This glossary
was provided by the Georgia Department
of Natural Resources, Air Protection
Branch, and edited for use in this web
site.
Acid rain -- Air pollution
produced when acid chemicals are incorporated into rain, snow, fog
or mist. The "acid" in acid rain comes from sulfur oxides and
nitrogen oxides, products of burning coal and other fuels and from
certain industrial processes. The sulfur oxides and nitrogen oxides
are related to two strong acids: sulfuric acid and nitric acid. When
sulfur dioxide and nitrogen oxides are released from power plants
and other sources, winds blow them far from their source. If the
acid chemicals in the air are blown into areas where the weather is
wet, the acids can fall to Earth in the rain, snow, fog, or mist. In
areas where the weather is dry, the acid chemicals may become
incorporated into dusts or smokes. Acid rain can damage the
environment, human health, and property.
Alternative fuels -- Fuels that
can replace ordinary gasoline. Alternative fuels may have
particularly desirable energy efficiency and pollution reduction
features. Alternative fuels include compressed natural gas,
alcohols, liquefied petroleum gas (LPG), and electricity. The 1990
Clean Air Act encourages development and sale of alternative fuels.
Attainment area -- A geographic
area in which levels of a criteria air pollutant meet the
health-based primary standard (national ambient air quality
standard, or NAAQS) for the pollutant. An area may have on
acceptable level for one criteria air pollutant, but may have
unacceptable levels for others. Thus, an area could be both
attainment and non-attainment at the same time. Attainment areas are
defined using federal pollutant limits set by EPA.
BACT -- Best available control
technology. It is an emission limitation that considers the cost of
energy, environment, and economics in developing a degree of
emission reduction that is achievable through application of good
production processes, control systems, and techniques. In no event
can BACT allow emissions of a pollutant in excess of a NSPS or a
NESHAPS. BACT is determined on a case-by-case basis, is applied to
each pollutant regulated under the Clean Air Act (federal) and is
used mostly in PSD permit work.
Carbon monoxide (CO) -- A
colorless, odorless, poisonous gas, produced by incomplete burning
of carbon-based fuels. including gasoline, oil, and wood. Carbon
monoxide is also produced from incomplete combustion of many natural
and synthetic products. For instance, cigarette smoke contains
carbon monoxide. When carbon monoxide gets into the body, the carbon
monoxide combines with chemicals in the blood and prevents the blood
from bringing oxygen to cells, tissues, and organs. The body's parts
need oxygen for energy, so high-level exposures to carbon monoxide
can cause serious health effects. Massive exposures to CO can cause
death. Symptoms of exposure to carbon monoxide can include vision
problems, reduced alertness, and general reduction in mental and
physical functions. Carbon monoxide exposures are especially harmful
to people with heart, lung, and circulatory system diseases.
CFCs (chlorofluorocarbons) --
These chemicals and some related chemicals have been used in great
quantities in industry, for refrigeration and air conditioning, and
in consumer products. CFCs and their relatives, when released into
the air, rise into the stratosphere, a layer of the atmosphere high
above the Earth. In the stratosphere, CFCs and their relatives take
part in chemical reactions which result in reduction of the
stratospheric ozone layer, which protects the Earth's surface from
harmful effects of radiation from the sun. The 1990 Clean Air Act
includes provisions for reducing releases (emissions) and
eliminating production and use of these ozone-destroying chemicals.
Clean Air Act (CAA) -- The
original Clean Air Act was passed in 1963, but our national air
pollution control program is actually based on the 1970 version of
the law. The 1990 Clean Air Act Amendments are the most far-reaching
revisions of the 1970 law. In this glossary, we refer to the 1990
amendments as the 1990 Clean Air Act.
Clean fuels -- Low-pollution
fuels that can replace ordinary gasoline. These are alternative
fuels, including gasohol (gasoline-alcohol mixtures), natural gas,
and LPG (liquefied petroleum gas).
Combustion -- Burning. Many
important pollutants, such as sulfur dioxide, nitrogen oxides, and
particulates (PM-10) are combustion products, often products of the
burning of fuels such as coal, oil, gas, and wood.
Compliance Advisory Panel (CAP)
-- A seven member panel appointed by the governor state legislature
and the Air permitting agency. The panel is composed of 4 small
business owners, one permitting representative, and two people to
represent the public at large. The CAP provides oversight to the
Small Business Assistance Program (SBAP).
Continuous emission monitoring systems
(CEMS) -- Machines which measure, on a continuous basis,
pollutants released by a source. The 1990 Clean Air Act requires
continuous emission monitoring systems for certain large sources.
Control technology; control measures
-- Equipment, processes, or actions used to reduce air pollution.
