Copyright 1999 The Tribune Co. Publishes The Tampa Tribune
The Tampa Tribune
November 28, 1999, Sunday, FINAL EDITION
SECTION: FLORIDA/METRO, Pg. 1
LENGTH: 1456 words
HEADLINE:
Cleaner, safer flow is 2002 water goal;
BYLINE: JAN
HOLLINGSWORTH, of The Tampa Tribune;
BODY:
New science, new health concerns and new standards have local water
suppliers weighing treatment options.
Sometime within the last few
months, consumers across the nation received an unprecedented mailing from
their local water suppliers: a comprehensive glimpse at what's coming out of
their taps.
According to the federally mandated "consumer
confidence reports," Bay area residents are regularly showering in
chloroform, cooking in radium and mixing baby formula with the lead-laced
liquid that flows from many plumbing fixtures.
All of this water -
without exception - meets or exceeds federal standards set by the
Environmental Protection Agency.
Municipal water supplies are
strictly monitored. Those that violate drinking-water standards face both
civil and criminal penalties. "EPA says if it meets this standard, it's declared
safe to drink," said David Henderson, water manager for St. Petersburg.
But compliance doesn't mean the water is necessarily safe for everyone,
according to water quality activists.
Microbes, metals and
chemicals may pose special risks to people with weak, aging or immature
immune systems.
"There's a lot of tension and disagreement over
the health effects of these things," said Paul Schwartz of Clean Water
Action, one of several organizations that lobbied for legislation requiring
local utilities to notify customers of contaminants in their water supply.
West Central Florida boasts some of the most intensive water treatment
in the nation. It also contains some of the highest levels of
trihalomethanes - the most common chemical contaminant in municipal water
supplies.
Trihalomethanes, which form when chlorine is added during the
water treatment process, can cause liver, kidney and nervous system
damage.
They also have been linked to bladder and colon cancers.
More recent and controversial research suggests the compounds may be
related to miscarriages and certain birth defects.
These, unlike
the cancers, appear to be related not to long-term exposure to unhealthy levels
of trihalomethanes, but to occasional spikes that can occur when extra
chlorine is added to the water supply.
"Typically, you could see
spikes of 200, 300 or 400 parts per billion," said Schwartz. "If the
science holds, this could be the largest single route of exposure to birth
defects that people have."
Federal law now requires water
suppliers to keep trihalomethane levels below an annual average of 100
parts per billion.
MOUNTING EVIDENCE of health problems has prompted the
EPA to lower that threshold to 80 parts per billion by 2002.
At
that time, the EPA also will institute new standards for previously unregulated
haloacetic acids - another family of disinfection byproducts hazardous to
consumers' health.
Utility associations and government agencies are
negotiating a second reduction that could lower the threshold for
trihalomethanes to as low as 40 parts per billion - a level that may pose a
problem for local water suppliers. Some already are contemplating how to
alter their current treatment process to meet the newly mandated 80 parts
per billion.
Florida generally tends to have higher levels of
chlorine byproducts than the rest of the nation, said
Joan Rose, a University of South Florida microbe specialist and a consultant to
the drinking-water industry.
"It's because of the natural organics
found in the waters here," said Rose.
Trihalomethanes, such as
chloroform, are created when decaying vegetation comes into contact with
chlorine. The more vegetation, the more chlorine, the longer they mix - the more
compounds are formed.
Add to that the potential microbial mayhem
wreaked by parasites, viruses and bacteria, and you have the classic
dilemma faced by the water industry: how to balance the risk of controlling
microbes with the risk of disinfecting them.
"You can be exposed
just once to E. coli and have hundreds of people sick and some dying," Rose
said. "It's kind of a risk trade-off."
Just how much risk is the
subject of vigorous debate.
According to St. Petersburg's consumer
confidence report, a person would have to drink two liters of water
containing the maximum level of contaminants every day for a lifetime to have a
1-in-1,000,000 chance of experiencing the described health effects.
