Loading (50 kb)...'
(continued)
In seeking EPA approval for inclusion of a site using an open path analyzer into the formal SLAMS/NAMS or PSD network, monitoring agencies must submit an analysis which evaluates both obscuration potential for a proposed path length for the subject area and the effect this potential is projected to have on the representativeness of the data record. This analysis should include one or more of the following elements, as appropriate for the specific circumstance: climatological information, historical pollutant and aerosol information, modeling analysis results, and any related special study results.
10.3 Spacing From Roadways. It is important in the probe and monitoring path siting process to minimize destructive interferences from sources of NO since NO readily reacts with O3. Table 4 below provides the required minimum separation distances between roadways and PAMS (excluding upper air measuring stations):
Table 4_Separation Distance Between Pams and Roadways
[Edge of Nearest Traffic Lane]
------------------------------------------------------------------------
Minimum
separation
distance
between
Roadway average daily traffic, vehicles per day roadways
and
stations in
meters \1\
------------------------------------------------------------------------
<10,000................................................. >10
15,000..................................................... 20
20,000..................................................... 30
40,000..................................................... 50
70,000..................................................... 100
>110,000................................................ 250
------------------------------------------------------------------------
\1\ Distance from the edge of the nearest traffic lane. The distance for
intermediate traffic counts should be interpolated from the table
based on the actual traffic flow.
10.4 Spacing From Trees. Trees can provide surfaces for adsorption and/or reactions to occur and can obstruct normal wind flow patterns. To minimize these effects at PAMS, the probe or at least 90 percent of the monitoring path should be placed at least 20 meters from the drip line of trees. Since the scavenging effect of trees is greater for O3 than for the other criteria pollutants, strong consideration of this effect must be given in locating the PAMS probe or monitoring path to avoid this problem. Therefore, the probe or at least 90 percent of the monitoring path must be at least 10 meters from the drip line of trees.
11. Waiver Provisions
It is believed that most sampling probes or monitors can be located so that they meet the requirements of this appendix. New stations with rare exceptions, can be located within the limits of this appendix. However, some existing stations may not meet these requirements and yet still produce useful data for some purposes. EPA will consider a written request from the State Agency to waive one or more siting criteria for some monitoring stations providing that the State can adequately demonstrate the need (purpose) for monitoring or establishing a monitoring station at that location. For establishing a new station. a waiver may be granted only if both of the following criteria are met:
The site can be demonstrated to be as representative of the monitoring area as it would be if the siting criteria were being met.
The monitor or probe cannot reasonably be located so as to meet the siting criteria because of physical constraints (e.g., inability to locate the required type of station the necessary distance from roadways or obstructions).
However, for an existing station, a waiver may be granted if either of the above criteria are met.
Cost benefits, historical trends, and other factors may be used to add support to the above, however, they in themselves, will not be acceptable reasons for granting a waiver. Written requests for waivers must be submitted to the Regional Administrator. For those SLAMS also designated as NAMS, the request will be forwarded to the Administrator. For those SLAMS also designated as NAMS or PAMS, the request will be forwarded to the Administrator.
12. Summary
Table 5 presents a summary of the general requirements for probe and monitoring path siting criteria with respect to distances and heights. It is apparent from table 5 that different elevation distances above the ground are shown for the various pollutants. The discussion in the text for each of the pollutants described reasons for elevating the monitor, probe, or monitoring path. The differences in the specified range of heights are based on the vertical concentration gradients. For CO, the gradients in the vertical direction are very large for the microscale, so a small range of heights has been used. The upper limit of 15 meters was specified for consistency between pollutants and to allow the use of a single manifold or monitoring path for monitoring more than one pollutant.
Table 5_Summary of Probe and Monitoring Path Siting Criteria
--------------------------------------------------------------------------------------------------------------------------------------------------------
Horizontal and
Height from ground to vertical distance Distance from trees Distance from
Scale [maximum probe or 80% of from supporting to probe or 90% of roadways to probe or
Pollutant monitoring path monitoring path A structures B to probe monitoring path A monitoring path A
length, meters] (meters) or 90% of monitoring (meters) (meters)
path A (meters)
--------------------------------------------------------------------------------------------------------------------------------------------------------
SO2 C,D,E,F........................ Middle [300m] 3-15.................. >1................ >10............... N/A.
Neighborhood, Urban,
and Regional [1km].
CO D,E,G........................... Micro Middle [300m] 3±0.5; 3-15.... >1................ >10............... 2-10; See table 2 for
Neighborhood [1km]. middle and
neighborhood scales.
O3 C,D,E........................... Middle [300m] 3-15.................. >1................ >10............... See table 1 for all
Neighborhood, Urban, scales.
and Regional [1km].
