WATER INFO
Select an option below from our Water Info area to investigate various water issues:
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Explanation Of Water Analysis
- Alkalinity
Alkalinity is water's acidneutralizing
capacity and is primarily
a function of carbonate, bicarbonate
and hydroxide content. Excessive
alkalinity levels may cause scale
formation. The aesthetic objective is
set at a maximum of 500 mg/L.
- Aluminum (Proposed SMCL: 0.05
mg/L)
Aluminum is widespread in the
environment. Intake occurs through
food, water and air. Aluminum has
been suspected of contributing to
Alzheimer's disease, but inadequate
scientific data exist to substantiate a
cause-effect relationship.
- Arsenic
Arsenic is a metalloid with four
oxidation states. It is widely
distributed throughout the earth's
crust and is present in trace amounts
in all-living matter. Arsenicals are
used commercially and industrially Ð
for example, as alloying agents, in
the processing of glass and pigment,
in the hide tanning process and as
pesticides, feed additives and
pharmaceuticals. Symptoms of acute
arsenic intoxication associated with
the ingestion of well water
contaminated with arsenic include
abdominal pain, vomiting and pain to
the extremities and muscles. The
IMAC for arsenic in drinking water
is 0.010 mg/L.
- Asbestos (Proposed MCL and
MCLG: 7 million fibers/liter over
10 microns long)
Asbestos occurs naturally in the
environment and has been used in
asbestos-cement pipes in water
distribution systems and in well
casings. It has been introduced into
drinking water through the corrosion
of asbestos-reinforced cement pipes
by water with a low pH. Water that
has high pH and low corrosivity
should prevent the deterioration of
pipes that would introduce asbestos
into water.
- Barium (MCL: 1.0 mg/L)
Barium is fatal to humans in high
doses (more than 550 mg). No study
appears to have been made of the
amounts of barium that can be
tolerated in drinking water, but
because of its toxic effects on the
heart, blood vessels and nerves, a
level with a large safety factor has
been set. Barium can accumulate in
the liver, lungs and spleen. It can
cause nervous system disorders, heart
disease and circulation impairment.
- Bicarbonate (HCO3)
Bicarbonate is the major form of
alkalinity. In excessive amounts,
bicarbonates, in conjunction with
calcium, may cause scale formation
in heated waters. See Total
Alkalinity.
- Cadmium (MCL: 0.01 mg/L)
As far as is known, cadmium is
biologically a nonessential, nonbeneficial
element of high toxic
potential. Evidence for the serious
toxic potential of cadmium is
provided by; a) poisoning form
cadmium-contaminated food and
beverages; b) epidemiological
evidence that cadmium may be
associated with renal arterial
hypertension under certain
conditions; c) epidemiological
association of cadmium with ÒItaiitaiÓ
disease in Japan: d) long-term
oral toxicity studies in animals. The
health effects of long-term exposure
in the U.S. appear to be for diet,
cigarette smoking and sege into the
groundwater from industrial plants
especially wastewater. Cadmium is
believed to be mutagenic but not
carcinogenic.
- Calcium (Ca)
The present of calcium in water
supplies results from passage
through or over limestone, dolomite
and other calcium containing
deposits. Small concentrations of
calcium carbonate combat corrosion
of metal pipes by laying down a
protective coating. Higher levels of
calcium salts can precipitate when
heated to form scale in boilers, pipes
and cooking utensils. Calcium contributes
to the total hardness of water.
There is no aesthetic objective or
maximum acceptable concentration
set for calcium. See Total Hardness.
- Carbonate (CO3)
Carbonates can only exist if the pH of
the water exceeds 8.3. This seldom
occurs in natural waters. No aesthetic
objective or maximum acceptable
concentration has been set for
carbonates alone. See Total
Alkalinity.
- Chlorides (CI)
Concentrations of chloride in excess
of 250 mg/L may impart a salty taste
to the water. Therefore, the aesthetic
objective is set at a maximum of 250
mg/L. However the salty taste is
variable and dependant on the
chemical composition of the water.
No evidence has been found to
indicate that ingestion of chloride is
harmful to humans. A high chloride
content may harm metallic pipes and
structures as well as growing plants.
- Chromium Total (MCL: 0.05
mg/L)
Chromium is toxic to humans,
produces lung tumors when inhaled
and causes skin irritations. Longterm
exposure may cause skin and
nasal ulcers. Chromium accumulates
in the spleen, bones, kidney and liver.
