100% efficiency at the stated
rating of water filtration.
To take in. Many things absorb
A chemical compound which
dissolves in water. Acids have sour taste and turn a vegetable dye called
litmus, red. An acid separates into two or more electrically charged parts
when it is dissolved in water.
Acid Rain -
The acidic rainfall which
results when rain combines with sulfur oxides emissions from combustion
of fossil fuels (coal).
Activated carbon -
Very porous carbon from wood,
coal, or lignite heated to very high temperatures to promote active sites
where contaminants can be adsorbed from water.
Activated carbon adsorption
The process of pollutants
moving out of water and attaching on to activated carbon.
Active ingredient -
The chemical in a pesticide
formulation designed to kill a pest.
Adsorption (adsorb) -
Adhesion of chemicals out
of water on to a surface.
The mixing or turbulent exposure
of water to air and oxygen to dissipate volatile contaminants and other
pollutants into the air.
Aggressive water -
Water which is soft and acidic
and can corrode plumbing, piping, and appliances.
The measurement of constituents
in a water supply which determine alkaline (opposite of acidic) conditions.
An underground waterway.
Artesian well -
A well drilled into a confined
aquifer where enough pressure exists for the water to flow to the surface
Reverse seepage of water in
a distribution system.
Reversing the flow of water
through a home treatment device filter or membrane to clean and remove
The process by which certain
metals and chemical levels in the tissue of organisms increase with higher
standing in the food chain.
Chemicals or metals that are
easily absorbed into the food chain are easily taken up by the intestines
in the human body.
To decompose by natural means.
The earth and all its ecosystems.
Water samples containing a
chemical of known concentration given a fictitious company name and slipped
into the sample flow of the lab to test the impartiality of the lab staff.
Highly salty and heavily mineralized
water containing heavy metal and organic contaminants. Brine usually accompanies
oil and gas deposits which exist far below drinkable groundwater supplies.
A class of compounds, used
as refrigerants and in other chemical processes, which deplete the ozone
layer in the stratosphere.
The national Community Water
Calcium Carbonate -
A white precipitate that forms
in water lines, water heaters, and boilers, etc. in hard water areas; also
Capillary zone -
Soil area above the water
table where water can rise up slightly through the cohesive force of capillary
The collective term for the
natural inorganic chemical compounds related to carbon dioxide that exist
in natural waterways.
A substance that causes cancer.
A tank used to collect rainwater
runoff from the roof of a house or building.
In water treatment, the use
of chemicals to make suspended solids gather or group together into small
Cold vapor -
Special method to test water
Coliform bacteria -
used in testing water to indicate the presence of pathogenic bacteria.
Cone of depression -
Natural depression in the
water table around a well during pumping.
Confined aquifer -
An aquifer that lies between
two impermeable rock layers.
Confluent growth -
In coliform testing, abundant
or overflowing bacterial growth which makes accurate measurement difficult
A protozoan one-half as large
as a red blood cell, cryptosporidium is so small and tough that it is very
hard to detect, much less kill. It causes acute health problems in healthy
individuals and may be fatal to individuals whose immune systems are compromised
by illness, old age, or medical treatments. See Protozoan.
basic genetic building block
material in chromosomes of a cell nucleus.
The product formed by the
decay of a radionuclide; usually a new element.
Deionized water -
Water free of inorganic chemicals.
Dental fluorosis -
Disorder caused by excessive
absorption of fluorine and characterized by brown staining of teeth.
Detection limit -
The lowest level that can
be determined by a specific analytical procedure or test method. The detection
limit of a test is determined by the test method itself or the analytical
instrument used in the test. The detection limit for TOX, for example,
is generally considered to be around 5 ppb. Therefore, if no organics are
detected the result will be expressed as < (less than) 5 ppb.
The movement and spreading
of contaminants out and down in an aquifer.
Water treatment method where
water is boiled to steam and condensed in a separate reservoir. Contaminants
with lower boiling points than water do not vaporize and remain in the
Halogenated organic chemicals
formed when water is disinfected.
Distilled water -
Water that has been treated
by boiling and condensation to remove solids, inorganics, and some organic
Two separate samples with
separate containers taken at the same time from the same place. This is
a quality control method. The two results should be very close.
A plant, like the earth, which
is capable of supporting life.
Negatively charged particles
orbiting the nucleus of a molecule.
Enteric viruses -
A category of viruses related
to human excreta found in waterways.
The science which investigates
the origin of diseases or abnormalities affecting human populations.
Toxic to the fetus.
Large scale treatment process
whereby small particles in flocs are collected into larger particles so
their weight causes them to settle to the bottom of the treatment tank.
This is accomplished by gentle stirring.
A pesticide specifically designed
to kill fungus.
Activated Carbon) -
pure carbon heated to promote
"active" sites which can adsorb pollutants. GAC is used in some home water
treatment devices to remove certain organic chemicals and radon.
Gamma radiation -
Electromagnetic ionizing radiation
which easily penetrates test biological tissue.
