Some post-Katrina floodwaters cleaner than expected

Some of the floodwaters pumped out of New Orleans by the U.S. Army Corps of Engineers — about 250 billion gallons all told, dumped mostly into Lake Pontchartrain — may not have been as toxic as initially feared. Researchers at Louisiana State University took samples five to nine days after the deluge and found that, in general, chemical levels in the water were similar to the area’s normal rain runoff. The samples did show high levels of sewage contamination, aligning with findings already published by the U.S. EPA, so returnees are being cautioned to protect themselves against possibly germ-laden residual sludge. The study also cautions that the results apply only to residential areas of New Orleans, not industrial areas. Being soaked with the equivalent of a couple years’ worth of storm runoff in just a few weeks may ultimately prove hazardous to Lake Pontchartrain’s wildlife — researchers say the state will need to stay on top of monitoring the lake and its critters for trouble.