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ENVIRONMENTAL PROTECTION FOR FURTHER INFORMATION CONTACT: 214–4897, or sent by e-mail to AGENCY Terence Fitz-Simons, EPA (MD–14), [email protected]. Research Triangle Park, NC 27711, (1) Community Action Programs: 40 CFR Part 58 telephone (919) 541–0889, e-mail fitz- Blueprint for Program Design (EPA 420– [email protected]. For health R–98–003). [FRL±6409±7] effects information, contact Susan Lyon Table of Contents Stone, EPA (MD–15), Research Triangle RIN 2060±AH92 Park, NC 27711, telephone (919) 541– I. Background 1146, e-mail [email protected]. A. What Are the Legislative Requirements? Air Quality Index Reporting B. What Is the History of the Air Quality SUPPLEMENTARY INFORMATION: In Index? AGENCY: Environmental Protection compliance with President Clinton’s C. What Programs Are Related to the AQI? Agency (EPA). June 1, 1998 Executive Memorandum on 1. Ozone and Particulate Matter NAAQS ACTION: Final rule. Plain Language in government writing, Revisions this package is written using plain 2. Real-Time Data Reporting Initiative SUMMARY: Today, EPA adopts revisions language. Thus, the use of ‘‘we’’ or ‘‘us’’ (Ozone Mapping Project) to the uniform air quality index used by in this package refers to EPA. The use 3. Community Action Programs States for daily air quality reporting to of ‘‘you’’ refers to the reader and may II. Rationale for Final Revisions the general public in accordance with include industry, State and local A. What Revisions Did We Propose? section 319 of the Clean Air Act (Act). agencies, environmental groups and 1. What Were the Proposed General These changes include the addition of other interested individuals. Changes? the following elements: a new category 2. What Were the Proposed Changes to the Availability of Related Information Sub-Indices? described as ‘‘unhealthy for sensitive B. What Were the Significant Comments groups;’’ two new requirements, first, to Certain documents are available from and Our Responses? report a pollutant-specific sensitive the U.S. Department of Commerce, 1. Comments and Responses on General group statement when the index is National Technical Information Service, Changes above 100, and second, to use specific 5285 Port Royal Road, Springfield, VA 2. Comments and Responses on Changes to colors if the index is reported in a color 22161. Available documents include: the Sub-Indices format; new breakpoints for the ozone (1) The Review of the National C. What Are the Final Revisions? 1. What Are the General Changes? (03) sub-index in terms of 8-hour Ambient Air Quality Standards for 2. What Are the Changes to the Sub- average 03 concentrations; a new sub- Ozone: Assessment of Scientific and Technical Information (‘‘Staff Paper’’) Indices? index for fine particulate matter (PM2.5); D. What Are the Related Informational and conforming changes to the sub- (EPA–452/R–96–007, June 1996, NTIS # Materials? indices for coarse particulate matter PB–96–203435, $67.00 paper copy and III. Regulatory and Environmental Impact (PM10), carbon monoxide (CO), and $21.50 microfiche). (Add a $3.00 Analyses sulfur dioxide (SO2). In addition, EPA is handling charge per order.) A. Executive Order 12866: OMB Review of changing the name of the index from the (2) Review of the National Ambient ‘‘Significant Actions’’ Pollutant Standards Index (PSI) to the Air Quality Standards for Particulate B. Regulatory Flexibility Analysis/Small Air Quality Index (AQI). This document Matter: Policy Assessment of Scientific Business Regulatory Enforcement discusses the development of related and Technical Information (‘‘Staff Fairness Act C. Unfunded Mandates Reform Act informational materials on pollutant- Paper’’) (EPA–452/R–96–013, July 1996, # D. Paperwork Reduction Act specific health effects and sensitive NTIS PB–97–115406, $47.00 paper copy and $19.50 microfiche). (Add a E. Executive Order 13045: Children’s groups and on precautionary actions Health that can be taken by individuals to $3.00 handling charge per order.) F. Executive Order 12848: Environmental reduce exposures of concern. This The guidance documents associated Justice document also discusses the with this rulemaking are available from G. Executive Order 12875: Enhancing interrelationship between the uniform EPA’s Office of Air Quality Planning Intergovernmental Partnerships air quality index and other programs and Standards in Research Triangle H. Executive Order 13084: Consultation that provide air quality information and Park, NC. Requests for these and Coordination with Indian Tribal Governments related health information to the general publications can be mailed to: Terence Fitz-Simons, EPA (MD–14), Research I. National Technology Transfer and public, including State and local real- Advancement Act time air quality data mapping and Triangle Park, NC 27711. Your request may also be phoned in to Terence Fitz- J. Congressional Review Act community action programs. IV. References Simons at 919–541–0889, or sent by e- EFFECTIVE DATE: October 4, 1999. mail to [email protected]. I. Background ADDRESSES: A docket containing (1) Guideline for Public Reporting of A. What Are the Legislative information relating to EPA’s revisions Daily Air Quality—Air Quality Index Requirements? of the air quality index (Docket No. A– (AQI) (EPA–454/R–99–010). 98–20) is available for public inspection (2) Guideline for Developing an Section 319 of the Act governs the in the Air and Radiation Docket and Ozone Forecasting Program (EPA–454/ establishment of a uniform air quality Information Center, U.S. Environmental R–99–009). index for reporting of air quality. This Protection Agency, South Conference The following document is available section directs the Administrator to Center, Room M–1500, 401 M St., SW, from EPA’s Office of Mobile Sources ‘‘promulgate regulations establishing an Washington, DC 20460, telephone (202) (OMS) in Ann Arbor, MI. Requests for air quality monitoring system 260–7548. The docket may be inspected this publication can be mailed to: throughout the United States which between 8 a.m. and 5:30 p.m. on Michael Ball, US EPA—National utilizes uniform air quality monitoring weekdays, and a reasonable fee may be Vehicle and Fuel Emissions Laboratory criteria and methodology and measures charged for copying. For the availability (NVFEL), 2000 Traverwood Dr., Ann such air quality according to a uniform of related information, see Arbor, MI 48103. Your request may also air quality index’’ and ‘‘provides for SUPPLEMENTARY INFORMATION. be phoned in to Michael Ball at 734– daily analysis and reporting of air

VerDate 18-JUN-99 19:40 Aug 03, 1999 Jkt 183247 PO 00000 Frm 00002 Fmt 4701 Sfmt 4700 E:\FR\FM\04AUR3.XXX pfrm03 PsN: 04AUR3 Federal Register / Vol. 64, No. 149 / Wednesday, August 4, 1999 / Rules and Regulations 42531 quality based upon such uniform air index values serve to divide the index broadening the ways in which State and quality index * * *’’. into categories, with each category being local agencies can meet the nationally identified by a simple informative uniform AQI reporting requirements, B. What Is the History of the Air Quality descriptor. The descriptors are intended and are contributing to State and local Index? to convey to the public information efforts to provide community health In 1976, we established a nationally about how air quality within each protection and to attain or maintain uniform AQI, called the Pollutant category relates to public health, with compliance with the NAAQS. We and Standards Index (PSI), for use by State increasing public health concerns being State and local agencies recognize that and local agencies on a voluntary basis conveyed as the categories range to the these programs are interrelated with (41 FR 37660). This uniform index was upper end of the scale. Additional AQI reporting and with the information established in light of a study conducted information about the general health on the effects of air pollution on public by EPA and the President’s Council on effects associated with each category, health that is generated through the Environmental Quality (CEQ, 1976). and precautions that sensitive groups periodic review, and revision when This study found that the 55 urban areas and the general public can take to avoid appropriate, of the NAAQS. in the U.S. and Canada reporting an exposures of concern, has been made index of air quality used 14 different The most recent revisions to the O3 available through an informational and PM NAAQS, the Ozone Mapping indices, in conjunction with different booklet, updated as appropriate, that Project, and community action programs cautionary messages, such that in also presents and explains the PSI (EPA, are discussed briefly below. In light of essence 55 different indices were being 1994). the interrelationships among these used to report air quality. This diversity In 1979, we made changes to the AQI, programs, we have developed today’s of indices sent a confusing message in part to reflect revisions to the revisions to the uniform AQI with the about air quality to the public. Based in NAAQS for O3, and to establish goal of creating a revised AQI that can part on this study, we developed an requirements for AQI reporting (44 FR effectively serve as a nationally uniform index to meet the needs of State and 27598). The requirement for State and link across these programs. In so doing, local agencies that has the following local agencies to report the AQI appears we intend to support and encourage advantages: it sends a clear and in 40 CFR part 58.50, and the specific State and local participation in real-time consistent message to the public by requirements (e.g., what to report, how data reporting initiatives and the providing nationally uniform to report, reporting frequency, development and implementation of information on air quality; it is keyed as calculations) are in appendix G to 40 community action programs that serve appropriate to the national ambient air CFR part 58. quality standards (NAAQS) and the public education and health protection C. What Programs Are Related to the significant harm level (SHL) 1 which goals. AQI? have a scientific basis relating air 1. Ozone and Particulate Matter NAAQS quality and public health; it is simple Historically, State and local agencies Revisions and easily understood by the public; it have used primarily the AQI, or other provides a framework for reflecting AQIs, to provide general information to On July 18, 1997, we revised the changes to the NAAQS; and it can be the public about air quality and its primary NAAQS for O3 and PM based forecasted to provide advance relationship to public health. In recent on a thorough review of the scientific information on air quality. years, many States and local agencies, as evidence linking exposures to ambient The PSI, which is also commonly well as EPA, have been developing new concentrations of these pollutants to referred to by some State and local and innovative programs and initiatives adverse health effects at levels allowed agencies as the AQI, includes sub- to provide more information to the by the previous NAAQS. In particular, indices for O3, PM, CO, SO2, and public, in a more timely way. These we replaced the 1-hour O3 NAAQS with nitrogen oxide (NO2), which relate initiatives, including real-time data an 8-hour O3 NAAQS and ambient pollutant concentrations to reporting through the Ozone Mapping supplemented the PM NAAQS with 24- index values on a scale from 0 through Project and community action programs, hour and annual standards for fine 3 500. This represents a very broad range can serve to provide useful, up-to-date, particulate matter (measured as PM2.5 ). of air quality, from pristine air to air and timely information to the public These decisions were challenged in the pollution levels that present imminent about air pollution and its effects. Such U.S. Court of Appeals for the District of and substantial endangerment to the information will help individuals take Columbia Circuit, and on May 14, 1999, public. The index has historically been actions to avoid or reduce exposures of the Court remanded them to the Agency normalized across pollutants by concern and can encourage the public to for further consideration, principally in defining an index value of 100 as the take actions that will reduce air light of constitutional concerns numerical level of the short-term (i.e., pollution on days when levels are regarding section 109 of the Act as averaging time of 24-hours or less) projected to be in air quality categories interpreted by EPA. American Trucking primary NAAQS for each pollutant and of concern to local communities. Thus, Associations v. EPA, Nos. 97–1440, 97– an index value of 500 as the SHL.2 Such these programs are significantly 1441 (D.C. Cir. May 14, 1999). On June 28, 1999, the U.S. Department of Justice 1 Significant harm levels are those ambient pollution, approaching the SHL, are in danger of on behalf of EPA filed a petition for concentrations of air pollutants that present an being reached. Changes to this emergency episode rehearing seeking review of the Court’s imminent and substantial endangerment to public program will be proposed in the near future. decision by the entire Court of Appeals. health or welfare, or to the environment, as Below an index value of 100, historically an established in 40 CFR 51.151. intermediate value of 50 was defined either as the The EPA is continuing to assess what 2 Intermediate index values of 200, 300, and 400 level of the annual standard if an annual standard further legal or administrative were defined and are the basis for the Alert, has been established (for PM10 and SO2), or as a proceedings may be appropriate in Warning, and Emergency episode levels included in concentration equal to one-half the value of the response to the Court’s decision, as well 40 CFR part 51, appendix L, as part of the short-term standard used to define an index value Prevention of Air Pollution Emergency Episodes of 100 (for O3 and CO). Coarse or inhalable 3 program. This program requires specified areas to particulate matter, PM10, refers to particles with an PM2.5 refers to particles with an aerodynamic have contingency plans in place and to implement aerodynamic diameter less than or equal to a diameter less than or equal to a nominal 2.5 these plans during episodes when high levels of air nominal 10 micrometers. micrometers.