Greenhouse effect -
Natural phenomenon whereby
increased C02 and other gases in the atmosphere cause radiation from the
sun to be trapped, leading to increases in global temperature and potential
large-scale climate changes.
Ground water -
Water from a well or underground
The time it takes for one-half
of a radioactive element or pesticide to decay. Halides or halogens - Chlorine,
bromine, or fluorine.
Halogenated organic chemical
Organic chemical containing
chlorine, bromine, or fluorine.
Hard water -
Water containing a high level
of calcium, magnesium, and other minerals. Hard water reduces the cleansing
power of soap and produces scale in hot water lines and appliances.
Heat of vaporization -
The amount of heat necessary
to convert a liquid (water) into vapor.
A pesticide specifically designed
to kill unwanted plants.
Hydrologic cycle -
Natural pathway water follows
as it changes between liquid, solid, and gaseous states.
Not permeable; does not permit
fluids to pass through.
Indicator organisms -
Microorganisms whose presence
is indicative of pollution or of more harmful microorganisms. Coliforms
are indicator organisms.
Indicator tests -
Test for a specific contaminant,
group of contaminants, or constituent which signals the presence of something
else (i.e., coliforms indicate the presence of pathogenic bacteria, high
turbidity indicates the possible presence of organics and microbiological
contamination, and a positive TOX result indicates the presence of manmade
Inert ingredient -
Nonreactive components in
a pesticide formulation or product used to "carry" the active ingredient.
Inorganic chemicals -
Those chemicals which do not
contain carbon; these include nitrates, fluoride, and metals.
A class of pesticides used
to kill undesirable insects.
Atoms of the same element
which have the same number of protons but a different number of neutrons
in the nuclei.
Water containing contaminants
which leaks from a disposal site such as a landfill or dump.
A metal known to be toxic
since Roman times, lead is still used in faucets today. As an additive
to tin, brass, or antimony, lead makes the metal softer and easier to work
with. The EPA has set no maximum contaminant (MCL) for lead. The expense
of replacing U.S. plumbing systems that contain lead is so astronomical
that it can only be done slowly and gradually.
Contaminant Level) -
the maximum level of a contaminant
to allowed in water by federal law. This level is based on health effects
as well as currently available treatment methods.
Milligrams of a contaminant
per liter of water; same as parts per million (ppm).
Manifest (hazardous waste
Written documentation of a
hazardous waste shipment that must accompany the waste from generator,
to transporter, to in disposal facility, and be signed by representatives
of each company.
Method blank -
Laboratory grade water taken
through the entire analytical procedure to determine if the samples are
being accidentally contaminated by chemicals in the lab.
A chemical which causes a
change in the genetic makeup of an organism which affects future generations.
Mutagenic activity -
The relative potential for
a specific substance, material, or water sample to alter genetic structure
and influence subsequent generations.
National Interim Primary Drinking
NPDES (permits) -
Issued under the National
Pollutant Discharge Elimination System for those companies discharging
pollutants directly into waterways in the United States.
Uncharged particles found
in the nucleus of an atom which contribute to the total weight of the atom.
A form of nitrogen most often
found in water.
Nonpoint source of pollution
These are wastes that come
from so many sources over such a wide area that they are impossible to
pinpoint or regulate. In the spring planting season, wastes from agricultural
fields and livestock are a significant source of cryptosporidium, triazines,
and nitrates. But suburban lawn chemicals also qualify as nonpoint wastes.
Well-meaning attempts to control nonpoint pollution have failed, at least
so far, because of an independent mindset in farmers and anti-environmental
sentiments in Congress.
Defined as chemicals containing
carbon. These include: 1.) natural - those from animal and plant life,
including coal and oil; and 2.) those synthesized by man - industrial solvents,
Organic fanning -
Farming technique which utilizes
only natural means to fertilize soil and control pests.
A class of organic pesticides
containing phosphorus, which interrupts nerve impulses along the central
nervous system leading to convulsions, paralysis, and death.
1.) In the lower atmosphere,
a colorless toxic gas formed by the reaction of nitrogen oxides and hydrocarbons
with sunlight, particularly in urban areas. It contributes to chronic human
respiratory disease. 2.) In the stratosphere, absorbs ultraviolet radiation
and protects life from excessive ultraviolet doses. 3.) Used as an alternate
form of water disinfection.
A class of chemical pollutants
formed through the breakdown of other chemicals or substances. For example,
the combustion of coal, wood, oil, and certain SOCs results in the formation
A measure of the acidity or
alkalinity of water; the pH scale is from 0 to 14 - seven is neutral, 0
is very acidic, 14 is very alkaline.
POE (Point of entry) -
Water treatment device situated
at the point where the water enters the house; treats all water entering
POU (Point of use) -
Home water treatment devices
located at the point where the water is used, at or near the faucet.
Parts per billion.
Parts per million.
Test or analytical procedure
which: 1.) measures specific chemicals such as pesticides, PCBs or fluoride;
or 2.) measures a group of chemicals or a characteristic such as pH, TOX,
In the process of radioactive
decay of one element, a new one is formed. The original elemental is called
Microorganism which can cause
A group of SOCs used in the
synthesis of a wide variety of chemicals and a ubiquitous class of pollutants.
