[CPEO-MEF] Colorado River Taint Worries Some Officials

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California/Nevada
Colorado River Taint Worries Some Officials

Perchlorate, a rocket fuel ingredient, enters Lake Mead near Las Vegas.
California is concerned about its effect on drinking water.

By Miguel Bustillo, Times Staff Writer

A toxic rocket fuel ingredient that is polluting the Colorado River --
the main water source for millions of Californians and most of the
nation's winter lettuce -- may be dangerous to public health even at
extremely low levels, state and federal environmental officials now
believe.

The U.S. Environmental Protection Agency and the California Office of
Environmental Health Assessment, which are independently working to set
the nation's first enforceable regulations on ammonium perchlorate, are
concluding from a number of new studies that the substance could lead to
health problems, even in trace amounts.

Those findings present a serious environmental problem for the
Southwestern United States, because the entire lower Colorado River is
polluted with small amounts of perchlorate from a now-closed Nevada
rocket fuel factory.

California officials first discovered the contamination five years ago,
and an effort has been underway since then to stem the pollutant's flow
from a desert wash near the factory into Lake Mead. But more than 500
pounds of perchlorate still enters the river system every day, and it
will be years before it is fully flushed out.

No one is saying a few glasses of tap water pose an immediate danger.

Environmental health scientists say there is an outside risk of
developing health problems from perchlorate, basing their estimates on
the assumption that a person would drink about two liters of the
slightly tainted water each day of a lifetime.

Nonetheless, environmental groups say perchlorate's presence in the
Colorado River raises questions about the safety of drinking the river's
water and of eating foods, such as lettuce, that are grown with it.

Questions are thought to be particularly significant for pregnant women
and babies. Perchlorate is known to affect the production of thyroid
hormones, which are considered critical to brain development, so fetuses
and newborn children may face a greater risk.

"The more we know about perchlorate, the more concerned we get, because
the science is pointing to low doses affecting brain functions," said
Gina Solomon, a health expert with the Natural Resources Defense
Council, an environmental group.

"The kind of things that low to moderate doses of perchlorate might do
include delays in things like language acquisition, motor coordination,"
Solomon said.

In all, more than 15 million people, including those in the urban
expanses of Las Vegas and much of Southern California, depend on
drinking water from the lower Colorado River. Roughly 15% of
California's water supply comes from the river.

Water siphoned off to the casinos of Las Vegas contains 10 to 12 parts
per billion of perchlorate, according to officials with the Southern
Nevada Water Authority. Water diverted downstream by the Metropolitan
Water District of Southern California is less polluted, usually
somewhere between 5 and 8 parts per billion. It is subsequently blended
with Northern California water before being piped to Southern California
consumers, reducing its contamination to below detectable levels.

This article can be viewed at:
http://www.latimes.com/la-me-perc2feb02,0,634029.story

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