Calculation Procedures


The District uses a web based program called EIS (Emissions Inventory System) to facilitate the implementation of the emissions inventory programs. EIS allows facilities to submit required inventory information and review their data online. Facilities that are subject to emissions inventory requirements and wish to utilize EIS may contact the District’s Emissions Inventory Section at 858-586-2600 or APCDEngineering@sdapcd.org to set up an account.  A guide to EIS can be found here.

If you have questions on how to complete the data request forms, common equipment types are listed below and contain links to the appropriate calculation procedure for each equipment type.  Instructions can also be found at the link below. Information regarding trade secrets can be found here.

Instructions for Data Request Forms

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Abrasive blasting operations in San Diego commonly use silica sand, steel grit, garnet, steel shot, shot peen, slags, walnut shell, glass bead, and aluminum oxide as blast materials. A variety of blast materials may be used on a wide range of coated and uncoated parts at one or more locations within a facility. These operations produce particulate matter emissions composed of the blast material, trace contaminants in the blast material, paint pigments, scale, and/or rust. The particulate emissions may contain varying concentrations of crystalline silica, aluminum, arsenic, cadmium, copper, chromium, iron, lead, manganese, nickel, zinc, and inert substances. Process parameters that affect emission rates include type of blast material, blast equipment, velocity, blast angle, distance to part, part dimensions, and dust controls. Accurate emission estimates require an evaluation of the blast area, procedures, and control equipment to determine particulate generation, collection, and removal efficiencies.

Emissions Inventory Instructions

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Emission Factor Tables

Bakeries can be major emission sources. Ethanol is produced by yeast added to the dough mixture during the fermentation (rising) stages of bread production and evaporated in the ovens during the baking process. Emissions are directly proportional to the amount of product generated. Particulate emissions from flour handling equipment is usually considered negligible due to baghouse controls. Natural gas combustion in the baking ovens can also result in emissions of NOx, CO, and trace amounts of acetaldehyde, acetone, benzene, isobutanol, toluene, and xylenes.

Emissions Inventory Instructions

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Emission Factor Tables

Combustion of diesel fuel in engines results in the release of several criteria pollutants and toxic air contaminants to the atmosphere. Emissions typically include NOx, SOx, ROG, PM, CO, hydrogen chloride, naphthalene, PAHs, propylene, toluene, and xylene, and some metals such as lead, manganese, nickel, and zinc, as well as other trace pollutants. Testing may include the speciation of non-methane organic compounds in the stack gas exhaust. Factors can also be derived by applying average destruction efficiency to combustible components of the fuel. Stack testing for metals is considered less reliable for emission estimation purposes than mass balance techniques based on fuel analyses.

Emissions Inventory Instructions

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Emission Factor Tables

Combustion of gaseous fuels (natural gas, digester gas, and landfill gas) in boilers, engines, turbines, flares, and other miscellaneous combustion devices results in the release of several criteria pollutants and toxic air contaminants to the atmosphere. Emissions typically include NOx, SOx, ROG, PM, CO, benzene, toluene, formaldehyde, xylenes, and other trace substances. Most emission factors are derived from source test results. This testing may include the speciation of nonmethane organic compounds and particulate matter in the stack gas exhaust. Factors can also be derived by applying an average destruction efficiency to combustible components of the gaseous fuel. A combination of both techniques has been used for equipment fired with digester gas and landfill gas.

Emissions Inventory Instructions

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Emission Factor Tables

Combustion of liquid fuels (residual oil, diesel fuel, jet fuel, kerosene, butane, and propane) in boilers, engines, turbines, and other miscellaneous combustion devices results in the release of several criteria pollutants and toxic air contaminants to the atmosphere. (Diesel-fired engines are discussed separately; see “Combustion – Diesel Fired Engines.”) Emissions typically include NOx, SOx, ROG, PM, CO, benzene, toluene, formaldehyde, xylenes, trace organic substances, and some metals. Most emission factors are derived from source test results and fuel analyses. Testing may include the speciation of non-methane organic compounds in the stack gas exhaust. Factors can also be derived by applying an average destruction efficiency to combustible components of the fuel. Stack testing for metals is considered less reliable for emission estimation purposes than mass balance techniques based on fuel analyses.

Emissions Inventory Instructions

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Emission Factor Tables

Several volatile substances are released to the atmosphere from solvent cleaning and degreasing operations. Emissions of volatile ingredients can be estimated with mass balance techniques based on purchase records, inventory records, and waste shipment receipts. Emissions from typical solvent and degreasing operations may include TOG, ROG, acetone, benzene, isopropanol, toluene, xylenes, methylene chloride, 1,1,1- trichloroethane, perchloroethylene, glycol ethers, chlorofluorocarbons, and unspecified hydrocarbons.

