A
AAA
Labelling system devised to define how water efficient appliances such as washing machines and dishwashers are. AAA = Excellent, AA = Good, A = Acceptable.
ANZECC
Australian and New Zealand Environment and Conservation Council provides a forum for the development of national land use policies to protect environmental quality and for the setting of national objectives for air, land and water quality.
ANZECC Guidelines
Australian Water Quality Guidelines for Fresh and Marine Waters published by ANZECC 1992. These guidelines provide reference levels for comparison with water quality results in storages and inflows.
Algal bloom
Rapid growth of algae in surface waters due to an increase in nutrients such as
nitrogen and phosphorus.
Alum
A double sulphate of aluminium and potassium. Used as a water treatment chemical in some parts of the world.
Aluminium (Al)
A naturally occurring element which can enter the water from the catchments.
Aquatic Organisms
Organisms which live in water - stored water, river and streams.
Australian Drinking Water Guidelines (ADWG)
The guidelines provide summary of the criteria, which represents the basis for identifying acceptable water quality.
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B
Benthic organisms
Organisms that live in or on the bottom of a body of water, including the ocean floor or
river bed.
Biodegradable
A substance that can be broken down into harmless products in the environment.
Biodiversity
Variety and number of different species living in an ecosystem or a defined geographic
area.
Biofilm
An accumulation in water pipes which may harbour microorganisms.
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C
Calcium (Ca)
A naturally occurring element which can enter the water from the catchments. It may also be added to water in the treatment process to reduce the acidity levels.
Catchment
An area of land surrounding a dam or water storage. Rain falling over the catchment drains to the dam and may contain nutrients, minerals and other contaminants collected from the land surfaces.
Catchment (Inner)
The area immediately surrounding a dam or stored water supply which is closed to access to protect water quality.
Catchment (Special Area)
See Catchment (Inner).
Catchment (Enclosed)
See Catchment (Inner).
Catchment (Outer)
Areas surrounding the inner catchment where human activity is permitted but may be restricted to protect water quality.
Chlordane
An organochlorine pesticide used to treat termites.
Chlorination
The application of chlorine to drinking water, waste water, or industrial waste to kill bacteria or to oxidise undesirable compounds.
Chlorine
To ensure good quality drinking water, chlorine is added to kill bacteria that may cause disease. We test for the residual chlorine that needs to be present to make sure that the water is disinfected all the way to your tap. The health guideline value for chlorine depends on the type used. Some systems use 'free' chlorine (5 mg/L) and others use monochloramines (3 mg/L)
Chloramination
The adding of chlorine followed by ammonia for longer lasting destruction of microorganisms in water.
Chlorophyll A
Produced by plants and indicates the potential presence of algae in stored water.
Coliforms (Total)
Total coliform bacteria are used as a scientific indicator of the quality of drinking water and of the possible presence of disease causing micro-organisms. They are measured in colony forming units per 100 mL
Colony Forming Unit (orgs)
Unit used to represent numbers of bacteria.
Conservation
Use, management and protection of resources so that they are not degraded, depleted or wasted and are available on a sustainable basis for present and future generations.
Cryptosporidium (Crypto.)
These micro-organisms occur in warm blooded animals and can sometimes find their way into the way supply. Disinfection and treatment processes normally inactivate or remove them from the water.
Cryptosporidiosis
A disease of humans caused by the ingestion of Cryptosporidium oocysts.
Customer Supply System
The network of pipes, pumps and local reservoirs that deliver water from the water filtration plants.
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D
Dam(s)
Artificial walls built to store water - principally for domestic consumption or irrigation.
Demand management
Strategies to reduce water consumption by residential, commercial and industrial consumers.
Disinfection
Inactivation (killing) of pathogens or organisms, capable of causing infectious disease, by chemical or physical processes.
Dissolved Oxygen
The amount of oxygen dissolved in water.
Distribution System
See Customer Supply System.
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E
E. coli
is a type of Thermotolerant Coliform bacteria, and is nearly always present in the gut of humans and other warm-blooded animals. E. coli is now generally regarded as the most specific indicator of faecal contamination, and therefore the more important indicator for public health.
Ecosystem
Community of organisms interacting with each other and the chemical and physical factors making up their environment.
Environmental indicators
Physical, chemical or biological features that can be monitored and used to measure changes in the environment.
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F
Faecal coliform
These are bacteria which inhabit the intestines of mammals and are present in faecal material. Faecal Coliforms are used as a scientific indicator to measure the cleanliness of water.
Fe (Iron)
A naturally occurring element which can enter the water from the catchments.
Ferric
A chemical containing iron. Used in the water filtration process to settle contaminants.
Ferric chloride.
This is an iron based chemical used as a water treatment chemical in some parts of the world.
Filtration (Water)
A process for removing particles from water by passing it through a porous barrier, such as a screen, membrane, sand or gravel. Often used in conjunction with a flocculant to settle contaminants.
Flocculant
A chemical which encourages heavy contaminants to gather together and settle from water more quickly in the treatment process.
Fluoride
Small amounts of fluoride are added for dental health reasons in accordance with legislation. It is measured in milligrams per litre (mg/L)
Flushing
A process of pipe cleaning through the increased flow of high pressure water.
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G
Giardia
These micro-organisms occur in warm blooded animals and can sometimes find their way into the way supply. Disinfection and treatment processes normally inactivate or remove them from the water.
Guideline Values
Values for water quality. Usually set as targets and not as minimum standards.
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H
Hazen Units (HU)
Unit of measurement for measuring colour.
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I
Indicators
Readings in test results which may indicate the presence of contaminants.
Inflows
Water flowing from the catchments to the dams through streams, rivers and creeks.
Iron (Fe)
These substances naturally occur at low levels in the water and may be responsible for taste and staining problems with water. They are measured in milligrams per litre (mg/L).