It occurs in some foods, in air
(including cigarette smoke) and in
some water supplies. The level of
chromium that can be tolerated over
a lifetime without adverse affects is
still undetermined. Chromium is
involved in use of blood sugar and is
considered an essential nutrient.
- Coliform Bacteria
The presence of coliform organisms
is an indication of pollution. The
maximum acceptable concentration
for total coliforms is no organisms
detectable per 100 mL of sample. If
any coliform organisms are detected,
the site should be resampled, and if
the presence of coliforms is
confirmed, the appropriate corrective
action should be taken.
The test for coliform bacteria has
been the standard test for
microbiological safety for several
decades. It is an excellent indicator
of possible contamination in
disinfected public water supplies.
The test evaluates for coliform
bacteria, which are widely
distributed in the environment in soil,
on plants, on animals and in very
large numbers in the feces of
mammals. When coliform are
present, it means water has been
exposed to one or more of these
sources. In disinfected systems, this
means the water has been
recontaminated or disinfection is
inadequate and the water may
contain pathogens (disease-causing
organisms).
Illness caused by pathogens
commonly transmitted by water
includes typhoid, cholera, dysentery,
htitis, giardiasis, polio,
ÒLegionnairesÓ disease, and several
gastrointestinal and influenza-like
illnesses. Coliform bacteria are not
considered pathogens though some
strains are opportunistic pathogens,
which means they may cause disease
among people whose local or general
natural defense mechanisms are
impaired. This is most likely among
the elderly, the very young and the ill
(such as burns or immunosuppressive
therapy).
- Color
The AO for color in drinking water is
²15 true color units (TCU). The
provision of treated water at or below
the AO will encourage rapid
notification by consumers should
problems leading to the formation of
color arise in the distribution system.
- Conductivity
Conductivity is an indicator of the
ionic content of water and is
measured in microseimens/cm
(us/cm). A level over 2000 us/cm is
considered high and is unsuitable for
watering plants.
- Copper (SCL: 1 mg/L)
Copper in drinking water normally is
not a concern, as the levels required
to produce health effects in most
people exceed the maximum possible
concentrations. Experience indicates
that copper at concentration levels
exceeding 2 mg/L causes blue-green
staining of plumbing fixtures and an
off taste. To many people, copper
imparts a detectable taste at a
concentration level of 1 mg/L. In
instances where high copper concentration
levels in the drinking water
are observed, it is likely that other
heavy metals are so present. Water
containing 4 mg/L copper was found
to impart a green tint to dyed hair.
- Fluoride
Fluoride levels over 1.5/L may cause
discoloring or mottling of teeth.
Levels between 1 and 1.5 mg/L will
give teeth greater resistance to decay.
At levels greater than 0.7 mg/L oral
supplements are NOT recommended.
If you have any questions or
concerns, please contact our dental
department or main office.
A fluoride concentration of
approximately 1 mg/L helps prevent
dental cavities and osteoporosis. At
concentrations below 0.7 mg/L,
fluoride would likely not be of
benefit. Caution: At concentrations
above 1.8 mg/L, fluoride may cause
staining of enamel of permanent
teeth. This is most commonly a
problem of children up to about 10
years old. Because this is the only
effect, recently increased the MCL
for fluoride. Crippling bone changes
may occur in some people if drinking
water is above 8 mg/L fluoride.
There is not conclusive evidence that
fluoride of fluoridation causes cancer
in humans.
- Hardness
Water hardness is mainly caused by
the presence of calcium and
magnesium and is expressed as the
equivalent quantity of calcium
carbonate. Scale formation and
excessive soap consumption are the
main concerns with hardness. When
heated, hard waters have a tendency
to form scale deposits. Depending on
the interaction of other factors such
as pH and alkalinity, hardness levels
between 80 and 100 mg/L are
considered to provide an acceptable
balance between corrosion and
incrustation. Water supplies with
hardness greater than 200 mg/L are
considered poor but tolerable; those
in excess of 500 mg/L are
unacceptable for most domestic
purposes. Because water softening
may introduce undesirably high
quantities of sodium into drinking
water, it is recommended that a
separate unsoftened supply be used
for drinking and cooking. The
aesthetic objective is set at a
maximum of 500 mg/L.
- Hydrogen Sulfide (H2S)
Testing for H2S should occur on site.
