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absorption: The physical uptake of water and any material dissolved in it.
acidic: Describing the chemical characteristic of acid. Technically, a pH value below seven.
activated carbon: Particles or granules of carbon used in water treatment because of their high capacity to selectively remove certain trace and soluble materials. Usually obtained by heating a carbon source (such as wood).
acute: Occurring immediately or in a short period of time (that is within hours or days); used to describe health effects that are experienced shortly after an exposure has occurred. Also see chronic.
adsorption: A process in which molecules are attracted to and retained on a surface (compare with absorption). In water treatment, the large surface area of activated carbon is used to remove low concentrations of contaminants.
aeration: The mixing of air and water, resulting in oxygen from the air dissolving in the water.
aerobic: As applied to water, refers to the presence of oxygen dissolved from the air (also see anaerobic).
algae: Microscopic plants which contain chlorophyll and live floating or suspended in water. They may also be attached to structures, rocks or other submerged surfaces. Excess algal growths can give tastes and odours to drinking water. Algae produce oxygen when exposed to sunlight and use oxygen in darkness. Their biological activities significantly affect the pH and dissolved oxygen concentrations of water.
algal bloom: The occurrence of a high concentration of microscopic plant life, such as green or blue-green algae (cyanobacteria), in a river, lake and reservoir, usually as a result of increased nutrient content.
alkaline: Describing the chemical characteristic that can neutralise acid. Technically, a pH value above seven.
anaerobic: As applied to water, refers to the absence of oxygen (also see aerobic).
ANCOLD: The Australian National Committee on Large Dams Incorporated (ANCOLD Inc) is an incorporated voluntary association of organisations and individual professionals with an interest in dams in Australia. Members include local, state and federal agencies, dam owners and operators, contractors, consultants and academics.
ANZECC: Australian and New Zealand Environment and Conservation Council. The members of the Council are the relevant government ministers from the various jurisdictions.
aquatic: Plant or animal life living in, growing in, or adapted to water.
aquifer: Soil or rock below the land surface that is saturated with water. A confined aquifer has layers of impermeable material above and below it and is under pressure. When the aquifer is penetrated by a well, the water rises above the top of the aquifer. In an unconfined aquifer, the upper water surface (water table) is at atmospheric pressure and thus is able to rise and fall.
ARMCANZ: Agriculture and Resource Management Council of Australia and New Zealand. The members of the Council are the relevant government ministers from the various jurisdictions.
artesian well: A well bored down to the point, usually at great depth, at which the water pressure is so great that the water is forced out at the surface.
Australian Drinking Water Guidelines: The key Australian reference to drinking water quality published by the National Health and Medical Research Council (NHMRC) and the Agriculture and Resource Management Council of Australia and New Zealand (ARMCANZ).
backflow: A reverse flow condition, created by a difference in water pressures, which causes water to flow back into the distribution pipes of a potable water supply from any source or sources other than an intended source. Also see cross-connection.
backwashing: In water treatment, the process of reversing the flow of water back through the filter media to remove the entrapped solids.
bacteria: Singular: bacterium. Microscopic single-celled organisms with rigid walls. Bacteria are found almost everywhere. Some bacteria in soil, water or air can cause human disease.
blue-green algae: See cyanobacteria.
capillary action: The movement of water through very small spaces due to molecular forces.
carcinogen: Any substance that tends to produce cancer in an organism.
catchment: The areas of land which collect rainfall and contribute to surface water (streams, rivers, wetlands) or to ground-water. A catchment is a natural drainage area, bounded by sloping ground, hills or mountains, from which water flows to a low point.
chloroform: A volatile organic compound formed as a byproduct of chlorination of natural waters. One of several compounds referred to as trihalomethanes. See disinfection byproducts.
chloramines: Compounds formed by the reaction of hypochlorous acid (or aqueous chlorine) with ammonia. Used to disinfect water supplies.
chlorination: The application of chlorine to water, generally for the purpose of disinfection.
chlorinator: A mechanical device which is used to add chlorine to water.
chronic: Occurring over a long period of time, either continuously or intermittently; used to describe ongoing effects that develop only after a long exposure, especially when referring to health (contrast with acute).
coagulant: Chemical used to coagulate · clump together · very fine particles into larger particles. Soluble salts of aluminium and ferric iron are the most commonly used coagulants in water treatment.
coagulation: The clumping together of very fine particles into larger particles caused by the use of chemicals (coagulants). The chemicals neutralise the electrical charges of the fine particles and destabilise the particles. This clumping together makes it easier to separate the solids from the water by settling, skimming, draining, or filtering.
coliform: A group of bacteria found in the intestines of animals (including humans) and also in soil, vegetation and water.
colloids: Very small, finely divided solids (particles that do not dissolve) that remain dispersed in a liquid for a long time due to their small size and electrical charge. When most of the particles in water have a negative electrical charge, they tend to repel each other. This repulsion prevents the particles from clumping together, becoming heavier, and settling out.
condensation: The process of water vapour in the air turning into liquid water. Condensation is the opposite of evaporation.
contaminant: Any physical, chemical, biological, or radiological substance or matter that has an adverse effect.
