Aldicarb - Aldicarb is a carbamate insecticide with structural formula:
2-methyl-2-(methylthio)propionaldehyde O-methylcarbamoyloxime. Aldicarb is the active substance in Temik pesticide,
which is effective against thrips, aphids, spider mites, lygus, fleahoppers, and leafminers but is primarily used as a
nematicide. Aldicarb is moderately toxic to fish. The half-life of aldicarb in water is from one day to a few months.
In pond water, aldicarb is broken down rapidly and has a half-life of five to 10 days. It is degraded by bacteria,
sunlight, and reactions with water. Because of its rapid degradation rate, levels in surface water may be lower than
those in groundwater.
Algae - Algae range from single-cell organisms to multicellular organisms, some
with fairly complex differentiated form and (if marine) called seaweeds. All lack leaves, roots, flowers, seeds and
other organ structures that characterize higher plants (vascular plants). They are distinguished from other protozoa
in that they are photoautotrophic, although this in not a hard and fast distinction as some groups contain members
that are mixotrophic, deriving energy from both photosynthesis and uptake of organic carbon.
Alkalinity - Alkalinity of water is its acid-neutralizing capacity. Because the
alkalinity of many surface waters is primarily a function of carbonate, bicarbonate and hydroxide content, it is taken
as an indication of the concentration of these constituents. The measured values also may include contributions from
borates, phosphates, silicates or other bases if these are present. Alkalinity in excess of alkaline earth metal
concentrations is significant in determining the suitability of water for irrigation.
Aluminum (Al) - Aluminum is the most abundant of all metals and the third most
abundant element in the earth's crust. Aluminum is too reactive chemically to occur in nature as a free metal.
Instead, it is found combined in over 270 different minerals. The chief source of aluminum is bauxite ore. It is
one of the few abundant elements that appear to have no beneficial function to living cells.
Ammonia-Nitrogen (NH3-N) - Ammonia, naturally occurring in surface and
wastewaters, is produced by the breakdown of compounds containing organic nitrogen. Ammonia is toxic to fish
at relatively low concentrations in pH-neutral or alkaline water. Plants are more tolerant of ammonia than animals
and invertebrates are more tolerant than fish.
Arsenic (Ar) - Arsenic is a semi-metal element in the periodic table. It is
odorless and tasteless. It enters drinking water supplies from natural deposits in the earth or from agricultural
and industrial practices. Higher levels of arsenic tend to be found more in ground water sources than in surface
Barium (Ba) - Barium is a lustrous, machinable metal which exists in nature
only in ores containing mixtures of elements. It is used in making a wide variety of electronic components, in
metal alloys, bleaches, dyes, fireworks, ceramics and glass. In particular, it is used in well drilling operations
where it is directly released into the ground. In water, the more toxic soluble barium salts are likely to be converted
to insoluble salts which precipitate. Barium does not bind to most soils and may migrate to ground water. It has a
low tendency to accumulate in aquatic life.
Benzene - Benzene is a clear, colorless aromatic liquid. It is highly flammable.
The greatest use of benzene is as a building block for making plastics, rubber, resins and synthetic fabrics like
nylon and polyester. Other uses include: as a solvent in printing, paints, dry cleaning, etc. If benzene is released
into soil, it will either evaporate very quickly or leach to groundwater. It can be broken down by some soil microbes.
It may also be degraded in some ground waters. If benzene is released into surface water, most of it should
evaporate within a few hours. Though it does not degrade by reacting with water, it may be degraded by microbes. It
is not likely to accumulate in aquatic organisms.
Cadmium (Cd) - Cadmium is a metal found in natural deposits as ores containing
other elements. The greatest use of cadmium is primarily for metal plating and coating operations, including
transportation equipment, machinery and baking enamels, photography, television phosphors. It is also used in
nickel-cadmium and solar batteries and in pigments. Some cadmium compounds are able to leach through soils to
ground water. When cadmium compounds do bind to the sediments of rivers, they can be more easily bioaccumulated
or re-dissolved when sediments are disturbed, such as during flooding. Its tendency to accumulate in aquatic life
is great in some species, low in others.
