7,054 0.003



CENTER ST/PARKS 7 REC FACILITY BRYSON CITY 7,057 0.015 0.015 0.013 0.012 0.008 0.004 0.002



Total Samples Total Sites Sampled 2000 data 37-059-0002 246 MAIN STREET DAVIE COOLEEMEE



63,272 8



8,249 0.071 0.054 0.055 0.049 0.019 0.018 0.004



37-109-0004 1487 RIVERVIEW ROAD LINCOLN LINCOLNTON 8,159 0.076 0.066 0.046 0.043 0.022 0.018 0.004



37-131-0002 RT 46 NORTHAMPTON GASTON 8,361 0.037 0.033 0.025 0.021 0.012 0.012 0.004



37-147-0099 US 264 NEAR WATER TOWER PITT FARMVILLE Total Samples Total Sites Sampled 1999 Data 37-051-1003 3625 GOLFVIEW ROAD CUMBERLAND HOPE MILLS



8,153 0.023 0.023 0.017 0.016 0.009 0.007 0.003



32,922 4



8,271 0.018 0.018 0.012 0.011 0.007 0.007 0.005



37-061-0002 HWY 50 DUPLIN KENANSVILLE 8,258 0.017 0.016 0.014 0.012 0.007 0.007 0.005



37-065-0099 7589 NC HWY EDGECOMBE 33-NW 8,125 0.060 0.024 0.012 0.011 0.008 0.007 0.005



37-101-0002 1338 JACK ROAD JOHNSTON CLAYTON 8,275 0.042 0.037 0.032 0.018 0.013 0.009 0.005



37-119-0034 PLAZA RD. & LAKEDELL MECKLENBURG CHARLOTTE 7,221 0.083 0.082 0.066 0.047 0.014 0.013 0.004



Total Samples Total Sites Sampled 40,150 5



48





Figure 5.15 Sulfur Dioxide: Second Highest 3-Hour Averages in the Most Recent Year of Data from 1999, 2000 or 2001



Figure 5.16 Sulfur Dioxide: Second Highest 24-Hour Averages in the Most Recent Year of Data from 1999, 2000 or 2001



49





5.7 Nitrogen Dioxide Nitrogen dioxide (NO2) concentrations were measured using EPA reference or equivalent continuous monitors in 2001 at one local program site in Forsyth County and one local program site in Mecklenburg County. From these two sites, 16,334 hourly NO2 measurements were reported. A map of the NO2 sampling sites is presented in Figure 5.17, and a summary of the 2001 NO2 data is given in Table 5.8. Each urban area site has only a few outlying high hourly sample values that are above the standard defined for the annual arithmetic mean. The arithmetic means (Table 5.7) are about 34 percent of the standard.



Figure 5.17 Location of Nitrogen Dioxide Monitoring Sites



Table 5.8 Nitrogen Dioxide in Parts Per Million for 2001



SITE NUMBER COUNTY 37-067-0022 FORSYTH 37-067-0041 MECKLENBURG Total Samples Total Sites Sampled



ADDRESS



1300 BLK. HATTIE AVENUE WINSTON-SALEM 1130 EASTWAY DRIVE CHARLOTTE



NUM OBS 8,530



ONE-HOUR MAXIMA



1ST 0.067 2ND 0.065



ARITH MEAN 0.016



7,804 0.074 0.069 0.018



16,334 2 50





5.8 Lead



The state and local program agencies have not performed routine analysis of ambient lead (Pb) in North Carolina since 1982. Lead monitoring was discontinued as a result of the low measurements and a continuing decrease in the lead concentrations being reported. The decrease in ambient Pb concentrations is due to the reduction and elimination of leaded gasoline, resulting in greatly reduced lead emissions from automobiles. The most recent year of data available prior to 1996-97 was in 1990. Because the previous data were so old, the state began metals analysis at three locations on 1996. These metal sites will be relocated to other locations in future years. The purpose of these sites is to gather background information about lead and other metals. No lead sites operated in 2001.



