- WASHINGTON, DC, December
(ENS) - Toxic chemicals are contaminating groundwater on every
inhabited continent, endangering the world's most valuable supplies of
freshwater, reports a new study from the Worldwatch Institute. This first
global survey of groundwater pollution shows that a toxic brew of
nitrogen fertilizers, industrial chemicals and heavy metals
- The study by the Washington, DC
based Worldwatch Institute
also found that the damage is often worst in
the very places where people
most need water.
- "Groundwater contamination
is an irreversible act
that will deprive future generations of one of
life's basic resources,"
said Payal Sampat, author of "Deep
Trouble: The Hidden Threat of Groundwater
- "In the next 50
years, an additional three billion
people are expected to inhabit the
Earth, creating even more demand for
water for drinking, irrigation and
industry. But we're polluting our cheapest
and most easily accessible
supply of water," Sampat said. "Most
groundwater is still
pristine, but unless we take immediate action, clean
not be there when we need it."
- Sampat's report details a flood
of polluted waters:
- * In the late 1990s, India's Central Pollution Control
Board found that groundwater was unfit for drinking in all 22 major
zones it surveyed.
* In Mexico's
Yucatán Peninsula, more than half of groundwater sampled
contained nitrate at levels above the safe limit.
Romania and Moldova, more than 35 percent of the sites sampled in
mid-1990s had nitrate concentrations higher than the health guideline.
* Researchers in the Netherlands found that 28 percent of
for drinking contained perchlorate, a solvent used
widely in dry cleaning,
at levels greater than 10 micrograms per liter.
* A survey of 15 Japanese cities found that 30 percent of
supplies contained varying levels of chlorinated
solvents, although just
three percent were above prescribed
* In Manila, where groundwater levels have fallen
50 to 80 meters (164
to 262 feet) because of overdraft, seawater has
flowed five kilometers
inland, contaminating the city's aquifer with
salt. Just two percent of
seawater mixed with freshwater makes the
water unusable for drinking or
irrigation. In Bangkok, Thailand, many
wells have been abandoned because
of saltwater intrusion.
* The U.S. Environmental Protection Agency (EPA) estimates that
gasoline storage tanks are leaking chemicals into
groundwater. In Santa
Monica, California, wells supplying half the
city's water have been closed
because of dangerously high levels of the
gasoline additive MTBE.
- * In the northern Chinese provinces of Beijing, Tianjin,
Hebei, and Shandong, nitrate concentrations in groundwater exceeded the
health guideline in more than half of the locations studied in
- Groundwater is an essential resource for sustaining civilization,
Sampat noted. About 97 percent of the planet's liquid freshwater is stored
in underground aquifers.
- Waste disposal sites, like the Lowry Landfill in Denver,
Colorado, can leak liquid wastes into groundwater, as seen in this photo from the 1970s.
(Two photos courtesy U.S. Environmental Protection Agency) Nearly one
of all humanity relies almost exclusively on groundwater for
including the residents of some of the largest cities in the
world, such as Jakarta, Dhaka, Lima and Mexico City. Almost
of the rural U.S. population, and 80 percent of India's
on groundwater for drinking.
- Groundwater irrigates some of
the world's most productive
cropland. More than half of irrigated
farmland in India, and 43 percent
in the United States, are watered by
groundwater. Irrigation already accounts
for about two thirds of water
- As rivers and lakes are dammed, dried up, or polluted,
food demand grows in the next 50 years, farmers will become increasingly
dependent on groundwater for irrigation, Sampat predicts.
- Aging underground
storage tanks can leak gasoline and
other contaminants into groundwater
Groundwater also plays a key ecological
role by replenishing rivers,
streams and wetlands. It provides much of
the flow for the Mississippi,
the Niger, the Yangtze and many other great
rivers - some of which
would otherwise not run year round.