Calcium (Ca) - Calcium is a soft grey alkaline earth metal, and is the fifth
most abundant element in the Earth's crust. It is essential for living organisms, particularly in cell physiology,
and is the most common metal in many animals. The most common forms of calcium are calcium carbonate (calcite) and
calcium magnesium carbonate (dolomite).
Carbamates - The carbamate pesticides are mainly used in agriculture, as
insecticides, fungicides, herbicides, nematocides, or sprout inhibitors. In addition, they are used as biocides
for industrial or other applications and in household products. These chemicals are part of the large group of
synthetic pesticides that have been developed, produced, and used on a large scale in the last 40 years. More than
50 carbamates are known.
Carbon Tetrachloride - Carbon tetrachloride is a clear heavy organic liquid
with a sweet aromatic odor similar to chloroform. Most of it is used to make chlorofluorocarbon propellants and
refrigerants, though this has been declining steadily. Other uses have included: use as dry cleaning agent and
fire extinguishers, in making nylon, as a solvent for rubber cement, soaps, insecticides, etc. Carbon tetrachloride
evaporates quickly from surface waters and soil. It does not bind to soil and may leach into ground water. It has a
low potential to accumulate in aquatic life.
Carbaryl - Carbaryl (1-naphthyl methylcarbamate) is a chemical in the
carbamate family used chiefly as an insecticide. It is a colorless white crystalline solid. Carbaryl does not
dissolve well in water and sticks to soil. Carbaryl ranges from slightly to highly toxic to several species of
fish. Carbaryl is very highly toxic to aquatic invertebrates such as shrimp and stoneflies. Carbaryl can also
damage frog tadpoles during their development.
Carbofuran - Carbofuran is a white crystalline solid with a slightly phenolic
odor. This broad spectrum insecticide is sprayed directly onto soil and plants just after emergence to control
beetles, nematodes and rootworm. The greatest use of carbofuran is on alfalfa and rice, with turf and grapes making
up most of the remainder. Earlier uses were primarily on corn crops. If released to soil or water, carbofuran will
be broken down by reactive chemicals and microbes, particularly in alkaline conditions. Carbofuran may leach
significantly in many soils. Leaching may not occur, in very high organic content soils. It is not expected to
accumulate in aquatic organisms.
Chloride (Cl-) - Chlorides are salts resulting from the combination of the gas
chlorine with a metal. Some common chlorides include sodium chloride (NaCl) and magnesium chloride (MgCl2). Chlorides
are not usually harmful to people. The salty taste produced by chloride concentrations is variable dependent on the
chemical composition of the water.
Chlorobenzene - Chlorobenzene is a colorless organic liquid with a faint,
almond-like odor. The greatest use of chlorobenzene is in the manufacture of other organic chemicals, dyestuffs
and insecticides. It is also a solvent for adhesives, drugs, rubber, paints and dry-cleaning, and as a fiber-swelling
agent in textile processing. Releases into water and onto land will either evaporate or be slowly degraded by microbes
in the soil or water. Since it does not bind to soils, it can be expected to leach into the groundwater. Little
accumulation is expected in fish and food products.
Chlorodibromomethane - Chlorodibromomethane is a colorless to yellow, heavy,
nonburnable liquid with a sweetish odor. This chemical is a possible contaminant of drinking water that has been
chlorinated to kill bacteria and viruses. Chlorodibromomethane may form when chlorine reacts with other naturally
occurring substances in water, such as decomposing plant material. In water, chlorodibromomethane is slowly broken
down at the water surface where oxygen is available, but breaks down much faster in deep water and in water that is
underground where there is a lot less oxygen. Chlorodibromomethane is mobile in soils and may seep into groundwater.
Chlorodibromomethane does not appear to concentrate in fish.
Chloroform - Chloroform is a colorless liquid with a pleasant, nonirritating
odor and a slightly sweet taste. It doesn't stick to soil very well and can travel through soil to groundwater.
Chloroform dissolves easily in water and some of it may break down to other chemicals. Chloroform lasts a long time
in groundwater. Chloroform doesn't appear to build up in great amounts in plants and animals.