The change in analytical laboratories from the EPA's National Particulate Analysis Program to the state program also changed the minimum detectable levels of the method from 0.01 to 0.04 g/m3, respectively. Concentrations of most metals are below detectable limits regardless of the method used. During 1999, a special study focusing on arsenic levels was undertaken. Lead, as well as 9 other toxic metals were analyzed on TSP samplers with PM10 filters at 10 ambient air monitoring sites, by a contract laboratory using inductively coupled plasma/mass spectrometry (ICP/MS). This method has a sensitivity of three orders of magnitude greater than the past methods. Of the 526 samples analyzed only 39 exceeded the minimum detectable level of 0.01 g/m3 and only 2 exceeded the minimum detectable level of 0.04 g/m3, with values of 0.04154 g/m3 and 0.04174 g/m3. This study was discontinued in 2000. The lead standard remains 1.5 g/m3 for a quarterly average.



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6 Air Quality Index



The Air Quality Index (AQI) was developed by the EPA to provide the public with a simple, accessible, and uniform assessment of air quality at a specific location, based on the criteria pollutants PM2.5, PM10, CO, O3 (both 1 and 8 hour values), SO2 and NO2. AQI measurements are made and reported in all U.S. metropolitan statistical areas (MSA) with a population over 350,000. Ambient concentrations for each of these seven pollutants are converted to a numerical scale ranging from 0 to 500, where 100 corresponds to the EPA primary standard for a 24-hour average (8-hour CO average, 1 and 8-hour O3 average) and 500 corresponds to a concentration associated with significant harm. The AQI is determined by the pollutant with the highest scaled concentration, and a subjective description of good, moderate, "unhealthy for sensitive groups", "unhealthy", very unhealthy, or hazardous is included with the report, with the descriptions corresponding to AQI values of 0-50, 51-100, 101-150, 151-200, 201-300, and 301-500, respectively. For AQI values between 101 and 500, an appropriate cautionary statement is included advising people susceptible to deleterious health effects to restrict activities and exposure to the ambient air.



An AQI of 101-200 (unhealthy for sensitive groups and unhealthy) can produce mild aggravation of symptoms in susceptible persons and possible irritation in healthy persons. People with existing heart or lung ailments should reduce physical exertion and outdoor activity. The general population should reduce vigorous outdoor activity. An AQI of 201 to 300 (very unhealthy) can produce significant aggravation of symptoms and decreased exercise tolerance in persons with heart or lung disease, and a variety of symptoms in healthy persons. Elderly people and those with existing heart or lung disease should stay indoors and reduce physical activity. The general population should avoid vigorous outdoor activity. The health effects of an AQI of over 300 (hazardous) include early onset of certain diseases in addition to significant aggravation of symptoms and decreased exercise tolerance in healthy persons. The elderly and persons with existing diseases should stay indoors and avoid physical exertion.



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At AQI values over 400, premature death of ill and elderly persons may result, and healthy people will experience adverse symptoms that affect normal activity. Outdoor activity should be avoided. All people should remain indoors, keeping windows and doors closed, and should minimize physical exertion. During winter months in North Carolina, carbon monoxide usually has the highest air quality index value, and in summer months the highest index value is usually due to ozone. In 2001, Charlotte area provided an AQI report to the public by telephone using computer-generated recorded voice announcements 24 hours daily. The AQI report also may be published by local newspapers or broadcast on radio and television stations. The Air Quality Index report is available by telephone for Charlotte area at 704-333- SMOG. We also provide an AQI Report on the North Carolina DAQ web site, (http://www.daq.state.nc.us/monitor). January through March PM10 and PM2.5 monitors operated on 27 of the 90 days; April through October, PM and ozone , monitors operated on 211 of the 214 days; and in November and December, PM10 and PM2.5 monitors operated on 16 of the 61 days. There were only 3 days on which an AQI value was "unhealthy for sensitive groups" or "unhealthy"; one occurred in June, and two during November1. Figure 6.1 shows the 2001 AQI time series for Asheville. Figure 6.2 shows summaries of the numbers of days each respective pollutant was responsible for the AQI, the number of days the AQI was in each respective health category, and the percentile distribution for each health category for Asheville. In the Charlotte-Gastonia-Rock Hill MSA, the AQI was "unhealthy for sensitive groups" or "unhealthy" on 28 out of 365 days monitored. All 28 of these days occurred between April and September.



