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Two important
items because they challenge earlier evaluations and public assurances that it
is safe to return to New Orleans:
Note that I’ve highlighted the project chemist’s credentials since this
will be a provocative message and no doubt challenged. Key to this is exposure
per and for how long. Sampling shows contamination By
Mike Dunne, Baton Rouge Advocate staff
writer , Oct. 07, 2005 Wilma Subra, a New Iberia chemist overseeing the sampling project, said
the results show that officials should not be allowing residents back home. If residents feel compelled to return,
they should wear
respirators, protective suits and gloves and boots, she said. "Babies shouldn't go in, pregnant women shouldn't go
in, elderly shouldn't go in," said Subra, who has worked with the U.S. Environmental
Protection Agency, serving as technical adviser for community groups living
near Superfund sites and sitting on several EPA science advisory committees. "If this was a waste site with chemicals exceeding the
(residential) criteria, they would not allow unrestricted access,"
Subra said. "There is a desperate need for EPA to come up with clean
criteria" for flooded neighborhoods before allowing residents to return. The samples were
collected in mid-September in Orleans and St. Bernard parishes by Altamont Environmental of Asheville, N.C., and analyzed by Pace Analytical of New Orleans, which is
an EPA-certified laboratory. Among the findings
were several samples with levels of polynuclear aromatic hydrocarbons, or PAHs, exceeding the EPA residential standard. Many of those PAHs are known or
suspected cancer-causing agents. In the Lower 9th Ward,
sediment tests revealed 12 PAHs.
One, benzo (a) pyrene, was detected at 195 parts per billion, three
times greater than the EPA Region 6 residential standard of 62 parts per
billion. Arsenic, a known
cancer-causing agent, was found at a concentration 75 times higher than the EPA
residential standard, she said. Subra said the results
mean residents could
face both short-term and long-term health risks, which could include
"respiratory problems, asthma, skin rashes and damage to internal organs
-- and, potentially, cancer over the long-term." Subra has already been
critical of the level of testing by EPA and the Louisiana Department of
Environmental Quality. Late Thursday, EPA
issued a press release that says sediment and water samples taken Sept. 26 did
show some elevated contaminants, including some PAHs. In each case, EPA says, levels were "below what Agency
for Toxic Substance of the Centers for Disease Control considers to be
immediately hazardous to human health." The LEAN tests of
sediment in the Lower 9th Ward show elevated levels of heavy metals, such as
lead, and volatile organic chemicals associated with petroleum products. On Agriculture Street,
designated as a Superfund site, 10 PAHs were found, with benzo (a) pyrene
detected at 2.7 times higher than the EPA residential standard. The arsenic concentration was 13.3
times higher than the EPA residential standard, Subra said. Sediment in the
Morrison Road area contained arsenic levels 28 times greater than the EPA
residential standard. In the Meraux
residential area, sediment was contaminated with elevated levels of benzene,
chlorobenzene, toluene and carbon disulfide and the heavy metals barium,
chromium and lead, Subra said. In a Chalmette
residential area, sediment was contaminated with elevated levels of
chlorobenzene, toluene, carbon disulfide, barium, cadmium, chromium and lead. Last week, Eric Olsen
of the Natural
Resources Defense Council,
a national environmental group, told a U.S. House of Representatives
subcommittee that 25 percent of EPA's own air tests show benzene levels
exceeding the National Institutes of Environmental Health and Safety two-week
exposure standard of 4 parts per billion. EPA's analysis
compared those levels to the acute exposure limit of 50 parts per billion -- a level safe only for
24-hour exposure times. http://www.2theadvocate.com/stories/100705/new_sampling001.shtml The ASCE report
confirms allegations by the private construction firm that built the floodwall
at the 17th St. Canal -- allegations that were rejected by the Corps and a
judge at the time -- that the soil foundations under the floodwall were weak
and gave way. The study also confirms the LSU Hurricane Center's conclusions two
weeks ago that the water was not high enough for the floodwalls to be overtopped. Civil
engineers live and die by core samples. Here is the website for the American
Society of Civil Engineers http://www.asce.org/asce.cfm Engineers Offer a New
Explanation of How Levees Broke
By Christopher Drew
and John Schwartz, New
York Times, Oct. 7, 2005 NEW ORLEANS - The first independent experts to examine the
