Basic Facts and Information about Water
Water is generally classified into two groups: Surface Water
and Ground Water. Surface water is just what the name implies;
it is water found in a river, lake or other surface impoundment.
This water is usually not very high in mineral content, and
many times is called "soft water" even though it
usually is not. Surface water is exposed to many different
contaminants, such as animal wastes, pesticides, insecticides,
industrial wastes, algae and many other organic materials.
Even surface water found in a pristine mountain stream possibly
contains Giardia or Coliform Bacteria from the feces of wild
animals, and should be boiled or disinfected by some means
prior to drinking. 
Ground Water is that which is trapped beneath the ground.
Rain that soaks into the ground, rivers that disappear beneath
the earth, melting snow are but a few of the sources that
recharge the supply of underground water. Because of the many
sources of recharge, ground water may contain any or all of
the contaminants found in surface water as well as the dissolved
minerals it picks up during it's long stay underground. Waters
that contains dissolved minerals, such as calcium and magnesium
above certain levels are considered "hard water"
Because water is considered a "solvent", i.e., over
time it can break down the ionic bonds that hold most substances
together, it tends to dissolve and 'gather up' small amounts
of whatever it comes in contact with. For instance, in areas
of the world where rock such as limestone, gypsum, fluorspar,
magnetite, pyrite and magnesite are common, well water is
usually very high in calcium content, and therefore considered
"hard".
Due to the different characteristics of these two types of
water, it is important that you know the source of your water
-- Surface or Ground. Of the 326 million cubic miles of water
on earth, only about 3% of it is fresh water; and 3/4 of that
is frozen. Only 1/2 of 1% of all water is underground; about
1/50th of 1% of all water is found in lakes and streams. The
average human is about 70% water. You can only survive 5 or
less days without water.
Basic Facts and Information
about Water | Reverse Osmosis
| Water Treatment Devices for Home Use
 ©
2003 American Star Water Treatment
What is Reverse Osmosis?
 In
order to reverse the natural tendencies of water and salt
movement and force clean water to flow from salty water, the
osmonic pressure must be overcome, i.e. osmosis must be reversed.
In order to reverse this flow of water, membrane systems,
and Reverse Osmosis systems in particular, utilize a special
constructed semi-permeable membrane element enclosed inside
a pressure vessel. Pressure is applied to reverse the flow
of water, the source of which is usually and existing, pressure
is applied to the feed stream, water molecules are passed
through the membrane while salts are retained in the feed.
Thus, utilizing the principles of water and salts movement,
and combining them with pressure and membrane technology,
the natural osmotic flow of solution is reversed.
Basic Facts and Information
about Water | Reverse Osmosis
| Water Treatment Devices for Home Use
©
2003 American Star Water Treatment
Water Treatment Devices for Home Use
The water quality problems described here may be resolved
by use of a drinking water treatment unit.
There are a wide variety of such devices available for home
use. Health Canada works closely with NSF International to
develop performance standards for water treatment devices.
Consumers are encouraged to purchase products that have been
certified to these standards.
Microbiological Contaminants
If elimination of the source of contamination is not possible
after shock chlorine disinfection, consider the installation
of a batch or continuous disinfection system or a new water
supply. Some suitable devices are described in Table 2.
Table 2: Household Drinking Water Disinfection
Devices
| Water
treatment method |
Uses
|
| Distillation |
Kills all microorganisms.
|
| Ultraviolet light |
Kills bacteria and viruses.
Use in conjunction with microfiltration to improve
inactivation and remove particulate matter, including
parasites. |
| Chlorination |
Kills bacteria and viruses.
Use in conjunction with microfiltration to improve
inactivation and remove particulate matter, including
parasites. |
| Ozonation |
Kills harmful microorganisms.
Use in conjunction with microfiltration to improve
inactivation and remove particulate matter, including
parasites. |
| Ceramic candle filtration |
Removes parasites and bacteria.
Use in conjunction with chlorination to remove viruses.
|
Chemical Contaminants
Well water should also be tested for hazardous chemicals
whenever contamination is suspected. Chemical analysis of
water samples can be provided by commercial testing laboratories.
Some provincial health laboratories will analyse water for
nitrate, which typically originates from farming activities
and seepage from septic tanks. High concentrations of nitrate
may cause “blue baby syndrome” (methaemoglobinaemia), a condition
in which methaemoglobin cannot release oxygen to body tissues,
and which mostly affects infants under three months of age.
Other chemical contaminants of concern include pesticides,
heavy metals and volatile organic compounds. Guidelines for
Canadian Drinking Water Quality provides a list of maximum
acceptable concentrations for these chemicals. If hazardous
chemical contaminants are detected, you should consider the
installation of a treatment device or a new water supply.
Some suitable units are listed in Table 3.
Table 3: Chemical Removal Devices
| Water
treatment method |
Uses
|
| Activated carbon filtration* |
Removes organic compounds,
including pesticides. |
| Reverse osmosis* |
Removes heavy metals and
nitrates; often used in combination with activated
carbon filters. |
| Distillation |
Removes heavy metals and
nitrates; often used in combination with activated
carbon filters. |
| Ozonation |
Removes organic compounds,
including pesticides; often used in combination
with activated carbon filters. |
* Should not be used with microbiologically unsafe waters
or water of unknown microbiological quality.
Hardness, Taste, Odour and Colour
Well water contains naturally occurring minerals, such as
calcium, iron and sulphur. Although these minerals are not
hazardous to human health, they can alter the hardness, taste,
odour or colour of the water when present in excess quantities.
Groundwaters may also contain natural organic materials (tannins).
Table 4 describes some signs that may indicate the presence
of these substances in your well water and some solutions.
In order to select the best treatment method, a full testing
of the suite of minerals should be conducted prior to the
purchase of a device.
Table 4: Common Aesthetic Water Quality Problems
and Solutions
| Problem |
Cause |
Solutions
|
| Hard water (scales/deposits
in kettles and water heaters) |
Excess calcium |
Water softeners*
Reverse osmosis
Distillation |
| Rusty (red to brown) staining
of fixtures and laundry and/or metallic taste |
Excess iron |
Chlorination-filtration
Greensand filtration
Aeration-filtration
Distillation |
| Black staining of fixtures
and laundry and/or metallic taste |
Excess manganese |
Chlorination-filtration
Greensand filtration
Aeration-filtration
Distillation |
| Rotten egg smell |
Hydrogen sulphide |
Chlorination-filtration
Greensand filtration
Aeration-filtration |
| Water has laxative effect |
Excess sulphates |
Reverse osmosis
Distillation |
| Turbidity/grittiness |
Mud/silt/clay/sediment in
water |
Sediment filters |
| Organic (tea) colour |
Tannins |
Chlorination-filtration
Ozonation-filtration |
* Individuals on sodium-restricted diets should consult their
physician before drinking artificially softened water. Iron
and manganese can also be removed by a softener, provided
the water is not too hard.
Basic Facts and Information
about Water | Reverse Osmosis
| Water Treatment Devices for Home Use
|
