U.S. Water News Online
LARAMIE, Wyo. -- The planting of 8,000 cottonwood and
willow trees, as well as native grass and alfalfa, has begun showing
results cleaning up a site contaminated with creosote, an
environmental engineer said.
From 1886 to 1983, Union Pacific Railroad treated railroad ties
with creosote on the site along the Laramie River south of Interstate
80. The process contaminated the groundwater with millions of gallons
of oil containing creosote.
The Environmental Protection Agency placed the site on its
Superfund list of hazardous waste sites. A cleanup plan was launched
that involved shifting the Laramie River 150 feet to the west.
Although the EPA deemed the site remediated in 1999, some traces
of contamination remained.
By planting trees, grass and alfalfa at the site, Union Pacific
hoped that microbes in the plants' roots would eat up the creosote.
The first seedlings were planted in 1999.
Engineers on the site believe the process has been working.
"These plants need water to survive. So they are pumping water to
the root zone," said Jennifer Uhland, an environmental engineer with
CH2Mhill, the consulting company for the project. "What happens is
the microbial body that is naturally occurring in the root system --
will degrade the contamination. They'll use it as a food source."
The trees were planted over 17 acres. They are native to the area
and can survive in the harsh climate. Also, they grow deep roots and
use a lot of water, making them effective in breaking down
contaminants, Uhland said.
Another 31 acres were planted with grasses selected for their
hardiness and deep roots.
Return to the
U.S. Water News' Archives page
Return to the U.S. Water
Use a comma to separate e-mail addresses:
Hi, I thought you might like to read this article.