In this printed report, we have summarized AQI statistics for six metropolitan areas in North Carolina. Table 6.1 shows the number of days in each health category at each area. (The Asheville area has two entries, "actual" and "adjusted", in Table 6.1, because it was not monitored every day of the year; the "adjusted" entry gives our estimate of the number of days that would have occurred in each category had all 365 days been monitored.) Asheville did not have AQI monitors operating every day of the year. During



1 If the unsampled days in November and December were proportioned the same way as the sampled days, the statistical expectation would have been 7.2 days of "unhealthy for sensitive groups" or "unhealthy".



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Figure 6.3 shows the 2001 AQI time series for Charlotte-Gastonia-Rock Hill. Figure 6.4 shows summaries of the numbers of days each respective pollutant was responsible for the AQI, the number of days the AQI was in each respective health category, and the percentile distribution for each health category for Charlotte-Gastonia-Rock Hill. In the Fayetteville MSA, the AQI was "unhealthy for sensitive groups" or "unhealthy" on 4 out of 365 days monitored. All 4 of these days occurred between May and September. Figure 6.5 shows the 2001 AQI time series for Fayetteville. Figure 6.6 shows summaries of the numbers of days each respective pollutant was responsible for the AQI, the number of days the AQI was in each respective health category, and the percentile distribution for each health category for Fayetteville. In the Greensboro-Winston-Salem-High Point MSA, the AQI was "unhealthy for sensitive groups" or "unhealthy" on 21 out of 365 days monitored. All 21 of these days occurred between May and September. Figure 6.7 shows the 2001 AQI time series for GreensboroWinston-Salem-High Point. Figure 6.8 shows summaries of the numbers of days each respective pollutant was responsible for the AQI, the number of days the AQI was in each respective health category, and the percentile distribution for each health category for Greensboro-Winston-Salem-High Point. In the Raleigh-Durham-Chapel Hill MSA, the AQI was "unhealthy for sensitive groups" or "unhealthy" on 10 out of 365 days monitored. All 10 of these days occurred between May and August. Figure 6.9 shows the 2001 AQI time series for Raleigh-Durham-Chapel Hill. Figure 6.10 shows summaries of the numbers of days each respective pollutant was responsible for the AQI, the number of days the AQI was in each respective health category, and the percentile distribution for each health category for RaleighDurham-Chapel Hill. In the Wilmington MSA, the AQI was never "unhealthy for sensitive groups" or "unhealthy" out of 365 days monitored. Figure 6.11 shows the 2001 AQI time series for Wilmington. Figure 6.12 shows summaries of the numbers of days each respective pollutant was responsible for the AQI, the number of days the AQI was in each respective health category, and the percentile distribution for each health category for Wilmington.



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Table 6.1 Air Quality Index Category Days in the Major Metropolitan Statistical Areas, 2001



MSA



STATISTICAL GOOD TREATMENT



MODERATE UNHEALTHY FOR SENSITIVE GROUPS



59.0 77 168.0 96.0 164.0 193.0 49.0 2.0 4.8 26.0 4.0 21.0 10.0 0.0



UNHEALTHY



Asheville Asheville Charlotte Fayetteville Greensboro Raleigh Wilmington actual adjusted actual actual actual actual actual 192.0 279.4 169.0 265.0 180.0 162.0 316.0 1.0 3.8 2.0 0.0 0.0 0.0 0.0



Figure 6.1 Daily Air Quality Index Values for Asheville



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Figure 6.2 Daily Air Quality Index Summary for Asheville



Figure 6.3 Daily Air Quality Index Values for Charlotte-Gastonia



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Figure 6.4 Daily Air Quality Index Summary for Charlotte-Gastonia



Figure 6.5 Daily Air Quality Index Values for Fayetteville, NC



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Figure 6.6 Daily Air Quality Index Summary for Fayetteville, NC



Figure 6.7 Daily Air Quality Index Values for Greensboro-Winston-Salem-High Point



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Figure 6.8 Daily Air Quality Index Summary for Greensboro-Winston-Salem-High Point