CRC: Cooperative Research Centre.
cross connection: Any actual or potential connection between a drinking (potable) water system and an unapproved water supply or other source of contamination.
CSIRO: Australia’s Commonwealth Scientific and Industrial Research Organisation.
cyanobacteria: A group of microorganisms with bacteria-like properties that can cause taste, odour and other problems in water supplies. Also known as blue-green algae.
desalination: The removal of dissolved salts (such as sodium chloride) from water by specific water treatment processes, for example reverse osmosis.
destratification: The development of vertical mixing within a lake or reservoir to remove layers of temperature, plant, or animal life. This vertical mixing can be achieved by mechanical means (pumps) or through the use of diffusers that release air into the lower layers of the water body.
disinfection: The process designed to kill most microorganisms in water, including essentially all pathogens.
disinfection byproduct: A compound formed by the reaction of a disinfectant, such as chlorine, with organic material in the water supply.
distribution system: A network of pipes leading from a water treatment plant to customers· plumbing systems.
dose-response: The quantitative relationship between the dose of an agent and an effect caused by the agent.
drainage basin: Land area where rain runs off into streams, rivers, lakes, and reservoirs. It is a land feature that can be identified by tracing a line along the highest elevations between two areas on a map, often a ridge. Also see catchment.
drinking water supplier: An organisation, agency or company that has responsibility and authority for treating and/or supplying drinking water.
drinking water supply system / water supply system: All aspects from the point of collection of water to the consumer. It can include catchments, ground-water systems, source waters, storage reservoirs and intakes, treatment systems, service reservoirs and distribution systems, and consumers plumbing.
effluent: Flow leaving a place or process. Sewage effluent refers to the flow leaving a sewage treatment process.
endemic: Something found in a particular people or location, such as a disease which is always present in the population.
enterovirus: A group of viruses that may infect the gastrointestinal tract of humans and animals. The presence of enteroviruses in water may indicate contamination.
epidemic: Widespread outbreak of a disease, or a large number of cases of a disease in a single community or relatively small area. Disease may spread from person to person, and/or by the exposure of many persons to a single source, such as a water supply.
epidemiology: A branch of medicine which studies the patterns of diseases in populations, and their causes. The objective of epidemiology is to understand how and why diseases occur so that ways can be developed to prevent or reduce disease.
epilimnion: The upper layer of water in a thermally stratified lake or reservoir. This layer consists of the warmest water and has a fairly uniform (constant) temperature. The layer is readily mixed by wind action.
eutrophication: The increase in the nutrient levels of a lake or other body of water. This usually causes an increase in the growth of aquatic animal and plant life.
evaporation: The process by which water or another liquid becomes a gas. Water from land areas, bodies of water, and all other moist surfaces is absorbed into the atmosphere as a vapour.
evapotranspiration: The combined processes of evaporation and transpiration.
exposure: Contact of a chemical, physical or biological agent with the outer boundary of an organism, for example inhalation, ingestion or contact with the skin.
faecal coliform: A subgroup of bacteria of the coliform type that live mainly in the gut of warm-blooded animals. The detection of faecal coliforms in water is an indication of poor water quality and the possibility of pathogenic organisms being present.
facultative: As applied to bacteria, can grow under aerobic or anaerobic conditions.
filtration: A process for removing particles from water by passage through porous media.
flagellates: Microorganisms that move by the action of tail-like projections.
flocculation: The gathering together of fine particles in water by gentle mixing after the addition of coagulant chemicals to form larger particles.
fluoridation: The addition of a chemical to increase the concentration of fluoride ions in drinking water to a predetermined optimum limit to reduce the incidence of tooth decay in children.
flushing: A method used to clean water distribution lines. Hydrants are opened and water with a high velocity flows through the pipes and removes deposits from them.
gastroenteritis: An inflammation of the stomach and intestine resulting in diarrhoea, with vomiting and cramps when irritation is excessive. When caused by an infectious agent, it is often associated with fever.
geosmin: Earthy-musty-smelling compound affecting the taste and odour of water. Released by blue-green algae (cyanobacteria).
