THE GARDEN CLUB
OF AMERICA
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DRINKING
WATER SAFETY
Do you know
what is in
your
drinking water? When we turn on the faucet, we expect clear, cool, life
sustaining water to flow. We can go without food for many days; but we
cannot
live for a week without water. We are supposed to drink eight glasses
of water
every day. Today run-off and acid rain as well as pollutants from many
other
sources flow into our streams, lakes, and aquifers.
HISTORY
In 1974,
Congress passed
the SAFE DRINKING
WATER ACT in
response to increasing chemical contamination
of public water sources. The
Act
directed the Environmental Protection Agency (EPA) to establish
drinking water
standards and to protect drinking water sources.
In 1986, the
Act was
revised to require
the EPA to set specific regulations for 84 known contaminants. They are called Maximum
Contaminant Levels
MCLs, the largest allowable amount of pollutants dissolved in water,
measured
in mg/L (milligrams per liter), or parts per million, (ppm).
Further
amendments to the
Safe
Drinking Water Act in 1996 require community water systems serving more
than
10,000 customers to provide annual water quality reports to their
customers,
beginning in 1999. The reports will list the contaminants that the EPA
now
regulates. Smaller water companies are allowed variances and can get
assistance
from a revolving fund to pay for infrastructure improvements.
THE
CONTAMINENTS
The
health-threatening
water
pollutants that are regulated by the EPA are divided into five groups:
Microorganisms, some naturally
occurring:
bacteria, viruses and parasites.
Synthetic Organic Chemicals
(SOCs):
fertilizers, pesticides, solvents, leakage from underground storage
tanks and
many other man-made products.
Inorganic Chemicals and Metals:
toxic
minerals such as mercury, lead, and arsenic.
Radionucleides: natural
and human made radioactive metals and minerals.
Additives: treatments
added to water
before delivery to consumers.
Bacteria in water can
cause
typhoid, cholera, and other
diseases. Fortunately, these can easily be detected and are killed when
treated
with chlorine. Since the early 1900’s, municipal water
systems have
treated
water with chlorine and have virtually eliminated these diseases. Viruses can be present in
untreated water
and most of them can be killed with chlorine disinfectant. Protozoan parasites like Giardia
and Cryptosporidium
occur as hard-shelled cysts that are resistant to chlorine disinfection. In April 1993, the
microorganism Cryptosporidium
found in Milwaukee’s
water supply made 400,000 people sick and killed 100.
There are
thousands of synthetic organic chemicals
(SOCs) used in manufacturing everything from fertilizers to
plastic
baby
bottles. They are often toxic. Pesticides are designed to kill living
organisms
that feed on valued crops. These compounds tend to persist in nature
and have
widespread effect on plants and animals. They are picked up in heavy
rain and
snowmelt run-off from agricultural areas, urban streets, and
construction
sites. SOCs can also occur in surface water as a result of airborne
particles
from incinerators and smokestacks.
Of the harmful minerals in water, cadmium,
lead,
and mercury are the most toxic.
Water
treatment plants do a good job in reducing them to safer levels,
meeting the
standards of the EPA. Lead can
leach
into our water supply from old pipes and faucets in our houses. The use
of
fertilizers and the raising of livestock contribute to high levels of nitrates and nitrites.
Sewers, septic
tanks, and industrial plants are other
sources of these pollutants.
Radioactive
materials occur
naturally. Uranium
mining can produce radioactive
runoff. Nuclear power plants and weapons facilities, as well as
disposal sites,
are man-made sources of radioactive minerals.
Radon is a naturally
occurring
gas that is a by-product of the
decay of radioactive minerals. If present, evaporation in an enclosed
space can
cause this odorless and colorless gas to be inhaled.
Chlorine is the
best-known
additive at public water treatment
plants. For over 80 years it has been used in almost every public water
system
in the United States and has
proven to
be very
effective as
a
disinfectant.
But now
there is
evidence that when chlorine combines with organic chemicals in water,
toxic
chemicals are sometimes formed. These toxic chemicals are called disinfection by-products.
Trihalomethanes
have received the most attention.
(On your water company’s report they might be
listed as primary compounds.)
Fluoride is added at
some water
treatment plants and is
thought to harden children’s teeth against decay. Its use
implications
are
still debated.
Flocculents are chemicals
added to
make particles coagulate for
more efficient filtering.
Most community
water
systems
produce high quality drinking water within the government standards.
Because
city water companies have large enough customer bases and can afford
more
modern water treatment facilities, city tap water is generally higher
quality
than water from small town or private water systems.
Water from
rivers and
lakes
(surface water) is usually low in minerals but might have pollutants
from
microorganisms, toxic organic chemicals, and nitrates. Surface water is
also
affected by illegal dumping and runoff from heavy rain, especially from
disturbed land.
Ground water is
usually
higher in
minerals and lower in microorganisms than surface water, but may
contain radon,
nitrates and other organic chemicals.
WHAT
CAN WE
DO TO HELP
We must
conserve water by
using
less in our homes and gardens. We must not dump or flush any chemical
materials
into drains, indoors or out. These include cleaners, polishes, paints,
motor
oils, fertilizers, and pesticides. We should also learn about our
watersheds.