Chlorophyll a (Chl a) - Chlorophyll a is a photosynthetic pigment which is found
in all green plants. Chlorophyll a is used as an algal biomass indicator. Biomass is a quantitative estimate of the
total mass of living organisms within a given area or volume. An excess of algae can lead to taste and odor issues
in drinking water.
Chromium (Cr) - Chromium is a metal found in natural deposits as ores
containing other elements. The greatest use of chromium is in metal alloys such as stainless steel; protective
coatings on metal; magnetic tapes; and pigments for paints, cement, paper, rubber, composition floor covering and
other materials. Its soluble forms are used in wood preservatives. When released to land, chromium compounds bind
to soil and are not likely to migrate to ground water. They are very persistent in water as sediments. There is a
high potential for accumulation of chromium in aquatic life.
Cobalt (Co) - Cobalt is a hard, lustrous, silver-grey metal. It is found in
various ores, and is used in the preparation of magnetic, wear-resistant, and high-strength alloys. Its compounds
are used in the production of inks, paints, and varnishes.
Conductivity - The conductivity of water provides information on its
chemical composition. Conductivity is a measurement of the ability of an aqueous solution to carry an electrical
current. There are several factors that determine the degree to which water will carry an electrical current.
These include: 1) the concentration or number of ions; 2) mobility of the ion; 3) oxidation state and 4) temperature
of the water.
Copper (Cu) - Copper is a metal found in natural deposits as ores containing
other elements. It is widely used in household plumbing materials. Copper may occur in drinking water either by
contamination of the source water used by the water system, or by corrosion of copper plumbing. Corrosion of plumbing
is by far the greatest cause for concern. Copper is rarely found in source water, but copper mining and smelting
operations as well as municipal incineration may be sources of contamination.
1,3-Dichloropropene - 1,3-Dichloropropene is a colorless liquid with a sweet
smell. It dissolves in water and evaporates easily. It is used mainly in farming as a pesticide. 1,3-Dichloropropene
in soil is likely to be broken down by microorganisms. It dissolves in water but breaks down slowly. Some
1,3-dichloropropene in water and soil evaporates rapidly into the air where it is broken down by sunlight. Some
1,3-dichloropropene in soil may travel deeper into the ground and reach groundwater.
Dissolved oxygen (DO) - The amount of oxygen freely available in water.
Traditionally, the level of dissolved oxygen has been accepted as the single most important indicator of a water
body's ability to support desirable aquatic life. DO is supplied to a waterbody through the diffusion of atmospheric
oxygen into the water and the photosynthetic production of oxygen by algae and aquatic weeds. Respiratory processes,
oxidation of inorganic wastes, and the decomposition of organic matter decrease oxygen concentrations in water.
E. Coli - E. coli is a member of the fecal coliform group of bacteria. This
organism in water indicates fecal contamination by warm blooded animals and may be an indicator of the presence of
Fecal coliform - Fecal coliform is a group of bacteria that can originate both
in feces and without the presence of feces. The presence of fecal coliform bacteria in aquatic environments may
indicate that the water has been contaminated with the fecal material of warm blooded animals. However, their
presence may also be the result of plants, cold-blooded organisms, and pulp or paper mill effluent.
Hardness - Hardness is a measurement of the mineral content of water. This
content usually consists of levels of metal ions, mainly calcium and magnesium in the form of carbonates, but may
include several other metals as well as bicarbonates and sulfates.
Lead (Pb) - Lead, a metal found in natural deposits, is commonly used in
household plumbing materials and water service lines. The greatest exposure to lead is swallowing or breathing in
lead paint chips and dust. Lead is rarely found in source water, but enters tap water through corrosion of plumbing
Macrophyte - Macroscopic forms of aquatic vegetation that encompasses macroalgae,
the few species of mosses and ferns adapted to the aquatic habitat, as well as true angiosperms.
Magnesium (Mg) - Magnesium is the ninth most abundant element in the universe
by mass. Magnesium occurs commonly in the minerals magnesite and dolomite. Magnesium ion is essential to all
Manganese (Mn) - Manganese is a grey-white metal resembling iron. It is found as
the free element in nature (often in combination with iron), and in many minerals. The free element is a metal with
important industrial metal alloy uses. Manganese ions are variously colored and are used industrially as pigments and
as oxidation chemicals.
