At a glance
Water is essential to sustain life and a satisfactory supply must be made available to consumers (WHO 2001). Water safety is characterised by microbiological, physical, chemical and radiological quality (NHMRC & ARMCANZ 1996). A poor water supply system can have negative health effects on people. Poorly treated or managed drinking water systems can result in an increase in illness (most likely gastrointestinal illness) in the community and visiting population. Visitors can also be more susceptible to endemic micro-organisms as they are potentially exposed to different, or higher, levels of pathogens than their place of residence (EnHealth 1999).
The dispersed Tasmanian population (Tasmania has a high proportion of its State population located outside its capital city compared with other states and territories) combined with land uses that can affect water quality, presents problems in the supply of clean drinking water to some rural communities.
The issue of drinking water quality is related closely to various influences of land use on catchment health and water quality. These are discussed in more detail in the Inland Waters and Wetlands Chapter. Water quality and water availability are closely related. In Tasmania there are limited numbers of relatively pristine catchments close to settlements that can be used to supply the highest quality drinking water quality to the major population centres.
This 'At a glance section provides information on the issue of drinking water quality. More detailed information and references are contained in the Drinking Water Quality Issue Report.
Recommendations are presented for the Settlements Chapter on Drinking Water Quality and Sustainable Housing.
- In the period 2001-02, DHHS reported that three bulk water supply systems (compared with six in 2000-01) did not comply with Public Health Act 1997 - Guidelines for Water Quality microbiological requirements (DHHS 2003).
- The quality of drinking water supplied to major urban centres is generally acknowledged to be very good in Tasmania. Hobart Water is in a relatively unique situation of sourcing a significant proportion of its raw water supply from highland catchments yielding high quality water. Microbiological quality of drinking water provided by Esk Water and Hobart Water complied with Public Health Act 1997 - Guidelines for Water Quality microbiological requirements. Cradle Coast Water has implemented an improvement program to enhance the microbiological quality of its drinking water (DHHS 2002).
- Major catchment studies for critical drinking water catchments are in progress or have been completed. For example, the Lake Fenton-Lady Barron Creek Catchment Study was undertaken by Hobart Water (a summary of the principal findings is contained in Lake Fenton/Lady Barron Creek Draft Catchment Management Study Case Study).
- Small local government water supply systems in remote areas experienced most problems with microbiological water quality. However, continuous improvement has been identified in the DHHS report on drinking water quality. The most recent report for 2001-02 reported a noticeable improvement in compliance. Sixteen local government water supply systems were taken off boil water alerts and the number of water supplies in compliance with national standards increased to 61 compared to 46 in 2000-01 (DHHS 2003).
- The Clean Water Program has aimed to implement cost effective solutions to water management problems in small towns. One of the most significant sources of water pollution in small towns in Tasmania is sewage effluent. Improving these problems can improve the quality of drinking water for downstream communities. The Clean Water Program was funded largely through the Natural Heritage Trust (NHT) and local government and is now winding down as a result of the completion of NHT1.
- Once poor water quality is identified, reporting mechanisms are required for notifying communities to boil water prior to use.
- There were 91 local government water supply systems operating in Tasmania during the reporting period. Of the 30 local government water supplies that had 'boil water alerts' in place during the reporting period, there were four systems that had temporary boil water alerts and 26 that were permanently in place because of either continuing poor water quality, or no disinfection (DHHS 2003).
- In sustaining water provision of the highest possible standard to major urban centres, water authorities are dealing with significant catchment management water issues. These occur even in relatively pristine catchments such as Lake Fenton-Lady Barron Creek and Mt Wellington. Protection of water supply catchments, which are relatively unaffected by human contact and largely free from atmospheric and environmental pollutants, is necessary to maintain the supply of high quality drinking water at a relatively low cost. The degradation of water quality from mountain catchments is largely related to the impact of public recreational access, and to infrastructure such as unsealed roads within the catchments. Hence, catchment management planning is integral to supplying customers with quality drinking water at a relatively low cost without the need for additional treatment of water (Hobart Water 2001).
- Effective water treatment facilities are highly costly, and local communities have considerable difficulty in affording the required technology. There may be benefits from a more regional or Statewide approach to the provision of these essential services, rather than the present system of highly dispersed, and locally managed and funded schemes.
- There is limited information for reporting on drinking water quality other than for microbial pollution through boil water alerts. The actual number of times readings exceeded the Australian Drinking Water Guidelines is not available publicly. Chemical testing is required when potential pollutants are identified in catchment surveys. However, catchment surveys that may prompt the need for chemical testing do not appear to be carried out regularly due to economic constraints on water supply authorities. DHHS notes that the focus of the Tasmanian Water Quality Guidelines testing requirements is to seek compliance with the microbiological sampling regimes detailed in the Australian Drinking Water Guidelines. This requires chemical testing when potential pollutants are identified in catchment surveys. Water suppliers are asked to test for harmful chemicals on a risk management basis using, for instance, Australian/New Zealand Standard AS/NZS 4360:1999 - Risk Management. For example, if a water supply is sourced from agricultural areas, pesticide testing should be undertaken in accordance with the procedures detailed in the Australian Drinking Water Guidelines and in accordance with a recognised risk management process (DHHS 2003).