Ozone precursors (for PAMS) C,D,E.. Neighborhood and Urban 3-15.................. >1................ >10............... See table 4 for all
[1 km]................ scales.
NO2 C,D,E.......................... Middle [300m] 3-15.................. >1................ >10............... See table 1 for all
Neighborhood and scales.
Urban [1km].
Pb C,D,E,F,H....................... Micro; Middle, 2-7 (Micro); 2-15 (All >2 (All scales, >10 (All scales).. 5-15 (Micro); See
Neighborhood, Urban other scales). horizontal distance table 3 for all
and Regional. only). other scales.
PM-10 C,D,E,F,H.................... Micro; Middle, 2-7 (Micro); 2-15 (All >2 (All scales, >10 (All scales).. 2-10 (Micro); See
Neighborhood, Urban other scales). horizontal distance Figure 2 for all
and Regional. only). other scales.
--------------------------------------------------------------------------------------------------------------------------------------------------------
N/A_Not applicable.
A Monitoring path for open path analyzers is applicable only to middle or neighborhood scale CO monitoring and all applicable scales for monitoring SO2,
O3, O3 precursors, and NO2.
B When probe is located on a rooftop, this separation distance is in reference to walls, parapets, or penthouses located on roof.
C Should be >20 meters from the dripline of tree(s) and must be 10 meters from the dripline when the tree(s) act as an obstruction.
D Distance from sampler, probe, or 90% of monitoring path to obstacle, such as a building, must be at least twice the height the obstacle protrudes
above the sampler, probe, or monitoring path. Sites not meeting this criterion may be classified as middle scale (see text).
E Must have unrestricted airflow 270° around the probe or sampler; 180° if the probe is on the side of a building.
F The probe, sampler, or monitoring path should be away from minor sources, such as furnace or incineration flues. The separation distance is dependent
on the height of the minor source's emission point (such as a flue), the type of fuel or waste burned, and the quality of the fuel (sulfur, ash, or
lead content). This criterion is designed to avoid undue influences from minor sources.
G For microscale CO monitoring sites, the probe must be >10 meters from a street intersection and preferably at a midblock location.
H For collocated Pb and PM-10 samplers, a 2-4 meter separation distance between collocated samplers must be met.
13. References
1. Bryan, R.J., R.J. Gordon, and H. Menck. Comparison of High Volume Air Filter Samples at Varying Distances from Los Angeles Freeway. University of Southern California, School of Medicine, Los Angeles, CA. (Presented at 66th Annual Meeting of Air Pollution Control Association. Chicago, IL., June 24–28, 1973. APCA 73–158.)
2. Teer, E.H. Atmospheric Lead Concentration Above an Urban Street. Master of Science Thesis, Washington University, St. Louis, MO. January 1971.
3. Bradway, R.M., F.A. Record, and W.E. Belanger. Monitoring and Modeling of Resuspended Roadway Dust Near Urban Arterials. GCA Technology Division, Bedford, MA. (Presented at 1978 Annual Meeting of Transportation Research Board, Washington, DC. January 1978.)
4. Pace, T.G., W.P. Freas, and E.M. Afify. Quantification of Relationship Between Monitor Height and Measured Particulate Levels in Seven U.S. Urban Areas. U.S. Environmental Protection Agency, Research Triangle Park, NC. (Presented at 70th Annual Meeting of Air Pollution Control Association, Toronto, Canada, June 20–24, 1977. APCA 77–13.4.)
5. Harrison, P.R. Considerations for Siting Air Quality Monitors in Urban Areas. City of Chicago, Department of Environmental Control, Chicago, IL. (Presented at 66th Annual Meeting of Air Pollution Control Association, Chicago, IL., June 24–28, 1973. APCA 73–161.)
6. Study of Suspended Particulate Measurements at Varying Heights Above Ground. Texas State Department of Health, Air Control Section, Austin, TX. 1970. p.7.
7. Rodes, C.E. and G.F. Evans. Summary of LACS Integrated Pollutant Data. In: Los Angeles Catalyst Study Symposium. U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Publication No. EPA–600/4–77–034. June 1977.
8. Lynn, D.A. et. al. National Assessment of the Urban Particulate Problem: Volume 1, National Assessment. GCA Technology Division, Bedford, MA. U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Publication No. EPA–450/3–75–024. June 1976.
9. Pace, T.G. Impact of Vehicle-Related Particulates on TSP Concentrations and Rationale for Siting Hi-Vols in the Vicinity of Roadways. OAQPS, U.S. Environmental Protection Agency, Research Triangle Park, NC. April 1978.