- Groundwater contamination is
widespread in industrialized
countries like the United States:
- * Since 1943,
billions of gallons of radioactive wastes
have been dumped into soils
and aquifers in Washington state by the Department
of Energy's Hanford
Nuclear Reservation. Some of this waste has a half-life
* 15 percent of shallow groundwater sampled below
cities and farms in the
U.S. in the mid-1990s had nitrate
concentrations that exceeded the guideline
for drinking water.
* One third of the wells tested in California's San Joaquin Valley
contained the pesticide DBCP at levels 10 times higher than the
allowed for drinking water - more than a decade after its use
- "One of the most disturbing aspects of the problem
groundwater pollution is essentially permanent," said Sampat.
- Underground injection
wells, like this
one in Florida, are often used to pump contaminants underground for
disposal (Photo courtesy University of Southern Florida)
- Water recycles very
slowly underground, too slowly to
flush out or dilute toxic chemicals.
Water that enters an aquifer remains
there for an average of 1,400
years, compared to only 16 daysfor rivers.
- Thus Londoners, for example,
may be drinking water that
fell as rain as long ago as the last ice
urgency of preventing groundwater contamination is
highlighted by the
costs of cleanup efforts. Water utilities in the midwestern
States, a region that is highly dependent on groundwater, spend
million each year to treat water for just one chemical, the pesticide
- The U.S. National Research Council estimates that the
cleaning up the known 300,000 to 400,000 heavily contaminated
where groundwater is polluted could be as high as U.S. $1 trillion
the next 30 years alone.
- "Patchwork, end of pipe solutions are simply not
enough," said Sampat. "To preserve this valuable resource, we
need to make systematic changes in the way we grow our food, manufacture
goods and dispose of waste."
- In California's Sacramento
Valley, water pumped from
underground aquifers is used for everything
from agricultural irrigation
to drinking water.
- The report proposes retooling
to reduce farm runoff, a leading source of
groundwater pollution. The EPA
estimates that cutting agricultural
pollution could eliminate the need
for at least U.S. $15 billion worth
of additional advanced water treatment
- Farmers from Indonesia to Kenya
are learning how to use
less chemicals while boosting yields. Since
1998, all the farmers in China's
Yunnan Province have eliminated their
use of fungicides, while doubling
rice yields, by planting more diverse
varieties of the grain.
- Water utilities in Germany now pay farmers to switch
to organic operations because it costs less than removing farm chemicals
from water supplies.
- Companies also need to take greater responsibility for
their toxic discharges. Sixty percent of the most hazardous liquid waste
in the United States - 34 billion liters (about nine billion gallons) per
year of solvents, heavy metals and radioactive materials - is injected
directly into deep groundwater via thousands of "injection
- Although the EPA requires that these effluents be injected
below the deepest source of drinking water, some have entered underground
water supplies in Florida, Texas, Ohio and Oklahoma.
- Manufacturers can reduce
groundwater pollution by reusing
materials and chemicals, keeping them
out of landfills and thereby reducing
leakages from landfills.
Companies are building "industrial symbiosis"
parks in which
the unusable wastes from one firm become the input for another.
- At Lawrence Livermore
National Laboratory in the U.S.,
researchers are testing a solar
detoxification process that can clean groundwater
of a range of
contaminants, including solvents, pesticides, wood preservatives,
and fuels. Such waste exchanges help an industrial park in Kalundborg,
Denmark, to keep more than 1.3 million tons of effluent out of landfills
and septic systems each year, the report notes.
- Manufacturers can also switch
to less toxic alternatives.
In Sweden, where chlorinated solvents are
being entirely phased out by
the end of 2000, some firms already report
economic savings from switching
to water based solvents derived from
biochemical sources such as citrus
fruits, corn, soybeans, and lactic
- Sampat calls on governments to find ways to encourage
reductions or replacement of toxic chemicals. One such tool is fiscal
Pollution taxes in the Netherlands, for example, have helped
slash discharges of heavy metals such as mercury and
arsenic into waterways
by up to 99 percent between 1976 and the
- The full report is available
for purchase at: http://www.worldwatch.org
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