DRINKING WATER QUALITY MONITORING
Council provides safe and reliable drinking water to approximately 18,000 people in the Singleton Local Government area every day. Our drinking water is regularly tested throughout the water supply system and analysed by independent NATA certified laboratories, as governed by the Australian Drinking Water Guidelines (ADWG) 2011.
If a problem with water supply is identified, the NSW Health Department will issue a boil water alert. Council consults with NSW Health to ensure current and emerging issues associated with drinking water quality are identified and assessed.
DRINKING WATER MANAGEMENT SYSTEM
A secure and safe supply of drinking water is fundamental to public health. The NSW Government has endorsed the Australian Drinking Water Guidelines 2011 (published by the National Health and Medical Research Council and the Natural Resource Management Ministerial Council).
Council’s Drinking Water Quality Management Manual and Supporting Documents has been structured by the 12 elements of the ADWG, as are the NSW Guidelines for Drinking Water Management Systems. It is made up of the following document hierarchy;
- Water Quality Statement; included in the Water Supply Services Policy
- Drinking Water Manual
- Supporting documents
Drinking Water System Analysis (separate report)
Risk Assessment Report (separate report)
Monitoring Plan (Appendix J - Drinking Water Manual)
Improvement Plan (Appendix I - Drinking Water Manual)
- Procedures in relation to the following topics:
Operation and maintenance (section 4 - Drinking Water Manual)
Emergency response (section 6 - Drinking Water Manual)
Quality assurance (Monitoring Plan and section 7 - Drinking Water manual)
Critical control point (Appendix D - Drinking Water Manual and Monitoring Plan)
COMMON QUALITY ISSUES
Discolouration – common referred to as dirty water, whilst unsightly is harmless. Can be caused by sudden increases in waterflow rate or a change in direction, stirring up sediment that settles in pipes over time. Burst pipes is another cause as water flow patterns are reversed in surrounding streets. Further Information on dirty water can be found here.
Earthy or Musty Odour and Taste - this is due to harmless, naturally occurring dissolved compounds in the water, called Geosmin and Methylisoborneol (MIB). Human noses and taste buds can detect Geosmin and MIB at very low concentrations. These compounds are sometimes present in drinking water, but not usually at noticeable levels. Changes in the temperature can increase some kinds of algae and bacteria naturally present in the water source that can cause a rise in Geosmin and/or MIB above the taste and odour threshold.
Unfortunately, Geosmin and MIB are not removed from water using routine treatment processes. However, the water is safe to drink and use for all normal purposes. Geosmin is only an aesthetic concern. Read more on Geosmin and MIB here.
Boil eater alert - sometimes, in extraordinary situations, it may be necessary for Council to issue a notice to potable or drinking water customers that indicates the water supply is not suitable for drinking; this is known as a ‘boil water alert’. These instances may include detection of contamination in the potable water system, failure of the treatment process (including exceedance of critical control points) or poor raw water quality. Under Section 22 of the Public Health Act 2010, the Chief Health Officer has the power to issue advice, for the benefit of the public, concerning the safety of drinking water and any possible risks to health.
Information on considerations in determining the need for a boil water alert and communication methods can be found in POL/26030 Water Supply Services Policy. Find the answers to some frequently asked questions on boil water alerts here.
Hardness – this is the amount of calcium and magnesium salts in water and is the characteristic that affects lathering of soap and scaling of hot water pipes, fittings and heaters. Ranges of hardness as per Australian Drinking Water Guidelines (ADWG) are:
- <60mg/L - soft possibly corrosive;
- 60-200mg/L - good quality;
- 200-500mg/L - increasing scaling problems; and
- >500mg/L - severe scaling.
ASBESTOS CEMENT WATER PIPES
The condition of all water supply assets, including asbestos cement pipes is monitored closely and pipes are replaced prior to deterioration. The Australian Drinking Water Guidelines 2011 and World Health Organisation have not set a guideline value for asbestos due to the absence of evidence that asbestos is hazardous to health in water. Any asbestos fibres that potentially make their way into drinking water are not considered to be hazardous to human health.
Asbestos in drinking water may come from a variety of sources including asbestos cement water pipes. In Australia more than 33% of all water supplies are delivered using asbestos cement water pipes. In Singleton 14% of the 288km water supply network is made from asbestos fibre cement pipes installed between 1960 and the early 1980’s.
Council is gradually replacing asbestos cement water pipes as part of its asset renewal program.