10. Ludwig, F.L., J.H. Kealoha, and E. Shelar. Selecting Sites for Monitoring Total Suspended Particulates. Stanford Research Institute, Menlo Park, CA. Prepared for U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Publication No. EPA–450/3–77–018. June 1977, revised December 1977.
11. Ball, R.J. and G.E. Anderson. Optimum Site Exposure Criteria for SO2 Monitoring. The Center for the Environment and Man, Inc., Hartford, CT. Prepared for U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Publication No. EPA–450/3–77–013. April 1977.
12. Ludwig, F.L. and J.H.S. Kealoha. Selecting Sites for Carbon Monoxide Monitoring. Stanford Research Institute, Menlo Park, CA. Prepared for U.S. Environmental Protection Agency, Research Park, NC. EPA Publication No. EPA–450/3–75–077. September 1975.
13. Ludwig, F.L. and E. Shelar. Site Selection for the Monitoring of Photochemical Air Pollutants. Stanford Research Institute, Menlo Park, CA. Prepared for U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Publication No. EPA–450/3–78–013. April 1978.
14. Lead Analysis for Kansas City and Cincinnati, PEDCo Environmental, Inc., Cincinnati, OH. Prepared for U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Contract No. 66–02–2515, June 1977.
15. Barltrap, D. and C. D. Strelow. Westway Nursery Testing Project. Report to the Greater London Council. August 1976.
16. Daines, R. H., H. Moto, and D. M. Chilko. Atmospheric Lead: Its Relationship to Traffic Volume and Proximity to Highways. Environ. Sci. and Technol., 4:318, 1970.
17. Johnson, D. E., et al. Epidemiologic Study of the Effects of Automobile Traffic on Blood Lead Levels, Southwest Research Institute, Houston, TX. Prepared for U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA–600/1–78–055, August 1978.
18. Air Quality Criteria for Lead. Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC EPA–600/8–83–028 aF-dF, 1986, and supplements EPA–600/8–89/049F, August 1990. (NTIS document numbers PB87–142378 and PB91–138420.)
19. Lyman, D. R. The Atmospheric Diffusion of Carbon Monoxide and Lead from an Expressway, Ph.D. Dissertation, University of Cincinnati, Cincinnati, OH. 1972.
20. Wechter, S.G. Preparation of Stable Pollutant Gas Standards Using Treated Aluminum Cylinders. ASTM STP. 598:40–54, 1976.
21. Wohlers, H.C., H. Newstein and D. Daunis. Carbon Monoxide and Sulfur Dioxide Adsorption On and Description From Glass, Plastic and Metal Tubings. J. Air Poll. Con. Assoc. 17:753, 1976.
22. Elfers, L.A. Field Operating Guide for Automated Air Monitoring Equipment. U.S. NTIS. p. 202, 249, 1971.
23. Hughes, E.E. Development of Standard Reference Material for Air Quality Measurement. ISA Transactions, 14:281–291, 1975.
24. Altshuller, A.D. and A.G. Wartburg. The Interaction of Ozone with Plastic and Metallic Materials in a Dynamic Flow System. Intern. Jour. Air and Water Poll., 4:70–78, 1961.
25. CFR Title 40 part 53.22, July 1976.
26. Butcher, S.S. and R.E. Ruff. Effect of Inlet Residence Time on Analysis of Atmospheric Nitrogen Oxides and Ozone, Anal. Chem., 43:1890, 1971.
27. Slowik, A.A. and E.B. Sansone. Diffusion Losses of Sulfur Dioxide in Sampling Manifolds. J. Air. Poll. Con. Assoc., 24:245, 1974.
28. Yamada, V.M. and R.J. Charlson. Proper Sizing of the Sampling Inlet Line for a Continuous Air Monitoring Station. Environ. Sci. and Technol., 3:483, 1969.
29. Koch, R.C. and H.E. Rector. Optimum Network Design and Site Exposure Criteria for Particulate Matter, GEOMET Technologies, Inc., Rockville, MD. Prepared for U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Contract No. 68–02–3584. EPA 450/4–87–009. May 1987.
30. Burton, R.M. and J.C. Suggs. Philadelphia Roadway Study. Environmental Monitoring Systems Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, N.C. EPA–600/4–84–070 September 1984.
31. Technical Assistance Document For Sampling and Analysis of Ozone Precursors. Atmospheric Research and Exposure Assessment Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711. EPA 600/8–91–215. October 1991.
32. Quality Assurance Handbook for Air Pollution Measurement Systems: Volume IV. Meteorological Measurements. Atmospheric Research and Exposure Assessment Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711. EPA 600/4–90–0003. August 1989.
