118.01.21 Ark. Code R. 011
The following rules adopted pursuant to Subchapter 2 of the Arkansas Water and Air Pollution Control Act (Arkansas Code Annotated [Ark. Code Ann.] § 8-4-101et seq.) shall be referred to as the "Arkansas Air Pollution Control Code," hereinafter the "Air Code," the "Code," or "Rule 18."
These rules are applicable to any source which emits or has the potential to emit any air contaminant as defined in Chapter 2 of Rule 18.
If any provisions of this Code or the application thereof to any person or circumstance is held invalid, such invalidity shall not affect other provisions or applications of this Code which can be given effect without the invalid provision or application, and to this end the provisions of this Code are declared to be severable.
When used in this Code:
"12-month period" means a period of twelve (12) consecutive months determined on a rolling basis with a new 12-month period beginning on the first day of each calendar month.
"Actual emissions" means the quantity of air contaminants emitted from a stationary source considering emissions control equipment and actual hours of source operation or amount of material processed.
"Air contaminant" means any solid, liquid, gas, or vapor or any combination thereof. The following shall not be considered air contaminants: water vapor, oxygen, carbon dioxide, nitrogen, hydrogen, and inert gases.
"Air contamination" means the presence in the outdoor atmosphere of one (1) or more air contaminants which contribute to a condition of air pollution.
"Air pollution" means the presence in the outdoor atmosphere of one (1) or more air contaminants in quantities, of characteristics, and of a duration that are materially injurious or can be reasonably expected to become materially injurious to human, plant, or animal life or to property, or that unreasonably interfere with enjoyment of life or use of property throughout the state or throughout the area of the state as shall be affected thereby.
"Commission" means the Arkansas Pollution Control and Ecology Commission.
"Conditions of air pollution" as distinguished from "air pollution" in a given area shall be deemed to exist when the Director finds that the National Ambient Air Quality Standards, as established from time to time by the EPA, have been exceeded in such area, or when the Director finds that extraordinary measures are necessary to prevent them from being exceeded.
"Conditions of episodic air pollution" in a given area shall be deemed to exist when the Director finds that meteorological conditions are such as to minimize the normal dispersion of air contaminants and that the following levels are determined to exist in a given area and that such levels can be reasonably expected to persist for twelve (12) or more hours or increase unless control actions are taken:
Sulfur dioxide (SO2) of a concentration equal to or greater than 800 µg/m3 (1.3 ppm) for any twenty-four (24) hour average (where µg/m3 means micrograms per cubic meter and where ppm means parts per million), or where particulate matter (PM) of a concentration equal to or greater than 375 µg/m3 for any twenty-four (24) hour average or where the coefficient of haze (COH) is equal to or greater than three (3.0) for any twenty-four (24) hour average, or where the product of SO2 and PM reported in µg/m3 for any twenty-four (24) hour average exceeds 65,000.
"Control apparatus" means any device which prevents, controls, detects, or records the emission of any air contaminant.
"Division" means the Division of Environmental Quality, or its successor. When reference is made in this rule to actions taken by or with reference to the Division, the reference is to the staff of the Division acting at the direction of the Director.
"Director" means the director of the Division, or its successor, acting directly or through the staff of the Division.
"EPA" means the United States Environmental Protection Agency.
"Equipment" means any device, except equipment used for any mode of vehicular transportation, capable of causing the emission of an air contaminant into the open air, and any stack, conduit, flue, duct, vent, or similar device connected or attached to, or serving the equipment.
"Federal Clean Air Act" or "Clean Air Act" or "FCAA" or "the Act" means the federal Clean Air Act, as amended, 42 U.S.C. 7401, et seq., and its implementing regulations as of the effective date of this rule.
"Fuel burning equipment" means equipment, the primary purpose of which is the production of thermal energy from the combustion of fuel by indirect heat transfer.
"Flue" or "stack" means any point in a source designed to emit solids, liquids, or gases into the air, including a pipe or duct but not including flares.
"Fugitive emissions" means those emissions which could not reasonably pass through a stack, chimney, vent, or other functionally equivalent opening.
"Hazardous air pollutant" or "HAP" means any pollutant listed pursuant to § 112 of the federal Clean Air Act, as amended, 42 U.S.C. § 7401et seq., as of the effective date of this rule.
"Garbage" means rejected food waste including waste accumulation of animal, fruit, or vegetable matter used or intended for food or that attend the preparation, use, cooking, dealing in or storage of meat, fish, fowl, fruit, or vegetable.