Giardia lamblia: a protozoan pathogen that can cause gastroenteritis (called giardiasis) if ingested. The infective form , known as a cyst, is shed in the faeces of people and animals.
Great Artesian Basin: Largest artesian ground-water basin in the world. It underlies approximately one-fifth of Australia and extends beneath the arid and semi-arid parts of Queensland, New South Wales, South Australia and the Northern Territory, stretching from the Great Dividing Range to the Lake Eyre depression. The Basin covers a total area of more than 1.7 million square kilometres and has an estimated water storage of 8,700 million megalitres.
greywater: Wastewater from clothes washing machines, showers, bathtubs, hand washing, and sinks.
ground-water: The supply of fresh water found beneath the Earth’s surface, usually in aquifers.
guideline value: The concentration or measure of a water quality characteristic that, based on present knowledge, does not result in any significant risk to the health of the consumer (health-related guideline value), or is associated with good quality water (aesthetic guideline value). See Australian Drinking Water Guidelines.
halogen: One of the chemical elements chlorine, bromine, or iodine.
hard water: Alkaline water containing dissolved salts that interfere with some industrial processes and prevent soap from lathering. The hardness of water is usually expressed as the equivalent concentration of calcium carbonate in milligrams per litre.
hazard: A biological, chemical or physical agent that has the potential to cause harm or loss.
Hazard Analysis and Critical Control Point (HACCP): A systematic methodology to control hazards in a process by applying a two-part technique: first, an analysis that identifies hazards and their severity and likelihood of occurrence; and second, identification of critical points where the hazards may be controlled, and the monitoring criteria to ensure that controls are working effectively. This system was introduced in the food industry and is now being applied in the Australian water industry to drinking water.
head loss: The pressure lost by water flowing in a pipe or channel as a result of turbulence caused by the velocity of flowing water and the roughness of the pipe, channel walls or restrictions caused by fittings.
headworks: Infrastructure at the water source, where water enters the distribution system.
heavy metals: Metallic elements with high atomic weights, for example, mercury, chromium, cadmium, arsenic, and lead. These elements can damage living things at low concentrations and tend to accumulate in the food chain.
herbicide: A compound, usually a synthetic organic chemical, used to kill or control plant growth.
heterotrophic plate count: A method for measuring the number of bacteria in a water sample able to grow on a simple organic medium.
humus: Organic portion of the soil remaining after prolonged microbial decomposition.
hydrology: The study of the occurrence, distribution and circulation of the natural waters of the earth.
hypochlorite: Chemical compounds containing available chlorine; used for disinfection. They are available as liquids (bleach) or solids (powder, granules and pellets).
hypolimnion: The lowest layer in a thermally stratified lake or reservoir. This stagnant layer of colder, more dense water, has a constant temperature.
infrastructure: Services and equipment needed to support urban communities, generally including water supply, stormwater and waste treatment facilities, electricity, telephones, roads and community services required for residential, commercial and industrial activities.
inorganic: Material such as sand, salt, iron, calcium salts and other mineral materials. Inorganic substances are of mineral origin. Also see organic.
integrated catchment management (ICM): The coordinated planning, use and management of water, land, vegetation and other natural resources on a river or ground-water catchment basis. ICM is based on cooperation between community groups and government agencies to consider all aspects of catchment management.
invertebrate: An organism without a backbone.
ion: An atom or group of atoms which has gained or lost electrons and carries an electric charge.
ISO 9001:1994 (Quality Systems): An international accredited standard that provides a generic framework for quality systems. Designed to assure conformance to specified requirements by a supplier at all stages during the design, development, production, installation, and servicing of a product. It sets out the requirements for an organisation to guarantee a consistent end product.