Figure 6.9 Daily Air Quality Index Values for Raleigh-Durham-Chapel Hill, NC 59





Figure 6.10 Daily Air Quality Index Summary for Raleigh-Durham-Chapel Hill



Figure 6.11 Daily Air Quality Index Values for Wilmington, NC 60





Figure 6.12 Daily Air Quality Index Summary for Wilmington, NC



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7 Acid Rain



7.3 Monitoring



7.1 Sources Acid rain is produced when nitrate and sulfate ions from automobile and industrial sources are released into the atmosphere, undergo a reaction with moisture in the air, and are deposited as acid precipitation. Acid ions are produced when sulfur dioxide and nitrogen oxides reach equilibrium with water to form sulfuric acid and nitric acid. 7.2 Effects Many agricultural crops in North Carolina are sensitive to acid rain. Forests are subject to mineral loss from acid rain exposure and may also suffer root damage. Acid fogs and mists, typical in the mountains of North Carolina, can expose trees and plants to even higher acid concentrations and cause direct damage to foliage. Lakes, rivers and streams that are too acidic can impede fish and plant growth.



Acid rain monitoring has been conducted nationally, including in North Carolina, since 1978 by the National Atmospheric Deposition Program (NADP) and the National Trends Network (NTN) which merged with NADP in 1982. In 2001, acid rain samples were collected at eight sites in North Carolina and one Tennessee site in the Great Smoky Mountains less than 10 miles from the western border of North Carolina. NADP conducts acid deposition monitoring using a wet/dry bucket type sampler. When rainfall is detected, a sensor is activated and a metal lid automatically covers and protects the dry sample, exposing the wet bucket to collect precipitation. Acidity is measured using a pH scale. The pH scale is numbered from 0 to 14, with 0 being extremely acidic and 14 being extremely basic. A substance with a pH of five is ten times as acidic as one with a pH of six, 100 times as acidic as a substance with a pH of seven, etc. Neutral water with an equal concentration of acid and base ions has a pH of seven. The pH of vinegar is approximately 2.8, and lemon juice has a pH of about 2.3. The pH of ammonia is approximately 12.



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Pure water in equilibrium with the air is slightly acidic and has a pH of approximately 5.6. The measurements of pH at the North Carolina monitoring sites in 2001 ranged from 4.43 to 4.88 with a mean of 4.63. The 2001 pH annual means for North Carolina from the NADP database are presented in Figure 7.1 and Table 7.1. Table 7.1 also exhibits conductivity averages and precipitation totals for rainfall. Measured concentrations of several other chemical constituents of precipitation are given in Table 7.2. The highest pH (and the least acid) precipitation occurred at the Sampson County site. This general area in southeastern North Carolina has the greatest numbers of animal producing farms. This area has the highest emissions of ammonia, a basic gas emitted from animal wastes. Table 7.2 shows that the ammonium concentration in precipitation is second-highest at the Sampson County site.



Figure 7.1 Annual Mean pH Values at North Carolina NADP Sites, 2001



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Table 7.1 pH, Conductivity in Microsiemans per Centimeter and Precipitation in Inches from the National Atmospheric Deposition Program for 2001.



County Site ID Address Bertie NC03 Lewiston Carteret NC06 Beaufort Macon NC25 Coweeta Rowan NC34 Piedmont Research Station Sampson NC35 Clinton Crops Research Station Scotland NC36 Jordan Creek Wake NC41 Finley Farm Yancey NC45 Mt. Mitchell Sevier (TN) TN11 Great Smoky Mountains National Park-Elkmont pH



Conductivity Precipitation



4.68 14.01 34.8



4.67 16.03 39.9



4.63 13.55 52.9



4.43 24.13 26.6



4.88 12.30 34.6



4.55 16.75 29.6



4.62 15.07 43.5



4.61 13.58 71.9



4.61 14.20 54.9



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Table 7.2 Ion Concentrations in Milligrams per Liter (Precipitation-weighted Annual Means) from the National Atmospheric Deposition Program Data for 2001.



County Site ID Bertie NC03 Beaufort NC06 Macon NC25 Rowan NC34 Sampson NC35 Scotland NC36 Wake NC41 Yancey NC45 Sevier (TN) TN11