"Incinerator" means all devices by which garbage, refuse, or other combustible material is reduced in volume by a combustion process in which the fuel/air ratio is or can be controlled so that the remaining solid residues contain little or no combustible material.
"National Ambient Air Quality Standards" or "NAAQS" means those ambient air quality standards promulgated by the EPA in 40 Code of Federal Regulations (C.F.R.) Part 50 as of the effective date of the federal rule published by EPA in the Federal Register on January 15, 2013 (78 FR 3086), as set forth in Appendix B of Rule 18.
"Opacity" means the degree to which air emissions reduce the transmission of light and obscure the view of an object in the background.
"Open fire" or "open burning" means a fire in which a material is burned in the open or in a receptacle having no means for significantly controlling the fuel/air ratio.
"Operator" means any person who leases, operates, controls, or supervises any equipment affected by these rules.
"Owner" means any person who has legal or equitable title to any source, facility, or equipment affected by these rules.
"Particulate matter" or "PM" means any airborne finely divided solid or liquid material with an aerodynamic diameter equal to or less than 100 micrometers.
"PM2.5" means particulate matter with an aerodynamic diameter less than or equal to a nominal two and one-half (2.5) micrometers as measured by a reference method based on Appendix L of 40 C.F.R. Part 50, as of the effective date of the federal rule published by EPA in the Federal Register on October 17, 2006 (71 FR 61226), or by an approved regional method designated in accordance with Appendix C of 40 C.F.R. Part 53.
"PM10" means particulate matter with an aerodynamic diameter less than or equal to a nominal ten (10) micrometers as measured by a reference method based on Appendix J of 40 C.F.R. Part 50, as of the effective date of the federal final rule published by EPA in the Federal Register on August 7, 1987 (52 FR 29467), or by an equivalent method designated in accordance with 40 C.F.R. Part 53.
"PM2.5emissions" means PM2.5 emitted to the ambient air as measured by an applicable reference method, or an equivalent or alternate method, specified in 40 C.F.R. Part 51, Appendix M as of the effective date of the federal final rule published by EPA in the Federal Register on April 2, 2014 (79 FR 18452), or by a test method specified in these regulations or any supplement thereto.
"PM10emissions" means PM10 emitted to the ambient air as measured by an applicable reference method, or an equivalent or alternate method, specified in 40 C.F.R. Part 51, Appendix M as of the effective date of the federal final rule published by EPA in the Federal Register on April 2, 2014 (79 FR 18452), or by a test method specified in these regulations or any supplement thereto.
"Potential to emit" means the maximum capacity of a stationary source to emit air contaminants under its physical and operational design. Any physical or operational limitation on the capacity of the source to emit an air contaminate, including, but not limited to, air pollution control equipment and restrictions on hours of operation or on the type or amount of material combusted, stored, or processed, shall be treated as part of its design only if the limitation or the effect it would have on emissions is practically enforceable. Secondary emissions do not count in determining the potential to emit of a stationary source.
"Refuse" means any combustible waste material containing carbon in a free or combined state, other than liquid or gases.
"Responsible Official" means one of the following:
"Salvage" means an operation conducted in whole or in part for the reclaiming of any product or material.
"Shutdown" means the cessation of operation of equipment.
"Startup" means the setting in operating of equipment.
"Stationary source" means any building, structure, facility, or installation which emits or may emit any air contaminant.
"Title I modification" means any modification as defined under any regulation promulgated pursuant to Title I of the federal Clean Air Act as of July 2, 2008. De Minimis changes under Rule 19, changes to state-only permit requirements, administrative permit amendments, and changes to the insignificant activities list are not Title I modifications.
"Trade waste" means any solid, liquid, or gaseous material resulting from construction of the prosecution of any business, trade or industry, or any demolition operation including, but not limited to, plastics, cardboard cartons, grease, oil, chemicals, and cinders.
"Total suspended particulate" or "TSP" means particulate matter as measured by the method described in Appendix B of 40 C.F.R. Part 50.
