Recovery Time Analysis in Lake Pontchartrain after Hurricane Katrina

After Hurricane Katrina hit the Gulf of Mexico in August 2005, floodwaters covering New Orleans were pumped into Lake Pontchartrain as part of rehabilitation process to make the city habitable again. The long term consequences of this environmentally critical decision were left to observation. This paper examines the likely response of Lake Pontchartrain to the load of contaminants that were possibly in the flood waters via modeling several hypothetical scenarios. As a preliminary outcome, this study provides a useful tool to assess the possible extent of damage inflicted on the natural water resources of Southern Louisiana or similar environments elsewhere. An unsteady state fugacity model is developed in order to examine the environmental effects of contaminants on surface water bodies which have different physicochemical characteristics. Since the available data on the event is limited, uncertainty analysis is necessary. Thus, as a secondary outcome, the study further investigates the effects of the uncertainty in the parameters used in the model on the outcome using Monte Carlo analysis. The results indicate that Lake Pontchartrain, which was recovering from earlier assaults on its water quality, will continue for a long while on its path to recovery. Application of the derived model to three contaminants shows that the recovery time of the lake for the contaminant levels to go back down to MCL (maximum contaminant levels) values range between about a year and sixty eight years for the three contaminants considered in this study.