VerDate 18-JUN-99 19:30 Aug 03, 1999 Jkt 183247 PO 00000 Frm 00003 Fmt 4701 Sfmt 4700 E:\FR\FM\04AUR3.XXX pfrm03 PsN: 04AUR3 42532 Federal Register / Vol. 64, No. 149 / Wednesday, August 4, 1999 / Rules and Regulations as its relevance to other rulemakings In this regard, the AQI is essentially a days above the numerical level of the such as this one. way of conveying scientific/medical standards. With respect to the present advice to the public in an easily These understandings were also rulemaking, we have concluded that it understood form. reflected in CASAC’s advice to the is appropriate to proceed with final As indicated below, there was broad Administrator during the O3 NAAQS action on the proposed AQI revisions. support in public comments for review, urging expansion of the public As indicated previously, section 319 of modifying and expanding the use of the health advisory system (i.e., a uniform the Act requires the Agency to establish AQI to take into account the expanded AQI) and communication to the public a uniform air quality index, and this understanding of air quality-health of the apparent nonthreshold nature of requirement is independent of the relationships that resulted from EPA’s the health effects. More specifically, a statutory provisions governing review of the latest scientific number of CASAC panel members establishment and revision of the information on the effects of PM and O3. recommended ‘‘that an expanded air NAAQS. Moreover, there is no statutory Other proposed revisions were designed pollution warning system be initiated so requirement that the AQI be linked to to enhance the effectiveness of the AQI that sensitive individuals can take the NAAQS, although EPA has used generally. The function the AQI serves appropriate ‘exposure avoidance’ NAAQS levels in the past as reference of conveying to the public information behavior’’ (Wolff, 1995). Consistent with points for the establishment of specific on daily air quality and associated this advice, in the preamble to the breakpoints within sub-indices. Nothing health risks is clearly important, and the proposed revisions to the O3 NAAQS in the Court’s opinion alters the season of higher pollution levels is (61 FR 65733–65734), the Administrator conclusions EPA reached in revising the imminent. For all the above reasons, we requested comment on the usefulness of air quality criteria for PM and O3 under see no reason to delay final action on providing specific health effects section 108 of the Act, or in the NAAQS the proposed revisions of the AQI. The information when ambient rulemakings, concerning the occurrence remainder of this section discusses concentrations are around the numerical of specific health effects at varying aspects of the O3 and PM NAAQS level of the standard, the concentrations of PM and O3 in the air. rulemakings as they relate to today’s appropriateness of using the AQI to Regardless of the outcome of the remand action. convey such information to the public, as to the NAAQS themselves, we believe As a result of the reviews of the the possible addition of two new AQI the scientific record and conclusions scientific information upon which the categories (one just above and one just underlying them are more than 1997 NAAQS for O3 and PM are based, below the numerical level of the sufficient as a basis for decisions on the an expanded understanding emerged as standard) and associated descriptors levels at which the public should be to the nature of the relationships and levels, as well as related health notified about health risks associated between exposure to ambient effects and cautionary statements. with daily air quality.4 concentrations of these pollutants and Broad support for modifying the AQI We do not regard this notification the health effects likely to be was received in public comments on function as involving the constitutional experienced, especially near the level of this aspect of the O3 NAAQS proposal, concerns raised in the Court’s opinion. the NAAQS. We and the Clean Air as discussed in the final rule The AQI has no bearing on pollution Scientific Advisory Committee establishing revisions to the O3 NAAQS control requirements for specific (CASAC) 5 recognized that for these (62 FR 38873–38874). Commenters sources; nor does it serve to implement pollutants there may be no thresholds overwhelmingly endorsed expanding the NAAQS involved in the litigation. below which health effects are not likely the use of the AQI for various reasons, Rather, it provides information on air to occur, but rather a continuum of although many expressed concern with quality and health that will help effects potentially extending down to the possible category descriptors individual citizens take prudent, self- background levels. As ambient suggested in the proposal (i.e., protective actions to avoid or reduce concentrations increase, the proportion ‘‘moderately good’’ and ‘‘moderately exposures of concern and to avoid of individuals likely to experience unhealthful’’). Many commenters felt contributing to air pollution on days effects and the seriousness of the health that an expanded AQI could help when unhealthy air quality is projected. effects increase. Thus, the 1997 particularly sensitive people take action standards were not considered risk free. to minimize their exposures, and that 4 Under section 319, the levels that are While the standards were intended to the AQI could be combined with appropriate for this purpose do not necessarily protect public health with an adequate community action programs to reduce depend on the NAAQS levels that may be appropriate under section 109. Depending on how margin of safety, in accordance with ambient concentrations when the the Agency chose to set an ambient standard, for section 109(b) of the Act, including the numerical level of the standard was example, it might conclude that the standard does health of sensitive groups, exposures to forecasted to be exceeded. Some not need to preclude certain effects falling below ambient concentrations just below the commenters endorsed increasing the the level of public health concern, and at the same time set the AQI in such a way as to assure that numerical level of the standards may specificity of health and cautionary sensitive individuals who might experience those result in exposures of concern for the statements related to the AQI categories. effects receive notification and advice on actions most sensitive individuals. Conversely, Commenters from State and local they might take to avoid them. Similarly, AQI exposures to ambient concentrations agencies encouraged us to develop any values might be set that are higher than the standard would permit but that would require more just above the numerical level of the approaches to revising the AQI in serious health warnings. This is not to say, standards are not likely to result in consultation with them, specifically in however, that the levels of the 1997 NAAQS are exposures of concern for most healthy the areas of sharing real-time monitoring irrelevant to decisions on the AQI breakpoints. To people. This expanded understanding is the contrary, the levels of the 1997 NAAQS are data, risk communication with the useful surrogates for a series of scientific reflected in the forms of the new public, and coordination of a national conclusions reached in the NAAQS rulemakings, standards, which allow for multiple program. based on the revised air quality criteria, regarding the nature, extent, and severity of health effects 5 CASAC is a scientific advisory committee 2. Real-time Data Reporting Initiative associated with varying concentrations of PM and established under the Act to review the scientific (Ozone Mapping Project) O3 in the air. Accordingly, later sections of this criteria and standards and to advise the notice make reference as appropriate to relevant Administrator on revision of the NAAQS, as The Ozone Mapping Project is part of levels of the 1997 NAAQS. appropriate. EPA’s Environmental Monitoring for

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Public Access and Community Tracking they can protect their health and actions to the AQI being adopted today, together (EMPACT) initiative—a new approach they can take to reduce pollution. with related informational materials, to providing timely environmental will significantly improve the 3. Community Action Programs information to communities. It is a effectiveness of communications with cooperative effort of the EPA, State and The implementation of community these groups. Public education, or local air pollution control agencies, and action programs (also referred to as programs directly targeting these regional organizations including the voluntary action programs or episodic groups, may provide the most Mid-Atlantic Regional Air Management emission control programs) is becoming significant benefits of a community Association (MARAMA), the Northeast increasingly popular across the country action program. Forecasting days with States for Coordinated Air Use as an innovative approach used to elevated pollution levels, and then Management (NESCAUM), the northeast reduce emissions of O3 precursors, CO, communicating effectively about air Ozone Transport Commission (OTC), and PM. Motivation for implementation quality and associated health effects, the Lake Michigan Air Directors of this type of program often stems from may help these groups selectively limit Consortium (LADCO), SouthEast States local government and business concerns their outdoor activities and, therefore, Air Resource Managers (SESARM), and about the NAAQS attainment status of limit their potential for exposures of Central States Air Resource Agencies the area and the restrictions, additional concern. (CenSARA). During the summer of 1998, controls, and costs associated with We are committed to providing States EPA’s Office of Air Quality Planning being classified as a nonattainment area. and local agencies with support in their and Standards assumed coordination of Many areas are also motivated by public efforts to meet air quality standards, to the project. health concerns and believe that inform the public about air quality, and increasing the amount of air quality The Ozone Map provides simple and to educate the public about the impacts information available to sensitive timely information about ground-level of air pollution. The revisions to the populations raises awareness and AQI being adopted today have as a goal O3. During the 1998 O3 season it was results in significant health benefits. available on EPA’s AIRNOW web site the creation of a revised AQI that can Specific goals which are usually (http://www.epa.gov/airnow) and on effectively serve as a nationally uniform associated with community action some local television and news reports. link across the range of programs (e.g., programs include: (1) Educate the It is an animated contour map that real-time data reporting initiatives, public and enhance protection of public community action programs) that have shows concentrations of O3, in health; (2) attain or maintain NAAQS these functions. categories ranging from good to attainment status and the associated In support of community action moderate to varying degrees of economic benefits; (3) meet specific programs, we have developed unhealthy, based on AQI values, as they emission reduction targets; and (4) informational materials related to the develop across the eastern United manage/reduce traffic congestion. AQI, including the health effects and States. In 1998, the map was created Community action programs are cautionary statements associated with from real-time, hourly O3 data provided usually voluntary and generally provide each category and more detailed health by a network of more than 400 air multiple steps that the public, business, effects information (see section II.D.), monitoring stations from South Carolina and industry can take to reduce available on the AIRNOW web site, that to Wisconsin and Maine. When emissions when higher levels of air State and local agencies may use to accessed on a computer, cautionary pollution are forecast to occur, enhance their community action statements for each category could be including in particular transportation- programs. Focusing on transportation displayed by running a cursor over the related measures such as trip reduction, measures that are often a major legend. Also available on the AIRNOW postponement of certain activities such component of community action web site were still maps of maximum as vehicle refueling, and maintenance of programs, EPA’s OMS has developed a values and forecasted values, and cars. The programs emphasize educating report entitled, ‘‘Community Action archived animated maps. In 1999, the the public about the impact of Programs: Blueprint for Program ozone mapping coverage is being individual activities on local air quality Design.’’ This document describes the expanded to include 31 States and over and the basics of air pollution. The major steps needed to put together a 1500 monitors across the eastern and educational component of these successful episodic control program and central U.S., and California. In addition, programs also helps to create a strong provides criteria that State and local TV weather service providers are link between environmental goals and agencies can use to examine and planning to carry the Ozone Map and associated public health benefits. evaluate their own programs. The report forecasts as part of their traditional Most of these programs are based on is available from OMS (see Availability weather packages for local TV stations. the categories of the AQI and make use of Related Information). Along with the Ozone Map, the of the AQI descriptors and related AIRNOW web site contains information health effects and cautionary statements II. Rationale for Final Revisions about O3 health effects in the ‘‘Health on action days. By linking action days In developing the revisions to the AQI Facts’’ section, and emission reduction to the AQI, local control programs hope that are being adopted today, we sought activities in the ‘‘What You Can Do’’ to alter individual behavior to reduce extensive input from State and local section. It also provides links to real- emissions and to reduce exposures to agencies and from the public. We time data, and community action the population. In addition to reduced sponsored a workshop with State and program web sites, that are maintained pollutant exposure of the general local agencies, participated in numerous by State and local agencies around the population due to improved air quality, meetings, prepared and made available country. The goals of the web site are to: there are other health benefits directly a staff draft revision to the AQI sub- (1) Provide real-time air pollution data associated with community action index for O3 for use during the 1998 O3 in an understandable, visual format, (2) programs that can be enhanced by season, and conducted several focus provide information about the public linkage to the AQI. Different population groups across the nation to obtain health and environmental effects of air groups are more sensitive to the harmful public input on the effectiveness of draft pollution, and (3) provide the public effects of the different air pollutants revisions to the AQI and related O3 with information about ways in which included in the AQI, and the revisions maps and informational materials. A

VerDate 18-JUN-99 16:03 Aug 03, 1999 Jkt 183247 PO 00000 Frm 00005 Fmt 4701 Sfmt 4700 E:\FR\FM\04AUR3.XXX pfrm01 PsN: 04AUR3 42534 Federal Register / Vol. 64, No. 149 / Wednesday, August 4, 1999 / Rules and Regulations detailed history of the process leading to TABLE 1.ÐPROPOSED CATEGORY for members of sensitive groups is the proposal and the rationale for the INDEX VALUES, DESCRIPTORS, AND entirely consistent with an original goal proposed revisions are described more COLORS that the index be based on the fully in the December 9, 1998 proposal relationships between pollutant notice (63 FR 67818–67834). The sub- Index values Descriptor Color concentrations and adverse health sections below contain a description of effects within various groups, e.g., the revisions we proposed, a discussion 0±50 ...... Good ...... Green aggravation of disease in people with of the significant comments we received 51±100 ...... Moderate ...... Yellow respiratory disease and incidence of 101±150 ...... Unhealthy for sen- Orange and our responses to them, and a respiratory effects in healthy people. sitive groups. Guidance on pollutant-specific summary of the AQI we are adopting 151±200 ...... Unhealthy ...... Red today. 201±300 ...... Very unhealthy .... Purple cautionary statements related to the 301±500 ...... Hazardous ...... Maroon categories of the AQI is discussed below A. What Revisions Did We Propose? in section II.D. The primary consideration that These proposed changes reflected the Consistent with the overarching goal shaped the proposed revisions was the addition of a new category above an AQI of national uniformity in the reporting importance of providing nationally of 100, created by dividing the current of air quality, we proposed that the uniform health information associated ‘‘unhealthful’’ category into two specific colors listed in Table 1 be with daily ambient levels of the air categories. associated with each category. While the pollutants included in the index, When air quality is in the ‘‘unhealthy AQI can be reported without the use of consistent with the requirement of for sensitive groups’’ range, people that colors (through text and numbers alone), section 319 of the Act for an index to are in the sensitive group, whether the when the index is reported using colors, achieve national uniformity in daily air sensitivity is due to medical conditions, we proposed to require that only these quality reporting. More specifically, the exposure conditions, or inherent specified colors be used. Three proposed changes to the AQI sub- sensitivity, may experience exposures of examples of AQI reports that use color concern. However, exposures to ambient indices for O3 and PM reflected the 1997 are the color bars that appear in many concentrations in this range are not revisions to the O3 and PM NAAQS. The newspapers, the color scales on State proposed general changes to the likely to result in exposures of concern and local agency web sites, and the for most healthy people. The descriptor structure of the AQI were based on the color contours of the Ozone Map. We ‘‘unhealthy for sensitive groups’’ was expanded understanding that emerged participated in many discussions with chosen to convey this message clearly. State and local agencies and during the O3 and PM reviews as to the Participants in focus groups (SAIC 1998) nature of the relationships between associations regarding which specific clearly understood that ‘‘sensitive exposure to ambient concentrations of colors should be associated with the groups’’ does not refer to the general these pollutants and the health effects AQI categories, particularly above an public, indicating that this descriptor likely to be experienced, consideration index value of 100. These discussions effectively communicates the intended of the implications of changes for the typically were in the context of either health message. This category would other pollutants, and broad input from the Ozone Mapping Project or include a caution that while perhaps of State and local agencies and the public. community action programs. It was interest to all citizens, would be of clear that the color associated with a The proposed general changes to the particular interest to individuals and AQI, together with related informational category can be part of the health effects families of individuals who are and cautionary message being conveyed. materials, were intended to expand the members of sensitive groups. use of the AQI to provide more Were various State and local agencies to As air quality moves into the use different colors to represent the pollutant-specific health information, ‘‘unhealthy’’ range, exposures are same category, and thus the same level especially when ambient concentrations associated with an increase in the of air quality, it could well send a are close to the level of the primary number of individuals who could confusing message about air quality and NAAQS. potentially experience effects and associated health effects to the public. includes a greater proportion of 1. What Were the Proposed General As an alternative to requiring the use members of the general public. Based on Changes? of specified colors, we solicited input received in the development of comment on the option of a. Categories and related descriptors, the proposal, the descriptor recommending, rather than requiring, index values and colors. The AQI ‘‘unhealthy’’ appropriately characterizes the use of these colors when reporting currently incorporates the pollutants O3, air quality in this range. agencies choose to report the AQI in PM, CO, SO2, and NO2. Index values In addition to an increasing number of color format. In soliciting comment on range from 0 to 500 6, and the index is exposures of concern, when air quality this alternative, we sought to allow segmented into five categories named by moves into the ‘‘unhealthy’’ range and communities maximum flexibility in descriptor words that were chosen to above, individuals who were affected at AQI reporting, while still preserving a characterize the relationship between lower levels, typically members of nationally uniform AQI. We, therefore, sensitive groups, are likely to daily air quality and public health. To requested that commenters addressing experience more serious health effects reflect better the current understanding this issue discuss how this more flexible than members of the general public. To of the health effects associated with approach would satisfy the statutory reflect this understanding, it is exposure to these air pollutants, we language requiring a nationally uniform appropriate to convey two messages in proposed to revise the AQI categories AQI if different colors may be used the cautionary statements for both the and descriptors, and to associate across the nation to represent the same ‘‘unhealthy’’ and ‘‘very unhealthy’’ specific colors with the categories as range of air quality. shown below in Table 1. categories. One message is directed to members of sensitive groups, and the b. Reporting requirements. We

