9.2.1 If desired, concentration of nitrogen dioxide may be calculated as p.p.m. NO,. p.p.m. (ug. NO,/m.) X 5.32 × 10-4 10. References. (1) Jacobs, M. B., and Hochheiser, S., "Continuous Sampling and Ultramicrodetermination of Nitrogen Dioxide in Air", Anal. Chem., 30 426 (1958). (2) Purdue, L. J., Dudley, J. E., Clements, J. B., and Thompson, R. J., "Studies in Air Sampling for Nitrogen Dioxide," I. A reinvestigation of the JacobsHochheiser Reagent. In Preparation. MEMBRANE FILTER 51.30 Request for 2-year extension. 51.31 Request for 18-month extension. 51.32 Request for 1-year postponement. Appendix A-Air Quality Estimation. Appendix B-Examples of Emission Limitations Attainable with Reasonably Available Technology. Appendix C-Major Pollutant Sources. Appendix D-Emissions Inventory Summary (Examples Regions). Appendix E-Point Source Data. Appendix H-Air Quality Data Summary. Appendix I-Projected Motor Vehicle Emissions. Appendix J-Required Hydrocarbon Emission Control as & Function of Photochemical Oxidant Concentrations. Appendix K-Control Agency Functions. Appendix L-Example Regulations for Prevention of Air Pollution Emergency Episodes. AUTHORITY: The provisions of this Part 51 issued under section 301(a) of the Clean Air Act (42 U.S.C. 1857(a), as amended by section 15(c) (2) of Public Law 91-604, 84 Stat. 1713. SOURCE: The provisions of this Part 51 appear at 36 F.R. 22398, Nov. 25, 1971, unless otherwise noted. Subpart A-General Provisions § 51.1 Definitions. structure, or installation which directly or indirectly results or may result in emissions of any air pollutant for which a national standard is in effect. (g) "Local agency" means any local government agency, other than the State agency, which is charged with the responsibility for carrying out a portion of a plan. (h) "Regional Office" means one of the ten (10) EPA Regional Offices. (1) "State agency" means the air pollution control agency primarily responsible for development and implementation of a plan under the Act. (j) "Local agency" means any air pollution control agency other than a State agency, which is charged with responsibility for carrying out a portion of a plan. (k) "Point source" means: (1) Any stationary source causing emissions in excess of 100 tons (90.7 metric tons) per year of any pollutant for which there is a national standard in a region containing an area whose 1970 "urban place" population, as defined by the Bureau of Census, was equal to or greater than 1 million or (2) Any stationary source causing emissions in excess of 25 tons (22.7 metric tons) per year of any pollutant for which there is a national standard in a region containing an area whose 1970 "urban place" population, as defined by the U.S. Bureau of the Census, was less than 1 million and (3) Without regard to amount of emissions, stationary sources such as those listed in Appendix C to this part. (1) "Area source" means any small residential, governmental, institutional, commercial, or industrial fuel combustion operations: onsite solid waste disposal facility; motor vehicles, aircraft, vessels, or other transportation facilities; or other miscellaneous sources such as those listed in Appendix D to this part, as identified through inventory techniques similar to those described in: "A Rapid Survey Technique for Estimating Community Air Pollution Emissions,” Public Health Service Publication No. 999-AP-29, October 1966. (m) "Region" means (1) an air quality control region designated by the Secretary of Health, Education, and Welfare or the Administrator, (2) any area designated by a State agency as an air quality control region and approved by the Administrator, or (3) any area of a State not designated as an air quality control region under subparagraph (1) or (2) of this paragraph. (n) "Control strategy” means a combination of measures designated to achieve the aggregate reduction of emissions necessary for attainment and maintenance of a national standard, including, but not limited to, measures such as: (1) Emission limitations. (2) Federal or State emission charges or taxes or other economic incentives or disincentives. (3) Closing or relocation of residential, commercial, or industrial facilities. (4) Changes in schedules or methods of operation of commercial or industrial facilities or transportation systems, including, but not limited to, short-term changes made in accordance with standby plans. (5) Periodic inspection and testing of motor vehicle emission control systems, at such time as the Administrator determines that such programs are feasible and practicable. (6) Emission control measures applicable to in-use motor vehicles, including, but not limited to, measures such as mandatory maintenance, installation of emission control devices, and conversion to gaseous fuels. (7) Measures to reduce motor vehicle traffic, including, but not limited to, measures such as commuter taxes, gasoline rationing; parking restrictions, or staggered working hours. (8) Expansion or promotion of the use of mass transportation facilities through measures such as increases in the frequency, convenience, and passengercarrying capacity of mass transportation systems or providing for special bus lanes on major streets and highways. (9) Any land use or transportation control measures not specifically delineated herein. (10) Any variation of, or alternative to, any measure