Drinking Water Quality

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Drinking Water Quality

In NSW, the Department of Health has endorsed the National Health and Medical Research Councils' Australian Drinking Water Guidelines 2011 (ADWG) as the definitive standards for drinking water quality for NSW communities. 

All public water supplies in NSW should aim to meet the ADWG to be satisfied with the safety of their drinking water supply. This includes any supply to the public, ranging from small-scale Bed and Breakfasts to the largest Water Supply Authority supplying millions of people.

Below are the test results from the NSW Health Drinking Water Quality Monitoring Program for the last 12 months. This report is updated monthly to include the most recent test results.

Drinking Water Quality Report December 2020.pdf

Our Total Hardness as CaC03 levels have been decreasing since October, 2019. This is due to the construction works to relocate the lime dosing plant from the old location at the bottom of Karangi Dam to inside the Water Treatment Plant.

Relocating the lime dosing facility to its new home within the Water Treatment Plant will improve the operation of the treatment plant. However, while the works are in progress, Council has not been able to treat the water with lime in the usual manner. To ensure our drinking water remains high quality and continues to meet ADWG standards, Council is treating the water with Sodium hydroxide to increase the alkalinity of water for the treatment process.

Lime is used to increase the pH and alkalinity of water in the treatment plant so that the important steps of coagulation and flocculation in the filtration process are optimised. Lime also increases the hardness of our drinking water so that it is less corrosive to the infrastructure needed to get the water to our taps.

Sodium hydroxide increases alkalinity, but it does not increase hardness. This is why our Total Hardness levels have fallen. Whilst our drinking water continues to meet the high standards of the ADWG, until our new lime plant is operational, our water will be softer and slightly more corrosive in the short term.

Council expected that relocation works would be finished and the usual lime dosing process would be resumed by the end of 19/20. However, implementation of COVID-19 workplace control measures has delayed progress and Council now anticipates completion in 20/21, dependent on further COVID-19 workplace control measures. 

Total Hardness levels will increase again from the time the lime plant is operational.

Council begins the process of creating the highest quality drinking water for our customers long before the water gets to your house.

Step 1 - Catchment and Raw Water Management
Protecting the quality of the raw water river sources by controlling land use in the areas upstream of the drinking water pump stations and carefully managing the raw water stored in our off stream storage Dams is a vital start to a top quality drinking water supply.

Initial Water Quality Protection

Step 2 - The Water Treatment Plant
The Karangi Water Treatment Plant assists Council to minimise any risk of contamination of the local water supply by blue/green algae and pathogen infection, and ensures that Australian Drinking Water Guidelines continue to be met. It also reduces problems created by iron and manganese in the water supply, which has resulted in Council having to carry out an extensive water mains flushing program in the past.

Step 3 - Water Mains Flushing and Reservoir Cleaning 
Having clean water is important, but just as important is having clean pipes to deliver the clean water through to residents. For this reason, Council provides a regular water mains flushing program to protect the quality of our drinking water. 

Step 4 - Water Quality Testing 
Despite managing and treating our water sources and water distribution network so that the Coffs Harbour Water Supply meets health and safety standards, Council also regularly tests the quality of our drinking water to ensure these health and standards are being met. 

Step 5 - Community Help to Protect Our Drinking Water
Council can only do so much to ensure residents have access to top quality drinking water. There are risks to our drinking water quality which are out of our hands and under the control of residents. You play a part in protecting your own water supply. 

One of the main risks to our drinking water supply which is controlled by residents is backflow of contaminated water back into the water supply network. 

Backflow Protection

​Yes, the Coffs Harbour water supply is fluoridated. Drinking water for the village of Nana Glen is not fluoridated as it is served by a seperate water supply.

The Coffs Harbour drinking water supply generally has an average water hardness under 60mg/L (as CaCO3) and therefore is considered "soft".

Water Hardness & Your Dishwasher

When there is a sudden increase in the rate of water flow through pipes or a change in direction, it is possible to stir up sediments that have settled in the pipes over a period of time. These sediments are then suspended in the water, giving it a discoloured appearance. Although unsightly, the suspended particles that cause discoloured water are harmless to health. The sediment contains very fine iron and manganese particles. Burst pipes can also result in discoloured water, due to the need to reverse water flow patterns in surrounding streets.

If the discolouration stains your washing, keep the articles immersed in water and call Council on 02 6648 4000 and we can deliver a cleaning agent to help remove stains from your washing.

​​If you experience white, cloudy or milky looking water it is caused by air in the water, and it is harmless. It can occur when work is carried out on water mains (eg. a burst water main) or when a faulty air valve allows air to enter the water pipe. If you leave the water to stand in a glass for a short period it will allow the air bubbles to be released and the water will return to a clear appearance.

​Testing is carried out regularly at 32 different sites throughout the City to ensure that drinking water is of good quality and meets the Australian Drinking Water Guidelines and  NSW Department of Health standards.

​Biological, Physical, Chemical and Radiological characteristics that may affect the quality of water are tested.

These water quality indicators can be categorised as:

  • Micro Biological: bacteria, algae.
  • Physical: temperature, turbidity, colour, dissolved solids, pH, dissolved oxygen, taste and odour.
  • Chemical: Inorganic chemicals, including arsenic, chloride, copper, iron, lead, manganese, nitrate, nitrite, sodium, tin, zinc etc., organic compounds and disinfection by-products.
  • Radiological: gross alpha and beta activity concentrations.

The NSW Department of Health runs a Drinking Water Quality Monitoring Program for all regional and rural Water Supply Authorities, such as Coffs Harbour Water. This program allows the State Government to monitor the quality of the drinking water supplied to the NSW community by rural or regional Water Supply Authorities, and their compliance to the ADWG.

To test the quality of the drinking water in the Coffs Harbour City Council area, NSW Health asks the National Association of Testing Authorities (NATA) Accredited Environmental Laboratory in Coffs Harbour to collect water samples on a monthly basis and send the water samples to the Forensic & Analytical Science Service (FASS) in Sydney for testing.

Environmental Laboratory

The Environmental Laboratory in Coffs Harbour also conducts weekly tests on pH, Turbidity, Alkalinity, E.coli, Manganese, Iron and Fluoride for Coffs Harbour Water, independent of the NSW Health Drinking Water Quality Monitoring Program. The Environmental Laboratory is also available to conduct tests on private water samples on a fee-for-service basis.

​The Coffs Harbour Laboratory is a NATA accredited market leader in providing chemical and microbiological analysis of drinking water, effluents, bore water, tank water, pools and environmental waters.  

You can contact them on 02 6648 4460.

​Residents brewing drinks at home may need to know certain quality characteristics of the Coffs Harbour City Council drinking water supply to successfully set up their home brew operations.

The data below was gathered over a 5 year period and covers the most common queries received by Council from the home brewing community.

Characteristic Average Min Max
Alkalinity as CaCO348.9242.065.0
Calcium (mg/L)20.2317.324.40
Chloride (mg/L)11.8710.013.00
Magnesium (mg/L)1.170.871.44
Sodium (mg/L)
Sulfate (mg/L)14.9112.023.0