6 proposed to change 40 CFR part 58.50 For NO2, the index ranges from 200 to 500, since other is directed to the general public. there is no short-term NAAQS for this pollutant. The use of a distinct cautionary message to require reporting of the AQI in all

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7 Metropolitan Statistical Areas (MSAs) at-risk from different pollutants, issuing forecasted O3 concentrations. Since we with a population over 350,000, instead advisories for all sensitive groups who have determined that forecasting would of all urbanized areas with a population may be affected at AQI values greater add much to the benefits of AQI over 200,000. This change was proposed than 100 clearly improves public health reporting, we indicated that we would for consistency with the other protection. Therefore, the proposed rule be making available guidance on monitoring regulations in part 58, which encouraged, but did not require, that starting a forecasting program (EPA are or will be based on MSAs. This AQI reports include: appropriate health 1999b) in an area or MSA where proposed change would not, however, effects and cautionary statements, all forecasting is not presently done. have a significant impact on who is AQI values greater than 100, the AQI for Included in the document is guidance required to report, since virtually the sub-divisions of the MSA (if there are on using hourly O3 concentrations as same number of cities would be covered important differences in air quality predictors for 8-hour averages. under the proposed reporting across sub-divisions of the MSA), c. Index name. Many State and local requirement as are covered under the possible causes for high index values, agencies encouraged us to change the existing requirement. and the actual pollutant concentrations. name of the PSI to the Air Quality Consistent with early input from State These topics were also discussed in our Index, or AQI, since many agencies and local agencies, we proposed to draft ‘‘Guideline for Public Reporting of already use the name AQI when change the rounding conventions used Daily Air Quality—Pollutant Standards reporting the AQI value to the public. to calculate index values corresponding Index (PSI)’’ that was made available on Most participants in the focus groups to pollutant concentrations at and above the AIRLINKS web site. preferred the name AQI, commenting the numerical level of the NAAQS to be The proposed rule emphasized the that it more clearly identified the index consistent with the rounding importance of forecasting the AQI by as relating to the quality of the air rather conventions used in defining the specifying that forecasted values should than to environmental pollution in NAAQS for each pollutant. This would be reported, when possible, but did not general. Based on these considerations, avoid situations where a health advisory require that forecasted values be we solicited comment on changing the could be issued that describes the air as reported. Given the importance of the index name from Pollutant Standards unhealthy, when in fact the numerical O3 sub-index in a large number of Index (PSI) to Air Quality Index (AQI). level of the standard has not been MSAs, and the use of an 8-hour 2. What Were the Proposed Changes to exceeded. averaging time for calculating the O 3 the Sub-Indices? The proposed rule retained the sub-index value, forecasting the O3 requirements to identify the area for index value is now more beneficial than To conform to the proposed general which the AQI is being reported, the before. For a health advisory system to changes to the AQI discussed above, time period covered by the report, the be effective, people need to be notified and to reflect the recent revisions to the ‘‘critical’’ pollutant for which the as early as possible to be able to avoid O3 and PM NAAQS, we proposed reported AQI value was derived, the exposures of concern. Because the O3 changes to the sub-indices for O3, PM, AQI value, and the associated category sub-index is based on 8-hour O3 CO, and SO2; no conforming changes are descriptor. Recognizing that many averages, forecasting O3 concentrations necessary for the NO2 sub-index. The agencies use a color format to report the clearly would have increased value in proposed sub-indices are summarized AQI, the proposed rule added the providing cautionary statements to the below in Table 2, in terms of pollutant requirement to report the associated public. We recognized that many State concentrations that correspond to category color if a color format is used. and local air agencies are already breakpoints in the index, and are Because different sensitive groups are issuing health advisories based on discussed in the following sections.

TABLE 2.ÐPROPOSED BREAKPOINTS FOR O3, PM2.5, PM10, CO, AND SO2 SUB-INDICES

O3 PM AQI value CO, 8-hr SO2, 24-hr 8-hr (ppm) 1-hr (ppm) PM2.5, 24-hr PM10, 24-hr (ppm) (ppm) (µg/m3) (µg/m3)

50 ...... 0.07 ...... 15 50 4 0.03 100 ...... 0.08 ...... 0.12 65 150 9 0.14 150 ...... 0.10 ...... 0.16 * 100 250 12 0.22 200 ...... 0.12 ...... 0.20 * 150 350 15 0.30 300 ...... 0.40 (1-hr) ... 0.40 * 250 420 30 0.60 400 ...... 0.50 (1-hr) ... 0.50 * 350 500 40 0.80 500 ...... 0.60 (1-hr) ... 0.60 * 500 600 50 1.00

* If a different SHL for PM2.5 is promulgated, these numbers will be revised accordingly.

a. Proposed ozone sub-index. On July hour average O3 concentrations protection to the public, especially 18, 1997, we revised the O3 primary measured at each monitor within an children active outdoors and other NAAQS to replace the 1-hour standard area (62 FR 38856–38896). These sensitive groups, against a wide range of with a new standard with an 8-hour proposed revisions were based on O3-induced health effects, including average at a level of 0.08 ppm and a findings from the most recent review of decreased lung function; increased form based on the 3-year average of the the NAAQS indicating that the new respiratory symptoms; hospital annual fourth-highest daily maximum 8- primary standard will provide increased admissions and emergency room visits

7 A complete list of MSAs and their boundaries can be found in the Statistical Abstract of the United States (1998).

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for respiratory causes, among children average) (62 FR 38652–38760). These PM2.5 concentration to be associated and adults with pre-existing respiratory revisions were based on findings from with a PM2.5 index value of 500 suggest disease such as asthma; inflammation of the most recent review of the PM a continuum of effects in this range, the lung; and possible long-term damage NAAQS that recently published studies with increasing PM2.5 concentrations to the lungs. In setting this standard, we have indicated that serious health being associated with increasingly larger recognized that there is no apparent effects were more closely associated numbers of people likely experiencing threshold below which health effects do with the levels of the smaller particle serious health effects (62 FR 38675; Staff not occur, that the standard is not risk subset of PM10. These health effects Paper, p. VII–27). The proposed free, and, thus, that exposures of include premature mortality and generally linear relationship between concern are possible below the increased hospital admissions and AQI values and PM2.5 concentrations in numerical level of the standard for some emergency room visits, primarily in the this range, rounded to increments of 50 extremely sensitive individuals. elderly and individuals with µg/m3 to reflect the approximate nature We proposed to set an index value of cardiopulmonary disease; increased of such a relationship, is consistent with 100 equal to the level of the 8-hour O3 respiratory symptoms and disease in this evidence. standard. Recognizing the continuum of children and individuals with Proposed conforming changes to the health effects, we considered the results cardiopulmonary disease; decreased PM10 sub-index. Consistent with the of a quantitative risk assessment lung function, particularly in children retention of the levels of the PM10 (Whitfield et al., 1996) in selecting 8- and individuals with asthma; and NAAQS, we proposed to retain the PM10 hour O3 concentrations to correspond to alterations in respiratory tract defense sub-index generally and to add a new index values of 50, 150 and 200. Since mechanisms. In addition, PM10 breakpoint at an index value of 150 to no human health effects information standards were retained at the same conform to the proposed additional AQI was available for 8-hour average O3 levels of 50 µg/m3 (annual) and 150 µg/ category. We proposed that this concentrations at significantly higher m3 (24-hour average) to continue to breakpoint be set at a PM10 24-hour levels, we proposed to retain the provide protection against health effects average concentration of 250 µg/m3, the breakpoints at the upper end of the AQI associated with the coarse particle mid-point between the breakpoints scale (between the ‘‘very unhealthy’’ subset of PM10, including aggravation of associated with index values of 100 and and ‘‘hazardous’’ categories and the SHL asthma and respiratory infections. To 200. We believe that the PM10 sub- which corresponds to the top of the PSI reflect these revisions to the PM index, with this conforming change, scale of 500) in terms of the existing 1- NAAQS, we proposed to add a new sub- remains appropriate for the public hour average concentrations. index for PM2.5, and to make conforming health protection purposes of the AQI. These proposed revisions reflect the changes to the sub-index for PM10, c. Proposed conforming changes to new 8-hour O3 NAAQS and will in consistent with the proposed general the CO and SO2 sub-indices. Since the almost all areas result in a more changes to the AQI. The proposed sub- current AQI sub-indices reflect the precautionary index than the current 1- indices are summarized in Table 2 and current NAAQS for CO and SO2, the hour sub-index. However, we discussed below. only change we proposed for these sub- recognized that a very small number of Proposed new PM2.5 sub-index. indices was to add a breakpoint to each areas in the U.S. have atypical air Consistent with the historical method of sub-index at an index value of 150 to quality patterns, with very high 1-hour selecting breakpoints of the AQI, we conform to the proposed additional AQI daily peak O3 concentrations relative to proposed to set an index value of 100 category. We proposed that these the associated 8-hour average at the level of the 24-hour PM2.5 breakpoints be set at concentrations at concentrations. In such areas, the use of NAAQS, 65 µg/m3, and an index value the mid-points between the breakpoints the current 1-hour sub-index may be of 50 at the level of the annual NAAQS, associated with index values of 100 and more precautionary on a given day than 15 µg/m3. Also consistent with the basic 200, consistent with the approach the proposed 8-hour sub-index. To structure of the AQI, the proposed described above for conforming changes allow for the reporting of the more upper bound index value of 500 to both the 1-hour O3 sub-index and the precautionary sub-index value, we corresponds to the SHL, established in PM10 sub-index. These proposed proposed to retain the 1-hour sub-index section 51.16 of the CFR under the breakpoints are summarized in Table 2 at and above AQI values of 100 and to Prevention of Air Pollution Emergency and will be reviewed in conjunction allow the reporting of the higher of the Episodes program. The SHL is set at a with the future reviews of the CO and two O3 sub-index values. Thus, both the level that represents an imminent and SO2 NAAQS. new 8-hour and the current 1-hour sub- substantial endangerment to public indices, as shown in Table 2, were health. When we propose revisions to B. What Were the Significant Comments included in the proposed appendix G. the Prevention of Air Pollution and Our Responses? Since for the large majority of areas the Emergency Episodes program, the This section describes the significant 8-hour sub-index will be more proposal will include a SHL for PM2.5. comments we received on proposed precautionary, we did not propose to In the interim, we proposed to establish revisions to the index and our general 3 require all areas to calculate both sub- a PM2.5 concentration of 500 µg/m to be responses to them. More detailed index values. Rather, we proposed to associated with a PM2.5 index value of comment summaries and responses are allow areas the flexibility to calculate 500. contained in a Response to Comments both sub-index values and, when both For intermediate breakpoints in the Document that is available in the docket sub-index values are calculated, to AQI between values of 100 and 500, (see ADDRESSES). require that the higher value be PM2.5 concentrations were proposed reported. We specifically solicited that generally reflect a linear 1. Comments and Responses on General comment on this proposed approach. relationship between increasing index Changes b. Proposed PM sub-index. On July values and increasing PM2.5 values. The a. Categories and related descriptors, 18, 1997, we revised the PM NAAQS by available scientific evidence of health index values and colors. With regard to adding a new set of standards for fine effects related to population exposures the proposed changes to the general particles, or PM2.5, set at levels of 15 µg/ to PM2.5 concentrations between the 24- structure of the index, we received m3 (annual) and 65 µg/m3 (24-hour hour NAAQS level and the proposed comments that focused on two major

