(Adopted: September 11, 1991; Amended: May 11, 1994)

Except as otherwise specifically provided in these Rules, and except where the context otherwise indicates, words used in these Rules are used in exactly the same sense as the same words are used in the Health and Safety Code of the State of California.

Agricultural Burning

  1. Any open outdoor fire used in agricultural operations necessary for the growing of crops or raising of fowl or animals, or in forest management or range improvement; or used in the improvement of land for wildlife and game habitat, or disease or pest prevention.
  2. Any open outdoor fire used in the operation or maintenance of a system for the delivery of water for purposes specified in subdivision (a) of this definition. Rule 307 shall not apply to such burning.

Agricultural Operation

The growing and harvesting of crops, or raising of fowl or animals for the primary purpose of making a profit, or providing a livelihood, or the conduction of agricultural research or instruction by an educational institution.

Agricultural Wastes


  1. unwanted or unsellable materials produced wholly from agricultural operation and
  2. materials not produced from agricultural operations, but which are intimately related to the growing or harvesting of crops and which are used in the field, such as fertilizer and pesticide sacks or containers where the sacks or containers are emptied in the field. This does not include, however, such items as shop wastes, demolition materials, garbage, oil filters, tires, pallets, and the like.

Air Contaminant or Pollutant

Any discharge, release, or other propagation into the atmosphere directly, or indirectly, caused by man and includes, but is not limited to, smoke, dust, charred paper, soot, grime, carbon, noxious acids, fumes, gases, odors, or particulate matter, or any combination thereof.

Air Pollution Control Officer

The Air Pollution Control Officer of the Northern Sierra Air Quality Management District.

Allowable Emissions

The emission rate calculated using the maximum design capacity of the source unless the source is subject to Permit to Operate conditions which limit the operating rate or hours of operation, or both, which is the most stringent of applicable emission limitations contained in these Rules and Regulations or the emission rate, if any, specified as a Permit to Operate condition.


Any addition to, enlargement of, replacement of, or any major modification or change of the design, capacity, process, or arrangement, or any increase in the connected loading of equipment or control apparatus, which will significantly increase or effect the kind or amount of air contaminants emitted.

Approved Ignition Devices

Means those instruments or materials that will ignite open fires without the production of black smoke by the ignition device, this would include such items as liquid petroleum gas (L.P.G.), butane, propane, or diesel oil burners, flares, or other similar material as approved by the Air Pollution Control Officer. This does not include tires, tar, tar paper, oil and other similar materials.


The California State Air Resources Board, or any person authorized to act on its behalf.

ARB-Certified Vapor Recovery System

A vapor recovery system which has been certified by the state board pursuant to Section 41954 of the Health and Safety Code.


The air that envelopes or surrounds the earth. Where air pollutants are emitted into a building not designed specifically as a piece of air pollution control equipment, such emissions into the building shall be considered to be an emission into the atmosphere.

Attainment Pollutant

A criteria pollutant in an Air Pollution Control District or sub- district zone designated by the Environmental Protection Agency as an attainment area or unclassified area for such pollutant.

Baseline Concentration

The ambient concentration level reflecting actual air quality as monitored or modeled as of:

  1. January 1, 1981, minus any contribution from major stationary facilities and major modifications on which construction commenced on or after January 5, 1975, for attainment pollutants; and
  2. the date an application for Authority to Construct is deemed complete by the Air Pollution Control Officer for nonattainment pollutants.

Best Available Control Technology

An emission limitation, based on the maximum degree of reduction for a criteria pollutant or precursor which would be emitted from any source or modification which the Air Pollution Control Officer, on a case-by-case basis, taking into account energy, environmental and economic impacts, and other costs, determines is achievable for such source or modification through application of production processes or available control methods, systems, and techniques, for such pollutant. In no case shall application of best available control technology result in emissions of any pollutant or precursor which would exceed the emissions allowed by 40 CFR Part 60 and 61. If the Air Pollution Control Officer determines that technological or economic limitations on the application of measurement technology to a particular class of sources would make the imposition of an emission standard infeasible, he may instead prescribe a design equipment, work practice or operations standard, or combination thereof. Such standard shall, to the degree possible, set forth the emission reduction achievable by implementation of such design, equipment, work practice or operation and shall provide for compliance by means which achieve equivalent results.