No person shall cause or permit the operation, construction, or modification of a stationary source, which actually emits:
seventy-five (75) tons per year or more of carbon monoxide;
forty (40) tons per year or more of nitrogen oxides;
forty (40) tons per year or more of sulfur dioxide;
forty (40) tons per year or more of volatile organic compounds;
twenty-five (25) tons per year or more of particulate matter;
ten (10) tons per year or more of direct PM2.5;
fifteen (15) tons per year or more of PM10;
one-half (0.5) ton per year or more of lead;
two (2) tons per year or more of any single hazardous air pollutant;
five (5) tons per year or more of any combination of hazardous air pollutants; or twenty-five (25) tons per year or more of any other air contaminant without first obtaining a permit from the Division.
Except as provided for by law or rule, the following stationary sources are required to obtain a permit under this chapter regardless of emissions:
No permit shall be granted or modified under this chapter unless the owner/operator demonstrates to the reasonable satisfaction of the Division that the stationary source will be constructed or modified to operate without resulting in a violation of applicable portions of this rule and without causing air pollution.
Issuance of a permit by the Division does not affect the responsibility of the owner/operator to comply with applicable portions of this rule.
Application of a permit shall be made on such forms and contain such information as the Division may reasonably require, including but not limited to:
If, while processing an application that has been determined to be complete, the Division determines that additional information is necessary to evaluate or take final action on that application, the Division may request such information in writing and set a reasonable deadline for a response.
Any owner/operator who fails to submit any relevant facts or who has submitted incorrect information, shall, upon becoming aware of such failure or incorrect submittal, promptly submit such supplementary facts or corrected information. In addition, an applicant shall provide additional information as necessary to address any relevant requirements that become applicable to the stationary source before final action is taken on its application.
The Division will review the application submitted under this chapter in order to ensure to their reasonable satisfaction that:
If the Division initially determines the requirements of Rule 18.304(A) are met, they shall prepare a draft permit which:
If the Division initially determines the requirements of this chapter are not met, they shall prepare a notice of intent to deny. This notice will state the reasons for the Division's denial of the stationary source's submittal.
The public shall have an opportunity to comment on the Division's proposed permit decision in accordance with Rule 18.305.
At the conclusion of the public comment period, the Division shall announce in writing its final permit decision.
No permit shall be issued, denied, or modified unless the public has first had an opportunity to comment on the information submitted by the owner/operator and the Division's analysis, as demonstrated by the permit record, of the effect of construction or modification on ambient air quality, including the Division's proposed approval or disapproval of the permit.
Pollutant | De Minimis Concentration | Averaging Time |
carbon monoxide | 500 µg/m3 | 8-hour |
nitrogen dioxide | 10 µg/m3 | annual |
PM2.5 | 2µg/m3 | 24-hour |
PM10 | 8 µg/m3 | 24-hour |
sulfur dioxide | 18 µg/m3 | 24-hour |
lead | 0.1 µg/m3 | 3-month |
Stationary sources and activities listed in Appendix A of this rule shall be considered to be insignificant and will not require a permit under this chapter or be included in a source's permit.
Stationary sources operating prior to July 30, 1969, and have not been modified since, will not be required to obtain a permit under this chapter.
A stationary source subject to the permitting requirements of Rule 26 and the requirements of this chapter, will only be required to obtain one permit which shall also contain the requirements unique to this rule.
A stationary source subject to the permitting requirements of Rule 19 and the requirements of this chapter will only be required to obtain one permit which shall also contain the requirements unique to this rule.
Any permit issued under this rule is subject to revocation, suspension, or modification in whole or in part, for cause, including without limitation:
The Director may cancel a permit if the construction or modification is not begun within 18 months from the date of the permit issuance or if the work involved in the construction or modification is suspended for a total of 18 months or more.
The Division may, after notice and opportunity for public participation provided under this chapter, issue a general permit covering numerous similar sources. Any general permit shall comply with all requirements applicable to other permits and shall identify criteria by which sources may qualify for the general permit. To sources that qualify, the Division shall grant the conditions and terms of the general permit. The source shall be subject to enforcement action for operation without a permit if the source is later determined not to qualify for the conditions and terms of the general permit.
Sources that would qualify for a general permit must apply to the Division for coverage under the terms of the general permit or must apply for a permit consistent with this chapter. The Division may grant a source's request for authorization to operate under a general permit, but such a grant shall not be a final permit action for purposes of judicial review. The Division will give notice of all applications for general permits pursuant to Ark. Code Ann. § 8-4-203(c).
Facilities which are now subject to this rule and were not previously subject to this rule shall be in full compliance within 180 days of the effective date of this rule. The Director may extend this compliance period on a case-by-case basis provided that the total compliance period does not exceed one year.
