Citizen's Guide
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What is Incineration?
Incineration is the process of burning hazardous
materials at temperatures high enough to destroy
contaminants. Incineration is conducted in an
"incinerator," which is a type of furnace designed for
burning hazardous materials in a combustion chamber.
Many different types of hazardous materials can be
treated by incineration, including soil, sludge, liquids,
and gases. Although it destroys many kinds of harmful
chemicals, such as solvents, PCBs (polychlorinated
biphenyls), and pesticides, incineration does not
destroy metals, such as lead and chromium.
How Does It Work?
Hazardous materials must be excavated or pumped
into containers before incineration. They may require
further preparation, such as grinding or removing
large rocks and debris, or removing excess water. The
materials are then placed in the combustion chamber
of an incinerator where they are heated to an extremely
high temperature for a specified period of time. The
temperature and length of time depend on the types of
wastes and contaminants present. Air or pure oxygen
may be added to the chamber to supply the oxygen
needed for burning. The destruction of contaminants
will depend on:
• Reaching the target temperature: Depending on
the contaminants present, the target temperature
may range from 1,600 to 2,500°F.
Contaminated
Waste
_^ Gases to
Air Pollution
Control Devices
First Combustion Chamber
• The length of time the waste is heated in the
combustion chamber: Typically, solid wastes
must be heated for 30 to 90 minutes, while liquid
and gaseous wastes may only require 2 seconds.
• Mixing of the waste material. Mixing helps all of
the waste to be heated to the proper temperature.
As the wastes heat up, the contaminants volatilize
(change into gases) and most are destroyed. Gases that
are not destroyed pass through a secondary combustion
chamber for further heating and destruction. The resulting
gases then pass though air pollution control equipment,
which removes particulate matter (extremely small
particles or liquid droplets) and "acid gases." Acid
gases such as sulfur dioxide are very corrosive.
Incinerators can be constructed for temporary use at
the site. However, in recent years, it has been more
common for the wastes to be loaded onto trucks for
transport to a permanent offsite facility. EPA requires
that an incinerator can destroy and remove at least
99.99 percent of each harmful chemical in the waste it
processes. When some extremely harmful chemicals
are present, EPA requires that an incinerator show it
can destroy and remove at least 99.9999 percent of
contaminants in the waste. Ash remaining at the bottom
of the combustion chambers likely will require disposal
in a hazardous waste landfill. However, the amount of
material that requires disposal after incineration is much
less than the initial amount of waste that was burned.
How Long Will it Take?
Incineration of all waste at a site might take a few weeks
to several years. The actual cleanup time will depend on
several factors. For example, it may take longer where:
• The amount of waste is large, requiring more time
to excavate or pump out.
• The waste contains large rocks or debris that
must be removed before incineration.
• The capacity of the incinerator is small.
These factors vary from site to site.
How an incinerator converts waste into ash and gases.
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Is Incineration Safe?
An incinerator that is properly designed and operated can safely destroy
harmful chemicals. Proper temperatures must be maintained for complete
incineration, and air pollution control equipment must be monitored to ensure
all contaminants are removed from the offgases. Hazardous materials
transported to offsite incinerators are covered or contained to prevent their
release.
How Might It Affect Me?
Residents and businesses near the site may see and hear large earth-moving
equipment such as backhoes that may be needed to excavate wastes for
incineration. They will notice increased truck traffic if wastes must be transported
to an offsite incinerator. Odors, smoke, and dust are not typically issues with
modern incinerators, though residents may occasionally see harmless white
steam that disappears quickly into the air.
Why Use Incineration?
Incineration can destroy a wide range of highly contaminated wastes and
greatly reduce the amount of material that must be disposed of in a landfill. For
small contaminated areas, excavation and transport to an offsite incinerator
can be a quick cleanup approach. A faster cleanup may be important when a
site must be cleaned up quickly to prevent immediate harm to people or the
environment.
Although incinerators require a
lot of fuel for their operation, the
heat generated sometimes can
be used to generate electric
power in a process called
"waste to energy."
Offsite incineration has been
selected or is being used at
over a hundred Superfund
sites, while onsite incineration
has been selected or is being
used at over 40 Superfund sites
across the country.
Example of offsite incinerator.
Example
Incineration was used as part
of the cleanup effort at the
MOTCO, Inc. Superfund site
in Texas. From the 1950s
through 1970s, the site was
contaminated with tar- and
petroleum-related chemicals
from tar recycling activities.
Investigation of the site
in the 1980s found seven
unlined waste disposal pits
containing 7 million gallons of
PCB-contaminated liquid and
18 thousand cubic yards of
sludge and tar. These wastes
had to be removed to prevent
further contamination of soil
and groundwater.
From 1993 to 1996, the
liquid, sludge, and tar were
excavated and transported
about 280 miles to an
incinerator in Louisiana. The
remaining contaminated
soil beneath these wastes
was covered with a cap and
surrounded by underground
slurry walls to prevent
release of any contaminants
that remained. Removal of
the contaminant sources was
expected to speed up the
cleanup of groundwater.
For More Information
For more information on this
and other technologies in the
Citizen's Guide Series, contact:
U.S. EPA
Technology Innovation &
Field Services Division
Technology Assessment Branch
(703)603-9910
NOTE: This fact sheet is intended solely as general information to the public. It is not intended, nor can it be relied upon, to create any
rights enforceable by any party in litigation with the United States, or to endorse the use of products or services provided by specific
vendors. The Agency also reserves the right to change this fact sheet at any time without public notice.
United States
Environmental Protection
Agency
Office of Solid Waste and
Emergency Response
(5102G)
EPA 542-F-12-010
September 2012
www.epa.gov/superfund/sites
www.cluin.org
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