Metals - The effects of metals in water and wastewater range from beneficial
through troublesome to dangerously toxic. Some metals are essential to plant and animal growth while others may
adversely affect water consumers, wastewater treatment systems and receiving waters. The benefits versus toxicity of
some metals depend on their concentrations in water. Some common metals include: aluminum, arsenic, barium, cadmium,
chromium, cobalt, copper, lead, manganese, mercury, nickel, selenium, silver, vanadium, and zinc.
Methomyl - Methomyl is a highly toxic compound used as a broad spectrum
insecticide. It is also used as an acaricide to control ticks and spiders. Methomyl is moderately to highly toxic
to fish and highly toxic to aquatic invertebrates. Aqueous solutions of methomyl have been reported to decompose
more rapidly on aeration, in sunlight, or in alkaline media.
Methyl Tertiary Butyl Ether (MTBE) - MTBE is achemical compound that is
manufactured by the chemical reaction of methanol and isobutylene. MTBE is produced in very large quantities
(over 200,000 barrels per day in the U.S. in 1999) and is almost exclusively used as a fuel additive in motor
gasoline. It is one of a group of chemicals commonly known as "oxygenates" because they raise the oxygen content
of gasoline. Low levels of MTBE can make drinking water supplies undrinkable due to its offensive taste and odor.
Nickel (Ni) - Nickel is a silvery white metal that takes on a high polish. It
occurs most usually in combination with sulfur and iron in pentlandite, with sulfur in millerite, with arsenic in
the mineral nickeline, and with arsenic and sulfur in nickel glance.
Nitrate+Nitrite Nitrogen (NO3+NO2) - Nitrates and nitrites are nitrogen-oxygen
chemical units which combines with various organic and inorganic compounds. In waters and wastewaters the forms of
nitrogen of the greatest interest are nitrate, nitrite, ammonia, and organic nitrogen. Since they are very soluble
and do not bind to soils, nitrates have a high potential to migrate to ground water. Because they do not evaporate,
nitrates/nitrites are likely to remain in water until consumed by plants or other organisms.
Nutrient - Any substance used by living things to promote growth. The term
is generally applied to nitrogen and phosphorus in water and wastewater, but is also applied to other essential
and trace elements.
Orthophosphate phosphorus (PO4) - Phosphorus occurs in natural waters and in
wastewaters almost solely as phosphates. They occur in solution, in particles or detritus, or in the bodies of aquatic
organisms. The growth of macrophytes and phytoplankton is stimulated principally by nutrients such as phosphorus and
pH - pH is a measure of the hydrogen ions in a solution. Measurement of pH is
one of the most important and frequently used tests in water chemistry.
Potassium (K) - Potassium compounds are used in glass, fertilizers, baking
powder, soft drinks, explosives, electroplating, and pigments. Potassium is an essential element in both plant and
Salinity - Dissolved salt content of a body of water. Salinity is an
ecological factor of considerable importance, influencing the types of organisms that live in a body of water.
Secchi Disk Transparency - The mean depth of the point where a weighted white
disk, 20 cm in diameter, disappears when viewed from the shaded side of a vessel and that point where it reappears
upon raising it after it has been lowered beyond visibility. The Secchi disk transparency is essentially a function
of the reflection of light from its surface and is therefore influenced by the absorption characteristics of both
the water and its dissolved and particulate matter.
Selenium (Se) - Selenium is a metal found in natural deposits as ores
containing other elements. The greatest use of selenium compounds is in electronic and photocopier components,
but they are also widely used in glass, pigments, rubber, metal alloys, textiles, petroleum, medical therapeutic
agents, and photographic emulsions. The toxicity of selenium depends on whether it is in the biologically active
oxidized form, which occurs in alkaline soils. These conditions can cause plant uptake of the metal to be increased.
It is known that selenium accumulates in living tissues.
Silver (Ag) - Silver is a very ductile and malleable (slightly harder than
gold) metal with a brilliant white metallic luster that can take a high degree of polish. Silver is found in native
form; combined with sulfur, arsenic, antimony, or chlorine and in various ores such as argentite (Ag2S), horn silver
(AgCl), and pyrargyrite (Ag3SbS3). This metal can also be produced during the electrolytic refining of copper.