Any operating scenario allowed for in a permit may be implemented by the facility without the need for any permit revision or any notification to the Division. It is incumbent upon the permit applicant to apply for any reasonably anticipated alternative facility operating scenarios at the time of permit application. The Division shall include approved alternative operating scenarios in the permit.
A permitted source may make changes within the facility that contravene permit terms without a permit revision if the changes:
(For the purpose of Rule 18.315(A) "modification" shall mean any physical change in or change in the method of operation of a stationary source which increases the emission rates of any air pollutant, specified above, previously registered with the Division or results in the emission of an air pollutant not previously emitted and registered with the Division.)
In determining the emissions of a source for purposes of demonstrating air pollution will not occur, the Division shall take into account any incremental increase in allowable emissions under these conditions.
In order to avoid conflicting and overlapping jurisdiction, it is the intention of this chapter to clarify the position that the Division occupies the field of control and abatement of air pollution and contamination; and no political subdivision of this state shall enact or enforce laws, ordinances, resolutions, rules or regulation in this field, unless such laws, ordinances, resolutions, rules or regulations are for the purpose of prohibiting burning in the open or in a receptacle having no means for significantly controlling the fuel/air ratio.
No person shall cause or permit the open burning of refuse, garbage, trade waste, or other waste material, or shall conduct a salvage operation by open burning.
The provisions of Rule 18.602 herein shall not apply to the following activities:
During conditions of air pollution, when declared by the Director to exist in any area of the State, all open burning in such area which otherwise is exempted in this Section, shall be discontinued as set forth herein, unless otherwise is specifically provided in the Director's public announcements pursuant to the provisions of Chapter 14 of this Code.
Upon application, the Division shall issue letters of authorization for open burning, provided that the applicant affirmatively demonstrates to the satisfaction of the Division, that there are no practicable, safe, and lawful alternative methods of disposal and that open burning is absolutely necessary and in the public interest and provided, further, that said applications contain such other information as the Division may reasonably require. Only letters of authorization issued by the Division satisfy this chapter. Open burning permits may also be required by the local public officers, boards, councils, or commissions for safety or other purposes; however, those permits do not satisfy the requirement to obtain an authorization under this chapter.
No person shall cause or permit the emission of air contaminants, including odors or water vapor and including an air contaminant whose emission is not otherwise prohibited by this Code, if the emission of the air contaminant constitutes air pollution.
The purpose of this chapter is to generally define the powers of the Division in requiring sampling, monitoring, and reporting requirements at stationary sources. The Division shall enforce all properly incorporated and delegated federal testing requirements at a minimum, and the Division reserves the right to require additional sampling, monitoring, and reporting requirements not already required in federal regulations. Any credible evidence based on sampling, monitoring, and reporting may be used to determine violations of applicable emission limitations.
Any stationary source subject to this rule shall be subject to the following requirements:
To provide any sampling ports, at the request of the Division, required for air emissions sampling, including safe and easy access to such ports.
To conduct air contaminant emissions sampling, at the request of the Division, to determine the rate, opacity, composition, and/or contaminant concentration of the emissions. All compliance testing shall be done at the expense of the permittee by an independent firm, unless otherwise approved by the Division. Sampling shall not be required for those pollutants monitored with continuous emissions monitors.
All compliance testing averaging times shall be consistent with the averaging times of the applicable emissions limitations stated in the applicable permit, which in no case shall be greater than the minimum averaging times of the applicable National Ambient Air Quality Standard.
Unless otherwise approved by the Division, all air contaminant emissions sampling shall be performed with the equipment being tested operating at least at 90% of its permitted capacity. Emissions results shall be extrapolated to correlate with 100% of permitted capacity to determine compliance.
Any equipment that is to be tested, at the request of the Division, shall be tested in accordance with the following time frames:
The Division shall require that all applicable testing be performed using the methods described in 40 C.F.R. Part 51, Appendix M as of the effective date of the federal final rule published by EPA in the Federal Register on April 2, 2014 (79 FR 18452), 40 C.F.R. Part 60, Appendix A, as of the effective date of the federal final rule published by EPA in the Federal Register on February 27, 2014 (79 FR 11257), 40 C.F.R. Part 61, Appendix B as of the effective date of the federal final rule published by EPA in the Federal Register on October 17, 2000 (65 FR 62161), and 40 C.F.R. Part 63, Appendix A as of the effective date of the federal final rule published by EPA in the Federal Register on December 29, 1992 (57 FR 62002). The Division may approve, at its discretion, alternative sampling methods that are equivalent to the specified methods. The results of such tests shall be submitted to the Division within the time frame and on such forms as required by the Division and federal regulations. The owner or operator of the equipment shall retain the results of such tests for at least five (5) years, and shall make the results available to any agents of the Division or the EPA during regular business hours.