VerDate 18-JUN-99 16:03 Aug 03, 1999 Jkt 183247 PO 00000 Frm 00008 Fmt 4701 Sfmt 4700 E:\FR\FM\04AUR3.XXX pfrm01 PsN: 04AUR3 Federal Register / Vol. 64, No. 149 / Wednesday, August 4, 1999 / Rules and Regulations 42537 issues. The first major issue was air pollution warning system (to) be initiated public. As noted by one State whether to add a category above or so that sensitive individuals can take commenter: below the standard, or both. In addition, appropriate exposure avoidance behavior,’’ however EPA has misrepresented the health We are satisfied and support the proposed related to that issue were comments category index values, descriptors and colors. about the proposed descriptor for the threat with the levels it has proposed. (Docket No. A–98–20, IV–D–17). [We] believe that the Air Quality Index * ** category we proposed to add above the has been a very effective communication tool level of the standard. The second major A State commenter that supported during the ozone season. It has been our issue regarded the particular colors, adding a category below the level of the experience that a category above the standard listed in Table 1, we proposed to standard observed that adding such a provides the proper communication to the affected populations without alarming or associate with each category. category would be consistent with desensitizing others. (Docket No. A–98–20, With regard to the general structure of EPA’s conclusion ‘‘that exposures to IV–G–04). the index, most commenters supported ambient concentrations just below the our proposal to add a category above the numerical level of the standard may Further, given the changes we have level of the standard. However, result in exposures of concern for the made to the PM2.5 sub-index, and the commenters from environmental groups most sensitive individuals.’’ (Docket No. expanded ‘‘moderate’’ range and the and several States suggested adding a A–98–20, IV–D–19). cautionary statements we have made available in guidance for use below the category below the level of the standard We understand and agree with the level of the 8-hour O3 standard, we do to provide additional caution for issues related to communication of risk not believe a category below the level of members of sensitive groups, instead of, below the levels of the 24-hour PM2.5 or in addition to one above. These the standard to caution members of and 8-hour O3 standards. For the PM2.5 sensitive groups would be an commenters expressed the view that the sub-index, we have addressed concerns proposed sub-indices, that added a appropriate distinction for any of the about health effects below the level of pollutants included in the index. We category above the standard, did not the 24-hour PM2.5 standard by revising sufficiently caution members of believe that the approach we have the PM2.5 sub-index so sensitive groups sensitive groups about health effects adopted retains the simplicity of the are cautioned below the 24-hour PM2.5 index while allowing for more detailed occurring below the level of the standard. Based on review of the standard. Specifically, their comments cautionary information to be made suggested revisions to the PM2.5 sub- available to the public when were in reference only to potential index that we received in comments, we health effects occurring below the 8- appropriate. believe this approach fully addresses With regard to the descriptor hour O3 and 24-hour PM2.5 standards. their concerns. The revision is ‘‘unhealthy for sensitive groups,’’ some Regarding health effects below the PM2.5 discussed in section II.B.2 below. standard, one State commenter took commenters expressed the view that For better communication of health exception with the statement in the this descriptor is misleading because it risk below the 8-hour O3 standard, we proposal that an additional category encompasses a large segment of the have addressed the issues raised by below the standard, while perhaps population. In addition, they argued, the commenters by revising the O3 sub- public will not know that for certain meaningful for O3, would not be an index. We have expanded the appropriate distinction for the other pollutants healthy people, especially ‘‘moderate’’ range of the 8-hour O3 sub- pollutants in the index. This commenter healthy children, are members of index to make it more precautionary. noted that ‘‘such a distinction would be sensitive groups. Noting that it is When air quality is in the ‘‘moderate’’ more imperative for other pollutants, prudent policy to assume that most risk range of the 8-hour O3 sub-index, we especially for PM where the level of the communication regarding air quality have provided health effects and 24-hour standard may be less protective impacts will be limited to the general cautionary statements, available in our of sensitive groups than the ozone descriptors, some of these commenters AQI Reporting Guidance document standard.’’ (Docket No. A–98–20, IV–D– requested that if we continue to (EPA, 1999a) (discussed in section II.D), 19). Agreeing with the importance of distinguish sensitive groups from the that may be used by State and local cautioning sensitive groups below the general population, that the descriptor agencies to caution unusually sensitive be changed from ‘‘unhealthy for level of the 24-hour PM2.5 standard, individuals below the level of the 8- another commenter noted ‘‘We believe sensitive groups’’ to ‘‘unhealthy for hour O3 standard. This revision is that adding a category below the level children and other sensitive groups,’’ so discussed in section II.B.2 below. of the standard is of particular that the public would receive a clear importance with respect to fine We do not believe it is necessary or message that children are members of a particles.’’ (Docket No. A–98–20, IV–D– appropriate to change the general sensitive group that may be at increased structure of the index by adding a new risk from exposure to ozone. (Docket 11). Regarding the O3 sub-index, some of the States and the environmental category below the level of the standard No. A–98–20, IV–D–2, IV–D–4 and IV– groups that endorsed adding a category to caution extremely sensitive D–11). We agree with the view of these below the level of the standard individuals. Based on the concerns of commenters, based on the responses of supported that position by noting that State and local agencies that the participants in the focus groups, that the we and CASAC stated that extremely addition of two new categories would public will not know that healthy sensitive individuals may be affected unduly complicate the index, we are people, including healthy children, may adding just one new category to be at risk when air quality is in the down to background levels of O3. One comment from an environmental group maintain the degree of simplicity ‘‘unhealthy for sensitive groups’’ range. noted that: strongly supported by State and local The suggested descriptor, however, is agencies, none of whom advocated the only appropriate for pollutants for The CASAC recognized that for O3 and fine addition of two new categories. As which children are a sensitive group. particle pollution, ‘‘there are no discernible described in section II.A.1 above, we Since the sensitive groups differ from thresholds below which health effects are not likely to occur in the most sensitive believe that adding a category above the one pollutant to another, and children individuals’ as it was advising EPA to set level of the standard makes a distinction are only part of the sensitive group for new health standards. We agree with CASAC that is useful for members of sensitive O3, PM2.5 and NO2, this descriptor is not and support the idea of setting ‘‘an expanded groups without alarming the general appropriate for the other pollutants. For

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When the standards to confusion about the health effects above standard, instead of the color are met, public health is protected. associated with high levels of CO. orange that we proposed. Primarily, Exposures to ambient concentrations Therefore, we do not believe it would be these commenters expressed the view just above the numerical level of the useful or prudent to adopt the that the color orange would not send a standards are not likely to result in descriptor ‘‘unhealthy for children and sufficiently strong message that the exposures of concern for most healthy other sensitive groups.’’ To increase standard has been exceeded. In the people. This is especially true for the 8- public awareness that healthy children proposal we indicated that because the hour O3 standard, which has a are members of the sensitive group for color red sends a strong cautionary concentration-based form designed to O3, we are adding the requirement that message, it is most appropriately used offer more protection from higher when the AQI value is above 100, when effects are likely to occur in the concentrations than from multiple reporting agencies include in their general population, and when more smaller exceedances of the standard. published report a statement describing serious effects are likely in members of The form of the 8-hour O3 standard the sensitive group for that particular sensitive groups. Many of these allows for multiple days above the level pollutant. The reporting requirement for commenters noted that since up to 30 of the standard, provided the 3-year pollutant-specific statements describing percent of the population could be average of the fourth-highest maximum sensitive groups is discussed below in considered to be in the sensitive group concentrations does not exceed the level section II.C.1.b on reporting for O3, when the standard is exceeded of the standard. This means that public requirements, and listed in appendix G. the general public should be alerted. health is protected, even when there are We believe that the requirement for These commenters expressed the view multiple days each year when ambient agencies to report the pollutant-specific that it is appropriate to use the color red O3 concentrations are above the level of statements identifying the groups at just above the level of the standard both the standard, as long as the standard is risk, when air quality is above an index to alert the public of potential health met. Therefore, it is inappropriate on value of 100, will more effectively risks and to encourage emission any given day to express a high level of communicate the risk associated with reduction actions. An environmental concern when air quality just exceeds specific air pollutants, and thereby group commented: the level of the standard. Besides better help members of the public While individuals that are sensitive to poor sending an inaccurate health effects reduce personal exposure. To the extent air quality may look at the daily listing in the message by using the color red with the possible with AQI reporting, this newspaper or call a message recorded by the category ‘‘unhealthy for sensitive requirement will also ensure that the state or local air agency, we know from groups,’’ another concern is the public is informed that children are part experience that air quality does not receive potential loss of credibility that could of the sensitive group for O3. This broad public attention until it is predicted or result from repeatedly sending a signal requirement will not only improve reaches the level of ‘‘code red.’’ At that point, disproportionate to the expected protection for healthy children, but also the television and radio media announces incidence of noticeable symptoms. If that people should restrict outdoor activity this were to happen, the AQI could lose healthy adults, the elderly, and people and take steps to not add more pollution to with heart and lung disease. We believe the air by carpooling, using less electricity, the power to influence people’s that another good way to address this or using mass transit. (Docket No. A–98–20, behavior to protect their health. One lack of awareness is to educate the IV-D–17). commenter from a State agency public, and the media and health care expressed this concern: Another commenter from a State professionals that inform the public, agency noted: One of our key concerns * * * is that the about the health effects message general public will become ambivalent if we associated with the category ‘‘unhealthy Considering that the definition of sensitive forecasted 20, 30, or more Code Red days for sensitive groups.’’ To help individuals for ozone includes healthy active over the course of an ozone season. Under accomplish the goal of educating the children and outdoor workers, a clear this scenario, people may not take adequate unambiguous message needs to be sent to the public, we will be expanding the precautions to protect themselves when an public so that they can respond accordingly. actual unhealthy level is reached. (Docket development of education and outreach For parents of active children, a message No. A–98–20, IV–G–05). materials and activities as described in which states that air quality is unhealthy, section II.D below. and displays it using the color red, sends a A commenter from another State agency expressed a similar view: With regard to the colors listed in clear message—even though it may carry Table 1, we received comments with it the risk that individuals not in the It is important to make sure that this concerning both the particular colors sensitive population might also take general message is not jeopardized by exposure avoidance measures. Issuing a treating the new 85 ppb, 8-hour standard as associated with the different categories message that air quality is unhealthy for the bright line between healthy and and whether specific colors should be sensitive individuals and displays it with a unhealthy. The Code Red message will not be required or recommended. The majority code orange runs the risk of having sensitive considered credible if it is issued between 40 of commenters, including most State individuals, or those guiding sensitive to 60 times a summer in our area. Last year and local agencies commenting, individuals (i.e., doctors and parents) not there were 54 days * * * where the 8-hour supported our proposed color scheme. prescribe any avoidance action because of the standard was exceeded. (Docket No. A–98– Many of those (commenters that did ambiguity of the message. (Docket No. A–98– 20, IV–G–13). support it), had used the same or a 20, IV-G–19). From the comments we have received similar color scheme associated with Additionally, these commenters and from our focus group research, we either community action programs or suggested that the color orange be used believe that the color red sends too ozone maps. Commenters that had used for the category they wanted us to add strong a message for use in the

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‘‘unhealthy for sensitive groups some pollutants includes healthy air pollution problems is to be category.’’ Additionally, based on the children and adults, be alerted to communicated effectively.’’ (Docket No. comments of State and local agencies potential health risks and that the A–98–20, IV–D–01). that have used the same or a similar general public be motivated to take In response to the first commenter’s color scheme, we believe that the color emissions reductions measures when air objections, we do not believe that orange sends an appropriate health quality is above the level of the requiring specific colors presents any message and yet a strong message that standard. In response to the concerns particular enforceability problems. This the standard has been exceeded. One expressed by these commenters, we are requirement is one of many contained in State commenter noted that their planning to significantly step up the the 40 CFR part 58 Ambient Air Quality environmental agency: development of education and outreach Surveillance requirements and would be enforceable in the same manner and to has been using a green/yellow/orange/red materials and increase activities to get communication system since 1993. The this message out, as discussed in section the same extent as any other media has used the red, orange and yellow II.D below. requirement of this section. As such, we air quality codes to convey a ‘‘the air is not Only two commenters recommended believe there is no difference in clean’’ message. In general, the media has against requiring specific colors. The enforceability between this and a used Code Red to convey a message that air first commenter did so on the grounds requirement for the use of particular pollution is or will be at a near emergency that requiring specific colors would be descriptors or air quality index values. level. Code Orange has connoted ‘‘very unenforceable, and may lead to We expect to work with EPA Regional dirty.’’ Code Yellow has, in general, been frustration and conflict. While Offices to ensure that they monitor State used to characterize air pollution as not too applauding our goal of establishing a implementation of the revised AQI and bad—but still not clean. (Docket No. A–98– work with the States to encourage 20, IV–G–13). consistent message, and agreeing that it is good to have as much national compliance. Another State commenter noted: consistency as possible, this commenter With regard to comments that our We disagree, however, with * * * [the] noted that efforts to legislate aesthetics requirement would preclude States from assertion that the ‘‘Code Orange’’ message in are uncomfortable, unwieldy and using other color schemes and action the PSI does not adequately protect public ultimately unnecessary. (Docket No. A– levels in their voluntary programs, it is health. Our experience * * * has been that 98–20, IV–D–11). The second important to note that the AQI addresses the health message can be effectively commenter noted that some States may the reporting of measured air quality delivered for Code Orange levels. We have elect to use Code Red for ozone action and does not impose any requirements received much feedback from the general or limitations on community action public about our ozone action day program, programs at levels other than what is being proposed and the regulation programs based on air quality forecasts. and the resounding message has been: Thank We recognize that a nationally uniform you for this program, I can now plan my day should not preclude them from doing to avoid exposure to high levels of ozone. that. (Docket No. A–98–20, IV–D–19). color scheme for AQI reporting will, as (Docket No. A–98–20, IV–G–05). On the other hand, there was very a practical matter, complicate a State’s strong support in the comments for us efforts to use other color schemes in In addition, ozone mapping projects action programs based on predicted air have successfully represented air to require that agencies that use color, use specific colors in AQI reporting. All quality, but they remain free to do so quality using the full AQI color scheme. under our regulations. In the Ozone Mapping Project, of the other commenters that addressed this issue, including a commenter from Because it is the fundamental goal of described in section I.C.2, the proposed the AQI to provide nationally uniform AQI color scheme was used successfully an environmental organization, supported requiring specific colors for information about daily air quality and during the 1998 O3 season. Participating all State/local agencies using a color the public health messages that are State and local agencies and regional appropriately associated with various organizations have selected the same format. The commenter from an environmental group noted: daily air quality levels, in a format that color scheme for use in the 1999 O3 is timely and easily understood, we season. Having used the proposed color EPA states that revisions to the PSI have continue to believe that requiring as a goal the creation of a nationally uniform scheme in their local O3 map, one specified colors when the AQI metropolitan air agency noted that link across a range of programs. We urge that this uniformity be achieved through the use categories are reported in color format is ‘‘EPA’s proposed color scheme of a national public health warning system both necessary and appropriate. Neither communicates clearly in a logical that is clear to the public. To this end, we of the commenters opposing this progression which in our experience is do support the EPA requiring that when requirement addressed how a more already understood by the public and colors are used by a state in its PSI, that the flexible approach of recommending the media.’’ (Docket No. A–98–20, IV– same color system incorporated in the PSI, specific colors, thereby allowing the use G–11). and not variants, be utilized by such state. of different colors to represent the same Because we believe the proposed (Docket No. A–98–20, IV–D–21). range of air quality, would satisfy the color scheme effectively and One of the many State commenters statutory language requiring a nationally appropriately communicates the health agreeing with us that such a uniform air quality index. Therefore, we effects message that was the basis for requirement was necessary for national are adopting the requirement, as setting the O3 and PM standards, we uniformity, noted that ‘‘Specific colors specified in appendix G below, that have adopted the color scheme as ** * associated with each category when State and local agencies report the proposed. However, we strongly agree should be required for national AQI in a color format, that the specific with the views expressed by uniformity and ease of understanding. colors listed in Table 1 be associated commenters that it is important for the Anything less would defeat the purpose with each category. health effects message associated with of a national index for comparing air b. Reporting requirements. We the category ‘‘unhealthy for sensitive quality in different locales.’’ (Docket No. received significant comments on groups’’ to be effectively communicated A–98–20, IV–D–07). Another State several issues related to the reporting to the public, health care providers and commenter made the point that requirements, including the population the media. It is very important that ‘‘Consistency of message is important, threshold and other aspects of the members of sensitive groups, which for especially if the regional nature of many reporting requirements, the appropriate