New Orleans levees said on Friday that the walls on two critical canals gave
way as the pressure from the floodwaters ripped through the soil beneath them,
shoving one of the earthen bases as far as 35 feet into a nearby neighborhood. The engineers said the findings, which they warned were
preliminary, raised questions about the design of the levees and the testing of
the relatively fragile soil during the construction of the walls. They also
said that on the 17th Street Canal, the source of the flooding in much of the
main part of the city, the flood wall broke in an area where a contractor had
complained to the U. S. Army Corps of Engineers that the soil that anchored the
wall was dangerously soft. The findings conflict with early evaluations by the Corps of
Engineers, which suggested that levees had collapsed because Hurricane Katrina's
surging waters spilled over the top of the flood walls and scoured away the
supporting soil on the other side. The team includes members of the American Society of Civil Engineers and a group from the University of
California, Berkeley that is funded by the National Science Foundation. They spent this week in New Orleans, working with the Corps and engineers from
Louisiana State University to examine what engineers now say were at least 10
separate breaches. The engineers, speaking at a news conference Friday, said
there was no
evidence of "overtopping" at the 17th Street or London Avenue canals,
which are of particular interest to the engineers because their breaches
devastated older parts of the city that do not usually flood. Robert Bea, a member of the Berkeley team, said the likeliest chain of events was that
water pushed sideways against the upper part of the walls during the storm
surge and that the intense pressure caused the weak soil to give way, sliding
the levee into the neighboring lawns. Had the pilings that
supported the flood wall been driven deeper, into firmer soil, he said,
it might have stayed put. Dr. Paul Mlakar, an investigator from the Corps, and
Professor Raymond Seed, a professor of engineering at Berkeley, said another
possibility was that the churning
waters scoured the base of the canal side of the levees, weakening their structure. Dr. Mlakar said the Corps now agrees that the levees at 17th
Street and London Avenue were not destroyed by being overtopped. Dr. Seed said
the water did not appear to have risen any higher than two and a half feet from
the top of the flood walls at those canals. Other levees were overtopped, including those on the Inner Harbor
Navigational Canal and the Mississippi River Gulf Outlet. The surge of water
over the levees along the Gulf Outlet canal extended for thousands of feet, Dr.
Mlakar said. The waters from those two canals inundated the city's Lower 9th
Ward and St. Bernard Parish, causing some of the worst flooding. At the northernmost breach of the London Avenue Canal and at
the 17th Street Canal, there was "soil mass movement," according to the engineers, and a
section of the 17th Street levee embankment was pushed 35 feet to the side by
the floodwaters. On the London Avenue Canal, a phenomenon known as "heave" appears to have occurred, meaning that the soil
shifted under the levee, causing the ground on the other side to rise sharply.
The instability could have caused the walls atop the shifting ground to
collapse. Questions of soil quality at the 17th Street Canal levee
have come under scrutiny in recent days because of a contractual dispute from
the 1990's between the Corps of Engineers and a contractor, Pittman
Construction, that was building the flood walls on top of the earthen levees. According to documents related to the case, the Corps
complained that several sections of the flood wall had shifted during
construction. The company contended that the soil was unstable and said the
Corps should have discovered that through tests before the project began.
Professor Bea said that in retrospect, it appeared that Pittman "kind of
telegraphed the problem." Although the Corps has not yet established whether the
sections of flood wall at issue in the legal dispute were the same ones that gave
way after Hurricane Katrina, engineers with the forensic team said that there
appeared to be some overlap. Professor
Bea suggested that the Corps might well have missed soil problems in its core
samples, since the soil appeared to vary in quality. "You can't take
borings every inch,"
he said. If the Corps had
determined that the soil was weak, it could have driven the sheet pilings that
form the spine of each levee farther into the ground than the standard 30 feet
in order to prevent shifting, Professor Bea said. "That would be No. 1 on the list," he
said. http://www.nytimes.com/2005/10/08/national/nationalspecial/08levee.html |
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