| Aluminum |
Aluminum is an extremely abundant metal in the earth’s crust. Levels of aluminum in
water are generally low, but can vary across Canada. Aluminum can leach from rock and soil to enter
any water source. It can also enter water sources through human activity such as mining or
industrial manufacturing processes.
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British Columbia is the only province that has a standard for aluminum, which is 9.5 mg/L. The
Canadian recommended standard for aluminum is 2.9 mg/L, and is based on neurological effects
observed in rats. Studies in humans have found possible associations between aluminum ingestion and
diseases of the nervous system. However, these studies have a number of design limitations and do
not provide strong evidence that aluminum can cause these diseases. Studies in animals have
consistently observed adverse effects on the nervous system following ingestion of high levels of
aluminum, which supports effects seen in human studies.
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| Antimony |
Antimony is a metal that is present naturally in small quantities in water, rocks, and
soils. The most common source of antimony in drinking water is the corrosion of antimony-containing
plumbing materials. In groundwater, sources of antimony also include mining wastes, manufacturing
effluent, leaching of fertilizers, leaching of landfills, and fossil fuel combustion products.
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Health basis of MAC: Microscopic changes in organs and tissues (thymus, kidney, liver, spleen,
thyroid)
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| Arsenic |
Arsenic is a natural element found in the Earth’s crust. Some areas of Canada have a
greater potential for elevated arsenic levels in drinking water. The most common source of arsenic
in groundwater is through erosion and weathering of soils, minerals, and ores. Industrial effluents
and pesticide runoff may also contribute arsenic to water in some areas.
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Health basis of MAC: Cancer (lung, bladder, liver, skin) (classified as human carcinogen)
Other: Skin, vascular and neurological effects (numbness and tingling of extremities)
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| Barium |
Barium is a common element in the earth’s crust, although only trace levels are
normally found in natural waters. Barium compounds are often used in oil and gas well drilling
operations. Industrial effluents may also contribute to barium in water in some areas.
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Health basis of MAC: Increases in blood pressure, cardiovascular disease |
| Boron |
Boron is a naturally occurring element found in rock and soil. Boron present in
groundwater may be natural or due to coal combustion products, municipal sewage, leaching of
landfill materials, and the production of fertilizers and pesticides.
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Health basis of MAC: Reproductive effects (testicular atrophy, spermatogenesis) |
| Cadmium |
Cadmium is a naturally occurring element found in very low concentrations in most
rocks. The main source of cadmium in drinking water is through corrosion of plumbing materials with
galvanized steel/iron components such as service lines, pipes, brass fittings, cement mortar linings
and well components such as casings and drop pipes. Other sources of cadmium in groundwater include:
mining and smelting operations, industrial operations, burning of fossil fuels, fertilizer
application, sewage sludge disposal, and leaching of landfills.
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Health basis of MAC: Kidney damage and softening of bone |
| Chromium |
Chromium is a metal found naturally in ores, soils, and plants. Chromium compounds from
natural sources are usually found in groundwater in trace amounts only. The most common man-made
sources of chromium in groundwater are burning of fossil fuels, mining effluent, and effluent from
metallurgical, chemical, and other industrial operations. Chromium may affect the taste or smell of
well water, but not at levels normally found in groundwater.
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Health basis of MAC: Hyperplasia of the small intestine from chromium (VI). |
| Copper |
Copper is found naturally in rock, soil, plants, animals, water, sediment, and air.
Copper is frequently found naturally in groundwater, however, levels are generally very low. Common
synthetic sources of copper include pesticide and mining processing waste. Copper is often used in
household plumbing materials, such as pipes and faucets. Corrosion of copper pipes is the greatest
source of copper in drinking water. If the source of copper is corrosion of plumbing materials, be
aware that other metals, such as lead or cadmium.
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Health basis of MAC: Gastrointestinal effects (short-term), liver and kidney effects (long-term).
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| Escherichia coli |
E. coli is a type of fecal coliform bacteria commonly found in the intestines of
animals and humans. E. coli is short for Escherichia coli. The presence of E. coli in water is a
strong indication of recent sewage or animal waste contamination. Sewage may contain many types of
disease-causing organisms.
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The presence of E. coli indicates recent faecal contamination and the potential presence of
microorganisms capable of causing gastrointestinal illnesses; pathogens in human and animal faeces
pose the most immediate danger to public health.
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| Fluoride |
Fluoride is a negative ion of the element fluorine, which can be found in various
chemical compounds. It is present in air, water, soil, and most foods. Fluoride found in well water
in Canada occurs naturally. The concentration of fluoride in a well water sample depends on a number
of factors, such as the amount of fluoride present in the rock through which the groundwater has
passed and whether the water chemistry is favorable for fluoride to remain dissolved.
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Basis of MAC: Moderate dental fluorosis (based on cosmetic effect, not health). |
| Free Cyanide |
Cyanide is a chemical unit that can be released into groundwater from natural
processes. Mining can also be a source of cyanide pollution to ground and surface water. Cyanide is
also used in electroplating, photographic development, making plastics, mining processes, and
herbicides. It is also released in car exhaust.
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Health basis of MAC: rapid breathing, tremors and other neurological effects (short-term), weight
loss, thyroid effects, nerve damage (long-term).