33. On-Site Meteorological Program Guidance for Regulatory Modeling Applications. Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711. EPA 450/4–87–013. June 1987.
[44 FR 27571, May 10, 1979; 44 FR 72592, Dec. 14, 1979, as amended at 46 FR 44170, Sept. 3, 1981; 51 FR 9598, Mar. 19, 1986; 52 FR 24744—24748, July 1, 1987; 52 FR 27286, July 20, 1987; 58 FR 8474, 8475, Feb. 12, 1993; 60 FR 52324, Oct. 6, 1995; 62 FR 38854, July 18, 1997; 64 FR 3036, Jan. 20, 1999]
Appendix F to Part 58—Annual SLAMS Air Quality Information
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1. General
2. Required Information
2.1 Sulfur Dioxide (SO2)
2.1.1 Site and Monitoring Information
2.1.2 Annual Summary Statistics
2.2 Total Suspended Particulates (TSP)
2.2.1 Site and Monitoring Information
2.2.2 Annual Summary Statistics
2.2.3 Episode and Other Unscheduled Sampling Data
2.3 Carbon Monoxide (CO)
2.3.1 Site and Monitoring Information
2.3.2 Annual Summary Statistics
2.4 Nitrogen Dioxide (NO2)
2.4.1 Site and Monitoring Information
2.4.2 Annual Summary Statistics
2.5 Ozone(O3)
2.5.1 Site and Monitoring Information
2.5.2 Annual Summary Statistics
2.6 Lead (Pb)
2.6.1 Site and Monitoring Information
2.6.2 Annual Summary Statistics
2.7 Particulate Matter (PM10)
2.7.1 Site and Monitoring Information
2.7.2 Annual Summary Statistics
2.7.3 Annual Summary Statistics
2.7.4 Episode and Other Unscheduled Sampling Data
1. General
This appendix describes information to be compiled and submitted annually to EPA for each ambient monitoring station in the SLAMS Network in accordance with §58.26. The annual summary statistics that are described in section 2 below shall be construed as only the minimum necessary statistics needed by EPA to overview national air quality status. They will be used by EPA to convey information to a variety of interested parties including environmental groups, Federal agencies, the Congress, and private citizens upon request. As the need arises, EPA may issue modifications to these minimum requirements to reflect changes in EPA policy concerning the National Ambient Air Quality Standards (NAAQS).
As indicated in §58.26(c), the contents of the SLAMS annual report shall be certified by the senior air pollution control officer in the State to be accurate to the best of his knowledge. In addition, the manner in which the data were collected must be certified to have conformed to the applicable quality assurance, air monitoring methodology, and probe siting criteria given in appendices A, C, and E to this part. A certified statement to this effect must be included with the annual report. As required by §58.26(a), the report must be submitted by July 1 of each year for data collected during the period January 1 to December 31 of the previous year.
EPA recognizes that most air pollution control agencies routinely publish air quality statistical summaries and interpretive reports. EPA encourages State and local agencies to continue publication of such reports and recommends that they be expanded, where appropriate, to include analysis of air quality trends, population exposure, and pollutant distributions. At their discretion, State and local agencies may wish to integrate the SLAMS report into routine agency publications.
2. Required Information
This paragraph describes air quality monitoring information and summary statistics which must be included in the SLAMS annual report. The required information is itemized below by pollutant. Throughout this appendix, the time of occurrence refers to the ending hour. For example, the ending hour of an 8-hour CO average from 12:01 a.m. to 8:00 a.m. would be 8:00 a.m.
For the purposes of range assignments the following rounding convention will be used. The air quality concentration should be rounded to the number of significant digits used in specifying the concentration intervals. The digit to the right of the last significant digit determines the rounding process. If this digit is greater than or equal to 5, the last significant digit is rounded up. The insignificant digits are truncated. For example, 100.5 ug/m3 rounds to 101 ug/m3 and 0.1245 ppm rounds to 0.12 ppm.
2.1 Sulfur Dioxide (SO2)
2.1.1 Site and Monitoring Information. City name (when applicable), county name and street address of site location. AIRS-AQS site code. AIRS-AQS monitoring method code. Number of hourly observations. (1) Number of daily observations. (2)
2.1.2 Annual Summary Statistics. Annual arithmetic mean (ppm). Highest and second highest 24-hour averages (3) (ppm) and dates of occurrence. Highest and second highest 3-hour averages (1, 3) (ppm) and dates and times (1) (ending hour) of occurrence. Number of exceedances of the 24-hour primary NAAQS. (3) Number of exceedances of the 3-hour secondary NAAQS. (3) Number of 24-hour average concentrations (4) in ranges:
------------------------------------------------------------------------
Range Number of values
------------------------------------------------------------------------
0.00 to 0.04 (ppm)................................. ...................