The Northern Sierra Air Quality Management District Board.

Bottom Loaded

A gasoline delivery vessel shall be considered to be bottom loaded when the fuel transfer and vapor return lines have separate, independent, and dedicated attachments on the truck or tank, when the inlet is flush with the tank bottom, and when the truck and trailer hatches remain closed during fuel transfer.

Breakdown Condition

An unforeseeable failure or malfunction of

  1. any air pollution control equipment or related operating equipment which causes a violation of any emission limitation or restriction prescribed by these Rules and Regulations,or by state law, or
  2. any in-stack continuous monitoring equipment, where such failure or malfunction:
  1. Is not the result of neglect or disregard of any air pollution control law or rule or regulation; and
  2. Is not intentional or the result of negligence; and
  3. Is not the result of improper maintenance;
  4. Does not constitute a nuisance;
  5. Is not a recurrent breakdown of the same equipment.

Brush Treated

The material has been felled, crushed or uprooted with mechanical equipment, or has been desiccated with herbicides.

Bulk Plant

An intermediate gasoline distribution facility consisting of gasoline loading facilities where delivery to the facility's storage containers is by tank truck.

Combustible or Flammable Waste

Means any garbage, rubbish, trash, rags, paper, boxes, crates, excelsior, ashes, offal, carcass of a dead animal, petroleum product waste or any other combustible or flammable refuse material.

Combustion Contaminant

Any particulate matter discharged into the atmosphere from the burning of any material which contains carbon in either the free or the combined state.

Condensed Fumes

Particulate matter generated by the condensation of vapors evolved after volatilization from the molten liquid state, or generated by sublimation, distillation, calcination or chemical reaction, when these processes create airborne particles.

Criteria Pollutant

An air pollutant regulated by a national ambient air quality standard contained within 40 CFR Part 50.

Designated Agency

Any agency designated by the A.R.B. and Northern Sierra Air Quality Management District as having authority to issue Agricultural Burn Permits.


The Northern Sierra Air Quality Management District.


Minute solid particles released into the air by natural forces or by mechanical processes such as crushing, grinding, milling, drilling, demolishing, shoveling, conveying, covering, bagging, sweeping, or other similar processes.


The act of releasing or discharging air contaminants into the ambient air from any source.

Emission Data

Measured or calculated concentrations or weights of air contaminants emitted into the ambient air. Production data used to calculate emission data is not emission data.

Emission Point

The place, located in a horizontal plane and vertical elevation, at which an emission enters the atmosphere.


Verifiable and legally binding.


Expose to view by digging.

Existing Retail Service Station

Any retail service station operating, constructed, or under construction as of December 15, 1988.

Floating Roof

A pontoon-type or double-deck type roof, resting on the surface of the liquid contents and equipped with a closure seal, or seals, to close the space between the roof edge and tank wall. The control equipment provided for in this section shall not be used if the gasoline or petroleum distillate has a vapor pressure of 11.0 pounds per square inch absolute or greater under actual storage conditions. All tank gauging and sampling devices shall be gas-tight expect when gauging or sampling is taking place.


Any source or collection of sources of air contaminants which are located on one or more contiguous or adjacent properties within the District and which is owned, operated, or under shared entitlement to be used by the same person. Items of air contaminant emitting equipment shall be considered aggregated into the same facility and items of non-air contaminant emitting equipment shall be considered associated with air contaminant emitting equipment only if:

  1. The operation of each item of equipment is dependent upon, or affects the process of, the others; and
  2. The operation of all such items of equipment involves a common raw material or product.
  3. Any establishment or installation and the associated equipment.

Federal Land Manager

The Secretary of the United States Department with authority over applicable federal lands, his authorized representative, or the President of the United States.


Any duct or passage for air, gases or the like, such as a stack or chimney.

Forest Management Burning

Means the use of open fires, as part of a forest management practice, to remove forest debris. Forest Management practice include timber operations, silvacultural practices or forest protection practices.

Fossil Fuel-Fired Steam Generator

Means a furnace or boiler used in the process of burning fossil fuel for the primary purpose of producing steam by heat transfer. "Fossil fuel" means natural gas, petroleum, coal, and any form of solid, liquid, or gaseous fuel derived from such materials.