VerDate 18-JUN-99 16:03 Aug 03, 1999 Jkt 183247 PO 00000 Frm 00011 Fmt 4701 Sfmt 4700 E:\FR\FM\04AUR3.XXX pfrm01 PsN: 04AUR3 42540 Federal Register / Vol. 64, No. 149 / Wednesday, August 4, 1999 / Rules and Regulations method of monitoring and reporting the through the State Implementation Plans comment, section 8 of appendix G PM sub-indices, the effect of AQI (SIPs). Guidance for air quality planning describes exceptions under which AQI changes relative to the SHL program, and implementation in MSAs that fall reporting becomes discretionary, either and the effective date of the final rule. within the boundaries of more than one for one pollutant or the entire index, for Since we received no significant State generally calls for the participating areas with good air quality. Regarding comments on our proposal to change the State and local agencies to identify, in these exceptions, a State commenter rounding conventions for calculating the SIPs for those States, who will be suggested that we require a minimum of the index to make them consistent with responsible for the preparation and 2 years at an AQI value lower than 50 the rounding conventions used in submission of the required elements, before allowing agencies to ‘‘opt out’’ of defining the NAAQS, we are adopting including AQI reports. Where a local or reporting the AQI for a particular that revision as proposed. With regard regional planning organization has been pollutant, so that for example, one to the population threshold, one designated to carry out such unusually good O3 season would not commenter expressed the view that the requirements, such an organization is make it possible for an agency to avoid change from requiring AQI reporting in the appropriate one to report the AQI. reporting high index values in urbanized areas with a population In any case, we encourage AQI reporting subsequent O3 seasons. (Docket No. A– greater than 200,000, to requiring on the sub-MSA level, especially where 98–20, IV–D–06). We believe that reporting in MSAs with populations the AQI differs within the MSA. requiring 2 years of index values lower greater than 350,000, would raise the Another commenter urged us to than 50 before allowing State and local threshold for the requirement and expand the requirement for AQI agencies discretion in reporting, while appear to mean that large segments of reporting to areas with populations less appropriate in some situations, may be the U.S. population would not have than 350,000, if these areas are likely unnecessary in others. We agree with access to AQI reporting. (Docket No. A– not to be in attainment for the 8-hour O3 this commenter that it is appropriate to 98–20, IV–D–03). We have adopted the standard. To support this position, the require reporting of higher index values, requirement for AQI reporting in MSAs commenter noted that O3 can be even if air quality has been good with populations greater than 350,000 to transported long distances downwind throughout the previous year. Therefore, be consistent with the State/Local Air from where it is generated, resulting in we have revised section 8 of appendix Monitoring Stations (SLAMs) serious air quality problems in G, such that when the criteria for an monitoring regulations in 40 CFR part downwind rural and smaller urban exemption are no longer met, the 58, since AQI reporting is based on areas. (Docket No. A–98–20, IV–G–27). responsible agency is required to report information from SLAMS monitors that We agree with this commenter that the AQI. Another commenter expressed are located and reported within the downwind areas may be significantly the view that we should strengthen the context of MSAs. The use of MSAs also affected by transport of O3 and minimum notification requirements, so provides for more stable reporting areas precursors. In section 5 of appendix G, that when the AQI value exceeds 100, since MSAs are usually defined by we encourage States to evaluate air State and local agencies are required to county boundaries that typically do not quality in affected areas downwind of report the index to all three media change, whereas the boundaries for MSAs to identify the potential for (print, radio and television) to help urbanized areas are very irregular, may significant transport-related air quality ensure that the public is informed that include parts of counties, and may impacts and to expand their AQI the standard has been exceeded. (A–98– change with each census. In selecting reporting to address these situations. We 20, IV–E–3) We agree that it is important have also changed the language in this the MSA population threshold of to inform the public when the AQI is section such that the affected area need 350,000, we tried to make the new above 100, and therefore have not be contiguous to the reporting MSA. reporting requirement equivalent to the On a related topic, one commenter strengthened the reporting provisions in old one. Under the new requirement, noted an example in which a MSA with section 6 of appendix G. In particular, virtually the same number of cities will a population greater than 350,000, has when the AQI exceeds 100, reporting be required to report the AQI as were not registered AQI values in excess of 50 agencies should expand reporting to all previously. Because urbanized areas and (such that AQI reporting would be major news media, and at a minimum, MSAs are not equivalent, we realize that discretionary), although values above should include notification to the media some areas will be required to report the 100 are registered infrequently at a with the largest market coverages for the AQI that were not required to do so national monument within the larger air area in question. before this rulemaking, and vice versa. basin. (Docket No. A–98–20, IV–G–17). Looking at these reporting provisions The regulation does not preclude any This commenter requested that we more broadly, we believe that it would area from reporting the AQI, and we revise the reporting requirements to add be very beneficial for reporting agencies encourage State and local air agencies to an air quality consideration to the to educate the media about alternative report the AQI whenever possible so population threshold as a second sources for this information, such as that people will be informed about local component of AQI reporting. To address web sites and community action air quality. one part of this comment, we encourage programs. Many State and local agencies Another commenter noted that some State and local air agencies to report the have web sites that provide quick access MSAs fall within the boundaries of AQI and issue forecasts for national to timely and accurate air quality and more than one State, and requested that parks or monuments whenever possible, related information. For State and local we identify which of the two or more since these are places people go to for agencies participating in the Ozone reporting agencies would be responsible activities that often involve prolonged Mapping Project, the media could be for reporting the AQI for the MSA. or vigorous exertion, thereby increasing directed to the AIRNOW web site as a (Docket No. A–98–20, IV–G–15). We the risk from air pollution. We have source of information about O3 air expect that decisions about AQI worked with the National Park Service quality and associated health effects for reporting in multi-State MSAs will be to develop appropriate guidance for yesterday, today and tomorrow. In made by participating agencies in the visitors and staff to use when index addition, this web site provides in- same manner as decisions about values are expected to be above 100 for depth information about O3 health activities to implement the standards O3. To address the other part of this effects, sources of emissions and simple

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Tools and programs such as these pollution emergency episode in proposed changes to the sub-indices can significantly improve the timeliness example guidance associated with the focused on the sub-indices that were of AQI reporting and provide additional SHL program, this commenter requested added for O3 (8-hour) and PM2.5. Since useful information. We believe that, in that we leave the AQI value of 200 as we did not receive specific comments the near future, the AQI will be reported the lower breakpoint of the ‘‘very on the conforming changes we proposed by the regional and national media in unhealthy’’ category, so that emergency to the CO, SO2 and PM10 sub-indices, ways, such as the Ozone Map, that will episodes would start when air quality is we are adopting these sub-indices as not be limited to specific MSAs. This classified as ‘‘very unhealthy’’ and proposed. type of approach will help provide AQI include appropriate-sounding health a. Ozone sub-index. We received reporting for areas that would otherwise effects and cautionary statements. significant comments on two issues not be covered, including, in some (Docket No. A–98–20, IV–D–22). We are related to the O3 sub-index. The first cases, rural and small urban areas and adopting the breakpoints as proposed, group of comments was in response to national parks. because we believe that it is important our request for comment on retaining Regarding reporting the PM sub- to be consistent in the treatment of the the 1-hour O3 sub-index in addition to indices, one commenter requested that category boundaries (e.g., 51 to 100, 101 the 8-hour O3 sub-index. The second group of comments focused on the we clarify whether PM2.5 and PM10 to 150, 151 to 200, etc.). When we appropriateness of providing should be treated as one pollutant (e.g., propose revisions to the requirements of precautionary language below the level reported simply as PM) or two different the SHL program, we plan to change all of the 8-hour O3 standard. Regarding the pollutants (e.g., reported separately). references to the ‘‘Alert Level’’ so they 1-hour sub-index, almost all of the (Docket No. A–98–20, IV–D–19). We will refer to air quality that exceeds the comments that addressed this issue expect State and local air agencies to ‘‘Alert Level,’’ rather than to air quality supported retaining the 1-hour O3 sub- report PM2.5 and PM10 separately, since that reaches the ‘‘Alert Level.’’ However, index. However, one State commenter there are two separate sub-indices with State and local agencies should not expressed the view that the proposal different sensitive groups, and different change their emergency episode plans at was unclear regarding how areas that health effects and cautionary this point simply because we are have not attained the 1-hour O3 statements. In response to this adopting this consistent approach to standard are to use the new 8-hour O3 comment, we have added clarifying setting AQI breakpoints. Eventually, language to section 9 in appendix G. In sub-index. This commenter also noted some agencies may have to revise that it might be confusing to report the addition, many commenters noted that emergency episode plans because we AQI based on the 8-hour O3 sub-index at the present time there is very little have revised the AQI value of 200 for monitoring for PM (both PM2.5 and in an area where the 1-hour O3 standard the 8-hour O3 sub-index. But we do not had not yet been attained. (Docket No. PM10) that is suitable for use in daily expect States to make any revisions to AQI reports, and requested guidance for A–98–20, IV–D–07). We are requiring their emergency episode plans until we the use of non-reference methods for the that all State and local agencies that promulgate the revised requirements. purpose of AQI reporting. Since PM is report the AQI for O3 calculate the 8- Finally, several commenters noted that often measured at intervals longer than hour O3 sub-index, even if the reporting in the proposal, we did not specify an every 24-hours, State and local agencies area has not attained the 1-hour effective date for the final revisions. are encouraged to use monitoring data standard. In addition to calculating the Some of these commenters suggested from continuous PM monitors for use in 8-hour O3 sub-index, which is required, that we extend the effective date, with AQI reporting, whenever possible. As the reporting agency may also calculate suggestions ranging from 60 days to noted by commenters, due to the lack of the 1-hour O3 sub-index, but this is not more than a year after publication. We appropriate monitoring information, at required. However, if the reporting are adopting an effective date of 60 days this time it may not be possible to report agency calculates both O3 sub-index the AQI for PM in many locations. To after publication. We believe that this values, it is required to report the higher assist State and local agencies in the use will allow adequate time for State and index value of the two. The AQI does of non-reference methods, we have local agencies to revise daily AQI not relate to attainment status; rather, it added language to section 10 of reports. We recognize that it may take is a tool for reporting daily air quality appendix G stating that non-reference longer to revise related informational and associated health information. We materials, such as printed documents, or methods may be used for the purpose of are retaining the 1-hour O3 sub-index AQI reporting if it is possible to related programs that agencies may only because we recognize that there are demonstrate a simple linear relationship want to revise. However, since this a very small number of areas in the U.S. between the non-reference and the rulemaking applies only to the that have atypical air quality patterns, reference methods. requirements for daily reporting of air with very high 1-hour daily peak O3 Regarding the effect of changes to the quality, we believe an effective date of concentrations relative to 8-hour AQI on the SHL program, we received 60 days is adequate. average concentrations. In such areas, two significant comments. One c. Index name. All commenters that an index value greater than 100 might commenter noted that our proposed expressed a view on the index name be calculated using the 1-hour sub- changes to the categories, to standardize supported changing the name of the index, even when the 8-hour sub-index them such that the upper bound falls on index from the Pollutant Standards might be below 100. For these areas, the an even number, rounded to 50 (e.g., Index (PSI) to the Air Quality Index use of the 1-hour sub-index is clearly 200), and lower bound falls on an odd (AQI), because this name clearly more precautionary. Because our major number (e.g., 201), resulted in the AQI identifies the index as relating to the interest is that appropriate breakpoint of 200 being the upper quality of the air. Accordingly, we are precautionary messages be issued, we