0.05 to 0.08....................................... ...................
0.09 to 0.12....................................... ...................
0.13 to 0.16....................................... ...................
0.17 to 0.20....................................... ...................
0.21 to 0.24....................................... ...................
0.25 to 0.28....................................... ...................
Greater than .28................................... ...................
------------------------------------------------------------------------
2.2 Total Suspended Particulates (TSP)
2.2.1 Site and Monitoring Information. City name (when applicable), county name and street address of site location. AIRS-AQS site code. Number of daily observations.
2.2.2 Annual Summary Statistics. Annual arithmetic mean (µg/m 3 ) as specified in appendix K of part 50. Daily TSP values exceeding the level of the 24-hour PM10 NAAQS and dates of occurrence. If more than 10 occurrences, list only the 10 highest daily values. Sampling schedule used such as once every six days, once every three days, etc. Number of additional sampling days beyond sampling schedule used. Number of 24-hour average concentrations in ranges:
------------------------------------------------------------------------
Range Number of values
------------------------------------------------------------------------
0 to 50 (µg/m \3\)......................... ...................
51 to 100........................................ ...................
101 to 150....................................... ...................
151 to 200....................................... ...................
201 to 250....................................... ...................
251 to 300....................................... ...................
301 to 400....................................... ...................
Greater than 400................................. ...................
------------------------------------------------------------------------
2.2.3 Episode and Other Unscheduled Sampling Data. List episode measurements, other unscheduled sampling data, and dates of occurrence. List the regularly scheduled sample measurements and date of occurrence that preceded the episode or unscheduled measurement.
2.3 Carbon Monoxide (CO)
2.3.1 Site and Monitoring Information. City name (when applicable), county name and street address of site location. AIRS-AQS site code. AIRS-AQS monitoring method code. Number of hourly observations.
2.3.2 Annual Summary Statistics. Highest and second highest 1-hour values (ppm) and date and time of occurrence. Highest and second highest 8-hour averages (3) (ppm) and date and time of occurrence (ending hour). Number of exceedances of the 1-hour primary NAAQS. Number of exceedances of the 8-hour average primary NAAQS. (3) Number of 8-hour average concentrations (4) in ranges:
------------------------------------------------------------------------
Range Number of values
------------------------------------------------------------------------
0 to 4 (ppm)....................................... ...................
5 to 8 (ppm)....................................... ...................
9 to 12............................................ ...................
13 to 16........................................... ...................
17 to 20........................................... ...................
21 to 24........................................... ...................
25 to 28........................................... ...................
Greater than 28.................................... ...................
------------------------------------------------------------------------
2.4 Nitrogen Dioxide (NO2)
2.4.1 Site and Monitoring Information. City name (when applicable), county name, and street address of site location. AIRS-AQS site code. AIRS-AQS monitoring method code. Number of hourly observations. (1) Number of daily observations. (2)
2.4.2 Annual Summary Statistics. Annual arithmetic mean (ppm). Highest and second highest hourly averages (3) (ppm) and their dates and time of occurrence. Highest and second highest 24-hour averages (2) and their date of occurrence (ppm). Number of hourly average concentrations in ranges. (1)
------------------------------------------------------------------------
Range Number of values
------------------------------------------------------------------------
.0 to .04 (ppm).................................... ...................
.05 to .08......................................... ...................
.09 to .12......................................... ...................
.13 to .16......................................... ...................
.17 to .20......................................... ...................
.21 to .24......................................... ...................
.25 to .28......................................... ...................
Greater than 0.28.................................. ...................
------------------------------------------------------------------------
2.5 Ozone (O3)
2.5.1 Site and Monitoring Information. City name (when applicable), county name and street address of site location. AIRS-AQS site code. AIRS-AQS monitoring method code. Number of hourly observations.
2.5.2 Annual Summary Statistics. Four highest daily maximum hour values (ppm) and their dates and time of occurrence. Number of exceedances of the daily maximum 1-hour primary NAAQS. Number of daily maximum hour concentrations in ranges:
------------------------------------------------------------------------
Range Number of values
------------------------------------------------------------------------
0 to .04 (ppm)..................................... ...................
.05 to .08......................................... ...................
.09 to .12......................................... ...................
.13 to .16......................................... ...................
.17 to .20......................................... ...................
.21 to .24......................................... ...................
.25 to .28......................................... ...................
Greater than .28................................... ...................
------------------------------------------------------------------------
2.6 Lead (Pb).
2.6.1 Site and Monitoring Information. City name (when applicable), county name, and street address of site location, AIRS-AQS site code. AIRS-AQS monitoring method code. Sampling interval of submitted data, e.g., twenty-four hour or quarterly composites.