% complete- Ca ness



94



Mg K Na NH4 NO3 Cl SO4



0.07 0.027 0.041 0.196 0.22 0.86 0.36 1.17



80 0.09 0.066 0.028 0.567 0.14 0.81 1.01 1.12



90 0.04 0.013 0.013 0.088 0.13 0.68 0.17 1.11



90 0.10 0.026 0.080 0.133 0.48 1.37 0.32 2.33



96 0.07 0.023 0.021 0.187 0.44 0.86 0.35 1.26



87 0.07 0.022 0.015 0.155 0.20 0.96 0.29 1.37



94 0.06 0.017 0.020 0.114 0.27 0.89 0.22 1.35



79 0.04 0.009 0.012 0.047 0.16 0.61 0.10 1.22



92 0.06 0.013 0.038 0.036 0.14 0.76 0.08 1.18



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References



Cornelius, Wayne L. (1996). Effects of North Carolinas Oxygenated Fuel Program on Ambient Carbon Monoxide Concentrations. Air Quality Section, Division of Environmental Management, N.C. Dept. Of Env., Health, and Nat. Res. Cornelius, Wayne L. (1997). Comparison of Nitrogenous Ion Deposition and Human and Animal Census Trends in Eastern North Carolina. Air Quality Section, Division of Environmental Management, N.C. Dept. Of Env., Health, and Nat. Res. Maynard, Andrew D. and Paul a. Jensen (2001). Aerosol Measurement in the Workplace. Chapter 25 in Aerosol Measurement: Principles, Techniques, and Applications, Second Edition, Paul A. Baron and Klause Willeke, eds., p. 779-799. NADP (National Atmospheric Deposition Program) (1995). Notification of Important Change in NADP/NTN Procedures on 11 January 1994. North Carolina Department of Environment, Health, and Natural Resources (1991a). 1989 Ambient Air Quality Report. Air Quality Section, Division of Environmental Management, N.C. Dept. Of Env., Health, and Nat. Res. North Carolina Department of Environment, Health, and Natural Resources (1991b). Ambient Air Quality Trends in North Carolina 1972-1989. Air Quality Section, Division of Environmental Management, N.C. Dept. Of Env., Health, and Nat. Res. United States Environmental Protection Agency [US EPA] (1993), Code of Federal Regulations, Title 40, Parts 1 to 51, Protection of Environment, (July 1 ed.). Office of the Federal Register (National Archives and Records Administration), Washington, DC. Watson, John G. and Judith C. Chow (2001). Ambient Air Sampling. Chapter 27 in Aerosol Measurement: Principles, Techniques, and Applications, Second Edition, Paul A. Baron and Klause Willeke, eds., p. 821-844 66





Appendix A. Air Pollution Monitoring Agencies



North Carolina State Headquarters



Division of Air Quality Raleigh Central Office 2728 Capital Boulevard 1641 Mail Service Center Raleigh, North Carolina 27699-1641 (919) 733-3340



North Carolina Regional Offices Asheville Regional Office 2090 U.S. Highway 70 Swannanoa, NC 28778 Phone: (828) 296-4500 Counties of Avery, Burke, Caldwell, Cherokee, Clay, Graham, Haywood, Henderson, Jackson, Macon, Madison, McDowell, Mitchell, Polk, Rutherford, Swain, Transylvania, and Yancey. Fayetteville Regional Office 225 Green Street, Suite 714 Fayetteville, North Carolina 28301 (910) 433-3300 Counties of Anson, Bladen, Cumberland, Harnett, Hoke, Montgomery, Moore, Robeson, Richmond, Sampson, and Scotland. Mooresville Regional Office 610 East Center Avenue, Suite 301 Mooresville, NC 28115 Phone: (704) 663-1699 Counties of Alexander, Cabarrus, Catawba, Cleveland, Gaston, Iredell, Lincoln, Rowan, Stanly and Union.



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Raleigh Regional Office 3800 Barrett Drive Raleigh, North Carolina 27609 (919) 791-4200 Counties of Chatham, Durham, Edgecombe, Franklin, Granville, Halifax, Johnston, Lee, Nash, Northampton, Orange, Person, Vance, Wake, Warren, and Wilson. Washington Regional Office 943 Washington Square Mall Washington, North Carolina 27889 (252) 946-6481 Counties of Beaufort, Bertie, Camden, Chowan, Craven, Currituck, Dare, Gates, Greene, Hertford, Hyde, Jones, Lenoir, Martin, Pamlico, Pasquotank, Perquimans, Pitt, Tyrrell, Washington, and Wayne. Wilmington Regional Office 127 Cardinal Drive Extension Wilmington, North Carolina 28405-3845 (910) 796-7215 Counties of Brunswick, Carteret, Columbus, Duplin, New Hanover, Onslow and Pender. Winston-Salem Regional Office 585 Waughtown Street Winston-Salem, North Carolina 27107 (336) 771-5000 Counties of Alamance, Alleghany, Ashe, Caswell, Davidson, Davie, Guilford, Rockingham, Randolph, Stokes, Surry, Yadkin, Watauga, and Wilkes.



