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Glossary for recycled water

Algae Comparatively simple chlorophyll-bearing plants, most of which are aquatic, and microscopic in size.
Anaerobic Conditions where oxygen is lacking; organisms not requiring oxygen for respiration.
Amenity horticulture pleasantness resulting from agreeable   Urban horticulture that makes your surroundings more pleasant such sporting fields, parks and gardens.
Biochemical oxygen demand (BOD) The decrease in oxygen content in a sample of water that is brought about by the bacterial breakdown of organic matter in the water.
Biosolid Sewage sludge, organic residual remaining after domestic sewage treatment.
Black water Water containing human excrement.
Campylobacter   A group of bacteria that is a major cause of diarrhoeal illness.
Cation exchange capacity (CEC) The sum of exchangeable cations that a soil can absorb at a specific pH. It is usually expressed din centimoles of charge per kilogram of exchanges (cmolc/kg).
Chloride Chloride in recycled waters comes from a variety of salts (including detergents) and is present as an ion (Cl-). In addition to its role in salinity, it can be toxic to plants, especially if applied directly to foliage and aquatic biota.
Chlorination Use of chlorine as a means of disinfection.
Coliform bacteria Group of bacteria whose presence in drinking water can be used as an indicator for operational monitoring (Also refered to as thermotolerant coliforms, total coliforms).
Contaminant Biological or chemical substance or entity, not normally present in a system, capable of producing an adverse effect in a biological system, seriously injuring structure or function.
Cryptosporidium Microorganism commonly found in lakes and rivers that is highly resistant to disinfection. Cryptosporidium has caused several large outbreaks of gastrointestinal illness, with symptoms that include diarrhoea, nausea and stomach cramps. People with severely weakened immune systems (ie severely immunocompromised people) are likely to have more severe and more persistent symptoms than healthy individuals (adapted from United States Environmental Protection Agency).
Cyanobacteria Bacteria containing chlorophyll and phycobilins, commonly known as ‘blue-green algae’.
Direct reuse The beneficial use of recycled water that has been contained during direct transfer from the wastewater treatment plant to the reuse site.
Direct potable use Water that has been highly treated to make it suitable for human drinking water use, and is conveyed directly from the wastewater treatment plant to the water supply system.
Disinfectant An oxidising agent (eg chlorine, chlorine dioxide, chloramines and ozone) that is added to water in any part of the treatment or distribution process and is intended to kill or inactivate pathogenic (diseasecausing) microorganisms.
Drinking water   Water intended primarily for human consumption (but excluding bottled water, for the purposes of these guidelines).
Effluent The out-flow water or wastewater from any water processing system or device.
Endocrine disrupter Substances that can stop the production or block the transmission of hormones in the body.
Enteric pathogen Pathogen found in the gut.
Environmental allocation of recycled water Allocation of recycled water directly to waterways or water bodies to benefit the environment.
Environmental flows Environmental allocation for surface water rivers, streams or creeks.
Environmental Management System The section of an overall management system which includes structure, planning activities, responsibilities, practices, procurements, processes and resources for developing, implementing, achieving, reviewing and maintaining an environmental policy.
Escherichia coli Bacterium found in the gut, used as an indicator of faecal contamination of water.
Eutrophication   Degradation of water quality due to enrichment by nutrients such as nitrogen and phosphorus, resulting in excessive algal growth and decay and often low dissolved oxygen in the water.
Exchangeable Sodium Percentage (ESP) The proportion of sodium adsorbed on soil clay mineral surface, as a percentage of total cation exchange capacity (used as a measure of soil sodicity).
Giardia lamblia A protozoan frequently found in rivers and lakes. If water containing infectious cysts of Giardia is ingested, the protozoan can cause a severe gastrointestinal disease called giardiasis.
grey water Wastewater from the hand basin, shower, bath, spa bath, washing machine, laundry tub, kitchen sink and dishwasher. Water from the kitchen is generally too high in grease and oil to be reused successfully without significant treatment.
Groundwater Water contained in rocks or subsoil.
Hazard A biological, chemical, physical or radiological agent that has the potential to cause harm.
Heavy metals Metallic elements with high atomic weights, eg mercury, chromium, cadmium, arsenic and lead. They can cause damage to living organisms at very low concentrations and tend to accumulate in the food chain.
Helminth A worm-like invertebrate of the order Helminthes. A human and other animal parasite.
Indirect potable reuse The derivation of drinking water from surface or groundwater reclamation containing some proportion of treated wastewater.