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are not retaining a complete 1-hour O3 notice’’ associated with moderate air for a pollutant (in this case, the 24-hour sub-index with ‘‘good’’ and ‘‘moderate’’ quality is inconsistent with the 8-hour PM2.5 standard) and the AQI value of 50 categories. Likewise, when ambient 8- O3 standard because the standard is at the level of the annual standard, if hour O3 concentrations are greater than intended to protect public health, even there is one, or at one-half the level of 0.374 ppm, reporting agencies must the health of sensitive populations, with the short-term standard.8 This method calculate the index value using the 1- an adequate margin of safety, the of structuring the index is appropriate hour O3 sub-index. This is because no industry commenter expressed the view for a ‘‘typical’’ suite of air-quality human health effects information is that we should omit from our materials standards, which includes a short-term available for higher 8-hour average O3 the health effects and cautionary standard designed to protect against the concentrations to use as a basis for statements suggesting that air quality health effects associated with short-term selecting 8-hour breakpoints and for meeting the level of the standard is a exposures and an annual standard developing appropriate health effects threat to health. We agree with the designed to protect against health effects and cautionary statements. We believe industry and State commenters that associated with long-term exposures. In that since State and local agencies are since the 8-hour O3 standard is intended such cases, the short-term standard in required to report the name of the to protect public health, including the effect defines the level of health pollutant responsible for an index value health of sensitive groups, with an protection provided against short-term greater than 100, but not the associated adequate margin of safety, that the term risks and thus is a useful benchmark averaging period, using the 8-hour O3 ‘‘limited health notice’’ may be against which to compare daily air- sub-index should not be confusing in misleading. However, we continue to quality concentrations. areas that have not yet attained the 1- believe that it is appropriate to provide In the case of the PM2.5 standards, hour O3 standard. guidance with cautionary language for however, EPA took a different approach to protecting against health risks Regarding the issue of alerting extremely sensitive individuals, not associated with short-term exposures. sensitive individuals below the level of populations or groups, below the level of the standard. This approach is For reasons discussed in the preamble the 8-hour O3 standard, some to the final standards, the annual and commenters not only suggested adding consistent with the advice of CASAC, and the way we discussed expanding 24-hour PM2.5 standards were designed a category below the level of the the use of the AQI, specifically to to work together for this purpose, and standard, but also suggested reducing caution extremely sensitive individuals the intended level of protection against the lower bound of the ‘‘moderate’’ below the level of the O3 standard, in short-term risk is not defined by the 24- category. (Docket No. A–98–20, IV–D– the O3 proposal and final decision hour standard but by the combination of 11, IV–D–17, IV–D–19, IV–G–21). We notices. the two standards working in concert. are not adding a category below the b. PM2.5 sub-index. We received a Indeed, the annual PM2.5 level of 15 µg/ level of the standard as discussed in number of comments regarding the m3 was intended to serve as the section II.B.1. above. However, to be PM2.5 sub-index, almost all of them principal vehicle for protection against somewhat more precautionary, we have focusing on our proposal to set the short-term PM2.5 exposures (by reducing expanded the ‘‘moderate’’ range by index value of 100 at the level of the 24- the entire distribution of PM2.5 reducing the lower bound of this hour standard (65 µg/m3). Some concentrations in an area), with the category from 0.070 ppm to 0.065 ppm commenters recommended setting an short-term standard serving essentially O3, 8-hour average. We believe that index value of 100, or otherwise to provide supplemental protection in setting the breakpoint between the providing for cautionary messages, at special situations. 9 Given the respective ‘‘good’’ and ‘‘moderate’’ categories at concentrations lower than 65 µg/m3. roles of the two standards, setting the this lower level, is appropriate, based in One commenter, for example, stated that AQI value of 100 at the level of the 24- part on risk estimates done in under the proposal ‘‘many areas of the hour standard would not reflect the conjunction with the review of the O3 country will likely violate the annual short-term health risks associated with NAAQS which suggested that risk to standard of 15 µg/m3 without ever (or lower concentrations, which the annual healthy people likely becomes hardly ever) reaching a PSI of 100 or a standard was designed to address. negligible at this level (Whitfield et al., category indicating some degree of Accordingly, we agree that it is 1996). This change is also responsive to unhealthfulness. This situation will appropriate to caution members of comments from State agencies that the result in an inconsistent and sensitive groups below the level of the proposed range of the ‘‘moderate’’ inappropriate message to the public, 24-hour standard and believe this category was so narrow (spanning only especially given the severe health effects should be done in a way that reflects the 15 ppb O3, as compared to 20 ppb range associated with fine particles.’’ (Docket intended roles of both standards in used in the Ozone Map in 1998) that it No. A–98–20, IV–D–11). protecting against short-term risks. would be more difficult to forecast In light of these comments, we have It would also be inappropriate to accurately and also would provide too reexamined the basis for selecting PM2.5 compare daily air-quality concentrations quick a transition from good to AQI breakpoints and agree that the sub- directly with the level of the annual unhealthy. (Docket No. A–98–20, IV–D– index as proposed would not adequately standard (by setting the AQI value of 10, IV–G–04). Conversely, an industry caution sensitive groups about potential 100 at that level), because the annual group and a State commenter took risks associated with short-term standard represents an average of many exception to issuing a ‘‘limited health exposures to PM2.5. This is essentially daily concentrations rather than daily notice’’ for O3 that we proposed as the because the proposed PM2.5 sub-index values per se. In the circumstances, we purpose of the ‘‘moderate’’ category. was developed using the Agency’s believe the guiding principle for PM2.5 (Docket No. A–98–20, IV–D–12, IV–G– historical approach to selecting index should be to set the AQI value of 100 14). The State commenter objected to breakpoints, which on examination does in a way that, at least conceptually, the use of the term ‘‘health notice’’ not correspond well with the way the reflects the general level of health below the level of the standard because PM2.5 standards were intended to protection against short-term risks it implies that the standard is not function. The historical practice has protective of public health. In addition been simply to set the AQI value of 100 8 See 63 FR 67819, 67829 (Dec. 9, 1998). to stating that the ‘‘limited health at the level of the short-term standard 9 See 62 FR 38669–71, 38676–77 (July 18, 1997).

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What Are the Final Revisions? in that the underlying logic of that required of specific sources. approach, as applied to a typical suite In short, EPA’s decision to treat the The sub-sections below only of standards, is also to set the AQI value annual standard as the principal vehicle summarize changes to the regulatory of 100 in a way that reflects the level of for protecting against short-term PM2.5 text. They do not describe all aspects of protection provided against short-term concentrations, although judged to be 40 CFR part 58.50 or appendix G. risks—that is, by setting it at the level the best approach based on the available 1. What Are the General Changes? of the short-term standard that provides health information, does present a Based on the proposed structure of the protection. In the case of PM2.5, as different situation than that involved in indicated above, the level of the 24-hour previous AQI rulemakings. As discussed the AQI, the comments we received and standard (65 µg/m3) is too high to reflect in the preamble to the final standards, our responses to them, as discussed the intended level of protection, and the the annual standard was intended to above, we are adopting the following µ 3 changes to the general structure and level of the annual standard (15 g/m ) reduce all PM2.5 concentrations, is too low. Between the two values, the including short-term peaks, in an area reporting requirements to the AQI. a. Categories and related descriptors, available health studies indicate a sufficiently to protect public health with index values and colors. We are continuum of risks associated with an adequate margin of safety, aside from adopting the index values, descriptors increasing PM concentrations, although special situations which the 24-hour and associated colors listed in Table 1 with significant uncertainties as to the standard was designed to address. As above. extent of the risk associated with single one commenter suggested, however, it peak exposures.10 Consistent with EPA’s b. Reporting requirements. We are would be possible for an area to violate revising 40 CFR 58.50 to require general practice of setting AQI the annual standard without ever breakpoints in symmetrical fashion reporting of the AQI in all MSAs with experiencing (or seldom experiencing) a population over 350,000. In appendix where health effects information does daily peaks that exceeded the level of not suggest particular levels,11 we G, we are adopting rounding the 24-hour standard. Moreover, it conventions to be used to calculate concluded that it is appropriate to set might be difficult, if not impossible, to the AQI value of 100 at the mid-point index values that are consistent with the predict in advance whether the annual rounding conventions used in defining of the range between the annual and the standard will be attained in a given area. 3 the NAAQS for each pollutant. 24-hour PM2.5 standards (40 µg/m ). For these reasons, as well as the The final rule retains the Given that decision, we also concluded uncertainties in the available health that it is appropriate to retain the level requirements to identify the area for information, it is inherently difficult to which the AQI is being reported, the of the annual standard for an AQI value judge the significance of single peak of 50, as proposed, and to set the AQI time period covered by the report, the concentrations when they occur. In ‘‘critical’’ pollutant for which the level of 150 at the level of the 24-hour view of the various uncertainties standard. reported AQI value was derived, the involved, particularly sensitive AQI value, and the associated category To reiterate, the purpose of setting the individuals may wish to avoid exposure AQI value of 100 somewhat below the descriptor. The final rule adds two to such concentrations, especially requirements: (1) To report the level of the 24-hour standard was to concentrations that approach the level reflect the dual role of the annual and associated category color if a color of the 24-hour standard. To facilitate format is used and, (2) to report the 24-hour PM2.5 standards in protecting such choices, consistent with the against short-term risks, and the aim pollutant-specific sensitive group for purposes of the AQI and the advice of any reported index value greater than was to select a breakpoint that would CASAC, we believe that cautioning serve as a rough surrogate for the 100. The final rule encourages, but does members of sensitive groups in the not require, that AQI reports include: general level of protection provided by µ 3 range of 40 to 65 g/m is appropriate. appropriate health effects and the two standards in combination. We did not receive any comments on Given the nature of the standards and cautionary statements, all AQI values the proposal to establish a concentration greater than 100, the AQI for sub- the available health information, a more of 500 µg/m3 to be associated with a exact approach was not possible. In this divisions of the MSA (if there are PM2.5 index value of 500, or our method important differences in air quality regard, setting the breakpoint at the of selecting the intermediate mid-point of the range between the across sub-divisions of the MSA), breakpoints. Therefore, we are adopting possible causes for high index values, annual and 24-hour standards, as 500 µg/m3 as the upper bound of the opposed to a level somewhat higher or and the actual pollutant concentrations. index.12 For intermediate breakpoints in lower within that range, simply In the case of rural or small urban the AQI between values of 150 and 500, reflected EPA’s general practice of areas that are significantly affected by we have adopted PM2.5 concentrations setting symmetrical breakpoints as pollutants transported from a MSA that generally reflect a linear indicated above, and does not imply any where the AQI is reported, the final rule relationship between increasing index sort of health-effects threshold. In recommends that the MSA report the values and increasing PM2.5 values. As particular, it does not reflect a judgment AQI for the affected areas as well. In discussed in the proposal, the generally about the extent of the risk associated addition, when the AQI is greater than linear relationship between AQI values with single peak concentrations of 100, reporting agencies should expand and PM2.5 concentrations in this range, PM2.5, as to which the available health AQI reporting to include all major news rounded to increments of 50 µg/m3 to information is inconclusive, or the level media. The final rule continues to allow reflect the approximate nature of such a at which EPA might set a 24-hour agencies to discontinue reporting for any pollutant, if index values for that standard if the annual standard did not 12 As discussed in the proposal, should the final pollutant have been below 50 for an SHL for PM2.5, when promulgated, be different from 10 See 62 FR 38670, 38677 (July 18, 1997). this concentration, we will revise this PM2.5 sub- entire season or a year. However, if in 11 See 63 FR 67824, 67832 (Dec. 9, 1998). index accordingly. subsequent years pollutant levels rise

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such that index values for that pollutant c. Index name. We are adopting the corresponding to the 8-hour O3 standard would be above 50, then the final rule name the Air Quality Index or AQI. and the PM2.5 standards, as well as requires that AQI reporting for that 2. What Are the Changes to the Sub- conforming changes to the CO, 1-hour pollutant resume. The final rule Indices? O3, PM10, and SO2 sub-indices. The emphasizes the importance of adopted breakpoints for the O3 (8-hour forecasting the AQI by specifying that Based on the proposed sub-indices, and 1-hour) PM2.5, PM10, CO and SO2 forecasted values should be reported, the comments we received and our sub-indices are listed in Table 3. when possible, but does not require that responses to them, as discussed above, forecasted values be reported. we are adopting new sub-indices

TABLE 3.ÐBREAKPOINTS FOR O3, PM2.5, PM10, CO, AND SO2 SUB-INDICES

O3 PM

AQI value CO, 8-hr (ppm) SO2, 24-hr (ppm) 8-hr (ppm) 1-hr (ppm) PM2.5, 24-hr PM10, 24-hr (µg/m3) (µg/m3)

50 ...... 0.06 ...... 15 50 4 0.03 100 ...... 0.08 ...... 0.12 40 150 9 0.14 150 ...... 0.10 ...... 0.16 65 250 12 0.22 200 ...... 0.12 ...... 0.20 * 150 350 15 0.30 300 ...... 0.40 (1-hr) ... 0.40 * 250 420 30 0.60 400 ...... 0.50 (1-hr) ... 0.50 * 350 500 40 0.80 500 ...... 0.60 (1-hr) ... 0.60 * 500 600 50 1.00

* If a different SHL for PM2.5 is promulgated, these numbers will be revised accordingly.

