At Mayak in the Urals, the site of the 1957 Kyshtym accident and the location of Lake Karachi, reputedly the most contaminated spot on earth, Parker's team determined that the contaminated sediments in the reservoirs on the Techa River presented a threat to the downstream population. The team made some recommendations to lessen the likelihood of failure of the dams as well as some recommendations to prevent a recurrence of the 1967 redistribution of radionuclides from Lake Karachi.
For the Mining and Chemical Combine (MCC) on the Yenisei River in Siberia and at the Siberian Chemical Combine at Tomsk, the site of a 1993 accident, Parker's team evaluated the health effect of the discharge of radioactive wastes to the Yenisei and Tom Rivers. They found that the contamination was far less than in the Techa River but, due to the unavailability of some site specific data, they were not able to predict the doses to the population from potential accidents that could arise from the storage of contaminated sediments in surface waste storage basins above the rivers.
The risks associated with a flood-related release of contaminated sediments in storage basins could be potentially significant. "Under normal circumstances, the high flows and thousands of kilometers of the Yenisei River from the plant to the Kara Sea provide the dilution required to prevent extensive contamination," Parker explains. "However, a release of highly contaminated sediments from basins above the river could result in extremely high contamination levels."
Parker and his associates studied the known and potential impacts of injecting liquid radioactive waste into deep wells at the MCC. "The MCC is one of two major Russian sites using deep-well injection to dispose of liquid radioactive waste," he says. "This practice, which has been largely replaced in modern times by solidifying radioactive waste, is controversial due to the fact that much is still uncertain about how wastes migrate in geological strata."
Parker's team examined the potential hazards of liquid waste injection associated with normal operating conditions of the plant as well as dangers posed by possible accidents and natural events. "We determined that none of the scenarios we investigated presented a significant risk to the public except for using the groundwaters contaminated by the deep well injection for drinking water. There are more attractive sources of groundwater in the vicinity, which are nearer the surface and with greater yields, so it is judged that the likelihood of using them is slight," Parker says.

From Rubble to Roadway in U.S.

The Vanderbilt Department of Civil and Environmental Engineering has been involved in post-Cold War clean-up in the United States as well.  The U.S. Department of Energy commissioned the CEE Department to recommend ways to recycle or dispose of some 30,000,000 tons of waste concrete from decommissioned military sites around the country. Parker and his team analyzed the problems and made recommendations that would result in recycling 45-85 percent of the projected amount of concrete rubble into general fill material and aggregate to be used in roadway and new construction.
"The plan could save the Department of Energy up to $1.3 billion," Parker says. "The volume of waste concrete being sent to landfills would be reduced as would the environmental burden of producing virgin aggregate and fill for new construction."
Associate Professor Alan Bowers is also involved in devising ways to clean up U.S. decommissioned sites. He studies ways to protect the atmosphere from chlorinated organic materials using filtering systems in the ground. The "horizontal barrier" under study uses iron filing, which reacts with harmful chemicals to keep them from evaporating into the air.
"We are the first ones to study the effectiveness and risks involved with this method," Bowers says. "We use probability models to assess the technique, which would also be helpful in cleaning up dry cleaning products in landfills and degreasers in defense installments."

Wastewater in Equatorial Countries

Although Richard E. Speece, Centennial Professor of Civil and Environmental Engineering, is also involved in bioremediation of U.S. government sites, his work on anaerobic treatment of domestic wastewater could make a significant improvement in the lives of millions of people living in poorer countries close to the equator.
Working with Ph.D. candidate Jorge Cevallos from Ecuador, Speece is developing a method of treating domestic wastewater in warm climates that is as effective but far less expensive than standard treatment techniques requiring oxygen. The method uses volcanic pumice (commonly found in equatorial countries) in reactors to adsorb the anaerobic bacteria which break down the wastes.
Speece's anaerobic reactor designs are also applied to the problem of bioremediating hazardous materials underground, where no oxygen is available. He is developing a configuration of pump-and-treat reactors that sequences the reactions to achieve maximum efficiency in purification. His method could also be useful in cleaning de-icers at airports.
Also looking at ground-level processes is Eugene LeBoeuf, assistant professor of civil & environmental engineering, who is examining methods of cleaning organic chemicals using the vegetation found naturally in soil. LeBoeuf is interested in how this humic matter acts as glassy polymers to react with harmful chemicals. He is studying the effectiveness of different types of humic matter under various climatic conditions.

Emissions and Wastewater in Tennessee

Professors Frank Parker, standing, (member of the National Academy of Engineering) and Ed Thackston, chair of CEE, confer on an assessment study.

The department's expertise in air pollution was brought to bear in a recent study of the Oak Ridge Incinerator's risk to health of the surrounding population.
Parker spearheaded the efforts of the Governor's Independent Panel to study allegations reported in a series of articles by the Tennessean newspaper on the impact of the Toxic Substances Control Act (TSCA) Incinerator on the health of workers at the East Tennessee Technology Park.
Edward L. Thackston, professor and chair of Civil and Environmental Engineering, participated in the study. "We found that emissions from the incinerator were tiny compared to what was expected and what was permitted under U.S. and Tennessee regulations," he says.
The panel did not find a direct causal relationship between the illnesses in Oak Ridge and the incinerator, Thackston notes, and did not recommend ceasing operation of the incinerator.
Frank Bowman, assistant professor of chemical engineering, also focuses on air quality and evaluates ways to assess behavior of aerosols in the atmosphere. In addition, he studies the formation of atmospheric ozone, a primary irritant in photochemical smog. These studies can lead to better evaluations of pollution control strategies.
Thackston was instrumental in helping the Nashville Metropolitan Government save approximately $106 million by eliminating two planned projects of the Combined Sewer Overflow Project.
"We determined that two of the CSO projects would not help solve the problem of untreated wastewater being discharged into the Cumberland River as a result of storms," Thackston explains. "We calibrated and refined a mathematical model to evaluate wastewater impacts on the river, which helped Consoer Townsend Envirodyne develop an integrated model for renovating the system at lower costs."

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