Emissions Inventory Instructions

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Emission Factor Tables

No tables or additional documents.

Dry cleaning operations release cleaning solvent vapors to the atmosphere. While perchloroethylene (tetrachloroethylene) is the primary solvent used in dry cleaning operations, some stoddard solvent facilities may still exist. Emission rates are dependent upon the type of equipment used by the facility, emission controls, and the volume of cleaning performed. Equipment types are typically described as closed-loop, dry to dry, or transfer machines. Control devices may include refrigerated condensers, carbon adsorbers, separators, stills, filters, and/or diatomaceous earth.

Emissions Inventory Instructions

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Emission Factor Tables

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Electro-chemical tank operations apply electric current through a conductive part submerged in a tank containing an electrolytic solution. Most of these operations are electroplating (metal ions in solutions are deposited on to the conductive part). However, there are some operations where the metal from the conductive part is transferred into the solution. Typically, when current passes through the metal part, gas bubbles (usually hydrogen gas) form in the tank solution. These bubbles burst and produce a mist of the tank solution. Foam additives or surface tension adjusters may be added in the tank solution to reduce the emissions. Wet scrubbers, mist eliminators, and HEPA filters may also be used to control emissions. Typical electro-chemical tank operations include decorative chrome plating, hard chrome plating, chromic acid anodizing, nickel plating, copper plating and cadmium plating.

Emissions Inventory Instructions

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Emission Factor Tables

Ethylene oxide (EtO) is used to sterilize heat sensitive hospital equipment. EtO readily reacts with biological organisms and is commonly used for sterilizing. The sterilant gas (composed of EtO and sometimes a diluent gas) is injected into a chamber exposing the desired materials to the sterilant gas. After the sterilizing time is complete, the sterilant gas is usually vented to a control device. The diluent gas may be composed of CFC’s, HCFC’s or CO2. Most local facilities using sterilizers are required to comply with District Rule 1203 and/or the federal NESHAP which requires EtO controls.

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Emission Factor Tables

Gasoline bulk storage tanks release reactive organic gas (ROG) vapors containing listed substances into the atmosphere. The majority of emissions can be categorized as bulk storage tank fitting losses, rim seal losses, working losses, deck seam losses, degassing releases, and refilling losses. Emission rates are highly dependent upon the storage tank size, construction, and design as well as annual fuel throughput. Most bulk gasoline storage tanks in San Diego County are equipped with either internal or external floating roofs. Fixed roof tanks are best quantified with the standard gasoline dispensing and storage procedures which can be modified to apply to any individual site's equipment and procedures.

Emissions Inventory Instructions

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Emission Factor Tables

Gasoline storage and dispensing operations at retail service stations and private facilities release ROG vapors containing listed substances into the atmosphere. These emissions occur during underground storage tank loading, tank breathing, spillage, and vehicle refueling. Emission rates are highly dependent upon the installation and performance of Phase I and Phase II vapor recovery equipment. The primary components of gasoline vapor are benzene, hexane, toluene, xylenes, and a mixture of other nonmethane hydrocarbons. Actual vapor concentrations of each component will vary depending upon the composition and temperature of the gasoline.

Emissions Inventory Instructions

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Emission Factor Tables

Gasoline vapor emissions occasionally occur at the pressure release valves on the tanker trucks during bulk loading operations.

Emissions Inventory Instructions

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Emission Factor Tables

Bulk fuel storage and dispensing facilities generate large volumes of gasoline vapor during the transport vehicle loading operations. These vapors are processed by a variety of control devices including chillers, condensers, carbon adsorption units, thermal oxidizers, and flares. The primary components of reformulated gasoline vapor are benzene, hexane, toluene, xylenes, and other nonmethane hydrocarbons. Since the vapor processors are designed to recover as much fuel as is economically possible, the actual composition of the released hydrocarbons may differ from gasoline vapor. In general, the larger organics compounds are recovered and the lighter ends are emitted.

Emissions Inventory Instructions

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Emission Factor Tables

On site vehicle traffic can produce a significant amount of particulate emissions for some industries. Sections 13.2.1 (10/97) and 13.2.2 (1/95) of AP-42 provide empirical procedures for estimating overall haul road particulate releases from both paved and unpaved surfaces. In general, the particulate emissions are proportional to the number of vehicle miles traveled, road surface silt conditions, vehicle speed, and vehicle weight. Haul road dust that is generated will contain several trace metals at PPMW levels. Default trace metal concentrations for San Diego County have been developed by analyzing multiple haul road silt samples taken from several mineral products industry sites.