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Local Agencies in North Carolina Forsyth County Environmental Affairs Department 537 North Spruce Street Winston-Salem, North Carolina 27101 (336) 703-2440 Mecklenburg County Air Quality 700 N. Tryon Street, Suite 205 Charlotte, North Carolina 28202-2236 (704) 336-5500 Western North Carolina Regional Air Quality Agency (Buncombe County and Asheville city) 49 Mount Carmel Road Asheville, NC 28806 (828) 250-6777 Tribal Agency in North Carolina Eastern Band of Cherokee Indians Tribal Environmental Office P. O. Box 455 Cherokee, North Carolina 28719 (828) 497-3814 Territory overlaps with portions of Swain and Jackson Counties



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Appendix B. Exceptional Events



Type of Event Natural Events Sustained high wind speeds Stagnations, inversions Unusual lack of precipitation Stratospheric ozone intrusion Volcanic eruption Forest fires High pollen count Unintentional Man-made Events Large structural fires Major traffic congestion due to accident or nonrecurring obstruction Chemical spills Industrial accidents Intentional Man-made Events Short-term construction/demolition Sandblasting High-sulfur oil refining Roofing operations Salting or sanding of streets Infrequent large gatherings Soot blowing from ships Agricultural tilling Prescribed burning Noncompliance of local sources



Pollutants Affected



particulate matter (PM) all pollutants PM O3 CO, SO2, PM CO, PM, O3 PM



CO, PM CO SO2, NO2, PM, CO SO2, NO2, PM, CO



PM PM SO2 PM, SO2 PM PM, CO PM PM CO, PM CO, SO2



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Appendix C. Box-And-Whisker Plots



A box-and-whisker plot (also called boxplot or schematic plot) is a schematic diagram useful for depicting the location, spread and skewness of a continuous data variable. Box plots are constructed from order statistics (data values sorted from smallest to largest). The "box" of the box plot is oriented parallel to a continuous scale and is defined by 3 points, (1) a line or point in the interior of the box at the median of the data (a point that divides the order statistics into two equal parts), and (2) upper and (3) lower fourths or quartiles. (Fourths divide the upper and lower halves of the data values into two equal parts; quartiles divide the entire range of the data into 4 equal parts. Fourths and quartiles are not necessarily the same, because there may be more than one number that appropriately divides a given set of data in the prescribed way, and different computational techniques [or computer programs] may make different choices.) The distance between the upper and lower fourth in the box plot is called the interquartile range. In most box plots, the length of each of the whiskers is 1.5 times the interquartile range or to the extreme (maximum or minimum) of the data, whichever is shorter. The endpoint of each whisker is called an inner fence. (In the box plots pictured below, the end of each whisker is marked by a "staple" for clarity.) There may be data points, called outliers, beyond the inner fences; if so, they are usually indicated individually on the box plot by a dot, small circle, or (as below) a short line segment perpendicular to the axis of the box. Box plots of variables with very long-tailed distributions may display two kinds of outlierssmall dots for those just beyond the inner fences and larger dots or circles for extreme outliers at a distance of more than 3.0 times the interquartile range beyond the fourths. This boundary between outliers and extreme outliers is termed the outer fence and usually not explicitly shown in the plot. The maximum and minimum values are always visible in a box-and-whisker plot as either the outermost outliers or, if there is no outlier, the position of the inner fence. Box plots may have additional, optional features, such as a point marker at the arithmetic mean or a distinctive display of a confidence interval for the median, which is calculated from the fourths. In the figure, the arithmetic mean is marked with an "X", and the confidence interval for the median is displayed as a shaded or colored range; it is also common to display the confidence interval by cutting notches in the sides of the box at its endpoints. Box plots are very useful for comparing two or more variables by placing two comparable variables side-by-side on the same scale (as in the figure). The statistics displayed can be directly compared, and statistical significance of difference between the medians can be assessed by examining overlap or lack of overlap of confidence intervals. 71





