CMU scientists find right bacteria to eat pollutants
from U.S. Steel plants
By Len Boselovic, Post-Gazette Staff Writer
People started calling Christine Schuster names when
they heard she was spreading bacteria around the west
side of U.S. Steel's Gary (Ind.) Works, North America's
largest steel complex.
"I was known as the bug lady around here for a short
period of time," said Schuster, whose job is making
sure Gary's west side complies with environmental regulations.
There are bad bugs and there are good bugs. With the
help of Carnegie Mellon University scientists, Schuster
deployed some good bugs to attack a problem with an intimidating
Carbonaceous Biological Oxygen Demand, or CBOD. Because
CBOD, carbon compounds in the 30 million gallons of water
Gary's west side discharges daily were consuming oxygen
in the waters of the Grand Calumet River, which flows
into Lake Michigan. The lack of oxygen threatened fish,
which breathe oxygen through their gills. CBOD wasn't
a problem until the river water was heated by the summer
sun, depriving it of even more oxygen.
In 1998, the Gary Works violated Indiana Department of
Environmental Management regulations governing CBOD six
times during the months of July, August and September.
The violations prompted state officials to order U.S.
Steel to take care of the problem.
Schuster put the price tag at $1 million, a lot of money
to solve what was essentially an issue only three months
of the year.
But working with U.S. Steel employees, an outside contractor
and CMU scientists, Schuster came up with a much less
expensive solution: germs.
"Bacteria work cheap, but they're slow," said
Edwin G. Minkley Jr., director of CMU's Environmental
U.S. Steel was already adding bacteria to its wastewater
treatment plant two years ago when CMU got involved at
the invitation of the late U.S. Steel President Paul Wilhelm,
a CMU trustee. The bacteria fed on carbons, so they attacked
the compounds in oils, greases, cleaners and caustic solutions
that made it into the wastewater produced at Gary's west
end, where sheet steel is coated and finished.
"For all intents and purposes, they're food for
bacteria," said Matthew S. Blough, a program manager
at the CMU center.
The problem was U.S. Steel wasn't using enough of the
right kinds of bacteria and wasn't adding them early enough
in the wastewater treatment process for the germs to do
their job. Once Minkley and Blough identified the right
bacteria for the job and recommended adding them earlier,
CBOD violations dropped.
Schuster said the west end exceeded the limits three
times in 1999 and once in 2000 before turning in a perfect
record last summer.
Minkley hopes to use bacteria to solve other problems
for U.S. Steel, including contaminants in the Peters Creek
Lagoon at the Clairton Works coke plant. Byproducts from
baking coal in Clairton's ovens have made their way to
Peters Creek where they are contained in a small area
with a high concentration of contaminants and a larger
area with a low concentration. After being trapped, the
water is treated and released into the stream.
The challenge was finding bacteria that could survive
in the water, which has a high alkali content. Minkley
and Blough believe that they've found bacteria that are
up to the job and want to put them to work in the larger
of the two areas. The state Department of Environmental
Protection has tentatively approved a pilot project this
spring to test the theory, Minkley says.