Clean Air Act
History of the Clean Air Act
• In October 1948, a thick cloud of air pollution
formed above the industrial town of Donora,
Pennsylvania.
• The cloud lingered for five days, killed 20 people
and caused sickness in 6,000 of the town's
14,000 people.
• In 1952, over 3,000 people died in what became
known as London's "Killer Fog." The smog was
so thick that buses could not run without guides
walking ahead of them carrying lanterns.
• Events like these alerted about the dangers that
air pollution poses to public health.
• The original Clean Air Act of 1963, was
established for the study and the cleanup of air
pollution.
• But there was no comprehensive federal
response to address air pollution until Congress
passed a much stronger Clean Air Act in 1970.
• In 1970 Congress created the EPA
and gave it the primary role in
carrying out the law.
• Since then EPA has been responsible
for a variety of Clean Air Act
programs to reduce air pollution
nationwide.
The U.S. Environmental Protection Agency
• (EPA or USEPA) is an agency of the federal
government of the United States charged with
protecting human health and with safeguarding
the natural environment : air, water, and land.
• The EPA was proposed by President Richard
Nixon and began operation on December 2,
1970.
• The EPA is not a cabinet agency, but the
Administrator is normally given cabinet rank.
• EPA's Role
• Under the Clean Air Act, EPA sets limits
on certain air pollutants, including setting
limits on how much can be in the air
anywhere in the United States.
• This helps to ensure basic health and
environmental protection from air pollution
for all Americans.
EPA's Role
• The Clean Air Act also gives EPA the
authority to limit emissions of air pollutants
coming from sources like chemical plants,
utilities, and steel mills.
Individual states or tribes may have
stronger air pollution laws, but they may
not have weaker pollution limits than those
set by EPA.
EPA's Role
• EPA must approve state and local agency
plans for reducing air pollution.
If a plan does not meet the necessary
requirements, EPA can take over
enforcing the Clean Air Act in that area.
EPA's Role
• EPA assists state and local agencies by
providing research, expert studies,
engineering designs, and funding to
support clean air progress.
Since 1970, Congress and the EPA have
provided several billion dollars to the
states, local agencies, and tribal nations to
accomplish this.
I CLASS
Air Pollution Control Acts and amendments
• The Air Pollution Control Act of 1955 was the
first federal legislation involving air pollution.
This Act provide funds for federal research in air
pollution.
• The Clean Air Act of 1963 was the first federal
legislation regarding air pollution control. It
established a federal program within the U.S.
Public Health Service and authorized research
into techniques for air pollution monitoring and
control.
Air Pollution Control Acts and amendments
• In 1967, the Air Quality Act was enacted to
expand federal government activities. In
accordance with this law, enforcement
proceedings were initiated in areas subject to
interstate air pollution transport.
• The federal government conducted extensive
ambient monitoring studies and stationary
source inspections.
• Also studies of air pollutant emission inventories,
ambient monitoring techniques, and control
techniques were studied.
National Ambient Air Quality Standards
(NAAQS)
• The Clean Air Act, which last amended in 1990,
required EPA to set National Ambient Air
Quality Standards for pollutants considered
harmful to public health and the environment.
• The Clean Air Act established two types of
national air quality standards.
• Primary standards
• Secondary standards
• Primary standards set limits to protect
public health, including the health of
"sensitive" populations such as
asthmatics, children, and the elderly.
• Secondary standards set limits to protect
public welfare, including protection against
reduced visibility, damage to animals,
crops, vegetations, and buildings and
other environmental components.
The EPA has set National Ambient Air Quality
Standards for six "criteria" pollutants.
• Units of measure are parts per million (ppm) by volume,
milligrams per cubic meter of air (mg/m3), and micrograms
per cubic meter of air (µg/m3).
• The six criteria air pollutants are:-
• Carbon monoxide
• Lead
• Nitrogen dioxide
• Particulate matter
• Ozone
• Sulphur dioxide
National Emissions Standards for Hazardous Air
Pollutants
• The National Emissions Standards for
Hazardous Air Pollutants (NESHAPs)
are emission standards set by the United
States EPA for an air pollutant not covered
by NAAQS that may cause an increase
fatalities or serious, irreversible, or
incapacitating illness.
National Emissions Standards for Hazardous Air
Pollutants
(NESHAP) Pollution sources
Most air toxics originate from human-made
sources, including
• mobile sources (e.g., cars, trucks, buses)
• stationary sources (e.g., factories,
refineries, power plants),
• indoor sources (e.g., building materials
and activities such as cleaning).
There are two types of stationary sources that generate
routine emissions of air toxics:
1. "Major" sources - are defined as “sources that
emit 10 tons per year of any of the listed toxic air
pollutants, or 25 tons per year of a mixture of air
toxics”.
• These sources may release air toxics from
equipment leaks, when materials are transferred
from one location to another, or during discharge
through emission stacks or vents
2. "Area" sources- smaller-size facilities that
release lesser quantities of toxic pollutants into
the air.
• Area sources are defined as “sources that emit
less than 10 tons per year of a single air toxic, or
less than 25 tons per year of a combination of air
toxics”.
• Though emissions from individual area sources
are often small, collectively their emissions can
be of concern - particularly where large numbers
of sources are located in heavily populated
areas.
Clean Air Act Amendments of 1977
• Major amendments were added to the Clean Air
Act in 1977 (1977 CAAA).
• The 1977 Amendments primarily concerned
provisions for the Prevention of Significant
Deterioration (PSD) of air quality in areas
attaining the NAAQS.
• The 1977 CAAA also contained requirements
pertaining to sources in non-attainment areas for
NAAQS.
“A non-attainment area is a geographic area that
does not meet one or more of the federal air
quality standards.” II CLASS
Prevention of Significant Deterioration (PSD)
•
The states are required to ensure areas already
in compliance with the national ambient air
quality standards do not deteriorate to or cross
those standards
.
• Such areas, must control the emissions of
certain pollutants such that the concentration of
those pollutants does not increase than the
allowable increment as set in the CAA.
Clean Air Act Amendments of 1990
• In 1990, Clean Air Act was revised and
expanded.
• 1. cost-effective approaches to reduce air
pollution.
• 2. Control of acid deposition (acid rain)
• 3. control of toxic air pollutants
• 4. stratospheric ozone protection
CONCLUSION
• By reducing air pollution, the Clean Air Act has led to
significant improvements in human health and the
environment.
• Since 1970, the six commonly found air pollutants have
decreased by more than 50 percent
• Air toxics from large industrial sources, such as chemical
plants, petroleum refineries, and paper mills have been
reduced by nearly 70 percent
• New cars are more than 90 percent cleaner and will be
even cleaner in the future, and
• Production of most ozone-depleting chemicals has
ceased.
• At the same time,
• the gross domestic products, or GDP, has
increased……
• energy consumption has increased and
• vehicle use has increased by almost 200
percent……………
How clean is clean……..???????
¼ of UNIT V