ISO 14001:1996 (Environmental Management Systems): An international accredited standard that provides a generic framework for guidance on the development and implementation of an environmental management system to minimise the impacts of business operations on the environment and to foster environmental sustainability.
leaching: The process by which soluble materials in soil, such as salts, nutrients, pesticide chemicals or contaminants, are washed into a lower layer of soil or are dissolved and carried away by water.
leachate: Solution containing dissolved substances as a result of rainwater percolating through soil or similar material.
log or logarithm: Mathematical concept which forms the basis for the pH scale.
mains: Large underground water or sewer pipes.
malignant: Very dangerous or harmful, causing or likely to cause death.
metabolism: The sum of the chemical reactions occurring within a cell or a whole organism.
methylisoborneol: Earthy-musty-smelling compound affecting the taste and odour of water. Released by blue-green algae (cyanobacteria).
microbial growth: Growth of microorganisms such as bacteria, algae, diatoms, plankton and fungi.
microgram per litre (·g/L): A measure of concentration of a dissolved substance. One microgram of a substance dissolved in each litre of water. This unit is equal to parts per billion (ppb) since one litre of water weighs one billion microgram.
micron (·m) : A unit of length. One millionth of a metre or one thousandth of a millimetre.
microorganisms: Living organisms that can be seen individually only with the aid of a microscope.
milligram per litre (mg/L): A measure of concentration of a dissolved substance. One milligram of a substance dissolved in each litre of water. This unit is equal to parts per million (ppm) since one litre of water weighs one million milligram.
mineralisation: The microbial conversion of an element from an organic to an inorganic state.
molecular weight: The molecular weight of a compound is the sum of the atomic weights of all of the elements in the compound.
mutagen: An agent that causes a permanent genetic change in a cell, that is change to the DNA, other than that which occurs during normal genetic recombination.
NOM: Natural organic matter. Usually responsible for any brown discolouration in water.
NTU: Nephelometric turbidity unit. The unit of measure for turbidity.
neurotoxicity: Exerting a destructive or poisonous effect on nerve tissue.
NHMRC: National Health and Medical Research Council. A major source of health policy advise for Australian governments.
nitrification: The biochemical transformation of ammonium nitrogen to nitrate nitrogen.
non-potable: Water that is considered unsafe and/or unpalatable for drinking.
nutrient: Any substance that is assimilated (taken in) by organisms and promotes growth.
organic: Substances that come from animal or plant sources. Organic substances always contain carbon. Also see inorganic.
osmosis: The passage of a liquid from a weak solution to a more concentrated solution across a semipermeable membrane. The membrane allows the passage of the solvent (water) but not the dissolved solids (solutes). This process tends to equalize the conditions on either side of the membrane. Also see reverse osmosis.
oxidation: The addition of oxygen, removal of hydrogen, or removal of electrons from an element or compound. It is the opposite of reduction. In the environment, organic matter is oxidized to more stable substances.
ozonation: The application of ozone to water for disinfection or for taste and odour control.
palatable: Palatable water is water of pleasing taste, odour and appearance.
parts per billion (ppb): A measurement of concentration on a weight or volume basis. This term is equivalent to microgram per litre, the preferred term. Used to describe extremely small concentrations.
parts per million (ppm): A measurement of concentration on a weight or volume basis. This term is equivalent to milligram per litre (mg/L), the preferred term.
pathogen: A disease-causing microorganism; includes various types of bacteria, viruses, fungi and protozoa.
pathology: The study of the effects of disease.
per capita use: The average amount (of water) used per person during a standard time period, generally per day.
permeable: Can be passed through. Term used to describe soil and rock and also in membrane technology.
permeability: In relation to ground-water, refers to the ability of soil or rock to transmit water.
pesticide: Any substance or chemical designed or formulated to kill or control animal pests. Also see herbicide.
pH: A measure of the basic (alkaline) or acidic condition of a solution. A pH of less than 7 is acidic, of 7 is neutral and of more than 7 is alkaline. Natural waters usually have a pH between 6.5 and 8.5.
photosynthesis: A process in which organisms, with the aid of chlorophyll (green plant pigment), convert carbon dioxide and inorganic substances into oxygen and additional plant material, using sunlight for energy. All green plants grow by this process.
phytoplankton: Small photosynthetic plant organisms in the aquatic environment.
porosity: In relation to ground-water, the capacity of soil or rock to hold water.
potable water: Water that is safe and satisfactory for drinking and cooking.
protozoa: Single-celled microscopic animal. Plural protozoa.
quality: The totality of characteristics of an entity that bear on its ability to satisfy stated and implied needs.
quality system: Organisational structure, procedures, processes and resources needed to implement quality management (ISO 8402:1994).
radionuclide: Any man-made or natural element which emits radiation in the form of alpha or beta particles, or as gamma rays.
raw water: Water in its natural state, before treatment; water entering the first treatment process of a water treatment plant.
renal: Pertaining to the kidney.
reservoir: Any natural or artificial holding area used to store, regulate, or control water.
respiration: The process in which an organism uses oxygen for its life processes.
