The decision to pour heavily contaminated floodwater from New Orleans streets into nearby Lake Pontchartrain was a difficult one and could pose environmental problems in the years ahead, the chief of the Environmental Protection Agency says.
“We were all faced with a difficult choice,” EPA Administrator Stephen Johnson said. “The choice was, we have to get the water out of New Orleans for the health and safety of the people and we need to put it someplace.”
But other experts say the lake’s environmental health is not threatened, despite millions of gallons of fetid floodwaters being pumped in from New Orleans every minute.
Meanwhile, concern lingers about the safety of the stricken city’s drinking-water supplies as crews work to restore service in the wake of Hurricane Katrina.
New Orleans’ drinking water comes from the Mississippi River, not the lake.
The 630-square-mile Lake Pontchartrain formed some 5,000 years ago by the meandering Mississippi River.
The Army Corps of Engineers is pumping contaminated floodwater into the lake, and its technicians are not adding chlorine or other disinfectants.
“You can’t chlorinate the water going into the lake,” said Edward Bouwer, a professor of environmental engineering at Johns Hopkins University, “because that would create other problems” that could possibly damage the lake’s health and alter its ecosystem, he said.
An EPA analysis of the stagnating floodwater conducted last week revealed a veritable zoo of microorganisms mixed with toxins, such as lead.
“We don’t know where the lead came from,” said Johnson. “The samples that were taken were not near any industrial area.”
But he noted the city was full of old homes with lead paint and asbestos, which is probably also in the water.
But Bouwer and other scientists emphasize that human bacteria in the water, such as E. coli and other intestinal coliform species, will not live long.
Pumping the water into the lake disperses the bacteria and exposes them to ultraviolet light.
“Once they are outside of us, these pathogens do not survive too long,” Bouwer said, adding that sunlight and age destroy the microbes. Coliform bacteria normally aid digestion.
Dr. Richard Besser, director of the Centers for Disease Control and Prevention’s response to Hurricane Katrina, said a bacterium related to three deaths in the storm’s aftermath probably will not harm lake waters or the fish. Vibrio vulnificus is common in shellfish often found in the Gulf of Mexico.
But some experts pointed to additional organisms that might flow into Lake Pontchartrain that can persist despite the presence of sunlight.
“There is a possibility of cryptosporidium and giardia being detected in the water” flowing out of New Orleans, said Charles O’Melia, a water quality expert at Johns Hopkins University.
Along with the toxic chemicals and sewage, the lake has become saltier.
The hurricane poured waves of saltwater into the lake, and the recovery effort will increase the salinity even more.
Environmentalists worry that could harm the lake’s cypress swamps.
Another option for disposing of the tainted floodwater would be to pour it into the Mississippi River, where it eventually would move into the Gulf of Mexico, said the EPA’s Johnson, but “our collective judgment was to put it into Lake Pontchartrain.”
He said the EPA was prepared to “take whatever steps we need to take” to deal with future environmental problems.
As for the city’s drinking water, many New Orleans inhabitants drank bottled water even before Katrina.
Residents of New Orleans are among millions of Americans who draw water from the Mississippi River. Normally, that water must be treated to be made fit to drink.
Sgt. John Zeller, a California National Guard engineer serving in the New Orleans area, said it will be at least three months before the city’s public water system is fully operational.
Some homes have running water now, but it is mostly untreated Mississippi River water.
For anyone wanting a bath, “It’s like jumping in the river right now,” he said.
Newsday, USA Today and The Associated Press contributed to this report.