delineated herein. (o) "Reasonably available control technology" means devices, systems, process modifications, or other apparatus or techniques, the application of which will permit attainment of the emission limitations set forth in Appendix B to this part, provided that Appendix B to this part is not intended, and shall not be construed, to require or encourage State agencies to adopt such emission limitations without due consideration of (1) the necessity of imposing such emission limitations in order to attain and maintain a national standard, (2) the social and economic impact of such emission limitations, and (3) alternative means of providing for attainment and maintenance of such national standard. (p) "Compliance schedule" means the date or dates by which a source or category of sources is required to comply with specific emission limitations contained in an implementation plan and with any increments of progress toward such compliance. (q) "Increments of progress" means steps toward compliance which will be taken by a specific source, including: (1) Date of submittal of the source's final control plan to the appropriate air pollution control agency; (2) Date by which contracts for emission control systems or process modifications will be awarded; or date by which orders will be issued for the purchase of component parts to accomplish emission control or process modification; (3) Date of initiation of on-site construction or installation of emission control equipment or process change; (4) Date by which on-site construction or installation of emission control equipment or process modification is to be completed; and (5) Date by which final compliance is to be achieved. (r) "Transportation control measure" means any measure, such as reducing vehicle use, changing traffic flow patterns, decreasing emissions from individual motor vehicles, or altering existing modal split patterns that is directed toward reducing emissions of air pollutants from transportation sources. (s) "Vehicle trip" means any movement of a motor vehicle from one location to another that results in the emission of air pollutants by the motor vehicle. (t) "Trip type" means any class of vehicle trips possessing one or more characteristics (e.g., work, nonwork; peak, off-peak; freeway, nonfreeway) that distinguish vehicle trips in the class from vehicle trips not in the class. (u) "Vehicle type" means any class of motor vehicles (e.g., precontrolled, heavy duty vehicles, gasoline powered trucks) whose emissions characteristics are significantly different from the emissions characteristics of motor vehicles not in the class. (v) "Traffic flow measure" means any measure, such as signal light synchroni zation, freeway metering and curbside parking restrictions, that is taken for the purpose of improving the flow of traffic and thereby reducing emissions of air pollutants from motor vehicles. (w) "Roadway type" means any class of roadway facility that can be broadly categorized as to function and assigned average speed and capacity values, e.g., expressway, arterial, collector, and local. (x) "Time period" means any period of time designated by hour, month, season, calendar year, averaging time, or other suitable characteristics, for which ambient air quality is estimated. [36 FR 22398, Nov. 25, 1971, as amended at 37 FR 26311, Dec. 9, 1972; 38 FR 15195, June 8, 1973; 38 FR 15835, June 18, 1973] § 51.2 Stipulations. Nothing in this part shall be construed in any manner: (a) To encourage a State to prepare, adopt, or submit a plan which does not provide for the protection and enhancement of air quality so as to promote the public health and welfare and productive capacity. (b) To encourage a State to adopt any particular control strategy without taking into consideration the cost-effectiveness of such control strategy in relation to that of alternative control strategies. (c) To preclude a State from employing techniques other than those specified in this part for purposes of estimating air quality or demonstrating the adequacy of a control strategy, provided that such other techniques are shown to be adequate and appropriate for such purposes. (d) To encourage a State to prepare, adopt, or submit a plan without taking into consideration the social and economic impact of the control strategy set forth in such plan, including, but not limited to, impact on availability of fuels, energy, transportation, and employment. (e) To preclude a State from preparing, adopting, or submitting a plan which provides for attainment and maintenance of a national standard through the Pollutant application of a control strategy not specifically identified or described in this part. (f) To preclude a State or political subdivision thereof from adopting or enforcing any emission limitations or other measures or combinations thereof to attain and maintain air quality better than that required by a national standard. (g) To encourage a State to adopt a control strategy uniformly applicable throughout a region unless there is no satisfactory alternative way of providing for attainment and maintenance of a national standard throughout such region. § 51.3 Classification of regions. This section establishes a classification system to categorize regions for purposes of plan development and evaluation. The requirements of this part vary according to the classification of each