Indirect reuse The subsequent beneficial use of water after it has been discharged from the wastewater treatment plant into a natural surface water or groundwater body, from which further water is taken, sometimes in an unplanned manner.
Leaching Fractions The ratio of actual drainage water to irrigation water applied. Where drainage water is water that moves past the rootzone.
Managed Aquifer Recharge  Managed aquifer recharge is a method of adding a water source, such as recycled water, to aquifers (underground reservoirs) under controlled conditions. (CSIRO definition).
Microorganism Organism too small to be visible to the naked eye. Bacteria, viruses, protozoa, and some fungi and algae are microorganisms.
Municipal Belonging to a town, city or district that has its own local government. For municipal use of recycled water, this refers to the town city or district irrigating race tracks, ovals, lawn bowls greens, roadsides, parklands, golf courses and any other area under their control.
Nitrogen An important nutrient found in high concentrations in recycled waters, originating from human and domestic wastes. A useful plant nutrient that can also cause off-site problems of eutrophication in lakes, rivers and estuaries. It can also contaminate ground waters.
Nitrification The oxidation of ammonia nitrogen to nitrate nitrogen in wastewater by biological means.
Pathogen A disease-causing organism (eg bacteria, viruses and protozoa).
pH An expression of the intensity of the basic or acid condition of a liquid. Natural waters usually have a pH between 6.5 and 8.5.
Phosphorus An important nutrient found in high concentrations in recycled waters, originating principally from detergents but also from other domestic wastes. A useful plant nutrient that can also cause off-site problems of eutrophication in water bodies.
Pollutant Substance that damages the quality of the environment.
Potable (drinking) water Water suitable on the basis of both health and aesthetic considerations for drinking or culinary purposes.
Quality Assurance (QA) All the planned and systematic activities implemented within the quality system, and demonstrated as needed, to provide adequate confidence that an entity will fulfil requirements for quality (AS/NZS ISO 8402:1994).
Reclaimed water A term often used to define water recycled from treated sewage.
Recycled water  Water taken from any waste (effluent) stream and treated to a level suitable for further use, where it is used safely and sustainably for beneficial purposes. This is a general term that can incuded reclaimed water.
Reverse osmosis An advanced method of wastewater treatment which relies on a semipermeable membrane to separate water from its impurities.
Risk The likelihood of a hazard causing harm in exposed populations in a specified time frame, including the magnitude of that harm.
Risk assessment The overall process of using available information to predict how often hazards or specified events may occur (likelihood) and the magnitude of their consequences (adapted from AS/NZS 4360:1999).
Salinity The presence of soluble salts in soils or waters. Electrical conductivity and total dissolved salts are measures of salinity.
Secondary effluent The liquid portion of wastewater leaving secondary treatment.
Secondary treatment Generally, a level of treatment that removes 85 per cent of BOD and suspended solids, generally by biological or chemical treatment processes. Secondary effluent generally has BOD < 30 mg/L, SS < 30 mg/L but may rise to >100 due to algal solids in lagoon or pond systems.
Sewage Sewage refers to material transported in sewerage system. Sewage is collected from all internal household drains; it contains all the contaminants of grey water and urine, in addition to high concentrations of faecal material from toilets and wastes from industrial and commercial premises. Sewage can therefore contain a range of human infectious enteric pathogens and a range of physical and chemical contaminants.
Sewerage The provision of drainage by sewers; the sewer system.
Sodium An element found endemic in the environment. High concentrations of sodium in soil relative to calcium and magnesium cause sodicity (ESP > 6 or SAR >3). This is a condition where the positively charged sodium ions cause the soil particles to repel each other, resulting in soil swelling, dispersion and reduced soil permeability.
Tertiary treatment Includes treatment processes beyond secondary or biological processes which further improve effluent quality. Tertiary treatment processes include detention in lagoons, conventional filtration via sand, dual media or membrane filters which may include coagulant dosing and land based or wetland processes.
Total Dissolved Salts (TDS) A measurement of the total dissolved salts in a solution. Majors salts in recycled water typically include sodium, magnesium, calcium, carbonate, bicarbonate, potassium, sulphate and chloride. Used as a measure of soil salinity with the units of mg/L.
Virus Molecules of nucleic acid (RNA or DNA) that can enter cells and replicate in them.
Wastewater Water which has been used for specific purspose and is no longer required or suitable for that purpose
Water recycling A generic term for water reclamation and reuse. It can also be used to describe a specific type of ‘reuse’ where water is recycled and used again for the same purpose eg recirculating systems for washing and cooling, with or without treatment in between.