United States
Environmental Protection
Agency
Vapor Extraction System
Expanded Into Northern Area
Description of the SVE
A key component of the American
Chemical Service site is the
system set up to vent volatile
organic compounds from the
ground under the site. It's called a
"soil vapor extraction" system, or
SVE. Here's how it works.
The system consists of a network
of wells drilled into the ground in
the containment area. These wells
allow removal of volatile organic
compounds from the soil and
debris above the water table.
A vacuum draws the vapors out of
the ground. They are routed to a
machine that burns the vapors at
1,750 degrees Fahrenheit. This
process converts the hazardous
substances to water vapor and
carbon dioxide, which are
released into the atmosphere.
Another waste product is mineral
acid, which is neutralized with a
base.
This process destroys more than
99 percent of the vapors.
Indiana Department of
Environmental Management
expects the process to destroy no
less than 3 pounds of vapors per
hour. The system is currently
destroying approximately 11
pounds per hour.
American Chemical Service Site
Griffith, Indiana
October 2003
A system designed to remove hazardous underground gases at the
American Chemical Service site has been expanded and now covers
the entire site. It's called a "soil vapor extraction" system, and it
consists of a network of wells placed into the ground to remove
volatile organic compounds, called VOCs, which are hazardous
chemicals that evaporate easily on contact with air.
The system was first installed in the southern part of the site by the
group of companies EPA has determined to be responsible for the
pollution. That part of the system has been removing VOCs for about
eight months and continues to function routinely.
More recently, the system has been expanded to the northern portion of
the site. This new section is gradually coming up to speed.
Also, a soil covering was installed around the former ACS plant to
help prevent rain water from washing through the contaminants into
the supplies of fresh water (called ground water) below. The cover also
helps the vapor extraction system work more efficiently.
Lightning causes shutdown
This summer, the water treatment plant was struck by lightning,
blowing out all the electronics in the building. The pumps were shut
down so workers could replace or repair the electrical components.
That work took a couple of weeks.
Having the pumps turned off for that long caused another problem.
Part of the water treatment process involves tiny organisms that eat
organic solvents in the ground water that is pumped out. Without a
regular source of food, some of these "bugs" died and had to be
replaced. The good news is that during the shutdown, no untreated
ground water was discharged from the treatment plant.
What's Coming
The current work at the ACS site is called "final cleanup," and it's
expected to be completed in mid-2005. Once this phase of the cleanup
is finished, there will be routine maintenance and operation activities
as the cleanup process continues.
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United States
Environmental Protection
Agency
Region 5
Office of Public Affairs (P-19J)
77 West Jackson Boulevard
Chicago, Illinois 60604
ACS Site: Vapor Extraction System Expanded
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