Sodium (Na) - Sodium occurs with silicates and with salt deposits. Sodium
compounds are used in many applications, including caustic soda, salt, fertilizers, and water treatment chemicals.
The ratio of sodium to total cations is important in agriculture and human physiology.
Sulfate (SO4-2) - Sulfates can be naturally occurring or the result of municipal
or industrial discharges. When naturally occurring, they are often the result of the breakdown of leaves that fall
into a stream, of water passing through rock or soil containing gypsum and other common minerals, or of atmospheric
deposition. Problems caused by sulfates are most often related to their ability to form strong acids which can
Tetrachloroethylene (PCE) - PCE is a colorless organic liquid with a mild,
chloroform-like odor. Its greatest use is in the textile industry and as a component of aerosol dry-cleaning products.
PCE released to soil will readily evaporate or may leach slowly to the groundwater. Its break down by soil microbes is
slow. PCE released to water will primarily evaporate and has little potential for accumulating in aquatic life.
Toluene - Toluene is an organic liquid with a sweet, benzene-like odor. The
largest chemical use for toluene is to make benzene and urethane. Toluene released to soil will be lost by evaporation
from near-surface soil and by leaching to the groundwater. Its breakdown by soil microbes is slow. Toluene evaporates
within a few hours when released to water and it has little tendency to accumulate in aquatic life.
Total Dissolved Solids (TDS) - Dissolved solids refer to minerals in solution.
Waters with high dissolved solids generally are of inferior palatability. Highly mineralized waters also are
unsuitable for many industrial applications.
Total Kjeldahl Nitrogen (TKN) - TKN is the most common analysis run to determine
the amount of organic nitrogen in water. The test includes ammonium and organic nitrogen. Molecules containing
organic nitrogen (e.g., simple amino acids, algal-derived humic substances) have been implicated as disinfection
by-product precursors and membrane foulant materials.
Total Phosphorus (TP) - TP is a measurement of all forms, both particulate and
dissolved, of phosphorus in water.
Total Suspended Solids (TSS) - Suspended solids refers to matter floating in
water or wastewater. Solids may affect water or effluent quality adversely in a number of ways. Waters high in
suspended solids may be aesthetically unsatisfactory for such purposes as bathing.
A measure of the distance of the vertical penetration of
light in lakes.
Trichloroethlyene - Trichloroethylene is a colorless or blue organic liquid
with a chloroform-like odor. The greatest use of trichloroethylene is to remove grease from fabricated metal parts
and some textiles. Trichloroethylene released to soil will either evaporate or leach into ground water. If released
to water, it will also quickly evaporate. It has only a moderate potential to accumulate in aquatic life.
Turbidity - Turbidity in water is caused by suspended and colloidal matter such
as clay, silt, finely divided organic and inorganic matter, plankton, and other microscopic organisms. Clarity of
water is important in producing products for human consumption and in many manufacturing operations.
Vanadium (V) - Vanadium is a soft and ductile, silver-grey metal. In biology,
a vanadium atom is an essential component of some enzymes, particularly the vanadium nitrogenase used by some
Volatile Organic Compounds (VOCs) - Many organic compounds have been detected
in ground and surface waters. Contamination may be due to past practice of on-site disposal of domestic and
industrial wastes or to illegal discharges. Organohalides, particularly trihaolmethanes, are present in most
chlorinated water systems. Toxicological studies on animals have shown that some of these organics have the potential
to cause birth defects and cancer.
Water Temperature - Water temperature is a function of ambient air temperatures
and is one of the most biologically important parameters affecting dissolved oxygen saturation, biological growth
rates, rates of chemical and biological reactions and the solubility of particulate compounds. Temperature readings
are used in the calculation of various forms of alkalinity, in studies of saturation and stability with respect to
calcium carbonate, in the calculation of salinity, and in general laboratory operations.
Zinc (Zn) - Zinc is a moderately-reactive bluish-white metal. Zinc is an
essential element, necessary for sustaining all life.