The extent of pollution reduction varies among technologies and
measures. In general, control technologies and measures that do the
best job of reducing pollution will be required in the areas with
the worst pollution. For example, the best available control
technology/best available control measures (BACT, BACM) will be
required in serious non-attainment areas for particulates, a
criteria air pollutant. A similar high level of pollution reduction
will be achieved with maximum achievable control technology (MACT)
which will be required for sources releasing hazardous air
pollutants.
Criteria air pollutants -- A
group of very common air pollutants regulated by EPA on the basis of
criteria (information on health and/or environmental effects of
pollution). Criteria air pollutants are widely distributed all over
the country. A National Ambient Air Quality Standard exists for each
criteria pollutant (particulate matter, sulfur dioxide, nitrogen
dioxide, ozone, carbon dioxide, and lead).
Emission -- Release of
pollutants into the air from a source. We say sources emit
pollutants. Continuous emission monitoring systems (CEMS) are
machines, which some large sources are required to install, to make
continuous measurements of pollutant release.
Enforcement -- The legal methods
used to make polluters obey the Clean Air Act. Enforcement methods
include citations of polluters for violations of the law (citations
are much like traffic tickets), fines, and even jail terms. EPA and
the state and local governments are responsible for enforcement of
the Clean Air Act, but if they don't enforce the law, members of the
public can sue EPA or the states to get action.
Hazardous air pollutants (HAPs)
-- Toxic chemicals that cause serious health and environmental
effects. Health effects include cancer, birth defects, nervous
system problems, and death due to massive accidental releases such
as occurred at the pesticide plant in Bhopal, India. Hazardous air
pollutants are released by sources such as chemical plants, dry
cleaners, printing plants, and motor vehicles (cars, trucks, buses,
etc.)
Inspection and maintenance program (I/M
program) -- Auto inspection programs are required for some
polluted areas. These periodic inspections, usually done once a year
or once every two years, check whether a car is being maintained to
keep pollution down and whether emission control systems are working
properly. Vehicles which do not pass inspection must be repaired.
Under the 1990 Clean Air Act, some especially polluted areas will
have to have enhanced inspection and maintenance programs, using
special machines that can check for such things as how much
pollution a car produces during actual driving conditions.
Interstate air pollution -- In
many areas, two or more states share the same air. We say these
states are in the same air basin defined by geography and wind
patterns. Often, air pollution moves out of the state in which it is
produced into another state. Some pollutants, such as the power
plant combustion products that cause acid rain, may travel over
several states before affecting health, the environment, and
property. The 1990 Clean Air Act includes many provisions, such as
interstate compacts, to help states work together to protect the air
they share. Reducing interstate air pollution is very important
since many Americans live and work in areas where more than one
state is part of a single metropolitan area.
LAER -- Lowest achievable
emission rate. Considered to be the lowest rate of emissions from a
source category which is contained in the State Implementation Plan,
or which is achieve in practice by such category of sources. This
term is most often associated with a nonattainment area.
Major source -- Under the PSD
regulations it is a facility, belonging to one or more of 28 source
categories, having the potential to emit 100 tons per year of a
pollutant regulated under the federal Clean Air Act (CAA). For
categories other than the 28 sources, the potential emission level
can not exceed 250 tons per year.
A major source for the purpose of Title V in
the CAA is a stationary source that has the potential to emit 100
tons per year a pollutant regulated under the CAA and/or a source
that has the potential to emit 10 tons per year for a single
hazardous air pollutant or 25 tons per year of a combination of all
hazardous air pollutants.
Material safety data sheets (MSDSs)
-- Product safety information sheets prepared by manufacturers and
marketers of products containing toxic chemicals. These sheets can
be obtained by requesting them from the manufacturer or marketer.
Some stores, such as hardware stores, may have material safety data
sheets on hand for products they sell.
Mobile sources -- Motor vehicles
and other moving objects that release pollution; mobile sources
include cars, trucks, buses, planes, trains, motorcycles and
gasoline-powered lawn mowers. Mobile sources are divided into two
groups: road vehicles, which includes cars, trucks, and buses, and
non-road vehicles, which includes trains, planes, and lawn mowers.
Monitoring (monitor) --
Measurement of air pollution is referred to as monitoring. EPA,
state, and local agencies measure the types and amounts of
pollutants in community air. The 1990 Clean Air Act requires states
to monitor community air in polluted areas to determine if the areas
are being cleaned up according to schedules set by law.
NAAQS -- National ambient air
quality standards. Ambient standards developed by EPA that must be
attained and maintained to protect public health. "Secondary" NAAQS
are necessary to protect the public welfare. NAAQS exist for
particular matter, sulfur dioxide, nitrogen dioxide, ozone, carbon
dioxide, and lead.
