GLIN==> Model gives contaminated harbors clean-up options

Model gives contaminated harbors clean-up options

December 14, 2009

 

FOR IMMEDIATE RELEASE

 

COLUMBUS, OH - With five environmental Areas of Concern on Lake Erie,
communities all along the North Coast need to know which options will best
help them to clean up their harbors. Often, the choices come down to capping
the area or dredging out the contaminated sediment. A new computer model
created by Ohio Sea Grant researchers Dr. Patrick Fox and Dr. John Lenhart
of Ohio State University's Department of Civil and Environmental Engineering
and Geodetic Science can help communities weigh which option may be best for
them. The model allows agencies to input the characteristics of the sediment
in their harbor to determine exactly how it will behave, helping in the
planning process.

 

"We determined that you need to pay attention to the release of very small
particles from the sediments," Lenhart explains. "Those tiny particles are
able to get through filters and presses. They're very mobile, and they often
have contaminants attached to them." This mobility causes problems in both
types of remediation, capping or dredging.

 

When a cap is created, the small particles get stirred up and many wind up
in the capping layer itself rather than being isolated below. "You're
actually moving the contaminates two-thirds of the way through the cap,
which means those contaminates are actually going to work their way through
the capping layer much sooner than anticipated, or they might even go all
the way through, depending on what the cap is made of," says Lenhart.

 

As for dredging, it turns out that in physically removing the sediment, you
end up widely disbursing the contaminant at a low-level concentration
because it's fairly difficult to completely contain the small particles.
Some residual contamination is always left behind. 

 

"The model is really a tool that can be used in risk assessment, remediation
plans, and engineering proposals," says Lenhart. "It can help communities
figure out the best course of action."

 

To read more about this Ohio Sea Grant-funded research, visit
http://ohioseagrant.osu.edu/_documents/twineline/v31i4.pdf

 

The Ohio State University's Ohio Sea Grant College Program is part of NOAA
Sea Grant, a network of 30 Sea Grant Programs dedicated to the protection
and sustainable use of marine and Great Lakes resources. For information on
Ohio Sea Grant and Stone Lab, visit ohioseagrant.osu.edu.

 

###

 

Contact: 

 

Dr. John Lenhart, Ohio State University, lenhart.49 at osu.edu, 614.688.8157

 

Dr. Patrick Fox, Ohio State University, fox.407 at osu.edu

 

 

Stacy Brannan

Associate Editor

Ohio Sea Grant and Stone Laboratory

1314 Kinnear Road

Columbus, OH 43212

614.247.7109

brannan.16 at osu.edu

 

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