Lauren Smith knew her science fair project might stir up mud.

"The idea was to see how much mercury was in sediment in the Savannah River," the 16-year-old John S. Davidson Fine Arts Magnet School junior said.

In a project that took several months, Lauren and her mentor - Savannah Riverkeeper director Frank Carl - tested sediment upstream and downstream of Olin Corp.'s Augusta Plant, which uses mercury in its chemical manufacturing processes.

Mercury readings were near-normal in the main river channel, but when samples were tested from a navigable tributary channel that discharges Olin's wastewater into the river, the results were far different.

"The levels in the river upstream and downstream from the Olin channel were 26 to 46 parts per billion." she said. "The samples in the channel were 36,000 to 62,000 parts per billion."

By comparison, the National Oceanic and Atmospheric Administration's standard for mercury in stream sediment ranges from 5 to 51 parts per billion - with levels more than 560 presumed to effect all nearby organisms.

The mercury concentrations were confirmed with certified equipment at the Savannah River Ecology Lab in South Carolina, Dr. Carl said.

Although the elevated mercury level was news to Georgia's Environmental Protection Division, it was by no means a surprise.

"What's in that channel may be historic," said Jim McNamara, a compliance officer in EPD's Hazardous Waste Management Branch whose responsibilities include the Olin site.

The 40-year-old plant has been permitted for more than 15 years to clean up a former landfill on the site that has contaminated groundwater with mercury, he said.

"Under the hazardous waste rules we have not required them to clean up their canal, and we never required them to test that channel," he said, noting that the canal is technically Olin's private property, and its canal is not regulated as state waters would be.

Generally, Olin's Augusta plant ranks at the top of the list in terms of consistent compliance with environmental regulations, Mr. McNamara said.

Its state permit provides for small releases of mercury to the river.

"As those plants go it's about as good as it gets, and it's the only facility of its size that ever aced an inspection - with no violations whatsoever," he said, adding that the company could choose to clean the canal or restrict access to the area.

Dr. Carl, whose Riverkeeper organization is an environmental advocacy group, said the channel probably should be cleaned up, given its proximity to the river.

"It's gross," he said, adding that he plans to ask EPD to conduct an independent sampling of the area to determine whether the mercury levels pose any hazard to fish or the nearby river.

A message left for Olin Plant Manager Lenny Scott was not returned Wednesday.

Mercury is categorized as a persistent bio-accumulative toxic because it can build up in the tissue of fish or animals that ingest it, and it can cause an array of health problems.

Lauren, whose parents are a biochemist and physician, exhibited her project last week at the 59th Georgia Science and Engineering Fair in Athens, where it earned a top 10 Grand Award and the U.S. Fish & Wildlife Service's first place prize in environmental science.

The project will be entered in the international science fair competition later this year in Indianapolis.

Reach Rob Pavey at 868-1222, ext. 119 or rob.pavey@augustachronicle.com.