U.S. Water News Online
WASHINGTON -- The debate about perchlorate contamination in
drinking water is getting more heated as environmentalists object to
a report claiming the widespread toxin is far less dangerous than was
A National Academy of Sciences panel has said that perchlorate, a
toxic chemical used in rocket fuel and explosives, is safe for
consumption at levels 20 times the standard being considered by the
Environmental Protection Agency.
The study is expected to influence the EPA as it develops its
first national standard for perchlorate in drinking water. But
environmentalists contended such a high standard could endanger
children's health while letting defense contractors off the hook for
"Wherever this standard is applied, most perchlorate contamination
sites will be wiped off the map," said Lenny Siegel, director of the
Center for Public Environmental Oversight in Mountain View, Calif.
"Millions of children and pregnant women will continue to be guinea
pigs in the great perchlorate exposure experiment."
The study comes after years of disagreement over how dangerous it
is for people to drink water tainted with perchlorate, a pervasive
leftover of Cold War defense manufacturing that has been found in
drinking water in 35 states. The chemical, which leaches easily into
groundwater from defense and manufacturing sites, can inhibit thyroid
function and is considered particularly dangerous to children.
While the chemical also is found in nature, the panel said its
presence in the environment primarily comes from the manufacture and
use of rocket fuels as well as explosives and fireworks.
The NAS panel recommended a level for safe human consumption that
translates to approximately 20 parts per billion in drinking water.
Two years ago, the EPA issued a preliminary recommendation of 1 part
"The committee disagrees with EPA's conclusion and thinks that
perchlorate exposure is unlikely to lead to thyroid tumors in
humans," the panel said in a statement accompanying its report.
The recommendation puts a new perspective on concerns in
Massachusetts, including worries about contaminated wells on Cape Cod
that may have been tainted by groundwater from the Massachusetts
Perchlorate has been found in at least 10 locations around the
state, and environmental officials are working on developing new
standards that would outline what levels are safe for human
Tests on some wells in Millbury last year revealed perchlorate
levels at 42.6 parts per billion at one well, and 18.45 parts per
billion at the other, according to the state Department of
Environmental Protections. DEP officials said then that the general
population should not drink water with more than 18 parts per
billion, while pregnant women, infants, and children younger than 12
should not drink water with levels at more than 1 part per billion.
The academy study was ordered by the Bush administration in 2003
to review the stricter standard the EPA had proposed in 2002. The
Pentagon had criticized that standard as too stringent and
recommended one as high as 200 parts per billion.
The Natural Resources Defense Council contended that documents
obtained under Freedom of Information Act requests showed the
Pentagon and the White House had sought to influence the scope of the
academy's study in order to get a weaker standard.
Local governments around the country already have begun trying to
hold defense contractors and the Pentagon liable for huge cleanup
costs to rid groundwater of the toxin.
Bob Hopkins, spokesman for the White House's Office of Science and
Technology Policy, said accusations of improper influence by
administration officials "couldn't be further from the truth."
The academy defended its work. "The government had no influence
over the conduct or outcome of this study," said E. William
Colglazier, the academy's executive officer. "The committee members
were highly competent, there were no conflicts of interest, and we
have full confidence in the report."
A few states have defined their own proposed limits on perchlorate
contamination in drinking water, though none is finalized.
California's standard is 6 parts per billion, while Massachusetts' is
1 part per billion.
Although California's standard would remain in place even if the
national standard were more lax, Californians would still be
affected. Contamination in the Colorado River, which provides
drinking water to 20 million people, comes from a site in Nevada.
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