2.6.2 Annual Summary Statistics. The four quarterly arithmetic averages given to two decimal places for the year together with the number of twenty-four hour samples included in the average, as in the following format:
------------------------------------------------------------------------
Quarterly
arithmetic
Quarter Number of 24-hour average
samples (µg/
m \3\)
------------------------------------------------------------------------
Jan.-March.......................... ...................... ..........
April-June.......................... ...................... ..........
July-Sept........................... ...................... ..........
Oct.-Dec............................ ...................... ..........
------------------------------------------------------------------------
2.7 Particulate Matter (PM10)
2.7.1 Site and Monitoring Information. City name (when applicable), county name, and street address of site location. AIRS-AQS site code. Number of daily observations.
2.7.2 Annual Summary Statistics. Annual arithmetic mean (µg/m 3 ) as specified in appendix K of part 50. All daily PM10 values above the level of the 24-hour PM10 NAAQS and dates of occurrence. Sampling schedule used such as once every six days, once every three days, etc. Number of additional sampling days beyond sampling schedule used. Number of 24-hour average concentrations in ranges:
------------------------------------------------------------------------
Range Number of values
------------------------------------------------------------------------
0 to 25 (µg/m \3\)........................... ...................
26 to 50........................................... ...................
51 to 75........................................... ...................
76 to 100.......................................... ...................
101 to 125......................................... ...................
126 to 150......................................... ...................
151 to 175......................................... ...................
176 to 200......................................... ...................
Greater than 200................................... ...................
------------------------------------------------------------------------
2.7.3 Annual Summary Statistics. Annual arithmetic mean (µg/m3) as specified in 40 CFR part 50, appendix N. All daily PM-fine values above the level of the 24-hour PM-fine NAAQS and dates of occurrence. Sampling schedule used such as once every 6 days, everyday, etc. Number of 24-hour average concentrations in ranges:
------------------------------------------------------------------------
Range Number of Values
------------------------------------------------------------------------
0 to 15 (µg/m3)..............................
16 to 30........................................... ...................
31 to 50........................................... ...................
51 to 70........................................... ...................
71 to 90........................................... ...................
91 to 110.......................................... ...................
Greater than 110................................... ...................
------------------------------------------------------------------------
2.7.4 Episode and Other Unscheduled Sampling Data. List episode measurements, other unscheduled sampling data, and dates of occurrence. List the regularly scheduled sample measurements and date of occurrence that preceded the episode or unscheduled measurement.
Footnotes
1. Continuous methods only.
2. Manual or intermittent methods only.
3. Based on nonoverlapping values computed according to procedures described in reference (1) or on individual intermittent measurements.
4. Based on overlapping running averages for continuous measurements as described in reference (1) or on individual measurement for intermittent methods.
Reference
1. “Guidelines for the Interpretation of Air Quality Standards” U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards, Research Triangle Park, NC 27711. OAQPS No. 1.2–008, February, 1977.
[44 FR 27571, May 10, 1979, as amended at 46 FR 44171, Sept. 3, 1981; 51 FR 9600, Mar. 19, 1986; 52 FR 24748, 24749, July 1, 1987; 59 FR 41628, Aug. 12, 1994; 62 FR 38854, July 18, 1997]
Appendix G to Part 58—Uniform Air Quality Index (AQI) and Daily Reporting
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General Requirements
1. What is the AQI?
2. Why report the AQI?
3. Must I report the AQI?
4. What goes into my AQI report?
5. Is my AQI report for my MSA only?
6. How do I get my AQI report to the public?
7. How often must I report the AQI?
8. May I make exceptions to these reporting requirements?
Calculation
9. How does the AQI relate to air pollution levels?
10. Where do I get the pollutant concentrations to calculate the AQI?
11. Do I have to forecast the AQI?
12. How do I calculate the AQI?
Background and Reference Materials
13. What additional information should I know?
General Requirements
1. What Is the AQI?
The AQI is a tool that simplifies reporting air quality to the general public. The AQI incorporates into a single index concentrations of 5 criteria pollutants: ozone (O3), particulate matter (PM), carbon monoxide (CO), sulfur dioxide (SO2), and nitrogen dioxide (NO2). The scale of the index is divided into general categories that are associated with health messages.
2. Why Report the AQI?
The AQI offers various advantages:
a. It is simple to create and understand.
b. It conveys the health implications of air quality.
c. It promotes uniform use throughout the country.
3. Must I Report the AQI?
You must report the AQI daily if yours is a metropolitan statistical area (MSA) with a population over 350,000.
