State of the Environment Report title
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2004 Report



Drinking water quality parameters

| Microbiological | Chemical | References |

Thirty parameters are used to monitor the quality of drinking water as part of the NSW Health Drinking Water Monitoring Program (NSW Health 2000). They include two microbiological parameters and 28 chemical parameters.

This page lists the microbiological parameters and chemical parameters measured, the threshold value of each from the Australian Drinking Water Guidelines 2004 (NHMRC and NRMMC 2004) and the basis on which the 2004 guideline value has been determined (that is, health, taste or aesthetic considerations). Notes are provided on some parameters for which reported values in local government areas within the Australian Capital Region exceeded the guideline values during the current reporting period.

Microbiological

Two microbiological parameters are monitored in drinking water, January 2001 to June 2004, as part of the NSW Health Drinking Water Monitoring Program. These are:

According to the Australian Drinking Water Guidelines 2004, these organisms should not be detected in a minimum 100 mL sample of drinking water.

Chemical

| Main tests (all government areas) | Other tests (some areas only) |

Parameters for main chemical analyses, all local government areas (see NSW Health 2000)

Main chemical parameters monitored in drinking water, January 2001 to June 2004, as part of NSW Health Drinking Water Monitoring Program
ParameterAustralian Drinking Water Guidelines 2004 valueConsideration for guideline valueNotes
Antimony0.003 mg/L HealthDrinking water supplies around Australia have not been routinely monitored for antimony and so it is not possible to compare reported exceedences with typical values (NHMRC and NRMMC 2004). There are no published methods for removal of antimony from drinking water (NHMRC and NRMMC 2004)
Arsenic0.007 mg/L Health
Barium0.7 mg/L Health
Boron4.0 mg/L
Cadmium0.002 mg/L Health
Chromium0.05 mg/L Health
Chloride250 mg/L AestheticNHMRC and NRMMC (2004) have not set a health-based guideline value for chloride. No health effects have been associated specifically with high total dissolved solids concentrations.
Copper2 mg/L Health
1 mg/L Aesthetic
Cyanide0.08 mg/L Health
Fluoride1.5 mg/L Health
Iodide0.1 mg/L Health
Lead0.01 mg/L Health
Manganese0.1 mg/L Aesthetic
0.5 mg/L Health
Mercury0.001 mg/L Health
Molybdenum0.05 mg/L Health
Nickel0.02 mg/L Health
Nitrate100 mg-NO3/L for adults and children over 3 months Health
Nitrite3 mg-NO2/L Health
pH6.5–8.5Guideline range based on minimising corrosion and encrustation of plumbing fittings and pipesThere is no health-based national guideline value for pH due to insufficient data. According to NHMRC and NRMMC (2004), new concrete tanks and cement-mortar lines pipes can significantly increase pH and a value up to 9.2 may be tolerated, provided microbiological monitoring indicates no deterioration in bacteriological quality.
Selenium0.01 mg/L Health
Silver0.1 mg/L Health
Sodium180 mg/L Taste
Sulfate250 mg/L Taste
Total Dissolved Solids (TDS)500 mg/L TasteWater with TDS up to 800 mg/L is still rated as fair. No health effects have been associated specifically with high total dissolved solids concentrations.
Turbidity5 NTU (Nephelometric Turbidity Unit)AestheticIf disinfection is required, then a turbidity of less than 1 NTU is desirable at the time of disinfection (NHMRC and NRMMC 2004).

Other parameters (applicable to some local government areas only)

Other chemical parameters monitored in drinking water, January 2001 to June 2004, as part of NSW Health Drinking Water Monitoring Program
ParameterAustralian Drinking Water Guidelines 2004 valueConsideration for guideline valueNotes
Aluminium0.2 mg/LAestheticNHMRC and NRMMC (2004) encourage water authorities to keep aluminium concentrations in finished waters at less than 0.1 mg/L.
Iron 0.3 mg/L TasteIron in drinking water would not become a health concern unless the concentration was above 3 mg/L, which is well in excess of the concentration that would cause the water to taste objectionable, and it is unlikely that such water would be consumed (NHMRC and NRMMC 2004).
Total Water Hardness200 mg/L (as calcium carbonate)Guideline value is aimed at minimising undesirable build-up of scale in hot water systemsNo adverse health effects have been associated specifically with high total dissolved solids concentrations.
Trihalomethanes (THMs)0.25 mg/LTHMs in drinking water arise largely as a chlorination disinfection byproduct, and involves reaction with naturally occurring organic material, such as humic and fulvic acids. The concentration of THMs range up to 0.6 mg/L in major reticulated supplies in Australia. NHMRC and NRMMC (2004) encourage action to reduce THMs, but with the caveat that disinfection should not compromised, as non-disinfected water poses significantly greater risk than THMs. According to the NHMRC and NRMMC (2004), THM concentrations fluctuating occasionally (for a day or two annually up to 1 mg/L) are unlikely to pose a significant health risk.

References

NHMRC and NRMMC (2004) Australian Drinking Water Guidelines 2004, National Water Quality Management Strategy, National Health and Medical Research Council and the Natural Resource Management Ministerial Council.

NSW Health (2000) Drinking Water Monitoring Program, October 2000, NSW Health Department, viewed 30 April 2005, http://www.health.nsw.gov.au/public-health/ehb/water/monitoring/DWMonitProgOct00.pdf.