Contaminant
Terms
Alkalinity (see pH)
Asbestos
Asbestos was used in cement water pipes in the early
1900s, and since it occurs naturally in rock, it is
commonly found in water supplies near mining operations.
Asbestos is linked to several types of cancers. Indications
are that most asbestos exposure is by inhalation rather
than ingestion; however the EPA has established an MCL
for asbestos fibers in water. Filters rated for asbestos
reduction will lessen this health threat.
Bacteria
One-celled organisms are present in everything from
water to food. Bacteria can be found in virtually any
water system. Municipal water systems check for harmful
bacteria levels on a regular basis. A water filtration
system certified Class I for particulate reduction by
NSF is a simple and cost-effective way to remove particles
1/2 micron in size and larger. Most bacteria are larger
than 1/2 micron.
Chloramines
Often the aftermath of the two step ammonia plus chlorine
disinfection method used at large, central municipal-type
treatment plants. They can produce a disagreeable taste
and odor. Chloramine removal is limited to physical
adsorption methods such as filtration using activated
carbon.
Chlorine
Chlorine is a disinfectant which wipes out bacteria
and is added to most all municipal water systems. Chlorine
may produce undesirable taste and odor in drinking water,
such as a "swimming pool" taste. The actual
health danger comes from some of the chemical compounds
chlorine forms by combining with organic molecules that
can be found in water. Activated carbon is the best
solution to reducing chlorine in water.
Cryptosporidium
A waterborne parasite that causes severe stomach cramping,
fever, vomiting and diarrhea that can last from 10 to
14 days in a healthy person. It can be fatal for persons
with immune deficiencies (eg. infants or the elderly).
Hundreds of thousands of people are sickened each year
when this parasite is present in the water. Cryptosporidium
can be found in virtually any surface water source.
Very fine filtration (submicron) is required for protection
from this contaminant. Be sure to look for NSF Standard
53 on the filters you purchase.
Cyst
Chlorine-resistant "capsules" which contain
parasites that, if ingested, may cause disease with
symptoms of severe abdominal cramping and diarrhea.
These parasites can be particularly dangerous for anyone
with comprised immune systems, such as HIV or cancer
patients. Cysts include Cryptosporidium, Giardia, Toxoplasma
and Entamoeba. Very fine filtration (submicron) is required
for protection from cysts. Be sure to look for NSF Standard
53 on the filters you purchase.
Giardia Lamblia
A one-celled, microscopic parasite that lives in the
intestines of people and animals. It is responsible
for an illness known as giardiasis. It causes severe
stomach cramping, fever, vomiting and diarrhea that
can last from four to six weeks in a healthy person.
This is the most common waterborne parasite. Those with
weakened immune systems are particularly vulnerable
to this cyst. Very fine filtration (submicron) is required
for protection from this contaminant. Be sure to look
for NSF Standard 53 on the filters you purchase.
Hard Water
Water that has picked up minerals such as calcium and
magnesium as it travels through certain types of rock
and soil. Approximately 85 percent of the country has
hard water. Hardness is measured in both parts per million
(ppm) and grains per gallon (gpg). Anything more than
one gpg or 17.1 ppm qualifies water as "slightly
hard." It is the minerals in water that can eventually
form scale deposits in water-using equipment.
Hydrogen Sulfide
Also referred to as "sulfur water", hydrogen
sulfide causes the rotten-egg smell sometimes present
in drinking water. It is an acid which can cause rapid
corrosion of all types of plumbing materials. The only
good remedy is chemical oxidation followed by filtration.
Lead
Lead is a heavy metal that has gained a great deal
of attention from the EPA, which in 1991 imposed new
standards for lead levels in drinking water that are
10 times more protective than levels previously thought
to be safe. It is estimated that 40 million Americans
currently drink water containing more lead than the
limit set by the EPA. Lead poisoning can cause mental
retardation and birth defects. Basic filtration rated
for lead reduction will offer protection.
Methyl Tert-Butyl Ether (MTBE)
A common gasoline additive that has been found to leak
into ground water supplies and contaminate drinking
water. It is made of methanol and a by-product of the
oil-refining process. The EPA has classified MTBE as
a possible carcinogen. Basic filtration rated for MTBE
reduction will offer protection.
Minerals and Heavy Metals
Dissolved solids such as sodium, nitrates, fluoride,
copper, chromium III and chromium VI and others.
Particulates
Particles such as dirt and rust as well as invisible
sub-micron particles including asbestos fibers, cysts,
oxidized/precipitated iron, manganese, aluminum, lead,
sulfide, algae and molds.
Off Tastes & Odors
Many things can contribute to bad smelling and tasting
water such as chemicals, organic matter, and the condition
of the water distribution system. If your water smells
or tastes like a "swimming pool," it is probably
due to chlorine that has been added for disinfection.
Although chlorine is very effective at killing harmful
bacteria and viruses, it frequently causes both an off
taste and odor. The addition of ammonia to produce monochloramine
(which lasts longer in the pipes) makes the taste and
odor even worse. One of the most effective treatments
for bad tasting water is a filter containing activated
carbon.
pH
pH is the chemical shorthand for how acidic or alkaline
your water is. A pH of "7" is considered "normal"
and neither acidic nor alkaline. If your water is below
"7" it is acidic and the risk of lead or other
metals in the water goes up. If it is above "7"
it is alkaline and will have a greater tendency for
scale to form.
Scale
This is the term that's used when minerals, usually
calcium and magnesium are deposited over time in water-using
equipment and appliances. Scaling has the potential
to block tubing and pipes, interfere with proper operation,
and reduces the overall life of equipment. Many treatments
exist to control or eliminate scale buildup in water-using
equipment. How "hard" the water is and how
the water will be used will determine which treatment
will be most effective.
Trihalomethanes (THMs)
Trihalomethanes are formed when chlorine reacts with
organic matter in water, such as from decaying leaves.
They have been linked to a higher incidence of cancer.
A filter with activated carbon rated for THM reduction
is an effective treatment.
Total Dissolved Solids (TDS)
Total Dissolved solids are not visible to the naked
eye. However, when water is frozen, ice cubes may look
cloudy.
Turbidity
Cloudiness results from suspended particles of dirt
in the water. These particles usually are in two categories:
larger, visible pieces that can easily be filtered out;
and minute, invisible particles that can make water
hazy. The more minute the particles, the finer the filter
required.
Volatile Organic Chemicals (VOCs)
VOCs are a group of water contaminants that can be
very dangerous if found in drinking water at unsafe
levels. They include some of the most common, most toxic,
and most widely distributed water contaminants. Examples
include pesticides, herbicides, or insecticides that
seep into the ground. VOCs are usually the result of
pollution and originate from areas of industrialization.
This category also includes total trihalomethanes. A
filter with activated carbon rated for VOC reduction
is an effective treatment.
For more information click
here to visit the EPA Safe Water Website. |