Imparts a rotten egg odor and taste
that makes water all but undrinkable
and also promotes corrosion. In
addition, it can foul the resin bed of
water conditioner. The use of a water
conditioner is not recommended
unless the water is first treated for
removal of sulfur. The aesthetic
objective for hydrogen sulfide is 0.05
mg/L.
- Hydrogen (OH)
Hydroxide contributes to 9 the total
alkalinity of water. It is almost never
present in natural waters. See Total
Alkalinity.
- Iron (Fe)
At levels above 0.3 mg/L, iron stains
laundry and plumbing fixtures and
causes undesirable taste. The
precipitation of excessive iron causes
a reddish brown color in the water. It
may also promote the growth of iron
bacteria, leaving a slimy coating in
the piping and toilet tanks. The
presence of iron bacteria can also
cause a Ôrotten egg' odor in the water
and sheen on the surface of the water.
The aesthetic objective is set at a
minimum of 0.3 mg/L.
- Lead (MCL: 0.01 mg/L)
Exposure to lead in water, either
brief or prolonged, can seriously
injure health. Prolonged exposure to
relatively small quantities (more than
0.01 mg/day) may affect health. Lead
exposure occurs from air, food and
water sources. All exposure is
additive. Lead accumulates in the
bones, resulting in elevated levels in
the blood. Known effects range from
subtle biochemical changes at low
levels of exposure to severe
neurological and toxic effects and
even death at much higher levels.
As with several other water
contaminants, children, infants and
fetuses are especially vulnerable to
lead. Infants and children absorb a
much greater portion of lead intake
than adults and their immature,
developing bodies and central
nervous systems are much more
sensitive to its effects. A child's
mental and physical development
can be irreversibly stunted by overexposure
to lead. Health effects
include reduced mental capacity
(even mental retardation), interference
with kidney and neurological
functions and hearing loss in
children. The proposed MCL should
be followed whenever pregnant
women, infants or children are
consuming water.
Water may be contaminated by lead
from rocks and soil. However, most
of Missouri has little lead in these
sources and most of the water's pH is
above neutral, where lead is less
soluble. There is little reason to
expect lead in water supplies.
Lead pipe was used for service
connections from water mains to
homes or businesses as late as the
1960s. The use of solder containing
lead has been made illegal for
potable water plumbing systems.
Industry standards now prevent the
use of lead as an additive in solder
used for plumbing.
- Magnesium (Mg)
Magnesium is present in all natural
waters and high levels in groundwater
are probably the result of
contact with magnesium containing
rock formations. Magnesium is a
major contributor to water hardness
and may also contribute undesirable
tastes to drinking water. The
aesthetic objective is set at a maximum
of 200 mg/L.
- Manganese (Mn)
Manganese can cause staining to
plumbing and laundry, and undesirable
tastes in beverages. Also, it
may lead to the accumulation of
bacterial growth in the piping and
toilet tanks. The aesthetic objective is
set at a maximum of 0.05 mg/L.
- Mercury (MCL: 0.002 mg/L)
Mercury is distributed throughout the
environment as a result of industrial
and agricultural applications. Large
increases in concentrations above
natural levels in water, soils and air
may occur in localized areas though
significant mercury problems are
rare in Missouri. Outside of occupational
exposure, food (particularly
fish) is typically the greatest
contributor to total mercury intake.
Poisoning is characterized by major
changes in the brain, including loss
of vision and hearing, intellectual
deterioration and even death.
- Nitrate (NO3)
The maximum acceptable
concentration of nitrate in drinking
water is 45 mg/L as NO3. In
excessive amounts it contributes to
the illness known as methemoglobinemia.
Sources of nitrate in
water include decaying plant or
animal material, agricultural
fertilizers, manure, domestic sewage
or geological formations containing
soluble nitrogen compounds.
- pH
Natural waters usually have pH
values in the range of 4 to 9 and most
are slightly basic (i.e. greater than 7)
because of the presence of
bicarbonates and carbonates.
Corrosion effects may become
significant as a pH below 6.5 and
scaling may become a problem at a
pH above 8.5. For this reason an
acceptable range for drinking water
pH is from 6.5 to 8.5.
- Potassium (K)
Potassium ranks seventh among the
elements in order of abundance, yet
its concentration in most drinking
waters seldom reaches 20 mg/L.
There is no maximum acceptable
concentration or aesthetic objective
set for this element.