Any stationary source subject to this rule shall, upon request by the Division:
Any stationary source subject to this rule shall, upon request of the Division:
Information and data shall be submitted to the Division by a responsible official on such forms and at such time intervals as prescribed by applicable federal regulations or the Division.
Emissions data obtained by the Division shall be correlated in units of applicable emissions limitations and be made available to the public at the Division's central offices during normal business hours.
Any source exceeding an emission limit established by this Code or applicable permit, shall be deemed in violation of said Code or permit and shall be subject to enforcement action. The Director may forego enforcement action for emissions exceeding any limits established by this Code or permit as a direct result of unavoidable upset conditions in the nature of the process, or unavoidable and unforeseeable breakdown of any air pollution control equipment or related operating equipment, or as a direct result of shutdown or start-up of such equipment for necessary scheduled maintenance, provided that all reasonable measures have been taken to immediately minimize or eliminate the excess emissions and the following requirements are met:
And that all reasonable measures have been taken to immediately minimize or eliminate the excess emissions.
Any person responsible for the operation of any equipment operating in compliance with the provisions of this Code but which can reasonably anticipate periods of non-compliance due to change of fuels, or lack thereof, shall file with the Division, for its approval prior to April 30, 1972, and on such forms and containing such information as the Division may reasonably require, an application which demonstrates to the Division's satisfaction:
Except for those persons who have filed for and received Division approval of applications submitted pursuant to the provisions of Rule 18.1101 or Rule 18.1102 hereof, the exceptions granted in said sections shall not be extended and shall be considered inapplicable during the existence of conditions of air pollution, as declared by the Director pursuant to provisions of Rule 18.604 if the affected sources are located in the area in which a condition of air pollution is so declared.
Nothing provided herein shall be construed to limit the Division's authority to require the installation and maintenance of control equipment as a condition of the granting of a permit or approval of an application.
An "emergency" means any situation arising from the sudden and reasonably unforeseeable events beyond the control of the source, including natural disasters, which situation requires immediate corrective action to restore normal operation, and that causes the source to exceed a technology-based emission limitation under the permit, due to unavoidable increases in emissions attributable to the upset condition. An emergency shall not include non-compliance to the extent caused by improperly designed equipment, lack of preventive maintenance, careless or improper operation, or operator error.
Unless prior written approval is obtained from the Director, no person shall build, erect, install, or use any article, machine, equipment, or other contrivance, the sole purpose of which is to dilute or conceal an emission without resulting in a reduction of the total amount of air contaminants emitted to the atmosphere. This rule does not apply to the control of odors or to the installation of stacks for which a permit has been issued as provided in Chapter 3 of this Code.
Within areas of high source density or higher receptor density and/or within areas affected by levels of air contamination, which, due to their intensity and/or duration, threaten to constitute a significant departure from the National Ambient Air Quality Standards, the Division may prescribe air quality control requirements that are more restrictive and more extensive than those provided in the regulations of general application within said areas. Such requirements may be kept in effect for such period and to such extent the Division deems necessary to adequately deal with such conditions.
In the event the Director finds the existence of a condition of air pollution pursuant to Chapter 2 of this Code or of episodic air pollution pursuant to Chapter 2 of this Code, or the Division imposes extraordinary air quality control requirements pursuant to Rule 18.1301, the Director shall summarize the conditions and the actions taken in response thereto and make said summary available to the news media and to the public, and shall continue to publish such summaries at regular intervals throughout the duration of said conditions and the actions.
Information which constitutes a trade secret shall be held confidential and segregated from the public files of the Division if requested in writing by the permit applicant in accordance with this subsection.
"The applicant agrees to act as an indispensable party and to exercise extraordinary diligence in any legal action arising from the Division's denial of public access to the documents or information claimed herein to be a trade secret."
If an applicant anticipates numerous permit modifications that may involve regulatory review of trade secrets, it may submit an omnibus affidavit establishing the prerequisites of Rule 18.1402(A)(1) and (2) and reference this document in future confidentiality claims.