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| Lead |
Lead is a naturally occurring element. However, naturally occurring lead is rarely
found dissolved in drinking water sources. The main source of lead in drinking water is through
corrosion of plumbing materials with lead or brass components, such as in some pipes, solder,
faucets, fittings, and older galvanized well liners.
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Health basis of MAC: Reduced intelligence in children measured as decreases in IQ is the most
sensitive and well established health effect of lead exposure. There is no known safe exposure level
to lead.
Other: Possible effects include behavioral effects in children. Reduced cognition, increased blood
pressure, and renal dysfunction in adults are also possible. Classified as probably carcinogenic to
humans
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| Manganese |
Manganese is a naturally occurring essential element found widely in air, water and
soil. It is prevalent across Canada in surface water and groundwater. The most common sources of
manganese in drinking water are naturally occurring and can be attributed to weathering of manganese
bearing rocks and soils. Other less common sources of manganese can be attributed to human
activities including mining and industrial activities, leachate from landfills and sewage effluent.
Manganese can make your water smell metallically, or like oil or asphalt.
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Health basis of MAC: Effects on neurological development and behaviour; deficits in memory,
attention, and motor skills.
Other: Formula-fed infants (where water containing manganese at levels above the MAX is used to
prepare formula) may be especially at risk.
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| Mercury |
Mercury is the only common metal which is liquid at ordinary temperatures. Possible
sources of mercury in drinking water include air pollution from coal combustion, waste incineration
and from metal refining operations and from natural mineral deposits in some hard rock areas.
Mercury can cause a metallic smell in water.
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Health basis of MAC: Irreversible neurological symptoms. |
| Nitrate (as N) |
Nitrate is a naturally occurring chemical made of nitrogen and oxygen and are found in
air, soil, water, and plants. In groundwater, nitrate primarily comes from decomposing plant and
animal material, agricultural fertilizers, manure, and domestic sewage. Groundwater wells can be
contaminated by leaching of chemical fertilizers, leaching of animal manure, and improperly treated
septic and sewage discharges.
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Health basis of MAC: Methemoglobinemia (blue baby syndrome) and effects of thyroid gland function in
bottle-fed infants.
Other: Classified as possible carcinogen under conditions that result in endogenous nitrosation
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| Nitrite (as N) |
Nitrite is a naturally occurring chemical made of nitrogen and oxygen. Nitrogen and
nitrogen compounds, such as nitrite, are found in air, soil, water, and plants.
In certain conditions, when oxygen is unavailable, nitrate may be converted to nitrite. Therefore
many sources of nitrate are also potential sources of nitrite. Sources of nitrite in groundwater
include: leaching of chemical fertilizers, leaching of animal manure, improperly treated septic and
sewage discharges, decaying plant or animal material, and erosion of natural deposits.
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Health basis of MAC: Methemoglobinemia (blue baby syndrome) and effects of thyroid gland function in
bottle-fed infants.
Other: Classified as possible carcinogen under conditions that result in endogenous nitrosation.
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| Selenium |
Selenium is found naturally in small quantities in rocks and soils and the presence in
groundwater depends of the rock and soil in the area. Other sources of selenium in groundwater
include contamination from copper and lead refinery effluent, municipal wastewater, hazardous waste
sites. For most people, food is one of the main sources of ingested selenium.
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Health basis of MAC: Chronic selenosis symptoms in humans following exposure to high levels.
Other: Hair loss, tooth decay, weakened nails and nervous system, disturbances at extremely high
levels of exposure
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| Strontium |
Strontium is a naturally occurring trace element found in seawater and soil. Strontium
can occur naturally in groundwater and surface water sources through the weathering of rocks and
soils or as a result of human activities such as mining and manufacturing operations.
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Health Basis of MAC: Bone effects (adverse effects on bone formation in infants as well as rickets,
osteomalacia)
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| Total Coliform |
Total Coliform is a large collection of different kind of bacteria that are common in
the environment (soil and vegetation) and are generally harmless. If a lab detects only coliform
bacteria in drinking water, the sample should also be tested for the presence of E.coli.
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Total coliforms are not used as indicators of potential health effects from pathogenic
microorganisms; they are used as a tool to determine how well the drinking water treatment system is
operating and to indicate water quality changes in the distribution system.
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| Uranium |
Uranium is a naturally occurring radioactive element that exists in soil and rock
throughout Canada. Naturally occurring uranium in groundwater comes from the dissolving of minerals
that contain uranium. Some human activities are also sources of uranium – mill tailings, emissions
from the nuclear industry, and the combustion of coal and other fuels.
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Health basis of MAC: Kidney effects (various lesions); may be rapidly reversible after exposure
ceases.
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| Zinc |
Zinc is a metal normally found in small amounts in nature. Although zinc occurs
naturally, most zinc finds its way into groundwater because of human activities. Galvanized liners
or fittings or metal pipes coated with zinc, present in many older wells or plumbing systems, can
leach zinc into drinking water.Well water may also be contaminated through processes, such as:
mining, lead-zinc smelters, steel production, coal burning, and hazardous waste disposal.
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British Columbia is the only province that has a MAC for zinc, which is 3 mg/L. This value is
specific to the protection of human health and water derived using a toxicological referenced value
protective of adults.
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