A group of SOC chemicals used
in plastics manufacturing to make them flexible and pliable. One of the
most widespread classes of pollutants due to their usage.
Concentrated amount of a contaminant
or contaminants existing in soil or groundwater.
The area taken up by contaminant(s)
in an aquifer.
A, solid which has come out
of an aqueous solution. For example, iron from groundwater precipitates
to a rust colored solid when exposed to air.
A chemical added to a water
sample to keep it stable and prevent compounds in it from changing to other
forms or microorganism densities from changing prior to analysis. Protons
- Positively charged particles found in the nucleus of an atom.
Protozoans are organisms,
such as cryptosporidium, that have a life-cycle with several stages, some
of which allow them to pass through a chlorine disinfection process unharmed.
To force a gas through the
water sample to liberate volatile chemicals or other gases from the water
so their level can be measured.
Purgeable organics -
Volatile organic chemicals
which can be forced out of the water sample with relative ease through
Testing the same sample four
times; this is often done as a quality control measure in screening tests
like TOC and TOX.
Quality assurance -
Efforts by a laboratory to
ensure their test results can be substantiated by other laboratories.
Quality control -
Actions taken by a lab to
ensure all variables and factors are considered in the measurement of a
sample and the interpretation of data to give a result. quantify - To measure
the amount of a chemical or substance in a sample.
Resource Conservation and
Recovery Act - federal legislation requiring that hazardous waste be tracked
from "cradle" (generation) to "grave" (disposal).
RO (Reverse osmosis) -
A water treatment method whereby
water is forced through a semipermeable membrane which filters out impurities.
Radioactive elements or atoms.
Recharge zone -
The area over which an aquifer
is replenished; for a confined aquifer the area would be small, but for
an unconfined aquifer the recharge zone would likely be the entire length
of the aquifer.
Replicate (sample analysis)
Analyzing the same sample
twice; should yield very similar results.
Residual chlorine -
The level of chlorine existing
in the distribution system after chlorination at the drinking water treatment
plant. The residual chlorine level will be a function of the level of microorganisms
and the potential for additional THM formation in the distribution system.
Organic Chemicals) -
Manmade chemicals containing
carbon, many are associated with chronic health effects.
SPC (Standard Plate Count)
or HPC (Heterotrophic Plate Count) -
A test which directly measures
the level of certain bacteria in a water sample.
Screening test -
A test that encompasses a
wide range of possible contaminants. Examples are: TOX, TOC, and VOA. See
also indicator tests.
A large scale water treatment
process where heavy solids settle out to the bottom of the treatment tank
Skeletal fluorosis -
A health effect of excess
fluoride leading to rheumatic effects, pain, and stiffness.
A quality control measure
where a known amount of chemical is added to the sample to determine how
well the chemical is recovered from the sample when analyzed.
Spring water -
According to the U.S. Food
and Drug Administration, spring water is water that comes out of the ground
on its own or is bottled near water that comes out of the ground on its
Surface impoundment -
An indented area in the land's
surface - pit, pond, US( lagoon - usually unlined and confined by natural
means and holds liquid waste.
Surface water -
Water from rivers and lakes.
Roughly half of all Americans get drinking water from surface water sources.
dissolved solids) -
The sum of all inorganic and
organic particulate; TDS is an indicator test usually reserved for wastewater
analysis, but is also a measure of the mineral content of bottled water
a class of volatile organic
chemicals created as a result of water chlorination.
TIC (Tentatively Identified
In GC/MS analysis, chemicals
identified by computer match that are not covered in the specific test
method. The accuracy of TIC levels is questionable.
TNTC (Too numerous to count)
a total coliform test result;
too many coliforms to count indicates heavy contamination.
TOC (Total Organic Carbon)
screening test which measures
the amount of organic carbon in the water sample.
TOX (Total Organic Halide)
screening test which measures
the level of level organic chemicals containing chlorine and bromine.
A chemical or substance which
causes abnormal formation of a fetus.
Turbidity (Turbid) -
The interference of light
passage by insoluble particulates in water. To water engineers, turbidity
means cloudiness. Turbidity in water can be harmless, or it may indicate
to water that extra filtration, flocculation, and sedimentation is needed.
Water disinfection treatment
method using ultraviolet light.
Unconfined aquifer -
An aquifer that is not confined
by impermeable rock above it so water recharge occurs across its entire
Organic Analysis) -
Testing procedure for volatile
organic chemicals; also called volatiles scan, volatiles screen, or referred
to by specific EPA method number, EPA 601 or EPA 602.
VOC (Volatile organic chemical)
An organic chemical which
can easily dissipate or evaporate into the air.
Broad term used to describe
different types of water filters.
Water table -
The surface of an unconfined
aquifer which fluctuates due to seasonal precipitation.
Wet methods -
A group of water tests usually
for determining the presence of inorganic chemicals, like nitrates, fluoride,
and dissolved solids. They are called wet methods presumably due to the
fact that they generally do not require the use of solvent extraction methods
that SOC testing does.