Facts and figures: Our water system
Total water consumption
Water use is billed three times a year in Muswellbrook Shire. Data from meter readings give a total figure for water use, which is used to balance against the volume of water pumped through each treatment facility. This gives a broad overview of the loads on the water network, and lets us know how much water is lost, for example, from main breaks and leaks. Highly abnormal figures may indicate unmetered services i.e. illegal connections or bulk water theft.
| Total kilolitres billed in the 2008 billing year | |
|---|---|
| Muswellbrook | 1,531,177 kL |
| Denman | 173,881 kL |
| Sandy Hollow | 15,729 kL |
| Total | 1,720,787 kL |
Regulation
Public health
The 2004 Australian Drinking Water Guidelines (ADWG) provides guidance to water authorities on what constitutes a good quality of water provided to the end user. The ADWG have been developed by the National Health and Medical Research Council (NHMRC) in collaboration with the Natural Resource Management Ministerial Council (NRMMC). The ADWG incorporate the “Framework for the Management of Drinking Water Quality”.
One of the highest priorities when supplying drinking water though a network is the quality provided to the end user. The Australian Drinking Water Guidelines provide Council with a benchmark of acceptable quality to consumers.
The Australian Drinking Water Guidelines are available on the National Health and Medical Research Council website. Muswellbrook Shire Council supplies the townships of Muswellbrook, Denman and Sandy Hollow with potable water under guidance of the ADWG 2004.
Monitoring water quality
Council’s Water and Waste’s laboratory and operational staff conduct daily in-house testing to ensure adherence to the Australian Drinking Water Guidelines. Water is sampled from within the water treatment process, and at several different locations within the water network of each township to be analysed for the following:
- Presence of bacteria (total coliforms and E. coli).
- Acceptable levels of pH, hardness, total dissolved solids, salts, true colour, turbidity, total and residual chlorine, alkalinity, ammonia, aluminium, iron and manganese.
- Monthly analysis of ammonia, copper, nitrites and nitrates, boron, chromium, sodium, sulphate and total bacterial counts.
Samples are sent weekly to independent, NATA (National Association of Testing Authorities) approved, external laboratories for bacterial and chemical testing, quality control and reporting to NSW Health. Each month, samples from Muswellbrook are sent away to be analysed for the presence of chlorination by-products, along with a full chemistry analysis.
This is also done for Denman and Sandy Hollow on a quarterly basis. The difference in sampling frequency and reporting requirements for each township is based on population levels as required in the ADWG. As fluoride is added to Muswellbrook treated water, this is also analysed and the results are reported monthly to NSW Health.
Aside from the compulsory testing, potable water is sampled daily at various points in the water network to ensure that satisfactory chlorine disinfection is maintained throughout the water networks in all areas in the shire. In addition, staff perform routine mains flushing in response to reports such as dirty water or air in pipes, as an integral part of supplying a quality product to the community.
Testing is also conducted to ensure adequate treatment plant performance; each week samples are obtained of the source ‘raw’ water before it enters each of the three treatment plants, along with samples of plant output ‘treated’ water. These samples are analysed in-house for total coliforms and E. coli, chlorine, turbidity, pH, total dissolved solids, alkalinity, hardness, aluminium, iron and manganese. These results are compared to ensure the plants are operating correctly and at their most efficient level. In Muswellbrook Water Treatment works, water flows through a series of fish tanks (similar to the coal mine canaries of days gone by) as a biological monitoring system, giving an early indication of water quality to guard against possible contamination of the river.
Event specific testing is also conducted on a needs basis, for example in the event of a flood or reported algal blooms upstream. When such events as these occur, samples are sent to independent laboratories for Cyanobacterial testing (blue-green algae), analysis for pesticides, Cryptosporidium and Giardia testing as required. Annual testing is conducted for the presence of organic contaminants from treatment chemicals and pipe construction, e.g. plasticisers, acrylamide, carbon tetrachloride.
Backflow prevention and rainwater tanks.
In most recently developed areas of Muswellbrook, water meters have been installed along with a testable, backflow prevention device. This is because many new homes have a rainwater supply plumbed into the dwelling. Council fully supports use of rain water in the home for non-potable purposes, for example, connected to toilets, laundries, and your garden taps. NSW Health has issued a guideline on the use of rainwater tanks where a public water supply is available; this can be found on the NSW Health website.
However, untreated rain water is of a lower quality than municipal treated drinking water, and without appropriate backflow prevention, it is possible to contaminate this supply with Council supply. Backflow occurs when water flows in the opposite direction to its normal or intended direction, e.g. caused by the reduction in mains water pressure resulting from a water main break, or where a consumer’s water pressure is greater than that in Council’s water supply main.
This type of cross contamination has occurred on occasions within the water industry, thankfully not in Muswellbrook Shire, and where these breaches have occurred there have been some serious consequences for public health.
It is extremely important that water fittings and pipe work in the home are installed by licensed plumbers in order to ensure that this type of situation does not occur. If you have any concerns about what you can and can’t do on your system on your property, contact Council during business hours for advice.
This page last updated 16 February, 2012 12:10 PM