This rule is effective ten (10) days after filing with the Secretary of State, the State Library, and the Bureau of Legislative Research.
RULE NO. 18
APPENDIX A
INSIGNIFICANT ACTIVITIES LIST
APPENDIX A: INSIGNIFICANT ACTIVITIES LIST
The following types of activities or emissions are deemed insignificant on the basis of size, emission rate, production rate, or activity. Certain of these listed activities include qualifying statements intended to exclude many similar activities. By such listing, the Division exempts certain sources or types of sources from the requirements to obtain a permit or plan under this rule. Listing in this part has no effect on any other law to which the activity may be subject. Any activity for which a state or federal applicable requirement applies (such as New Source Performance Standards [NSPS], National Emissions Standards for Hazardous Air Pollutants [NESHAPs], or Maximum Achievable Control Technology [MACT]) is not insignificant, even if this activity meets the criteria below.
Group A
The following emission units, operations, or activities must either be listed as insignificant or included in the permit application as sources to be permitted. The ton-per-year applicability levels are for all sources listed in the categories (i.e., cumulative total).
This does not apply to generators which provide electricity to the distribution grid.
1 The treatability study or pollution prevention program must be approved separately. The activity creating the emissions must also be determined to be insignificant as discussed in the introduction to this group.
Group B
The following emission units, operations, or activities need not be included in a permit application:
2 Cleaning and painting activities qualify if they are not subject to VOC or HAP control requirements. Asphalt batch plant owners/operators must get a permit.
3 "Moved by hand" means that it can be moved by one person without assistance of any motorized or non-motorized vehicle, conveyance, or device.
4 Brazing, soldering, and welding equipment, and cutting torches related to manufacturing and construction activities that emit HAP metals are more appropriate for treatment as insignificant activities based on size or production thresholds. Brazing, soldering, and welding equipment, and cutting torches related directly to plant maintenance and upkeep and repair or maintenance shop activities that emit HAP metals are treated as trivial and listed separately in this appendix.
5 Exemptions for storage tanks containing petroleum liquids or other volatile organic liquids are based on size and limits including storage tank capacity and vapor pressure of liquids stored and are not appropriate for this list.
RULE NO. 18
APPENDIX B: NATIONAL AMBIENT AIR QUALITY STANDARDS LIST
The National Ambient Air Quality Standards are listed in the table below.
Pollutant | Final Rule Cite | Final Rule Date | Primary / Secondary | Averaging Time | Level | Form | Applicable Chapters |
Carbon Monoxide | 76 FR 54294 | August 31, 2011 | Primary | 8-hour | 9 ppm | Not to be exceeded more than once per year | All Chapters |
1-hour | 35 ppm | All Chapters | |||||
Lead | 73 FR 66964 | November 12, 2008 | Primary and secondary | Rolling 3 month average | 0.15 µg/m3 | Not to be exceeded | All Chapters |
Nitrogen Dioxide | 75 FR 6474 | February 9, 2010 | Primary | 1-hour | 100 ppb | 98th percentile, averaged over 3 years | All Chapters |
61 FR 52852 | October 8, 1996 | Primary and secondary | Annual | 53 ppb | Annual Mean | All Chapters | |
Ozone | 73 FR 16436 | March 27, 2008 | Primary and secondary | 8-hour | 0.075 ppm | Annual fourth-highest daily maximum 8-hr concentration, averaged over 3 years | All Chapters |
Particle Pollution, PM2.5 | 78 FR 3085 | January 15, 2013 | Primary | Annual | 12 µg/m3 | Annual mean, averaged over 3 years | All Chapters |
71 FR 61144 | October 17, 2006 | Secondary | Annual | 15 µg/m3 | |||
Primary and secondary | 24-hour | 35 µg/m3 | 98th percentile, averaged over 3 years | All Chapters | |||
Particle Pollution, PM10 | 71 FR 61144 | October 17, 2006 | Primary and secondary | 24-hour | 150 µg/m3 | Not to be exceeded more than once per year on average over 3 years | All Chapters |
Sulfur Dioxide | 75 FR 35520 | June 22, 2010 | Primary | 1-hour | 75 ppb | 99th percentile of 1-hour daily maximum concentrations, averaged over 3 years | All Chapters |
38 FR 25678 | September 14, 1973 | Secondary | 3-hour | 0.5 ppm | Not to be exceeded more than once per year | All Chapters |
118.01.21 Ark. Code R. 011