Fugitive Dust

Solid particulate matter that becomes airborne, other than that emitted from an exhaust stack, as a direct result of operation of a facility.


Any organic liquid (including petroleum distillates and methanol) having a Reid vapor pressure of four (4) pounds or greater and used as a motor vehicle fuel or any fuel which is commonly or commercially known or sold as gasoline.

Gasoline Storage Tank

Any storage container, reservoir, or tank used for the storage of gasoline that is equipped with no vapor control, or is equipped with splash loading, submerged fill pipe loading, or Phase I or Phase II vapor recovery loading systems.

Gasoline Vapors

The organic compounds in the displaced vapors including any entrained liquid gasoline.

Hearing Board

The appellate review board of any county or regional air pollution control district as provided for in the Health and Safety Code of the State Code of the State of California.


An operation in which combustion is carried on for the principal purpose, or with the principal result of oxidizing a waste material to reduce its bulk or facilitate its disposal.


Any furnace or other closed fire chamber used to dispose of combustible waste by burning and from which the products of combustion are directed through a flue or chimney.


The placement, assemblage or construction of equipment or control apparatus at the premises where the equipment or control apparatus will be used, including all preparatory work at such premises.

Institutional Facility

Any hospital, boarding home, school or like facility.

Leak Free

A liquid leak of less than four drops per minute.

Lowest Achievable Emission Rate

A liquid leak of less than four drops per minute.

Lowest Achievable Emission Rate

For any source, the most stringent of:

  1. The most effective emission limitation which the Environmental Protection Agency certified is contained in the implementation plan of any state approved under the Clean Air Act for such class or category of source, unless the owner or operator of the proposed source demonstrates to the satisfaction of the Air Pollution Control Officer that such limitation is not achievable; or
  2. The most effective emissions control technique which has been achieved in practice for such category or class of source; or
  3. Any other emissions control technique found, after public hearing, by the Air Pollution Control Officer to be technologically feasible and cost effective for such class or category of sources or for a specific source.

In no event shall the application of lowest achievable emission rate allow for emissions in excess of those allowable under 40 CFR Part 60.

Major Facility

A Major Facility is a Major Source

Major Source

A "major source" is a stationary source which has the potential to emit a regulated air pollutant (or precursor) or a hazardous air pollutant (HAP) in quantities equal to or exceeding the lesser of any of the following thresholds:

  1. 100 tons per year (tpy) or 1000 pounds per day of any regulated air pollutant;
  2. 50 tpy of volatile organic compounds or oxides of nitrogen for a federal nonattainment area classified as serious, 25 tpy for an area classified as severe, or, 10 tpy for an area classified as extreme;
  3. 70 tpy of PM10 (particulate matter of 10 microns or less) for a federal PM10 nonattainment area classified as serious;
  4. 10 tpy of one HAP or 25 tpy of two or more HAPs; or
  5. Any lesser quantity threshold promulgated by the U.S. EPA.

Major Modification

Any modification of a facility which increases the actual emission or potential to emit a criteria pollutant or precursor by 100 tons per year or 1000 pounds per day or more. Emission increases shall include all accumulated increases in actual emissions or potential to emit at the facility since January 1, 1981, or since the date of issuance of the most recent Authority to Construct for initial construction or major modification of the facility.


Any physical change in, change in method of operation of, or addition to an existing stationary source, except that routine maintenance or repair shall not be considered to be a physical change. A change in the method of operation, unless previously limited by a Permit to Operate condition, shall not include:

  1. An increase in the production rate, if such increase does not exceed the operating design capacity of the source.
  2. An increase in the hours of operation.
  3. A change in ownership of a source.

Motor Vehicle

As defined in Section 415 of the Vehicle Code.

Multiple-Chamber Incinerator

Any article, machine, equipment, contrivance, structure or part of a structure, used to dispose of combustible refuse by burning, consisting of three or more refractory lined combustion furnaces in series, physically separated by refractory walls, inter-connected by gas passage ports or ducts employing adequate design parameters necessary for maximum combustion of the material to be burned.

No-Burn Day

Means any day on which agricultural burning is prohibited by the ARB, the Air Pollution Control Officer or the fire agency with appropriate jurisdiction.

Nonattainment Pollutant

A criteria pollutant in an Air Pollution Control District or sub- district zone designated by the Environmental Protection Agency as a nonattainment area for that pollutant.