4. What Goes Into My AQI Report?
i. Your AQI report must contain the following:
a. The reporting area(s) (the MSA or subdivision of the MSA).
b. The reporting period (the day for which the AQI is reported).
c. The critical pollutant (the pollutant with the highest index value).
d. The AQI (the highest index value).
e. The category descriptor and index value associated with the AQI and, if you choose to report in a color format, the associated color. Use only the following descriptors and colors for the six AQI categories:
Table 1_AQI Categories
------------------------------------------------------------------------
And this color
For this AQI Use this descriptor 1
------------------------------------------------------------------------
0 to 50.......................... ``Good''............ Green.
------------------------------------------------------------------------
51 to 100........................ ``Moderate''........ Yellow.
------------------------------------------------------------------------
101 to 150....................... ``Unhealthy for Orange.
Sensitive Groups''.
------------------------------------------------------------------------
151 to 200....................... ``Unhealthy''....... Red.
------------------------------------------------------------------------
201 to 300....................... ``Very Unhealthy''.. Purple.
------------------------------------------------------------------------
301 and above.................... ``Hazardous''....... Maroon.\1\
------------------------------------------------------------------------
1 Specific colors can be found in the most recent reporting guidance
(Guideline for Public Reporting of Daily Air Quality_Air Quality Index
(AQI)).
f. The pollutant specific sensitive groups for any reported index value greater than 100. Use the following sensitive groups for each pollutant:
------------------------------------------------------------------------
When this pollutant has an index value Report these sensitive groups
above 100 * * * * * *
------------------------------------------------------------------------
Ozone................................... Children and people with
asthma are the groups most at
risk.
------------------------------------------------------------------------
PM2.5................................... People with respiratory or
heart disease, the elderly
and children are the groups
most at risk.
------------------------------------------------------------------------
PM10.................................... People with respiratory
disease are the group most at
risk.
------------------------------------------------------------------------
CO...................................... People with heart disease are
the group most at risk.
------------------------------------------------------------------------
SO2..................................... People with asthma are the
group most at risk.
------------------------------------------------------------------------
NO2..................................... Children and people with
respiratory disease are the
groups most at risk.
------------------------------------------------------------------------
ii. When appropriate, your AQI report may also contain the following:
a. Appropriate health and cautionary statements.
b. The name and index value for other pollutants, particularly those with an index value greater than 100.
c. The index values for sub-areas of your MSA.
d. Causes for unusual AQI values.
e. Actual pollutant concentrations.
5. Is My AQI Report for My MSA Only?
Generally, your AQI report applies to your MSA only. However, if a significant air quality problem exists (AQI greater than 100) in areas significantly impacted by your MSA but not in it (for example, O3 concentrations are often highest downwind and outside an urban area), you should identify these areas and report the AQI for these areas as well.
6. How Do I Get My AQI Report to the Public?
You must furnish the daily report to the appropriate news media (radio, television, and newspapers). You must make the daily report publicly available at one or more places of public access, or by any other means, including a recorded phone message, a public Internet site, or facsimile transmission. When the AQI value is greater than 100, it is particularly critical that the reporting to the various news media be as extensive as possible. At a minimum, it should include notification to the media with the largest market coverages for the area in question.
7. How Often Must I Report the AQI?
You must report the AQI at least 5 days per week. Exceptions to this requirement are in section 8 of this appendix.
8. May I Make Exceptions to These Reporting Requirements?
i. If the index value for a particular pollutant remains below 50 for a season or year, then you may exclude the pollutant from your calculation of the AQI in section 12.
ii. If all index values remain below 50 for a year, then you may report the AQI at your discretion. In subsequent years, if pollutant levels rise to where the AQI would be above 50, then the AQI must be reported as required in sections 3, 4, 6, and 7 of this appendix.
Calculation
9. How Does the AQI Relate to Air Pollution Levels?
For each pollutant, the AQI transforms ambient concentrations to a scale from 0 to 500. The AQI is keyed as appropriate to the national ambient air quality standards (NAAQS) for each pollutant. In most cases, the index value of 100 is associated with the numerical level of the short-term standard (i.e., averaging time of 24-hours or less) for each pollutant. Different approaches are taken for NO2, for which no short-term standard has been established, and for PM2.5, for which the annual standard is the principal vehicle for protecting against short-term concentrations. The index value of 50 is associated with the numerical level of the annual standard for a pollutant, if there is one, at one-half the level of the short-term standard for the pollutant, or at the level at which it is appropriate to begin to provide guidance on cautionary language. Higher categories of the index are based on increasingly serious health effects and increasing proportions of the population that are likely to be affected. The index is related to other air pollution concentrations through linear interpolation based on these levels. The AQI is equal to the highest of the numbers corresponding to each pollutant. For the purposes of reporting the AQI, the sub-indexes for PM10 and PM2.5 are to be considered separately. The pollutant responsible for the highest index value (the reported AQI) is called the “critical” pollutant.
