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:

• Escherichia coli
• Thermotolerant coliform bacteria

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

Parameter	Australian Drinking Water Guidelines 2004 value	Consideration for guideline value	Notes
Antimony	0.003 mg/L	Health	Drinking 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)
Arsenic	0.007 mg/L	Health
Barium	0.7 mg/L	Health
Boron	4.0 mg/L
Cadmium	0.002 mg/L	Health
Chromium	0.05 mg/L	Health
Chloride	250 mg/L	Aesthetic	NHMRC 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.
Copper	2 mg/L	Health
	1 mg/L	Aesthetic
Cyanide	0.08 mg/L	Health
Fluoride	1.5 mg/L	Health
Iodide	0.1 mg/L	Health
Lead	0.01 mg/L	Health
Manganese	0.1 mg/L	Aesthetic
	0.5 mg/L	Health
Mercury	0.001 mg/L	Health
Molybdenum	0.05 mg/L	Health
Nickel	0.02 mg/L	Health
Nitrate	100 mg-NO3/L for adults and children over 3 months	Health
Nitrite	3 mg-NO2/L	Health
pH	6.5–8.5	Guideline range based on minimising corrosion and encrustation of plumbing fittings and pipes	There 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.
Selenium	0.01 mg/L	Health
Silver	0.1 mg/L	Health
Sodium	180 mg/L	Taste
Sulfate	250 mg/L	Taste
Total Dissolved Solids (TDS)	500 mg/L	Taste	Water 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.
Turbidity	5 NTU (Nephelometric Turbidity Unit)	Aesthetic	If 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

Parameter	Australian Drinking Water Guidelines 2004 value	Consideration for guideline value	Notes
Aluminium	0.2 mg/L	Aesthetic	NHMRC 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	Taste	Iron 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 Hardness	200 mg/L (as calcium carbonate)	Guideline value is aimed at minimising undesirable build-up of scale in hot water systems	No adverse health effects have been associated specifically with high total dissolved solids concentrations.
Trihalomethanes (THMs)	0.25 mg/L		THMs 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.