PRIVATE
WELLS
Over 15 million
private
wells
supply drinking water to American families. Well water is ground water
and
needs to be tested periodically. The EPA does not require testing, but
homeowners with wells should test their water for bacteria and nitrates
at
least once a year and for chemicals every three years. If
gastrointestinal
illness develops among well water users, the supply should be tested
immediately and the local health department consulted.
Local extension agencies or health departments
have the names of local water testing laboratories. The National
Testing
Laboratories can be reached at 1-800-458-3330 or on the Internet at www.watercheck.com.
Well owners
should be
aware of the
aquifer that supplies their water. How deep is it? What is the source?
Is there
new development in the neighborhood that would threaten draw downs?
Could there
be contamination from agriculture in the area?
TESTING
Public water
systems are
required by
the Safe Drinking Water Act to test their water on a regular basis and
report
the results to the state and the EPA. You can get these results by
calling your
water company. If you want to have your own tap water tested, use a
laboratory
certified by the EPA. Your state water agency can give you the name and
number
of your water company and the name and number of testing laboratories
in your
area.
TYPES
OF FILTERS
Carbon filters
remove
many organic
chemicals and chlorine and radon. Carbon filters should be of good
quality and
maintained properly. Because bacteria can grow on some filters, it is
imperative that carbon filters be changed frequently.
Reverse osmosis
units
remove most
toxic minerals and organic chemicals but generally do not remove radon
or
chlorine. They
should be used with
carbon filters. Reverse osmosis units are slow and should only be used
for
drinking water at a spigot. The purified water becomes aggressive and
can
corrode the pipes of the delivery system. These pipes and faucets
should not be
made of lead or lead components.
Distillation
removes
pollutants by
boiling water and cooling the steam so it condenses back into water.
Distillation is slow and expensive and distilled water is poorly
buffered.
Therefore, distilled water can be highly aggressive and should be
stored in
glass or other inert containers.
Water softeners
remove
calcium and
magnesium from “hard” water and make it clean
better. However, calcium
and
magnesium are considered human nutrients.
The healthiest
water is
free of
pollutants but contains beneficial minerals like calcium and magnesium.
WHAT
ABOUT BOTTLED WATER?
Bottled water
is now a
four
billion dollar a year industry in this country. Not only are there
questions
about the origin of the water and what is in it, but the plastic bottle
itself
can be suspect. Then there is the problem of disposing of all the
plastic
bottles.
Bottled water
includes drinking water, purified water,
natural-source water, and specialty waters. The Food and
Drug
Administration sets standards for bottled water used in interstate
commerce.
Drinking water has been
partially
purified but still has its good
minerals. It is probably from a municipal water system. Home delivery
water and
the gallon jugs in the market come under this category.
Vending
machines
generally
dispense good quality water at a better price than bottled water;
however,
there may be a problem with the containers used for water by the
consumer. They must
be perfectly clean and
of good
quality plastic or glass.
Purified water has had all
its minerals
removed by distillation,
filtration, etc. Because purified water becomes
“aggressive” and reacts
with
the surface of its container, it should always be kept in glass
containers, not
plastic. Some bottled water has been totally purified and then trace
amounts of
minerals (potassium, calcium, and magnesium) are added for taste and to
minimize the “aggressive” tendencies of purified
water.
Natural-source
bottled
water comes
from a naturally occurring spring
or aquifer that may or may not have been tested and may or may not have
contaminants. The companies’ reputations depend on the safety
of their
bottled
water. Labels
should give information
about the water source and the analysis.
Bottled water is regulated by the Food and Drug
Administration;
more can
be learned by calling 1-888-INFO-FDA.
Bottled water
suppliers
can belong
to the International Bottled Water
Association (IBWA), that
sets
quality standards for its members. Some bottlers also obtain
certification from
the independent non-profit testing group NSF
International (National Sanitation Foundation). IBWA contracts
with NSF International to do unannounced third party
independent inspections of all IBWA member-bottling facilities. Check
labels to
see if the bottler belongs, or call 1-800-WATER-11. NSF International
can be
reached at 1- 800-NSF-MARK, or on the Internet at www.nsf.org.
LEARN
ABOUT YOUR WATER
Call your water
company.
Ask where your
water
comes from,
surface or ground water.
Ask how it is
treated,
how it is
disinfected and if there are disinfection by-products.
Ask to receive
their
annual water
quality report.
Call your State
Water
Agency.
Ask if they
publish a
newsletter
about your drinking water.
Call your
regional office
of the
EPA and/or the EPA Safe Drinking Water Hotline: (1-800-426-4791).
On the Internet
you can
reach the
EPA’s Office of Ground Water and Drinking Water at http://www.epa.gov./OGWDW.
Call the US
Geological
Water
Survey Information Clearing House at 1-888-ASK-USGS.
For more
information:
Lewis, Scott
Alan, The
Sierra
Club Guide to Safe Drinking Water, Sierra Club Books, San
Francisco.
Ingram, Colin, The
Drinking
Water Book, Ten Speed Press, Berkeley, California.
NSF
International, Consumer
Drinking Water Book
The
Sierra Club Magazine
Reprint
permission granted
September 1999