region, in order that the time and resources to be expended in developing the plan for that region, as well as the substantive content of the plan, will be commensurate with the complexity of the air pollution problem. The classification will be based upon measured ambient air quality, where known, or, where not known, estimated air quality in the area of maximum pollutant concentration. All regions will be classified by the Administrator after consultation with State agencies. Each region will be classified separately with respect to each of the following pollutants: Sulfur oxides, particulate matter, carbon monoxide, nitrogen dioxide, and photochemical oxidants. (a) For sulfur oxides and particulate matter, each region will be classified into one of three categories, defined as Priority I, Priority II, or Priority . (1) (1) Ambient concentration limits, expressed as micrograms per cubic meter and parts per million by volume (p.p.m. in parentheses) which define the classification system for sulfur oxides and particulate matter are: (ii) The more restrictive classification will be chosen where there is a difference between the maximum value(s) and the annual averages e.g., if a region is Priority I with respect to an annual average and Priority II with respect to a 24-hour maximum value, the classification will be Priority I. (2) Procedures which may be used, where appropriate, to estimate air quality in regions where no measured data or inadequate data exist are described in Appendix A to this part. (b) For carbon monoxide, nitrogen dioxide, and photochemical oxidants, each region will be classified into one of two categories defined as Priority I or Priority III. (1) Ambient concentration limits which define the classification system are: (i) Carbon monoxide: Priority I: Equal to or above 55 milligrams per cubic meter (48 p.p.m.), 1-hour maximum, or 14 milligrams per cubic meter (12 p.p.m.), 8-hour maximum; Priority III: Below such values. (ii) Nitrogen dioxide: Priority I: Equal to or above 110 micrograms per cubic meter (0.06 p.p.m.) annual arithmetic mean; Priority III: Below such value. (iii) Photochemical oxidants: Priority I: Equal to or above 195 micrograms per cubic meter (0.10 p.p.m.), 1hour maximum; Priority III: Below such value. (2) In the absence of measured data to the contrary, classification with respect to carbon monoxide, photochemical oxidants and nitrogen dioxide will be based on the following estimate of the relationship between these pollutants and population: Any region containing an area whose 1970 "urban place” population, as defined in the U.S. Bureau of Census, exceeds 200,000 will be classified Priority I. All other regions will be classified Priority III. (3) Where a region is classified Priority I on the basis of population, the air quality data requirements of § 51.14 (e) (1) shall apply. If these data indicate the pollutant concentrations are below the values stipulated in subparagraph (1) of this paragraph, the region will be reclassified Priority III. (4) Classifications with respect to hydrocarbons will be the same as the classifications with respect to photochemical oxidants. (c) Where a region is classified Priority I on the basis of measured or estimated air quality levels reflecting emissions predominantly from a single point source, it shall be further classified Priority IA. The requirements applicable to Priority IA regions shall be the same as those for other Priority I regions, except that the requirements applicable to Priority II regions under §§ 51.16 and 51.17 shall apply. A procedure for estimating air quality levels reflecting emissions from a single point source is described in Appendix A to this part. § 51.4 Public hearings. (a) (1) Except as otherwise provided in subparagraph (2) of this paragraph, the State shall, prior to the adoption of any plan or any revision thereof required by § 51.6(a) or prior to the submission to the Administrator of any individual compliance schedule pursuant to § 51.15 (a) or any revision pursuant to § 51.6(d), conduct one or more public hearings on such plan, schedule, or revision. Separate hearings may be held for plans to implement primary and secondary standards. (2) No hearing shall be required for any change to an increment of progress in an approved individual compliance schedule unless such change is likely to cause the source to be unable to comply with the final compliance date in the schedule. The requirements of §§ 51.6 and 51.8 shall be applicable to such schedules, however. (b) Any hearing required by paragraph (a) of this section shall be held only after reasonable notice, which shall be considered to include, at least 30 days prior to the date of such hearing(s): (1) Notice given to the public by prominent advertisement in the region affected announcing the date (s), time (s), and place(s) of such hearing (s); (2) Availability of each proposed plan or revision for public inspection in at least one location in each region to which it will apply, and the availability of each compliance schedule for public inspection in at least one location in the region in which the affected source is located; (3) Notification to the Administrator (through the appropriate Regional Office); (4) Notification to each local air pollution control agency in each region to which the plan, schedule, or revision will apply; and 97-025-73-15 |