- Selenium (MCL: 0.01 mg/L)
There is considerable difficulty in
determining the toxic levels of
selenium intake in humans because
the diet contains an unknown variety
of selenium compounds in varying
mixtures. Signs of toxicity have been
seen at an estimated intake of 0.7 to
7 mg/day. Possible health effects
include growth inhibition, skin
discoloration, dental and digestive
problems, liver damage, and
psychological disorders. Some
studies have raised concern over the
possible carcinogenic properties of
this element, but at this time it is not
believed to be carcinogenic.
- Silver (MCL: 0.05 mg/L)
The need to set water standard for
silver arises from its intentional
addition to water as a disinfectant.
(No public water system in Missouri
uses silver as a disinfectant.) The
chief effect of silver on humans is a
condition called argyria or argyrosis,
and unsightly, permanent blue-gray
discoloration of the skin, eyes and
mucous membranes. Because silver,
once absorbed, is held indefinitely in
the body tissue, a maximum level has
been set. However, because skin
discoloration is the only known
health effect and because it is
considered an aesthetic effect, has
proposed making it a secondary
standard.
- Sodium (Na)
Weathering of salt deposits and
contact of water with igneous rock
provide natural sources of sodium.
Another potential source of sodium
in water supplies is the watersoftening
process, which replaces
calcium and magnesium (hardness)
with sodium. Persons on sodiumrestricted
diets should consult with
physicians. The aesthetic objective is
set at a maximum of 200 mg/L.
- Sulfates (SO4)
Sulfate occurs naturally in water and
may be present in natural waters in
concentrations ranging from a few to
several thousand mg/L.
Concentrations in excess of 500
mg/L, especially if the magnesium
content is also high, may have a
laxative effect or cause
gastrointestinal irritation. It may also
result in a noticeable taste. The
aesthetic objective is set at a
maximum of 500 mg/L.
- Sum of Ions
Sum of ions indicates the
concentration of ions in the water
(i.e. dissolved solids). The aesthetic
objective for total dissolved solids is
a maximum of 500 mg/L.
- Tannins
Tannic acid is formed by decaying
organic matter. Tannins alone are not
harmful, although they can affect the
proper operation of chemical free
iron filters.
- Total Dissolved Solids (TDS)
Is a measure of the ability of a water
to carry an electric current. This
ability depends on the presence of
ions and is therefore an indication of
the concentration of ions (i.e.
dissolved solids) in the water. Waters
with high dissolved solids generally
are of inferior palatability and also
may leave a white film on dishes, etc.
The aesthetic objective for total
dissolved solids is 500 mg/L and is
approximately equivalent to a
conductivity of 500 uS/cm.
- Trihalomethanes
THMs are formed in drinking water
primarily as a result of chlorination
and/or bromination of organic matter
present naturally in raw water
supplies. Chloroform is the THM
detected most frequently and at the
highest concentrations in drinking
water. Available data are consistent
with the hypothesis that ingestion of
chlorinated drinking water, if not
THMs specifically, may be casually
related to cancers of the bladder and
colon (chloroform and other THMs
account for up to 50% by weight of
the total chlorination by-products in
drinking water). Chloroform has
been found to be carcinogenic in two
animal species in the most extensive
bioassays conducted to date and has
been classified as being probably
carcinogenic to humans.
- Turbidity
Turbidity in water is caused by
suspended matter, such as clay, silt,
finely divided organic and inorganic
matter, soluble colored organic
compounds, plankton and other
microscopic organisms. Turbidity in
excess of 5 NTU becomes apparent
and may be objected to by a majority
of consumers. Therefore, an AO of ²
5 NTU has been set for water at the
point of consumption.
- Uranium2
Uranium is a naturally occurring
element, consisting of a mixture of
three radionuclides, all of which
decay by alpha emission. Uranium is
used primarily as fuel in nuclear
energy plants. It may enter drinking
water from naturally occurring
deposits or as a result of human
activity, such as mill tailings and
phosphate fertilizers.
Nephritis is the primary chemically
induced effect of uranium in animals
and humans. Lesions are seen in the
kidney at both glomerular and
tubular levels. At sublethal levels,
regeneration of the injured tubular
epithelium begins two to three days
after exposure.
The MAC for uranium in drinking
water, derived from the aDE, is
0.02mg/L.
- Zinc (SMCL: 5 mg/L)
Zinc is found in some natural waters,
most frequently in areas where it is
mined. It is not considered detrimental
to health unless it occurs in
very high concentrations. However, it
does give an undesirable taste and
appearance to drinking water, which
is the reason for the secondary
standard classification.
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