Appendix D. Nonattainment and North Carolina



What is nonattainment and what are the sources of the pollutants? The United States Environmental Protection Agency (EPA) sets National Ambient Air Quality Standards. North Carolina monitors concentrations of air pollutants in the ambient air. Some of these monitors have measured concentrations of ozone and carbon monoxide exceeding the standards. Areas that have not met the National Ambient Air Quality Standards can be classified by EPA as "nonattainment". Mobile sources such as cars and trucks are the primary cause of carbon monoxide and ozone precursors. About 90 percent of the carbon monoxide emissions come from motor vehicles. In the urban areas, 60 percent of the nitrogen oxides and 25 percent of the man-made hydrocarbons or volatile organic compound emissions come from motor vehicles; the rest comes from off-road vehicles, utility and industrial boilers, petroleum marketing, factories, businesses, and households. Nitrogen oxides react with volatile organic compounds and sunlight in warm weather to produce ozone.



Why is my county nonattainment? EPA guidance recommends that an entire Metropolitan Statistical Area (MSA) be designated nonattainment when a monitor is found to be violating the National Ambient Air Quality Standards (NAAQS). This policy is due to the regional nature of certain pollutants, like ozone. Ozone is formed in the atmosphere under complex chemical reactions. Sometimes the ozone levels are higher just downwind of urban areas because of the time it takes the pollutants to react to form ozone. Therefore, larger areas are designated nonattainment to represent the likely area contributing to the air quality problems.



Once we are nonattainment, what is the process for becoming attainment? North Carolina is required by the federal Clean Air Act and EPA to produce and implement emission reduction plans and show that these plans are strong enough to produce compliance with the standards. The plans could involve resource-intensive monitoring, emissions inventory, modeling, public participation, and strategy formulation efforts. There are deadlines for producing the plans and for achieving compliance with the standards. EPA must approve the plans. How does the public get involved in the formulation of the emission reduction plans, known as State Implementation Plan (SIP) revisions? Local agencies and officials, as well as state agencies, will be involved in drawing up the SIP 72





revisions. There will be public meetings or special citizen panels. When draft SIP revisions are done, there will be public hearings on them. The SIP revisions must be approved by the N.C. Environmental Management Commission and possibly by local bodies as well. The N. C. General Assembly also reviews the SIP. EPA's approval process also includes an opportunity for public comment.



How will it affect citizens? Emission reduction strategies fall into several categories. Motor vehicle inspection/maintenance may be required for hydrocarbons, carbon monoxide, and nitrogen oxides. Traffic patterns may be altered by changing roads or traffic signals. Both new and existing factories and business may have to reduce emissions by installing control equipment or changing processes. Cleaner burning gasoline may be required. More controls will be required on utility and industrial boilers. All of these measures may mean higher costs to the public.



What happens if North Carolina refuses to address these air pollution problems? Under the Clean Air Act, EPA has the authority to apply sanctions. EPA can require more stringent offsets for new facilities of major pollutant sources, and may withhold federal highway construction funds in the nonattainment areas. What is the likelihood of receiving sanctions if we are showing progress in reducing pollution? North Carolina can avoid sanctions if it produces and carries out SIP revisions that EPA approves by the deadlines. If pollution concentrations do not recede and attain the standards as projected, the EPA could impose construction bans. However, EPA has some discretion about imposing sanctions. Sanctions are a last step to persuade states to take required positive action. What does inspection/maintenance cost? As of December, 2001, the inspection/maintenance (I/M), or motor vehicle tailpipe testing process, costs the motorist $30.00. If a vehicle fails the test, it must be repaired. A waiver is available if a vehicle still fails after $200.00 worth of repairs have been done. The $200.00 limit does not apply to tampered or misfueled vehicles. The inspection/maintenance program includes tests for hydrocarbon (HC) and carbon monoxide (CO) emissions for the following counties, Mecklenburg, Wake, Guilford, Forsyth, Durham, Gaston, Cabarrus, Orange, and Union. The number of counties will increase to 48 by 2006 under the Clean Air bill passed in 2000. The cost for this new test was set by the General Assembly during the 2001 legislative session. Currently, only gasoline powered motor vehicles built after 1974, excluding the current model year and motorcycles, are inspected in these counties. Inspection/maintenance pass/fail levels vary with vehicle age and pollutant.



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