U.S. plans to reroute river around toxic muck
Project will steer Little Menomonee past Superfund cleanup
By DON BEHM
Milwuakee Journal Sentinel
A six-mile stretch of the Little Menomonee River on Milwaukee's
northwest side will be rerouted at a cost of $10 million
so that it no longer flows over mud laced with cancer-causing
chemicals, federal officials have announced.
Creating a new riverbed is an extremely rare solution
for preventing public contact with chemical wastes, but
it is practical for this small stream, said Russ Hart,
remedial project engineer with the U.S. Environmental
Protection Agency in Chicago.
"We're trying to accomplish two goals with this one step,"
Hart said. "We wanted to make sure the hazardous substances
are out of the river. And by designing a new channel,
we can return some of the natural meander to the stream."
"The work will provide a safe recreational corridor for
the city," Hart said.
The Little Menomonee River flows out of wetlands on the
Milwaukee County-Ozaukee County border before it enters
the city's only federal Superfund priority cleanup site
immediately downstream of W. Brown Deer Road.
From 1921 to 1976, heavy rains and spring floods washed
creosote off the grounds of a wood preserving plant that
operated on the river's banks south of the street. For
all those years, black, gooey toxic waste flowed into
the Little Menomonee, where it was carried six miles downstream
to the confluence with the Menomonee River north of W.
Creosote contains chemicals known as polycyclic aromatic
hydrocarbons, or PAHs. The chemicals are known to cause
cancer in humans. People who have contact with the compounds
can suffer skin burns, as Milwaukee residents learned
in June 1971.
Twenty teenagers who had volunteered to remove trash
from the river on a summer weekend that month received
deep red skin burns after wading into the stream near
N. 98th St. and W. Mill Road.
The public had not been aware of the presence of creosote
in the Little Menomonee River prior to the incident, officials
said at the time.
The former wood preserving plant was not listed with
the Superfund program until 1985. Now, 17 years later,
the EPA will begin overseeing the final three-year stage
of its cleanup, Hart said.
Built in 1921
The T.J. Moss Tie Co. built the original plant in 1921.
Workers there treated railroad ties with a mixture of
fuel oil and creosote, a wood preservative derived from
Timbers were stacked outdoors, allowing the chemicals
to drip onto the soil. Creosote waste also was dumped
into ponds and pits that drained into the river.
Kerr-McGee Chemical LLC in Oklahoma City bought the property
in 1963 and operated the plant under the name Moss-American
from 1965 until 1976, when it was shut down. Buildings
were razed in 1978.
Later that year, Kerr-McGee donated 65 acres to Milwaukee
County for parkland. After the site is restored, the county
will maintain the open space as floodplain for the river,
said Milwaukee County Supervisor Rob McDonald, who represents
A 23-acre section of the Superfund site is owned by Union
Kerr-McGee agreed to pay for the cleanup in 1991. The
company estimates it will cost $30 million - a third of
that to reroute the river - to do the job, said Debbie
Schramm, Kerr-McGee's manager of corporate communications.
Beginning in early October, contractors for Kerr-McGee
will excavate the first 1.14 miles of new channel for
the narrow river, removing an estimated 25,000 cubic yards
of clean soil, from W. Brown Deer Road downstream to the
Wisconsin & Southern Railroad bridge north of W. Bradley
When the river's flow is diverted to its new home sometime
this winter, workers will dredge about 5,000 cubic yards
of heavily contaminated muck from the former channel,
according to the EPA's Hart. Then the old riverbed will
be filled with soil from the new channel.
There is not adequate space in the river's floodplain
from the railroad bridge to Bradley Road to accommodate
a new channel. Consequently, muck will be dredged from
that one-tenth of a mile stretch of the Little Menomonee
to remove the PAHs.
Contaminated sediments will be stored at the former plant
site while awaiting treatment. Chemicals will be removed
so that the material can be placed as fill elsewhere on
Completed next year
Next spring and summer, Kerr-McGee and the EPA will complete
cleanup plans for the second stretch of the Little Menomonee,
about 2.24 miles from W. Bradley Road downstream to Mill
Work there, including the digging of a new channel, will
begin in October 2003, according to Hart.
Cleanup of the final 2 1/2 miles of stream will be completed
the following year.
As of December, Kerr-McGee already had spent $19 million
on three earlier stages of the Moss-American cleanup,
according to Schramm. The three activities included:
- Removing 1,100 gallons of a heavy concentrate of creosote
and fuel oil from a depth of 9 to 10 feet beneath the
surface at the Moss-American property. Six wells slowly
pumped out the chemicals from 1995 to 1999.
- Installing a groundwater treatment system that began
operating in the summer of 2000. For the remainder of
this decade, air and nutrients will be injected below
ground to spur bacteria to digest contaminants in groundwater.
- Heating 137,000 tons of highly contaminated soil from
the plant site. Thermal treatment destroyed the chemicals.