Votre eau est-elle potable?
Globalement, 30 000 personnes meurent chaque jour d'une maladie
attribuable à l'eau. Dans les nations en voie de développement, 80 % des
maladies proviennent d'eaux contaminées.
Ici au Canada, à cause de plusieurs facteurs, la qualité de l'eau
peut véritablement inquiéter les citoyens. Une façon économique et
efficace de déterminer la qualité de l'eau d'une maison est de la faire
vérifier.
Depuis quelques années, plusieurs types de tests de la qualité de
l'eau potable sont disponibles aux consommateurs partout au Canada.
Il est important de vous assurer que le test que vous choisissez suit
les Directives canadiennes sur la qualité de l'eau.
Les principaux polluants incluent : les bactéries, le plomb, les
pesticides, le chlore, les nitrates et les nitrites. Il est aussi utile de
déterminer l'acidité et l'alcalinité de l'eau.
L'eau provenant de chaque robinet devrait être vérifiée au moins une
fois par an, et deux fois par an si vous obtenez votre eau d'un puits.
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Is Your Drinking Water
Safe?
A Guide to Water Testing
Brett Hopkins
Silver Lake Research - Watersafe
March 2002
lobally,
30 000 deaths occur daily from water-related diseases. In developing
nations, 80% of illnesses occur due to contaminated water . Here in
Canada, due to a number of factors, water quality can present a very real
concern for citizens.
Canadian Water Quality
Canadian water quality is
determined by the Canadian
Water Quality
Guidelines
issued by the government's
Federal-Provincial
Subcommittee on
Drinking Water. These guidelines recommend maximum acceptable levels in
drinking water for physical, chemical, radiological and microbiological
substances. Water that contains contaminants in amounts in excess of these
maximum safety levels can potentially cause adverse health effects. These
guidelines are used by government agencies to effectively assess water
quality problems and are subject to review and revision, as new
information becomes available.
Recently, these guidelines have come under increasing criticism
because, unlike in the United States, where the United States
Environmental Protection Agency's (USEPA) maximum contaminant levels in
water are standards enforced by law, Canada's Water Quality Guidelines are
in effect recommendations which do not necessarily have the force of law
behind them. Because of this difference, responsibility for water quality
rests with the administrators of the myriad local and municipal water
systems across Canada.
In recent years, some of these water systems have proved themselves to
be ineffective in preventing contamination of the water supply. In May
2000, this ineffectiveness was most disastrously evident in Walkerton,
Ontario, where E. Coli bacteria contamination of the town water supply
resulted in seven deaths and over 2 000 illnesses . In 2001, almost 400
cases of contaminated water were reported in Ontario alone, affecting
towns, schools, trailer parks and homes . In North Battleford,
Saskatchewan, last spring thousands of residents became ill when the water
supply became contaminated by the parasite cryptosporidiosis. As of March,
year?, 50 communities in Saskatchewan have been under water advisories and
two under emergency boil water orders .
Most of these cases occur in areas serviced by small water systems that
don't have the funds to purchase or operate the high-quality filtration
systems in use by the larger municipal water systems in Canada's larger
cities. Millions of people across Canada rely on these small systems for
their water (there are 5 000 small water systems in Ontario alone ).
Because of these factors, it is imperative that Canadians know what is
in the water they drink.
Water Testing at Home -
What You Can Do To Eliminate the Unknown
Water testing is an inexpensive and effective way of determining the
quality of home drinking water. Many home drinking water test kits have
become available to the consumer in recent years and can be found in local
hardware stores, health food stores and supermarkets across Canada. Many
of these tests are simple cardboard strip tests that, after being exposed
to water, inform the user of the level of contamination by color change.
Home tests are now available for bacteria, lead, pesticides, nitrates,
nitrites, arsenic, chlorine, pH and hardness and can be purchased as
individual tests or "all in one" test kits that include
combinations of tests for any or all of the above contaminants.
It is important to make sure that the test you decide to use is
calibrated to Canadian Water Quality Guidelines. Most calibrated tests
will list this on the packaging. These tests will also include information
on what to do if your water is contaminated.
Water should be tested at least once a year at all faucets in the home
and twice a year if you rely on a well for your water. If you have had
problems with your water previously, testing your water at least once
every 1-2 months is recommended.

Here are brief descriptions of some major contaminants and their
effects:
Bacteria
Toxic bacteria may enter the water supply from human or animal wastes
or natural sources. Multiplying rapidly, they may release a variety of
potent, damage causing molecules called endotoxins. Many strains of
bacteria are not toxic, but some can cause very serious illness. Even mild
cases can result in diarrhea, vomiting, cramps, and other gastrointestinal
symptoms. Since contaminated water may not taste or smell bad, most cases
of water-borne disease are not likely to be identified as such.
Lead
Since lead was used extensively in plumbing until the 80's, many homes
and buildings have pipes and plumbing fixtures that contain lead. Lead can
leach from pipes into household water, making this plumbing a major source
of toxic lead poisoning. Lead poisoning is so toxic that even very low
levels can be dangerous. Lead consumption and poisoning has been linked to
learning disabilities, muscle and bone disorders and kidney damage. Lead
levels should be tested at each faucet in the home, especially if plumbing
fixtures could date from the 80's or before.
Pesticides
Pesticides are chemicals used to eliminate weeds, insects and other
harmful elements in crops. Atrazine and simazine are two of the pesticides
most commonly found to contaminate drinking water. Millions of pounds of
these two chemicals are introduced into the environment each year as
herbicides and left to potentially leak into the soil, and then into
groundwater, lakes and rivers that are sources of drinking water. These
chemicals are so toxic that the USEPA-mandated maximum contaminant level
in drinking water is equivalent to less than one drop in a large swimming
pool.
Chlorine
Chlorine is used extensively to purify water. The consumption of
chlorine in very small amounts will likely not cause serious harm, but its
by-products, including chloroform, which are produced when chlorine mixes
with organic matter, can be extremely harmful. Drinking water with high
levels of chlorine by-products has been linked to some forms of cancer.
Nitrates & Nitrites
When animal and human wastes or field fertilizers come into contact
with water, they produce nitrates and nitrites. Both are dangerous to
children and can cause "Blue Baby Syndrome," a lethal form of
birth defect in infants.
pH and Hardness
PH and Hardness do not directly cause harm but can cause a variety of
secondary effects if not treated. If water acidity is too high, corrosion
can leach out lead from pipes and plumbing (see lead above), as well as
damage plumbing and water heating systems. Water hardness is primarily
caused by calcium and magnesium compounds. These chemicals are not easily
detected, but the negative effects include scaling of pots and pans and,
if left untreated, damage to plumbing and water heaters.
If your water tests positive for any of the above contaminants, the
USEPA has a Safe Water Hotline accessible from the USA and Canada, at
1-800-426-4791. The agency can give you expert advice on what steps to
take to rid your water of dangerous contaminants.
Links and Information
Silver Lake Research
specializes in developing, manufacturing, and marketing do-it-yourself
test kits for contaminants in food and water supplies. These easy-to-use
kits produce results that are calibrated to the EPA's exacting Maximum
Contaminant Level (MCL) standards. Silver Lake Research also manufactures
test kits for food safety applications, used by processors, veterinarians,
and livestock producers. For more information about Silver Lake Research,
call 1-888-438-1942, log on to www.watersafetestkits.com
or write to:
PO Box 686, Monrovia, CA 91017.
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