MESL

MESL - Lake Pontchartrain Pollution


HURRICANE KATRINA: Lake Pontchartrain Pollution and Environmental Management:

Research Group:

Sinem G. Kılı, Kijin Nam and Mustafa M. Aral

Hurricane Katrina left behind a devastating city with lots of problems to tackle. The flood waters which have filled the city have to be drained in order to make the city livable once again. Even though draining the flood waters into Lake Pontchartrain seems to be an effective solution for now, the long term pollution effects of this process are not yet known as the water being drained into the lake contains various potentially hazardous chemicals. Dilution is expected to take effect in cleaning up these contaminants in the lake. Nevertheless, all chemicals behave differently and they do partition into different pathways when introduced into an open system such as a lake. Some of the contaminants volatilize, some of them adsorb to solid materials and some of them stay in aqueous phase. In any attempt to determine the fate of these chemicals, existence of sediment, biota and air phases must be considered. This paper addresses this issue trough application of fugacity analysis to Lake Pontchartrain. Using fugacity analysis, a chemical equilibrium between phases can be established and partitioning among different compartments can be predicted.

Once draining of flood waters is completed, the lake would, over time, will come back to its original chemical composition through reactions, outflows, volatilization and sedimentation. Living organisms in the lake will be affected from the input of chemicals as well. Some of the chemicals, that have tendency to bioaccumulate, will enter food chain. The amount of a chemical in each phase can be calculated using fugacity approach, and simple mass balance calculations may give us an estimate of how long it would take for the lake to replenish. The analysis of the water being drained into the Lake Pontchartrain is not yet known. Therefore, in this study contaminants representing certain groups of chemicals are examined using existing data. Benzene representing volatile aromatic compounds, lindane representing pesticides and lead representing a metal has been selected in this study. 

Preliminary results show that, wind effects thus volatilization becomes a very important process for clean up of compounds such as benzene. However, this may create air pollution in the vicinity of the lake. A hydrophobic contaminant such as lindane ends up in sediments, which would bring about more costly clean up procedures for sediments. It is expected that, this study will show how effective dilution will be as a means of self-cleaning and will direct researchers in the right direction regarding the behavior of different compounds in Lake Pontchartrain.

FUGACITY ANALYSIS OF LAKE PONTCHARTRAIN

To evaluate the fate of potential pollutants pumped back into the lake we used the dynamic fugacity analysis approach to estimate the time it may take for Lake Pontchartrain to go back to its pristine conditions. This analysis is relatively simple and provides us with first estimates to answer this question. The outcome of this study is summarized in the linked document -- please click on the link.

THREE DIMENSIONAL TIDAL HYDRODYNAMIC MODEL FOR LAKE PONTCHARTRAIN.

Fate and transport of contaminants in Lake Pontchartrain is mainly governed by the tidal hydrodynamics and the chemical kinetics of the contaminants pumped into the lake. For this more complete analysis, when compared to the analysis discussed above, a three dimensional tidal hydrodynamic model of the lake need be developed. Our first attempts in this direction can be found in the links below. To view the results of these simulations you need to have an ".AVI" file player (such as MS Windows Media Player) installed on your computer.

Please view introductory slide presentation first.

Wind induced velocity distribution patterns in Lake Pontchartrain without tidal effects. (Requires a MS Windows Media Player)

Wind induced velocity distribution patterns in Lake Pontchartrain with tidal effects. (Requires a MS Windows Media Player)

At this time this study is ongoing. Please visit this site often to review the results of this research program.

 


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