10. Where Do I Get the Pollutant Concentrations To Calculate the AQI?
You must use concentration data from population-oriented State/Local Air Monitoring Station (SLAMS) or parts of the SLAMS required under 40 CFR 58.20 for each pollutant except PM. For PM, you need only calculate and report the AQI on days for which you have measured air quality data (e.g., particulate monitors often report values only every sixth day). You may use particulate measurements from monitors that are not reference or equivalent methods (for example, continuous PM10 or PM2.5 monitors) if you can relate these measurements by statistical linear regression to reference or equivalent method measurements.
11. Do I Have to Forecast the AQI?
You should forecast the AQI to provide timely air quality information to the public, but this is not required. If you choose to forecast the AQI, then you may consider both long-term and short-term forecasts. You can forecast the AQI at least 24-hours in advance using the most accurate and reasonable procedures considering meteorology, topography, availability of data, and forecasting expertise. The document “Guideline for Developing an Ozone Forecasting Program” (the Forecasting Guidance) will help you start a forecasting program. You can also issue short-term forecasts by predicting 8-hour ozone values from 1-hour ozone values using methods suggested in the Reporting Guidance, “Guideline for Public Reporting of Daily Air Quality.”
12. How Do I Calculate the AQI?
i. The AQI is the highest value calculated for each pollutant as follows:
a. Identify the highest concentration among all of the monitors within each reporting area and truncate the pollutant concentration to one more than the significant digits used to express the level of the NAAQS for that pollutant. This is equivalent to the rounding conventions used in the NAAQS.
b. Using Table 2, find the two breakpoints that contain the concentration.
c. Using Equation 1, calculate the index.
d. Round the index to the nearest integer.
Table 2_Breakpoints for the AQI
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These breakpoints Equal these AQIs * *
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PM10 ----------------------- Category
O3 (ppm) 8-hour O3 (ppm) 1- PM2.5 (µg/ (µg/ CO (ppm) SO2 (ppm)
hour 1 m3 ) m3 ) NO2 (ppm) AQI
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0.000-0.064....................... ............ 0.0-15.4 0-54 0.0-4.4 0.000-0.034 ( 2 ) 0-50 Good.
0.065-0.084....................... ............ 15.5-40.4 55-154 4.5-9.4 0.035-0.144 ( 2 ) 51-100 Moderate.
0.085-0.104....................... 0.125-0.164 40.5-65.4 155-254 9.5-12.4 0.145-0.224 ( 2 ) 101-150 Unhealthy for
sensitive groups.
0.105-0.124....................... 0.165-0.204 \4\ 65.5-150.4 255-354 12.5-15.4 0.225-0.304 ( 2 ) 151-200 Unhealthy.
0.125-0.374....................... 0.205-0.404 \4\ 150.5-250.4 355-424 15.5-30.4 0.305-0.604 0.65-1.24 201-300 Very unhealthy.
( 3 )............................. 0.405-0.504 \4\ 250.5-350.4 425-504 30.5-40.4 0.605-0.804 1.25-1.64 301-400 .....................
( 3 )............................. 0.505-0.604 \4\ 350.5-500.4 505-604 40.5-50.4 0.805-1.004 1.65-2.04 401-500 Hazardous.
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1 Areas are generally required to report the AQI based on 8-hour ozone values. However, there are a small number of areas where an AQI based on 1-hour
ozone values would be more precautionary. In these cases, in addition to calculating the 8-hour ozone index value, the 1-hour ozone index value may be
calculated, and the maximum of the two values reported.
2 NO2 has no short-term NAAQS and can generate an AQI only above an AQI value of 200.
3 8-hour O3 values do not define higher AQI values (>= 301). AQI values of 301 or higher are calculated with 1-hour O3 concentrations.
4 If a different SHL for PM2.5 is promulgated, these numbers will change accordingly.
ii. If the concentration is equal to a breakpoint, then the index is equal to the corresponding index value in Table 2. However, Equation 1 can still be used. The results will be equal. If the concentration is between two breakpoints, then calculate the index of that pollutant with Equation 1.You must also note that in some areas, the AQI based on 1-hour O3 will be more precautionary than using 8-hour values (see footnote 1 to Table 2). In these cases, you may use 1-hour values as well as 8-hour values to calculate index values and then use the maximum index value as the AQI for O3. (continued)