Offset Fill Pipe

A fill pipe on a stationary storage tank which is loaded from the side and has its discharge opening entirely submerged when the liquid is eighteen (18) inches above the bottom of the tank.

Open Out-Door Fire

As used in this regulation means: Combustion of any combustible material of any type, outdoors in the open air, where the product of combustion is not directed through a flue.


Any physical action resulting in a change in the location, form or physical properties of a material, or any chemical action resulting in a change in the chemical composition or the chemical properties of a material.

Orchard or Citrus Heaters

Any article, machine, equipment, or other contrivance, burning any type of fuel or material capable of emitting air contaminants, used or capable of being used for the purpose of giving protection from frost damage.

Owner or Operator

Any person who owns, operates, controls or supervises an affected facility, or a stationary source of which an affected facility is a part.

Particulate Matter

Is any material except uncombined water, which can exist in a finely divided form as a liquid or solid at standard conditions.

Permissive Burn Day

Means any day on which agricultural burning is not prohibited by the ARB.


Any person, firm, association, organization, partnership, business trust, corporation, company, contractor, supplier, installer, operator, user or owner, any government agency or public district or any officer or employee thereof.

Phase I Vapor Recovery System

An ARB-certified gasoline vapor recovery system which recovers vapors during the transfer of gasoline from delivery vessels into stationary storage tanks.

Potential to Emit

  1. Emissions Unit: The "potential to emit" for an emissions unit is the maximum capacity of the unit to emit a regulated air pollutant or HAP considering the unit's physical and operational design. Physical and operational limitations on the emissions unit shall be treated as part of its design, if the limitations are set forth in permit conditions which address applicable federal requirements. Physical and operational limitations shall include, but are not limited to, the following: limits placed on emissions and restrictions on hours of operation and type or amount of material combusted, stored, or processed.
  2. Stationary Source: The "potential to emit" for a stationary source is the sum of the potential to emit from all emissions units at the stationary source. If two or more HAPs are emitted at a stationary source, the potential to emit for each of those HAPs shall be combined to determine applicability. Fugitive emissions shall be considered in determining the potential to emit for:
    1. sources as specified in 40 CFR Part 70.2 Major Source (2), and
    2. sources of HAP emissions. Notwithstanding the above, any HAP emissions from any oil or gas exploration or production well (with its associated equipment) and any pipeline compressor or pump station shall not be aggregated with emissions of similar units for the purpose of determining a major source of HAPs, whether or not such units are located in contiguous areas or are under common control.


Parts per million by volume expressed on a dried gas basis.


A directly emitted pollutant that, when released into the atmosphere, forms or causes to be formed or contributes to the formation of a secondary pollutant which is a criteria pollutant. The following precursor-pollutant transformations shall be included in the determination of secondary pollutant concentrations: non-methane hydrocarbons - ozone; nitrogen oxides - nitrogen dioxide; sulfur oxides - sulfur dioxide.

Pressure Tank

A tank which maintains working pressure sufficient at all times to prevent hydrocarbon vapor or gas loss to the atmosphere.

Process Weight Per Hour

The total weight, including contained moisture, of all materials introduced into any specific process, which process may cause any discharge into the atmosphere. Solid fuels charged will be considered as part of the process weight, but liquid and gaseous fuels and combustion air will not. (The Process Weight Per Hour will be derived by dividing the total process weight by the number of hours in one complete operation from the beginning of any given process to the completion thereof, excluding any time during which the equipment is idle.)

Public Record

Means any record made available to the public by law containing information relating to the conduct of the public's business that is prepared, owned, used or retained by the District, except "trade secrets" as defined in Rule - 514 C, Regulation V.

Range Improvement Burning

The use of open fires to remove vegetation for a wildlife, game or livestock habitat or for the initial establishment of an Agni- cultural practice on previously uncultivated land.


Means handwriting, typewriting, printing, photostating, photographing, and every other means of recording upon any form of communication or representation, including letters, words, pictures, sounds, or symbols, or any combination thereof, and all papers, maps, magnetic or paper tapes, photographic films and prints, magnetic or punched cards, drums, and other documents.

Residential Rubbish

Rubbish originating from a single or two family dwelling on its premises, limited to the following material: wood, paper, cloth, cardboard, tree trimmings, leaves, lawn clippings and dry plants.