Nitrogen oxides (NOx) -- A
criteria air pollutant. Nitrogen oxides are produced from burning
fuels, including gasoline and coal. Nitrogen oxides are smog
formers, which react with volatile organic compounds to form smog.
Nitrogen oxides are also major components of acid rain.
Non-attainment area -- A
geographic area in which a criteria air pollutant level is higher
than allowed by the federal standards. A single geographic area may
have an acceptable level for one criteria air pollutant, but have
unacceptable levels of one or more other criteria air pollutants.
Thus, an area can be both an attainment and non-attainment area at
the same time. Sixty percent of Americans are estimated to live in
non-attainment areas.
NSR -- New source review. NSR
typically means any new source locating in a, e.g., ozone
nonattainment area that will emit volatile organic compounds (VOCs)
and/or oxide of nitrogen (NO) in certain amounts. These sources
must: undergo a new source review that provides for offsetting
emissions for any increases in the emissions of these two
pollutants; use the lowest achievable emissions technology to
control emissions; apply for a construction permit; and meet other
state requirements before the new emission from the source can be
permitted. Existing sources, located in the ozone nonattainment
area, that emit these two pollutants and plan to change their
operational methods that will cause an increase in the emissions of
these two pollutants must apply for a modification permit and under
go a review similar to a new source.
NSPS -- New source performance
standards. These are federal EPA emission standards for certain air
pollutants that are emitted from new, modified, or reconstructed
stationary emission sources which reflect the use of best available
control technology
NESHAPS -- National emission
standards for hazardous air pollutants.
Offset -- A method used in the
1990 Clean Air Act to give companies, which own or operate large
(major) sources in non-attainment areas, flexibility in meeting
overall pollution reduction requirements when changing production
processes. If the owner or operator of the source wishes to increase
releases of a criteria air pollutant, an offset (reduction of a
somewhat greater amount of the same pollutant) must be obtained
either at the same plant or by purchasing offsets from another
company.
Ozone -- A gas which is a
variety of oxygen. The oxygen gas found in the air consists of two
oxygen atoms stuck together; this is molecular oxygen. Ozone
consists of three oxygen atoms stuck together into an ozone
molecule. Ozone occurs in nature; it produces the sharp smell you
notice near a lightning strike. High concentrations of ozone gas are
found in a layer of the atmosphere -- the stratosphere -high above
the Earth. Stratospheric ozone shields the Earth against harmful
rays from the sun, particularly ultraviolet B. Smog's main component
is ozone; this ground-level ozone is a product of reactions among
chemicals produced by burning coal, gasoline and other fuels, and
chemicals found in products such as solvents, paints, and hair
sprays.
Particulates: particulate matter (PM-10)
-- Particulate matter is a criteria air pollutant and is a finely
divided particle with an aerodynamic diameter of 10 micrometers or
less. Particulate matter includes dust, soot and other tiny bits of
solid materials that are released into and move around in the air.
Particulates are produced by many sources, including burning of
diesel fuels by trucks and buses, incineration of garbage, mixing
and application of fertilizers and pesticides, road construction,
industrial processes such as steel making, mining operations,
agricultural burning (field and slash burning), and operation of
fireplaces and wood stoves. Particulate pollution can cause eye,
nose, and throat irritation and other health problems.
Permit -- A document that
resembles a license that is required by the Clean Air Act for big
(major) sources of air pollution, such as power plants, chemical
factories and, in some cases, smaller polluters. Usually permits are
issued by states, but if EPA has disapproved part or all of a state
permit program, EPA will issue the permits in that state. The 1990
Clean Air Act includes requirements for permit applications,
including provisions for members of the public to participate in
state and EPA reviews of permit applications. Permits contain
information on all the regulated pollutants at a source. Permits
include information on which pollutants are presently released, how
much pollution the source is allowed to release, and the control
measures necessary to meet pollutant release requirements. Permits
are required both for the operation of plants (operating permits)
and for the construction of new plants. The 1990 Clean Air Act
introduced a nationwide permit system for air pollution control.
Permit fees -- Fees paid by
businesses required to have a permit. Permit fees are like the fees
drivers pay to register their cars. Money from permit fees helps pay
for state air pollution control activities.
Pollutants (pollution) --
Unwanted chemicals or other materials found in the air. Pollutants
can harm health, the environment and property. Many air pollutants
occur as gases or vapors, but some are very tiny solid particles:
dust, smoke, or soot.
Primary standard -- A pollution
limit based on health effects. Primary standards are set for
criteria air pollutants.
PSD -- Prevention of significant
deterioration. This term refers to regulations that requires a major
new source or an existing source making majoring modifications to be
permitted by the state before construction is started if they are
located in an attainment area.