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Emission Factor Tables

Natural gas fired crematories and incinerators that combust human remains, animal remains, refuse, agricultural products, or medical waste are sources of carbon monoxide, nitrogen oxides, particulate matter, organic compounds, sulfur oxides and trace toxic substances. Incinerators used for cremation purposes are called "retorts" and the remains are referred to as "charges." Emissions of trace toxics substances may include hydrogen chloride, formaldehyde, benzene, toluene, mercury, hexavalent chromium, PAH's, and other heavy metals. Incinerators in San Diego County typically have a primary burner in the main chamber and a secondary burner/afterburner in the flue stack. Most permits include lb/hour charge rate limitations and periodic particulate matter source testing requirements. Emissions from these processes are highly dependent upon equipment type, control devices, operating conditions, fuel type, process time, and waste stream composition.

Emissions Inventory Instructions

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Emission Factor Tables

Landfills are emission sources of particulates and gases. Active sites conduct many activities that produce particulate emissions including, but not limited to; cover material quarrying, soil screening, rock crushing, open cover material storage piles, haul roads, solid waste compaction, cover application, composting, and green waste recycling. Particulate emissions from inactive landfills are usually limited to short term cover maintenance projects. Landfill gases containing methane, carbon dioxide, hydrogen sulfide, and a wide variety of organic compounds are released from the decomposition of waste at all sites. The quantity of landfill gas released depends primarily on the size, age, and moisture content of each disposal site. Additionally, combustion by-products are emitted from landfills equipped with flares and energy recovery systems. Emission estimation techniques used by the District are generally based upon methods and emission factors specified in AP-42.

Emissions Inventory Instructions

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Emission Factor Tables

Actual processing of raw ores and scrap metal for purification purposes is not common in San Diego County. Most "smelting" and "foundry" activities currently in San Diego County are actually melting and casting operations using relatively pure metal ingots. Local facilities employ relatively small crucible and pot furnaces to melt ingots prior to casting into dies and molds for small parts, tools, and plaques. Some particulates, alloy additives, flux, and trace metal contaminants from both the melting pot and the casting area are emitted into the air.

Emissions Inventory Instructions

Emissions Inventory Instructions - Kirksite

Emissions Inventory Instructions - Lead

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Emission Factor Tables

Asphaltic concrete plants are significant sources of particulate, combustion, and trace organic emissions. These emissions usually include NOx, CO, SOx, TOG, ROG, TSP, PM10, arsenic, beryllium, cadmium, chromium, hexavalent chromium, lead, manganese, mercury, nickel, zinc, benzene, formaldehyde, toluene, Xylenes, and various polycyclic aromatic hydrocarbons (PAH's). Asphalt production consists of several interrelated processes including aggregate storage areas, conveyors, aggregate transfer points, a rotary aggregate dryer, weigh hoppers, asphaltic cement (oil) heating & storage, screens, pugmills, product storage silos, drop zones, and haul roads. The dryer, weigh hoppers, pugmill, and asphalt storage silos are typically vented to a common baghouse.

Emissions Inventory Instructions - Natural Gas Fired

Emissions Inventory Instructions - Distillate Fired

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Emission Factor Tables

Active quarry operations use a variety of equipment and techniques to dislodge, secure, and transport large quantities of rock and soil. Quarry locations vary from soft, wet, river bed, sand deposits to hard rock, drill and shoot, granite cliff faces, etc. Quarry operations in San Diego County typically involve heavy duty earth moving equipment consisting of front end loaders, bulldozers, scrapers, and transport vehicles. Many sites blast the rock deposits regularly and include large open material storage areas for processed material. Quarries may or may not be located next to rock and sand processing plants. Substantial haul road distances and traffic is not uncommon.

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Emission Factor Tables

Concrete batch plants are sources of particulate emissions containing arsenic, beryllium, cadmium, chromium, lead, manganese, nickel, selenium, zinc, and crystalline silica. Concrete is a mixture of water, sand, aggregate, and cement occasionally supplemented by small quantities of fly ash and organic additives. The composition of a typical yd3 (4000 lbs) is; 1900 lbs course aggregate, 1240 lbs sand, 500 lbs cement / fly ash, and 360 lbs water. Production equipment usually consists of aggregate bins, conveyors, cement storage silos, fly ash storage silos, a weigh hopper, a mixer, and transport trucks. The concrete may be centrally mixed (at batch plants), transit mixed (added wet to trucks and mixed enroute), or dry batch loaded (mixed with water at destination). All of these concrete batch plants utilize enclosed silos with sock (bag) filters for cement and fly ash storage.

Emissions Inventory Instructions

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Emission Factor Tables

Concrete batch plants are sources of particulate emissions which typically contain arsenic, beryllium, cadmium, chromium, lead, manganese, mercury, nickel, selenium, zinc, and crystalline silica. Concrete is a mixture of water, sand, aggregate, and cement occasionally supplemented by small quantities of fly ash and organic additives. The composition of a typical yd3 of concrete (4000 lbs) is; 1900 lbs course aggregate, 1240 lbs sand, 500 lbs cement / fly ash, and 360 lbs water.