reverse osmosis: The application of pressure to a concentrated solution which causes the passage of a liquid from the concentrated solution across a semipermeable membrane. The membrane allows the passage of the solvent (water) but not the dissolved solids (solutes). The liquid produced is demineralized water. Also see osmosis.
risk: The probability of a specified hazard causing harm.
risk management: The systematic evaluation of the water supply system, the identification of hazards and hazardous events, the assessment of risks, and the development and implementation of preventive strategies to manage the risks.
runoff: That portion of catchment rainfall which does not evaporate or infiltrate into the ground but runs across the surface.
salinity: The concentration of dissolved salts, usually sodium chloride, in water.
sand filter: Device to remove suspended solids from water by passage through a bed of sand.
sanitary survey: An on-site assessment of the adequacy of the water sources, facilities, equipment, operation, and maintenance of a public water systems for producing and distributing safe drinking water.
sediment: Usually applied to material suspended in water or recently deposited from suspension. In the plural the word is applied to all kinds of deposits from the waters of streams, lakes, or seas.
sedimentation: A water treatment process in which solid particles settle out of the water being treated in a large clarifier or sedimentation basin.
service pipe: A pipeline extending from the water main to the building served or to the consumers system.
service reservoir/tank: A storage for drinking water generally within the distribution system used to meet fluctuating demands, accommodate emergency requirements and/or equalise operating pressures.
SODIS: Solar water disinfection. A water treatment process depending on solar energy only to disinfect small quantities of water for use mainly at household level.
soft water: Water having a low concentration of calcium and magnesium ions.
solvent: A substance that dissolves other substances, thus forming a solution. Water dissolves more substances than any other, and is known as the universal solvent.
source water: See raw water.
Standards Australia: Previously the Standards Association of Australia but since 1 July 1999 Standards Australia International Limited has been a public company limited by guarantee. The lead organization in Australia in the promotion, publication and acceptance of standards for business and the community to increase efficiency and enhance product quality.
storage reservoir: A natural or artificial impoundment used to hold water before its treatment and/or distribution.
stormwater: Technically, all runoff is stormwater. However, the term "stormwater" is generally used in reference to urban runoff in constructed stormwater drainage systems.
stream: A general term for a body of flowing water; a natural water course containing water at least part of the year. In hydrology, it is generally applied to water flowing in a natural channel as distinct from a canal.
surface water: All water naturally open to the atmosphere (rivers, lakes, reservoirs, streams, impoundments, seas, estuaries, etc.).
suspended solids: Solids that float on the surface or are suspended in water, and which are largely removable by filtering.
thermocline: The middle layer in a thermally stratified lake or reservoir. In this layer there is a rapid decrease in temperature with depth. Also called the metalimnion.
total dissolved solids (TDS): The concentration of dissolved solids in water. TDS is measured on a sample of water that has passed through a very fine mesh filter to remove suspended solids. The water passing through the filter is evaporated and the residue represents the dissolved solids.
toxicity: The quality or degree of being poisonous or harmful to plant, animal or human life.
toxicology: Study of poisons, their effects, antidotes and detection.
transpiration: The process by which water vapour is released to the atmosphere by living plants.
tributary: A smaller river or stream that flows into a larger river or stream. Usually, a number of smaller tributaries merge to form a river.
trihalomethane (THM): One of a family of organic compounds named as derivatives of methane. THMs are found among the byproducts of chlorination of drinking water that contains organic material.
turbidity: The cloudy appearance of water caused by the presence of suspended and colloidal matter. The water quality parameter indicating the clarity of water.Turbidity is measured by the amount of light that is reflected off particles in the water. It is measured by a nephelometer in nephelometric turbidity units (NTU).
valve: A device that opens and closes to regulate the flow of water or other fluids.
vertebrate: Organisms that possess a backbone.
virus: A large group of infectious agents, much smaller than bacteria, that are able to be viewed only through an electron microscope. They are not cells, but biologically active particles that vary in size from 0.01 to 0.1 microns.
water cycle: The circulation of water on Earth as it evaporates from the sea and lakes, condenses into clouds and falls again as precipitation (rain, hail, sleet, snow).
water quality: A description of the chemical, physical and biological characteristics of water for a particular purpose.
water supplier: The owner or operator of a public water system.
watershed: See catchment.
water supply system: The collection, treatment, storage, and distribution of potable water from source to consumer.
water table: The level of ground-water in an unconfined aquifer. This level can be very near the surface of the ground or far below it.
zoonoses: Diseases and infections that are naturally transmitted between vertebrate animals and humans.
Consumer's Guide to Drinking Water - May 2006 [an error occurred while processing this directive]