RACT -- Reasonably available
control technology. It is usually an emission limit set by a state
air program and is the basis for emission rates used in their SIP.
It usually applies to sources in attainment areas and in most cases
is less stringent than the NSPS level of control.
Reformulated gasoline --
Specially refined gasoline with low levels of smog-forming volatile
organic compounds (VOCs) and low levels of hazardous air pollutants.
The 1990 Clean Air Act requires sale of reformulated gasoline in the
nine smoggiest areas. Some reformulated gasolines were sold in
several smoggy areas before passage of the 1990 Clean Air Act.
SBA -- Small Business
Administration
SBAP -- Small Business
Assistance Program
SBDC -- Small Business
Development Center
Secondary standard -- A
pollution limit based on environmental effects such as damage to
property, plants, or visibility. Secondary standards are set for
criteria air pollutants.
State Implementation Plan (SIP)
-- A detailed description of the programs a state will use to carry
out its responsibilities under the Clean Air Act. This includes such
things as rules and regulations, plans to control ozone, and ambient
air standards used by a state to reduce air pollution. The Clean Air
Act requires that EPA approve each state implementation plan.
Smog -- A mixture of pollutants,
principally ground-level ozone, produced by chemical reactions in
the air involving smog-forming chemicals. A major portion of
smog-formers comes from burning petroleum-based fuels such as
gasoline. Other smog-formers, volatile organic compounds, are found
in products such as paints and solvents. Smog can harm health,
damage the environment and cause poor visibility. Major smog
occurrences are often linked to heavy motor vehicle traffic,
sunshine, high temperatures and calm winds, or temperature inversion
(weather condition in which warm air is trapped close to the ground
instead of rising).
Source -- Any place or object
from which pollutants are released. A source can be a power plant,
factory, dry cleaning business, gas station, or a farm. Cars,
trucks, and other motor vehicles are sources. Consumer products and
machines used in industry can also be sources.
Stationary source -- A place or
object from which pollutants are released which stays in place.
Stationary sources include power plants, gas stations, incinerators,
and houses.
Sulfur dioxide -- A criteria air
pollutant. Sulfur dioxide is a gas produced by burning coal, most
notably in power plants. Some industrial processes, such as
production of paper and smelting of metals, produce sulfur dioxide.
Sulfur dioxide is closely related to sulfuric acid, a strong acid.
Sulfur dioxide plays an important role in the production of acid
rain.
Synthetic minor permit -- A
permit with practically, enforceable conditions issued to a
facility. These conditions limit the amount of regulated pollutant
emissions so the permitted amount of actual emissions from the
facility is below potential major source emission levels. These
major source thresholds are usually 100 tons per year under Title V,
50 tons per year VOC/NO in the nonattainment area for ozone; 100/250
tons per year for P.D; 10 tons per year for a single hazardous air
pollutant; 25 tons per year for a combination of all hazardous air
pollutants; and 50 tons per year for a new source review.
Title V permit -- Is a federal
operating permit program adopted and implemented by the state. The
basic program elements typically specify that major sources will
submit an operating application to the specified state environmental
regulatory agency according to a schedule. EPA and the affected
states will review the permit issuance. The pubic also has an
opportunity to comment on the permit, which is renewable every five
years. Minor changes to the permit can be made without opening the
permit for public participation.
Ultraviolet B (UVB) -- A type of
sunlight. The ozone in the stratosphere filters out ultraviolet B
rays and keeps them from reaching the Earth. Ultraviolet B exposure
has been associated with skin cancer, eye cataracts, and damage to
the environment. Thinning of the ozone layer in the stratosphere
results in increased amounts of ultraviolet B reaching the Earth.
Vapor recovery nozzles --
Special gas pump nozzles that reduce the release of gasoline vapor
into the air gas is pumped into car tanks. There are several types
of vapor recovery nozzles. Therefore, nozzles may not look the same
at all gas stations. The 1990 Clean Air Act requires the
installation of vapor recovery nozzles at gas stations in smoggy
areas.
Volatile organic compounds (VOCs)
-- Organic chemicals all contain the element carbon (C). Organic
chemicals are the basic chemicals found in living things and in
products derived from living things, such as coal, petroleum, and
refined petroleum products. Many of the organic chemicals we use do
not occur in nature, but were synthesized by chemists in
laboratories. Volatile chemicals readily produce vapors at room
temperature and normal atmospheric pressure. Vapors escape easily
from volatile liquid chemicals. Volatile organic chemicals include
gasoline, industrial chemicals such as benzene, solvents such as
toluene and xylene, and tetrachloroethylene (perchloroethylene, the
principal dry cleaning solvent). Many volatile organic chemicals,
such as benzene, are also hazardous air pollutants.