Not true, said Stig Regli, an environmental engineer at the EPA's Office
of Groundwater and Drinking Water. "There's a lot of uncertainty about the
magnitude of the risks associated with chlorinated water," Regli said.
David Ozonoff, a Boston University professor, said that though the
increased health risk is likely small for individuals, it still poses a
public health concern.
"When you expose large populations, you can wind
up with an appreciable burden of disease," said Ozonoff, who sits on a
National Academy of Sciences panel that reviews drinking-water contaminants.
Infants, the elderly, people undergoing chemotherapy or organ
transplants and others with compromised immune systems are particularly
vulnerable to trihalomethanes and other contaminants.
"One out of every
four people could be classified in one vulnerable population or another," said
USF's Rose.
DRINKING BOTTLED WATER, which also has its share of
contaminants, may reduce exposure to the chlorine
byproducts, but it does nothing to address exposure through inhalation
and skin absorption.
"Those are both significant routes of
exposure," Ozonoff said. "You are probably going to get a pretty hefty
dose by taking a bath or taking a hot shower."
More advanced water
treatment techniques and stricter enforcement of laws that keep source water
clean would reduce the problem of disinfection byproducts, said Schwartz,
who suggests that polluters pick up the tab for filtration and monitoring
of public water supplies.
"Water utilities don't create the problem.
They have to pay for something someone is sending them," Schwartz said.
The Hillsborough River is the primary source of water for half a million
Tampa residents. The rest of West Central Florida relies mainly on ground
water drawn from the Floridan aquifer.
Because surface water contains
more organic material than ground water, Tampa has instituted a number of
treatments aimed at reducing the formation of trihalomethanes.
Filters
remove vegetation from the water, and ammonia is added during chlorination to
inhibit the disinfection byproducts.
Tampa converted to this
so-called chloramination process nearly two decades ago.
Hillsborough
County is planning to convert to the process sometime after the first of the
year.
Utilities in Pasco County and Pinellas County also are considering
adding ammonia to their disinfection regimen.
"It is sort of a
quick fix that can help reduce the trihalomethanes," said Erik Olson, an
attorney for the Natural Resources Defense Council who heads up the
organization's safe drinking-water program.
Meanwhile, Tampa is
poised to sink $ 49 million into a project that will expand its water
treatment capacity and convert to ozonation - a disinfection process
widely used in Europe and Japan.
The city in 1998 reported an
annual trihalomethane average of 84.9 parts per billion. That number was
reduced to 58.4 in its August report, well below the standard of 80 that will
take effect in 2002.
"We still don't know what the ultimate
regulation may be in 2004," said Mike Bennett, Tampa's water production
manager.
Although pumping ozone into the water supply eliminates the
byproducts of chlorination, it also creates other unhealthy compounds,
Bennett said. But these are more easily neutralized than those associated
with chlorine.
Ozone also is more effective in killing microbes and
eliminating other contaminants.
And there is the added benefit of
improved taste and odor, a common complaint of Tampa water customers.
"We think ozone is going to help us on all of those fronts," Bennett
said. (CHART) Drinking water resources For more
information about drinking-water contaminants, contact your local water supplier
or call: The Safe Drinking Water Hot Line 1-800-426-4791 or Clean
Water Action (202) 895-0420, Ext. 105 Or go to
www.epa.gov/safewater/dwinfo/fl.htm (CHART) It isn't all water
(For complete chart, please see microfilm.) Source: U.S.
Environmental Protection Agency Tribune photo illustration/graphic
Jan Hollingsworth covers the environment and can be reached at
jhollingsworth@tampatrib.comor (813) 259-7607. Read about more
environmental issues on The Tampa Tribune's Web site at
www.tampatrib.com/news/enviro.htm
GRAPHIC:
CHART 2
LOAD-DATE: December 3, 1999