Resource Recovery Facility

Any facility at which solid waste is processed for the purpose of extracting, converting to energy, or otherwise separating and preparing solid waste for reuse. Energy conversion facilities must utilize solid waste to provide more than 80% of the heat input to be considered a resource recovery facility.

Retail Service Station

Any new or existing motor vehicle fueling service station subject to payment of California sales tax on gasoline sales.

Secondary Emissions

Emissions within the District from:

  1. all cargo carriers, excluding motor vehicles as defined in the Vehicle Code, which load or unload at a facility, and
  2. all off-site support facilities which would be constructed as a result of construction or modification of a facility.


As used in these Rules and Regulations, unless some other code is specifically mentioned, all section references are to the Health and Safety Code as such code reads on January 1, 1976.

Silvacultural Practices

Means the establishment, development, care, and reproduction of stands of timber.

Solid Waste Dump

Means any accumulation for the purpose of disposal of any solid waste.


Any machine, equipment, apparatus, device, process, or combination thereof, which emits or may emit air contaminants to the atmosphere through a common duct or vent to a single emission point.

Source Operation

The last operation preceding the emission of an air contaminant, which operation

  1. results in the separation of the air contaminants from the process materials, or in the conversion of the process materials into air contaminants, as in the case of combustion of fuel, and
  2. is not an air pollution abatement operation.

Standard Conditions

As used in these regulations, "Standard Conditions" are a gas temperature of 60 degrees Fahrenheit and a gas pressure of 14.7 pounds per square inch absolute. Results of all analysis and tests shall be calculated and reported at this gas temperature and pressure.

Standard Cubic Foot of Gas

The amount of gas that would occupy a volume of one (1) cubic foot, if free of water vapor, at standard conditions.

Submerged Fill Pipe

Any fill pipe which has its discharge opening entirely submerged when the liquid level is six inches (6") above the bottom of the tank. "Submerged fill pipe", when applied to a tank which is loaded from the side, means any fill pipe which has its discharge opening entirely submerged when the liquid level is eighteen inches (18") above the bottom of the tank.

Tahoe Basin

That area, within the State of California, as defined by the California Nevada Interstate Compact, Article 11, Paragraph C, as contained in Section 5976 of the State Water Code.

Tank Replacement

Replacement of one or more stationary storage tanks at any facility.

Temporary Source

Any source or activity causing emissions which operates within a single Air Pollution Control District for less than two (2) years in any ten (10) year period, including, but not limited to, pilot plants, portable facilities and construction activity.

Title V Permit

A permit issued, renewed, amended, or revised pursuant to Title V of the Clean Air Act of 1990, 40 CFR Part 70, and Rule 522 Federal Operating Permits.


The volume of gasoline dispensed at a facility.

Timber Operations

The cutting or removal of timber or other forest vegetation.

Topping Off

To attempt to dispense gasoline to a motor vehicle fuel tank after a vapor recovery dispensing nozzle has shut off automatically. The filling of those vehicle tanks which, because of the nature and configuration of the fill pipe, causes premature shut off of the dispensing nozzle, and which are filled only after the seal between the fill pipe and the nozzle is broken, shall not be considered topping off.

Total Reduced Sulfur (TRS)

Total reduced sulfur contained in hydrogen sulfide, mercaptans, dimethyl sulfide, dimethyl disulfide or other organic sulfide compounds, all expressed as hydrogen sulfide. Sulfur dioxide, sulfur trioxide, or sulfuric acid are not to be included in the determination of TRS.

Vapor Leak

Any source of gasoline vapors which cause a combustible gas detector meter reading of 100 percent of the LEL. A marginal vapor leak may be verified by conducting a pressure/vacuum leak test. A vapor leak does not include any vapor resulting from liquid spillage or liquid leaks.

Vapor Recovery System

A vapor gathering system capable of collecting and or destroying hydrocarbon vapors and gases that are normally discharged to the atmosphere during a transfer of organic liquid from one container to another container.

Vapor Tight

A leak of less than 100 percent of the lower explosive limit on a combustible gas detector measured at a distance of 2.5 cm (one inch) from the source or no visible evidence of air entrainment in the sight glass of a liquid delivery hose.