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K
Kilolitre
One thousand litres of water or one tonne.
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L
Leached
The collection of minerals, elements and salts in water as it passes through the environment.
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M
Manganese (Mn)
These substances naturally occur at low levels in the water and may be responsible for taste and staining problems with water. They are measured in milligrams per litre (mg/L).
Maximum
The highest measure recorded.
Median
The middle reading in a series.
Megalitre
Measurement of volume equal to one million litres. One megalitre is approximately the
volume of a one metre deep Olympic-sized swimming pool.
Microgram
Unit of measurement which is equivalent to 0.0001 of gram.
Microgram per litre (ug/L)
Unit of measurement which is equivalent to 0.0001 of gram.
Micro-organisms
The organisms which are invisible or only barely visible with the unaided eye.
Milligram
Unit of measurement which is equivalent to 0.001 of a gram.
Milligrams per litre (mg/L)
Unit of measurement which is equivalent to 0.001 of a gram expressed per litre.
Millilitre
Unit of measurement which is equivalent to 0.001 of a litre.
Mineral Elements
Naturally occurring elements which can enter the water from the catchments.
Minimum
The lowest recorded reading.
Monitoring
An on-going testing program to assess potential changes in circumstances.
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N
Nephelometric Turbidity Units (NTU).
Unit of scientific measurement used to represent the level of suspended material in solution.
NH&MRC
The National Health and Medical Research Council. An advisory body to the Australian Government.
NH&MRC Guidelines
Advisory standards established by the NH&MRC with respect to the performance of products to ensure they are within safe levels. The latest drinking water guidelines were agreed in 1996.
Naturally Occurring
Within the natural environment as minerals, elements, salts, and other contaminants.
Nitrogen (N)
A naturally occurring element which can enter the water from the catchments. Is used by plants as a nutrient.
Nutrients
Compounds required for growth by plants and other organisms. Major plant nutrients are phosphorus and nitrogen.
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O
Organochlorine pesticide
An organic compound containing chlorine. They are not easily broken down and can persist in the environment for a long time. Includes chlordane, dieldrin and aldrin which have been banned in NSW.
Organophosphate pesticide
Pesticides which are made up of hydrocarbon compounds which contain phosphorus, for example, chlorpyrifos and parathion. They are best known for their ability to persist in the environment, however, they degrade in the environment faster than organochlorine pesticides.
Orgs/100mls
Organisms per 100mls
Outer Catchment
See Catchment (Outer).
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P
pH
A measure of the alkalinity or acidity of water expressed on a scale from 1 to 14: 1 is most acidic, 7 neutral and 14 most alkaline.
Parasites
An organism which relies on a host organism to grow.
Pathogens
Disease-causing organisms, such as bacteria and viruses.
Per Capita Demand
Refers to the demand per head of population.
Phosphorus (P)
A naturally occurring element which can enter the water from the catchments.
Protocol
An agreement between NSW Health and Sydney Water which covers testing, monitoring and providing information to the public about microorganisms.
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R
Regulators
Organisations which set regulations and standards for Sydney Water to meet. For example, the Environment Protection Authority, NSW Health and the National Health and Medical Research Council.
REP
Regional Environmental Plan.
Reference Levels
Guideline values used for comparison with water quality data. See ANZECC guidelines.
Reservoir
An artificial body of water.
Risk assessment
Process of gathering data and making assessments to estimate short and long-term harmful affects on human health or the environment from exposure to hazards associated with a particular product or activity.
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S
SEPP
State Environmental Planning Policy - a statutory planning instrument.
Sediment
Soil or other particles that settle to the bottom of lakes, rivers, oceans and other
waters.
Special Areas
Lands mostly around drinking water storages that were originally set aside for the protection
of drinking water quality. The lands are declared as Special Areas under the Sydney Water Act
1994 ("The Act""). Parts of the Special Areas are also National Parks, nature
reserves and State Recreation Areas and are jointly managed by Sydney Water and NPWS.
Soluble
Able to be dissolved in water.
Suspended solids
Particles in water that can be removed by sedimentation or filtration.
Swabbing
The cleaning of mains using mechanical in-pipe cleaning tools.
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T
Thermotolerant Coliforms
are a type of coliform that can grow at higher temperatures than other Total Coliforms. They are also known as Faecal Coliforms.
Total Coliforms (TC's)
Total Coliforms are a family of bacteria commonly found in the environment. Some members of the family come from the environment and other members from intestines of humans and other warm-blooded animals. Due to their widespread occurrence in most soil and water environments, they are no longer regarded as the most reliable indicator of human or animal contamination. E. coli is now regarded as a more important indicator organism for public health.
Trihalomethanes (THMs)
THM's are formed in water when chlorine reacts with small amounts of naturally occurring organic matter. THM's are measured in mg/L.
Treatment (Water)
The filtration and disinfection process.
True Colour
Water should be virtually colourless. It is measured in Hazen Units (HU).
Turbidity
This is a measure of suspended material in water that may cause it to look muddy or discoloured. It is measured in Nephelometric Turbidity Units (NTU)
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W
Wastewater
Another name for sewage.
Water Filtration Plant (WFP)
A treatment plant that improves water quality by removing impurities through filtration.
Water Supply System
The network of pipes, pumps and local reservoirs that deliver water from the water filtration plants.
Water Treatment Plant
See Water Filtration Plant.
Water reuse
The use of water more than once, following treatment of wastewater to an appropriate
quality standard and delivery to the point of use.
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Z
Zinc
Zinc is a naturally occurring element which can enter the water from the catchments and is also used as a coating to prevent corrosion of iron and steel products which may be responsible for taste problems with water. It is measured in milligrams per litre (mg/L).
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