MAHONING RIVER A natural cleanup of man-made mess?

A study is to determine whether microbes can eat away pollutants.
By PETER H. MILLIKEN
VINDICATOR STAFF WRITER
A six-month study will be launched Saturday to help determine whether microbes can clean up the industrial contaminants in sediment from the Mahoning River banks and bottom.
A mixture of microbes, enzymes and nutrients will be released at 1 p.m. into a 50-foot-by-50-foot area of the river and its west bank above the Liberty Street dam in Girard.
The microbes are naturally occurring bacteria, fungi, algae and protozoa, which came from the soil along the river and have been fortified in a laboratory. No viruses or genetically engineered microbes will be used.
The cost and effectiveness of the method, known as bioremediation, will be evaluated in the $100,000 study being conducted by Waste Science Inc. of Rockville, Md., for the Eastgate Regional Council of Governments.
"We're just trying to see if this type of cleanup method would work for the Mahoning River in conjunction with the dredging," said Kimberly Mascarella, Eastgate's director of environmental planning.
Dredging
The bioremediation study is part of a $3 million feasibility study sponsored by the Army Corps of Engineers to find the best way to clean up the river. Another cleanup method under consideration in the Corps study is a $100 million project to dredge a 31-mile section of the river from Warren to the Pennsylvania line to remove the sediments.
In the Corps study, whose preliminary conclusions are scheduled for release by the end of next summer, the Corps is also considering removing some dams in the river, which trap sediment. The dams, some of them more than a century old and some now reduced to rubble, were built for navigation and industrial purposes.
The actual cleanup may involve bioremediation on the riverbank to avoid disturbing vegetation there, combined with dredging of the river bottom, Mascarella said. As for sediments trapped behind the dams, "They would have to dredge those sediments out first and then consider removing that dam," she said.
A unique river
"The Mahoning River is a unique urban river because it has an intact streamside forest. For an urban river, that's very rare. Usually, there's development right down to the water," she noted. "The bioremediation method is less intrusive (than dredging), and, if it can work, it can spare the riparian (streamside) zone from being dredged," Mascarella explained.
"It's a wide variety of [contaminants]. It's like a toxic cocktail," of oils, pesticides and metals in the sediment, said Katy Makeig, founder and president of Waste Science Inc., a 10-year-old environmental consulting firm.
"When you use microbes, you're kind of working within the system and the natural balance of the ecology to help you," Makeig explained. "One of the advantages of this method is that you're not digging up a lot of soils and then wondering where to put them," she said.
"They're fortified and they're targeted specifically for the contaminants that are out there," she said of the microbes.
"They use the contamination as food, eat it up, and, as soon as the food source is gone, they die back to their natural population levels," she said.
With their growth spurred by the enzymes and nutrients, the microbes will change the chemical state of the metal pollutants, rendering them unavailable as contaminants, and eat and destroy the remaining contaminants, she said. The metal pollutants include barium, chromium, iron, manganese, nickel and zinc.
Since 1988, the Ohio Department of Health has advised the public against swimming or wading in this 31-mile section of the river, or eating fish caught there, because its bottom and bank sediment contains cancer-causing industrial pollutants.
How it's done
The mixture of microbes, enzymes and nutrients to be applied to the river was prepared in the laboratory of Lambda Bioremediations Systems Inc. of Columbus, a subcontractor of WSI.
There will be an odor of gases given off by the microbes for about two days after the application, Makeig said. The microbes will survive the winter, but won't be very active during the winter, she added.
Some 300 gallons of the liquid mixture will be injected into the riverbank and sprayed over the riverbank surface so it can be washed into the soil during rain or flooding, she said.
In the underwater portion of the test site, the mixture will slowly be dispersed through 24 porous bags placed on the river bottom and filled with carbon pellets, which will be laden with the microbes, Makeig explained. "They'll sit there, and they'll act as little incubators," for the microbes, she said of the bags.
"There are eight major communities that lie along the industrialized part of the river that could use this river for economic development and quality of life and increasing property values," and for recreation, Mascarella said.
"Right in our backyard, we have this river, and we can't use it because it's contaminated. And we can't eat the fish out of it because there's an Ohio Department of Health advisory telling us that we shouldn't. The river deserves to be cleaned up," Mascarella concluded.