Chemicals in New Orleans floodwater from residential neighborhoods posed little risk to people but may raise a long-term hazard to wildlife in Lake Pontchartrain, a new study reported Tuesday.
In general, water samples taken soon after the flood caused by Hurricane Katrina found that the water resembled normal rain runoff in its chemical makeup, said the study's lead author, John Pardue.
Still, people returning to their homes should protect themselves from germs that may be left behind in the sludge, he said.
The study, funded by the institute, found high levels of fecal bacteria in the water, just as previously published testing by the federal Environmental Protection Agency did. Normal rainwater in the area has high levels too because of leaky sewers, but Katrina flooding was different because of its sheer volume, Pardue said.
The study didn't sample water from industrial areas, and researchers cautioned that their results can't be used to assess non-residential areas. Their findings were published online Tuesday by the journal Environmental Science & Technology, the AP reports.
Virtually all the floodwater that once covered New Orleans has been pumped into Lake Pontchartrain, and Pardue said he and his colleagues are now analyzing the sediment it left behind.
As for the impact of the pumped water on the lake, Pardue said it didn't introduce any new chemicals but provided a large dose in a short time. He noted that all rainwater that falls in New Orleans is eventually pumped into the lake. A.M.