Emissions Inventory Instructions- Central Mix Concrete Plant

Emissions Inventory Instructions- Cement Treated Base (CTB) Plant

Emissions Inventory Instructions - Transit Mix Concrete Plant

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Emission Factor Tables

Some mineral product industry quarry locations require rock drilling and blasting to loosen desired aggregate deposits. Particulate emissions occur whenever rock and soil are drilled and blasted.

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Emission Factor Tables

Open material storage piles (sand, aggregate, etc.) exist at nearly all mineral product industry sites. These storage areas are sources of particulate emissions caused by pile formation, wind erosion, and vehicle traffic (e.g., skip loaders, front end loaders, etc.).

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Emission Factor Tables

Surface coating operations using paints, coatings, thinners, and cleanup solvents result in the release of volatile solvents and/or particulates to the atmosphere. Emissions of volatile ingredients can be estimated using mass balance techniques, purchase records, inventory records, MSDS sheets, and waste shipment receipts. Emissions of nonvolatile solids can be estimated using transfer efficiencies, fall out fractions, capture efficiencies, and solids to the coated part and a control device capture and removal efficiency. VOC emissions typically include TOG, ROG, benzene, toluene, xylenes, methylene chloride, 1,1,1-trichloroethane, perchloroethylene, alcohols, glycol ethers, while pigments often contain copper, chromium, lead, zinc, and crystalline silica.

Emissions Inventory Instructions

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Emission Factor Tables

  • Site Specific Controls, yet to be listed

Many products are manufactured from polyester resin and fiberglass reinforced plastic (FRP). During the manufacturing process, liquid polyester resins are mixed with cross linking agents and catalysts to initiate polymerization reaction which produces a "cured," hard plastic part of the desired shape. Chopped glass fiber may be mixed with the resin for additional structural strength. Materials may be vapor suppressed or non-vapor suppressed. 

Instructions

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Emission Factor Tables

Several types of printing processes exist throughout San Diego County. Each type of printing process typically involves unique products, equipment, inks, solvents, application methods, and drying procedures. The most common process types are flexographic, gravure, silk-screening, lithographic heatset, lithographic nonheatset (newspaper), and letterpress. All printing operations emit some volatile substances into the atmosphere by evaporation. Actual emission rate are, however, highly dependent upon process type.

Emissions Inentory Instructions

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Emission Factor Tables

District Rule Development staff conducted a study of Safety Kleen degreasers in 1996. These enclosed degreasing units are distributed throughout the County and used by many facilities. Safety Kleen owns the equipment and provides a regular solvent disposal and recharge service to the user. The actual solvent usage for each device at each site is often unrecorded or over reported as the full capacity of the degreasing unit. Generally, these solvents are low-volatile hydrocarbon mixtures with trace quantities of benzene, toluene, and xylenes. Emissions are typically a very small percentage of the overall solvent throughput.

Instructions -Safety Kleen

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Emission Factor Tables

A variety of soil/vapor extraction devices have been installed at contaminated properties for site remediation purposes. These devices are most often used to mitigate gasoline spills but can also be effective for a wide range of volatile organic solvents. The equipment usually consists of a blower with air extraction wells vented to an activated carbon filter. On some sites, the activated carbon may be replaced with a thermal oxidizer, catalytic oxidizer, scrubber, or passive vent. In nearly all instances, the basic operating principle involves the passing of clean air through the contaminated soil to remove a volatile contaminant.

Emissions Inventory Instructions

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Emission Factor Tables

 

Most electronic manufacturing facilities use some type of soldering operation to form a conductive connection between electronic components and a circuit board. These operations often involve equipment described as wave soldering, hydrosquegees, solder levelers, solder reflow, solder coating, drag soldering, solder plating, and/or hand soldering. Soldering materials usually consist of a conductive metal (solder) and an organic liquid (flux). Emissions of metal fumes are assumed to be negligible since typical soldering temperatures are well below the boiling point of the metal. The solder process does, however, result in the evaporation of some volatile organics in the flux.

Emissions Inventory Instructions

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Emission Factor Tables

  • None Listed at This Time

Metal deposition processes are versatile fabrication techniques used by many aerospace, military, and industrial operations. Deposition processes are used to modify metallic parts for a variety of reasons that include restoring desired dimensions, improving abrasion resistance, improving temperature resistance, increasing corrosion protection, providing electrical shielding, and increasing conduction. While many different types of deposition processes and equipment exist, most operations currently found in San Diego County can be broadly categorized into two groups; flame spray and plasma arc.

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Emission Factor Tables

Many industrial and manufacturing facilities regularly use a variety of welding processes and materials.

Emissions Inventory Instructions

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Emission Factor Tables