These sub-indices are presented in brochure), with final revisions to the general information about O3. more detail in appendix G to reflect the AQI, and will identify sensitive groups Information about ground-level as changes to the numerical rounding in the health effects statements for each contrasted to stratospheric O3 may be conventions for calculating index of the pollutants, and include the found in EPA’s publication ‘‘Ozone: values. pollutant-specific health effects and Good Up High, Bad Nearby.’’ The EPA’s cautionary statements discussed above. video, ‘‘Ozone Double Trouble’’ also D. What Are the Related Informational A colorful fact sheet, called the ‘‘Air provides information about ground-level Materials? Quality Guide,’’ provides information and stratospheric O3 and the health The primary documents associated about the AQI, O3 health effects and the effects associated with exposure to with the AQI and this rulemaking, are sources of ground-level O3 is available ground-level O3, or smog. our guidance on AQI reporting, on the AIRNOW web site. A revised In addition to the products discussed ‘‘Guideline for Public Reporting of Daily booklet, ‘‘SMOG—Who Does It Hurt?,’’ above, to address the concerns of Air Quality—Air Quality Index (AQI)’’ provides information for the general commenters that when air quality is in (EPA 1999a), and our guidance on AQI public about O3 health effects and is the ‘‘unhealthy for sensitive groups’’ forecasting, ‘‘Guideline for Developing based on scientific information gained range the public will not understand an Ozone Forecasting Program’’ (EPA in the recent review of the O3 standard. that the standard has been exceeded or 1999b). These documents are available ‘‘SMOG—Who Does It Hurt?’’ was who is at risk, we are going to on AIRLINKS (http://www.epa.gov/ designed to provide, in simple language, significantly increase education and airlinks). The AQI Reporting document enough detail for individuals to outreach related to the AQI. At this contains information regarding the AQI understand who is at most risk from O3 point, we are still in the process of requirements and recommendations, exposure and why, the nature of O3 planning specific new products or example AQI reports, and a list of MSAs health effects, and a detailed activities, but have decided what required to report the AQI. It also explanation of how individuals can general direction these efforts will take. includes pollutant-specific health reduce the likelihood of exposure using First, we plan to increase our contacts effects and cautionary statements for use common everyday activities as with the news providers to better inform with the index, for O3, PM2.5, PM10, CO, examples. We are also developing a them about the importance of including and SO2. The AQI Forecasting shorter, summary pamphlet about O3 accurate, timely and understandable document explains the steps necessary health effects to complement the information in their broadcasts and to start an air pollution forecasting ‘‘SMOG—Who Does It Hurt?’’ booklet. reporting, and to enlist them as full program. Included in the document is We expect the AQI brochure, ‘‘SMOG— partners in the implementation of the guidance on using hourly O3 Who Does It Hurt?’’ and the shorter AQI. Second, we plan to form new concentrations as predictors for 8-hour summary pamphlet about O3 health associations with health care providers averages. effects to be available in paper format to keep them informed about air Other related informational materials and on the AIRNOW web site early in pollution health effects, since these are also available. The brochure ‘‘The the 1999 ozone season. In addition, we professionals are the most trusted Pollutant Standards Index’’ (EPA 1994) will translate the Air Quality Guide, the source of health effects information. contained general information about the AQI brochure, ‘‘SMOG—Who Does It Third, we plan to increase direct health effects and air quality, and Hurt?’’, and the shorter summary outreach to the public through a variety general precautions that sensitive pamphlet into Spanish. These materials of means, including materials tailored to groups and the general public can take will be available on a Spanish page on school-age children, the Spanish- to avoid exposures of concern. It is the AIRNOW web site. speaking community, and others. being revised to be consistent with the There are other materials available on Finally, we plan to work with public new name (i.e., the Air Quality Index the AIRNOW web site that provide health interest organizations to support

VerDate 18-JUN-99 19:40 Aug 03, 1999 Jkt 183247 PO 00000 Frm 00016 Fmt 4701 Sfmt 4700 E:\FR\FM\04AUR3.XXX pfrm03 PsN: 04AUR3 Federal Register / Vol. 64, No. 149 / Wednesday, August 4, 1999 / Rules and Regulations 42545 their efforts to provide more immediate U.S.C. 605(b), this requirement may be section 203 of the UMRA, EPA has and interactive education and outreach waived if EPA certifies that the rule will determined that this rule contains no to all of these groups. not have a significant economic impact regulatory requirements that might on a substantial number of small significantly or uniquely affect small III. Regulatory and Environmental entities. Small entities include small governments. This rule requires Impact Analyses businesses, small not-for-profit reporting of the Air Quality Index only A. Executive Order 12866: OMB Review enterprises, and governmental entities in MSAs with populations greater than of ‘‘Significant Actions’’ with jurisdiction over populations less 350,000, and therefore does not affect than 50,000 people. small governments. Under Executive Order 12866, the Today’s final decision to revise the Agency must determine whether a AQI program modifies existing air D. Paperwork Reduction Act regulatory action is ‘‘significant’’ and, quality reporting requirements for Today’s final decision does not therefore, subject to Office of MSA’s with populations over 350,000 establish any new information Management and Budget (OMB) review people. Today’s final decision will not collection requirements beyond those and the requirements of the Executive establish any new regulatory which are currently required under the Order. The order defines ‘‘significant requirements affecting small entities. On Ambient Air Quality Surveillance regulatory action’’ as one that may: the basis of the above considerations, Regulations in 40 CFR part 58 (OMB (1) Have an annual effect on the EPA certifies that today’s final decision #2060–0084, EPA ICR No. 0940.15). economy of $100 million or more or will not have a significant economic Therefore, the requirements of the adversely affect in a material way the impact on a substantial number of small Paperwork Reduction Act do not apply economy, a sector of the economy, entities within the meaning of the RFA. to today’s action. productivity, competition, jobs, the Based on the same considerations, EPA environment, public health or safety, or E. Executive Order 13045: Children’s also certifies that the new small-entity Health State, local, or tribal governments or provisions in section 244 of the Small communities; Business Regulatory Enforcement Executive Order 13045, entitled (2) Create a serious inconsistency or Fairness Act (SBREFA) do not apply. ‘‘Protection of Children from otherwise interfere with an action taken Environmental Health Risks and Safety or planned by another Agency; C. Unfunded Mandates Reform Act Risks’’ (62 FR 19885, April 23, 1997), (3) Materially alter the budgetary Title II of the Unfunded Mandates requires Federal agencies to ensure that impact of entitlements, grants, user fees, Reform Act of 1995 (UMRA), Public their policies, programs, activities, and or loan programs or the rights and Law 104–4, establishes requirements for standards identify and assess obligations or recipients thereof; or Federal agencies to assess the effects of environmental health and safety risks (4) Raise novel legal or policy issues their regulatory actions on State, local, that may disproportionately affect arising out of legal mandates, the and tribal governments and the private children. To respond to this order, President’s priorities, or the principles sector. Under section 202 of the UMRA, agencies must explain why the set forth in the Executive Order. The EPA generally must prepare a written regulation is preferable to other EPA has determined that the revisions statement, including a cost-benefit potentially effective and reasonably to air quality index reporting in this analysis, for proposed and final rules feasible alternatives considered by the final rule would not have an annual with ‘‘Federal mandates’’ that may agency. In today’s final decision, EPA effect on the economy of $100 million result in expenditures to State, local and identified children as one of the or more or adversely affect in a material tribal governments, in the aggregate, or sensitive groups which may be at way the economy, a sector of the to the private sector, of $100 million or increased risk of experiencing the economy, productivity, competition, more in any 1 year. In addition, before effects of concern following exposure to jobs, the environment, public health or EPA establishes any regulatory O3, PM2.5 and NO2.5. The AQI categories, safety, or State, local, or tribal requirements that may significantly or descriptors, and health effects and governments or communities, and uniquely affect small governments, cautionary statements as proposed, for therefore did not prepare a regulatory including tribal governments, it must the first time reflect consideration of the impact assessment. The OMB has have developed under section 203 of the increased health risk to children which advised us this final decision should be UMRA a small government agency plan. may result from such exposures. construed as a ‘‘significant regulatory The plan must provide for notifying Promulgation of the proposed AQI is action’’ within the meaning of Executive potentially affected small governments, one potentially effective alternative that Order 12866. Accordingly, this action enabling officials of affected small was considered. However, based on was submitted to the OMB for review. governments to have meaningful and comments that the public may not be Any changes made in response to OMB timely input in the development of EPA aware that healthy, active children are suggestions or recommendations will be regulatory proposals with significant included in the sensitive groups for O3, documented in the public record and Federal intergovernmental mandates, PM2.5 and NO2, we have adopted the made available for public inspection at and informing, educating, and advising additional requirement that reporting EPA’s Air and Radiation Docket small governments on compliance with agencies must include a pollutant- Information Center (Docket No. A–98– the regulatory requirements. specific statement of the sensitive 20). The EPA has determined that today’s groups when an index value of 100 is final decision would not include a exceeded. For example, when reporting B. Regulatory Flexibility Analysis/Small Federal mandate that may result in an AQI value of 110 for ozone, the Business Regulatory Enforcement estimated costs of $100 million in any reporting agency must include a Fairness Act 1 year to either State, local, or tribal statement that children and people with Under the Regulatory Flexibility Act governments, in the aggregate, or to the asthma are the groups most at risk. (RFA), 5 U.S.C. 601 et seq., EPA must private sector. Accordingly, EPA has Whenever the AQI value is above 100 prepare a regulatory flexibility analysis determined that the provisions of for a pollutant, and children are one of assessing the impact of any proposed or section 202 of the UMRA do not apply the sensitive groups for that pollutant, final rule on small entities. Under 6 to this rulemaking. With regard to the AQI report must include a statement

VerDate 18-JUN-99 19:30 Aug 03, 1999 Jkt 183247 PO 00000 Frm 00017 Fmt 4701 Sfmt 4700 E:\FR\FM\04AUR3.XXX pfrm03 PsN: 04AUR3 42546 Federal Register / Vol. 64, No. 149 / Wednesday, August 4, 1999 / Rules and Regulations that children are at risk. Therefore, This rule does not establish a wholly uniquely affect communities of Indian today’s action does comply with the new requirement but rather modifies tribal governments. To the extent that requirements of E.O. 13045. existing reporting requirements which air pollution from upwind MSAs State and local governments have been significantly affects any lands within F. Executive Order 12848: implementing for approximately 20 Indian country, this impact is not a Environmental Justice years. While these changes are result of, or affected by, today’s rule and Executive Order 12848 requires that significant in many ways, they are not would be addressed under existing each Federal agency make achieving expected to result in a significant requirements governing the environmental justice part of its mission increase in reporting burdens. implementation of air quality standards. by identifying and addressing, as Nonetheless, EPA engaged in extensive appropriate, disproportionately high consultation with State and local I. National Technology Transfer and and adverse human health or governments in the development of the Advancement Act environmental effects of its programs, proposed and final rules, and this Section 12(d) of the National policies, and activities on minorities consultation is discussed and Technology Transfer and Advancement and low-income populations in the documented elsewhere in today’s notice Act of 1995 (NTTAA), Public Law 104– United States. and in the notice of proposed 113, section 12(d) (15 U.S.C. 272 note) The nature of today’s action is to rulemaking. inform the general public, including directs EPA to use voluntary consensus minorities and low-income populations, H. Executive Order 13084: Consultation standards in its regulatory activities about the nature of the air pollution in and Coordination With Indian Tribal unless to do so would be inconsistent the areas in which they live. Today’s Governments with applicable law or otherwise action establishes a uniform tool for Under Executive Order 13084, EPA impractical. Voluntary consensus States to use to develop programs which may not issue a regulation that is not standards are technical standards (e.g., will caution particularly sensitive required by statute, that significantly or materials specifications, test methods, people to minimize their exposures and uniquely affects the communities of sampling procedures, and business educate the public about general health Indian tribal governments, and that practices) that are developed or adopted effects associated with exposure to imposes substantial direct compliance by voluntary consensus standards different pollution levels. States may costs on those communities, unless the bodies. The NTTAA directs EPA to also use information established as part Federal government provides the funds provide Congress, through OMB, of the AQI to trigger programs designed necessary to pay the direct compliance explanations when the Agency decides to reduce emissions to avoid costs incurred by the tribal not to use available and applicable exceedances of the NAAQS. Therefore, governments, or EPA will consult with voluntary consensus standards. This today’s action will help facilitate public those governments. If EPA complies by action does not involve technical participation, outreach, and consulting, Executive Order 13084 standards. Therefore, EPA did not communication in areas where requires us to provide to OMB, in a consider the use of any voluntary environmental justice issues are present. separately identified section of the consensus standards. preamble to the rule, a description of G. Executive Order 12875: Enhancing J. Congressional Review Act the extent of our prior consultation with Intergovernmental Partnerships representatives of affected tribal The Congressional Review Act, 5 Under Executive Order 12875, EPA governments, a summary of the nature U.S.C. 801 et seq., as added by the Small may not issue a regulation that is not of their concerns, and a statement Business Regulatory Enforcement required by statute and that creates a supporting the need to issue the Fairness Act of 1996, generally provides mandate upon a State, local or tribal regulation. In addition, Executive Order that before a rule may take effect, the government, unless the Federal 13084 requires us to develop an agency promulgating the rule must government provides the funds effective process permitting elected submit a rule report, which includes a necessary to pay the direct compliance officials and other representatives of copy of the rule, to each House of the costs incurred by those governments, or Indian tribal governments ‘‘to provide Congress and to the Comptroller General we will consult with those governments. meaningful and timely input in the of the United States. The EPA will If EPA complies by consulting, development of regulatory policies on submit a report containing this rule and Executive Order 12875 requires us to matters that significantly or uniquely other required information to the U.S. provide to OMB a description of the affect their communities.’’ Senate, the U.S. House of extent of our prior consultation with Today’s rule implements Representatives, and the Comptroller representatives of affected State, local requirements specifically set forth by General of the United States prior to the and tribal governments, the nature of the Congress in section 319 of the Act publication of the rule in the Federal their concerns, copies of any written without the exercise of any discretion Register. This rule is not a ‘‘major rule’’ communications from the governments, by us. Accordingly, the requirements of as defined by 5 U.S.C. 804(2). and a statement supporting the need to section 3(b) of Executive Order 13084 issue the regulation. In addition, do not apply to this rule. IV. References Executive Order 12875 requires us to This rule governs the reporting of air CEQ, (1976) A Recommended Air Pollution develop an effective process permitting quality by States for MSAs and, in some Index, report prepared by the Federal elected officials and other cases, areas that are significantly Interagency Task Force on Air Quality representatives of State, local and tribal affected by transport of pollutants from Indicators, Council on Environmental governments ‘‘to provide meaningful MSAs. In extensive public and Quality, Environmental Protection intergovermental coordination efforts Agency, and Department of Commerce. and timely input in the development of EPA, (1994) Measuring Air Quality: The regulatory proposals containing during the development of the proposal, Pollutant Standards Index, U.S. significant unfunded mandates.’’ EPA received no information which Environmental Protection Agency, Office Today’s rule implements would suggest that the rule will impose of Air Quality Planning and Standards requirements set forth in section 319 of new requirements on Indian tribal (MD–10), Research Triangle Park, NC, the Act and thus is required by statute. governments nor will it significantly or 27711, EPA 451/K–94–001.

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EPA, (1999a) Guideline for Public Reporting 2. Section 58.50 is revised to read as 2. Why Report the AQI? of Daily Air Quality—Air Quality Index follows: The AQI offers various advantages: (AQI), U.S. Environmental Protection a. It is simple to create and understand. Agency, Office of Air Quality Planning § 58.50 Index reporting. b. It conveys the health implications of air and Standards, Research Triangle Park, (a) The State shall report to the quality. NC, 27711, EPA–454/R–99–010. general public through prominent notice EPA, (1999b) Guideline for Developing an c. It promotes uniform use throughout the Ozone Forecasting Program, U.S. an air quality index in accordance with country. the requirements of appendix G to this Environmental Protection Agency, Office 3. Must I Report the AQI? of Air Quality Planning and Standards, part. Research Triangle Park, NC, 27711, EPA– (b) Reporting is required by all You must report the AQI daily if yours is 454/R–99–009. Metropolitan Statistical Areas with a a metropolitan statistical area (MSA) with a EPA, (1999c) The Air Quality Index, U.S. population exceeding 350,000. population over 350,000. Environmental Protection Agency, Office (c) The population of a Metropolitan 4. What Goes Into My AQI Report? of Air Quality Planning and Standards, Statistical Area for purposes of index Research Triangle Park, NC, 27711, in i. Your AQI report must contain the preparation. reporting is the most recent decennial following: Science Applications International U.S. census population. a. The reporting area(s) (the MSA or Corporation, (1998) Report of Eight 3. Appendix G to part 58 is revised to subdivision of the MSA). Focus Groups on the Ozone Map, the read as follows: b. The reporting period (the day for which Pollutant Standards Sub-index for the AQI is reported). Ozone, and the Ozone Health Effects Appendix G to Part 58—Uniform Air Quality Index (AQI) and Daily c. The critical pollutant (the pollutant with Booklet, Science Applications the highest index value). Reporting International Corporation, McLean, VA. d. The AQI (the highest index value). U.S. Department of Commerce, (1998) General Requirements e. The category descriptor and index value Statistical Abstract of the United States, associated with the AQI and, if you choose U.S. Bureau of the Census. 1. What is the AQI? Whitfield, R.G.; Biller, W.F.; Jusko, M.J.; 2. Why report the AQI? to report in a color format, the associated Keisler, JM (1996) A probabilistic 3. Must I report the AQI? color. Use only the following descriptors and assessment of health risks associated 4. What goes into my AQI report? colors for the six AQI categories: with short-term exposure to tropospheric 5. Is my AQI report for my MSA only? ozone. Report prepared for U.S. EPA, 6. How do I get my AQI report to the TABLE 1.ÐAQI CATEGORIES OAQPS. Argonne National Laboratory; public? Argonne, IL. 7. How often must I report the AQI? For this AQI Use this And this Wolff, G.T., (1995) Letter from Chairman of 8. May I make exceptions to these reporting descriptor color 1 the Clean Air Scientific Advisory requirements? Committee to the EPA Administrator, Calculation 0 to 50 ...... ``Good'' ...... Green. dated November 30, 1995. EPA–SAB– CASAC–LTR–96–002. 9. How does the AQI relate to air pollution 51 to 100 ...... ``Moderate'' ...... Yellow. levels? List of Subjects in 40 CFR Part 58 10. Where do I get the pollutant 101 to 150 ...... ``Unhealthy for Orange. Environmental protection, Air concentrations to calculate the AQI? Sensitive pollution control, Intergovernmental 11. Do I have to forecast the AQI? Groups''. 12. How do I calculate the AQI? relations, Reporting and recordkeeping requirements. Background and Reference Materials 151 to 200 ...... ``Unhealthy'' ...... Red. Dated: July 23, 1999. 13. What additional information should I 201 to 300 ...... ``Very Purple. know? Carol M. Browner, Unhealthy''. Administrator. General Requirements 301 and above ``Hazardous'' .... Ma- Accordingly, 40 CFR part 58 is 1. What Is the AQI? roon.1 amended as follows: The AQI is a tool that simplifies reporting 1 Specific colors can be found in the most air quality to the general public. The AQI PART 58ÐAMBIENT AIR QUALITY recent reporting guidance (Guideline for Public incorporates into a single index Reporting of Daily Air QualityÐAir Quality SURVEILLANCE concentrations of 5 criteria pollutants: ozone Index (AQI)). 1. The authority citation for part 58 (O3), particulate matter (PM), carbon monoxide (CO), sulfur dioxide (SO2), and f. The pollutant specific sensitive groups continues to read as follows: nitrogen dioxide (NO2). The scale of the for any reported index value greater than 100. Authority: 42 U.S.C. 7410, 7601(a), 7613, index is divided into general categories that Use the following sensitive groups for each and 7619. are associated with health messages. pollutant:

When this pollutant has an index value above 100 * ** Report these sensitive groups * **

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.

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When this pollutant has an index value above 100 * ** Report these sensitive groups * **

NO2 ...... Children and people with respiratory disease are the groups most at risk.

ii. When appropriate, your AQI report may ii. If all index values remain below 50 for Monitoring Station (SLAMS) or parts of the also contain the following: a year, then you may report the AQI at your SLAMS required under 40 CFR 58.20 for a. Appropriate health and cautionary discretion. In subsequent years, if pollutant each pollutant except PM. For PM, you need statements. levels rise to where the AQI would be above only calculate and report the AQI on days for b. The name and index value for other 50, then the AQI must be reported as which you have measured air quality data pollutants, particularly those with an index required in sections 3, 4, 6, and 7 of this (e.g., particulate monitors often report values value greater than 100. appendix. only every sixth day). You may use c. The index values for sub-areas of your Calculation particulate measurements from monitors that MSA. are not reference or equivalent methods (for d. Causes for unusual AQI values. 9. How Does the AQI Relate to Air Pollution example, continuous PM10 or PM2.5 monitors) e. Actual pollutant concentrations. Levels? if you can relate these measurements by 5. Is My AQI Report for My MSA Only? For each pollutant, the AQI transforms statistical linear regression to reference or ambient concentrations to a scale from 0 to equivalent method measurements. Generally, your AQI report applies to your 500. The AQI is keyed as appropriate to the MSA only. However, if a significant air national ambient air quality standards 11. Do I Have to Forecast the AQI? quality problem exists (AQI greater than 100) (NAAQS) for each pollutant. In most cases, You should forecast the AQI to provide in areas significantly impacted by your MSA the index value of 100 is associated with the timely air quality information to the public, but not in it (for example, O3 concentrations numerical level of the short-term standard but this is not required. If you choose to are often highest downwind and outside an (i.e., averaging time of 24-hours or less) for forecast the AQI, then you may consider both urban area), you should identify these areas each pollutant. Different approaches are long-term and short-term forecasts. You can and report the AQI for these areas as well. taken for NO2, for which no short-term forecast the AQI at least 24-hours in advance 6. How Do I Get My AQI Report to the Public? standard has been established, and for PM2.5, using the most accurate and reasonable for which the annual standard is the You must furnish the daily report to the procedures considering meteorology, principal vehicle for protecting against short- topography, availability of data, and appropriate news media (radio, television, term concentrations. The index value of 50 forecasting expertise. The document and newspapers). You must make the daily is associated with the numerical level of the ‘‘Guideline for Developing an Ozone report publicly available at one or more annual standard for a pollutant, if there is Forecasting Program’’ (the Forecasting places of public access, or by any other one, at one-half the level of the short-term means, including a recorded phone message, standard for the pollutant, or at the level at Guidance) will help you start a forecasting a public Internet site, or facsimile which it is appropriate to begin to provide program. You can also issue short-term transmission. When the AQI value is greater guidance on cautionary language. Higher forecasts by predicting 8-hour ozone values than 100, it is particularly critical that the categories of the index are based on from 1-hour ozone values using methods reporting to the various news media be as increasingly serious health effects and suggested in the Reporting Guidance, extensive as possible. At a minimum, it increasing proportions of the population that ‘‘Guideline for Public Reporting of Daily Air should include notification to the media with are likely to be affected. The index is related Quality.’’ the largest market coverages for the area in to other air pollution concentrations through 12. How Do I Calculate the AQI? question. linear interpolation based on these levels. The AQI is equal to the highest of the i. The AQI is the highest value calculated 7. How Often Must I Report the AQI? numbers corresponding to each pollutant. for each pollutant as follows: You must report the AQI at least 5 days per For the purposes of reporting the AQI, the a. Identify the highest concentration among week. Exceptions to this requirement are in sub-indexes for PM10 and PM2.5 are to be all of the monitors within each reporting area section 8 of this appendix. considered separately. The pollutant and truncate the pollutant concentration to responsible for the highest index value (the one more than the significant digits used to 8. May I Make Exceptions to These Reporting reported AQI) is called the ‘‘critical’’ express the level of the NAAQS for that Requirements? pollutant. pollutant. This is equivalent to the rounding i. If the index value for a particular conventions used in the NAAQS. pollutant remains below 50 for a season or 10. Where Do I Get the Pollutant b. Using Table 2, find the two breakpoints year, then you may exclude the pollutant Concentrations To Calculate the AQI? that contain the concentration. from your calculation of the AQI in section You must use concentration data from c. Using Equation 1, calculate the index. 12. population-oriented State/Local Air d. Round the index to the nearest integer.

TABLE 2.ÐBREAKPOINTS FOR THE AQI

These breakpoints Equal these AQIs *** Category O3 (ppm) O3 (ppm) PM2.5 PM10 1 3 3 CO (ppm) SO2 (ppm) 8-hour 1-hour (µg/m ) (µg/m ) NO2 (ppm) AQI

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 sen- sitive 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. 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.

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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 between two breakpoints, then calculate the footnote 1 to Table 2). In these cases, you breakpoint, then the index is equal to the index of that pollutant with Equation 1. You may use 1-hour values as well as 8-hour corresponding index value in Table 2. must also note that in some areas, the AQI values to calculate index values and then use However, Equation 1 can still be used. The based on 1-hour O3 will be more the maximum index value as the AQI for O3. results will be equal. If the concentration is precautionary than using 8-hour values (see

II− I = Hi Lo ()C− BP+ I (Equation 1) p − p Lo Lo BPHI BP Lo

Where: b. Find the breakpoints for 1-hour O3 at Background and Reference Materials

Ip = the index value for pollutantp 0.156 ppm as 0.125 ppm and 0.164 ppm, corresponding to index values 101 and 150; 13. What Additional Information Should I Cp = the truncated concentration of Know? pollutantp c. Find the breakpoints for 8-hour O3 at BPHi = the breakpoint that is greater than or 0.130 ppm as 0.125 ppm and 0.374 ppm, The EPA has developed a computer equal to Cp corresponding to index values 201 and 300; program to calculate the AQI for you. The µ 3 BPLo = the breakpoint that is less than or d. Apply Equation 1 for 210 g/m , PM10: program works with Windows 95, it prompts equal to Cp for inputs, and it displays all the pertinent 150− 101 IHi = the AQI value corresponding to BPHi ()210− 155+ 101 = 128. information for the AQI (the index value, Ilo = the AQI value corresponding to BPLo. 254− 155 color, category, sensitive group, health iii. If the concentration is larger than the e. Apply Equation 1 for 0.156 ppm, 1-hour effects, and cautionary language). The EPA highest breakpoint in Table 2 then you may O3: has also prepared a brochure on the AQI that use the last two breakpoints in Table 2 when explains the index in detail (The Air Quality you apply Equation 1. 150− 101 Index), Reporting Guidance (Guideline for ()0.. 156− 0 125+ 101 = 140 Example 0.. 164− 0 125 Public Reporting of Daily Air Quality) that provides associated health effects and iv. Using Table 2 and Equation 1, calculate f. Apply Equation 1 for 0.130 ppm, 8-hour cautionary statements, and Forecasting the index value for each of the pollutants O3: measured and select the one that produces Guidance (Guideline for Developing an the highest index value for the AQI. For 300− 201 Ozone Forecasting Program) that explains the example, if you observe a PM10 value of 210 ()0.. 130− 0 125+ 201 = 203 steps necessary to start an air pollution 3 − µg/m , a 1-hour O3 value of 0.156 ppm, and 0.. 374 0 125 forecasting program. You can download the an 8-hour O3 value of 0.130 ppm, then do g. Find the maximum, 203. This is the AQI. program and the guidance documents at this: The minimal AQI report would read: www.epa.gov/airnow. a. Find the breakpoints for PM10 at 210 µg/ v. Today, the AQI for my city is 203 which m3 as 155 µg/m3 and 254 µg/m3, is very unhealthy, due to ozone. Children [FR Doc. 99–19433 Filed 8–3–99; 8:45 am] corresponding to index values 101 and 150; and people with asthma are the groups most BILLING CODE 6560±50±P at risk.

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