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Drinking water quality
We are committed to providing high quality drinking water and test regularly to ensure we comply with many important regulations around drinking water. Find out more about how we manage drinking water quality and any issues, including instances of discoloured water.

Central Coast Council is committed to providing high quality drinking water for all residents.

The Central Coast has the third largest urban water supply system in New South Wales, after Sydney and the Hunter region. The system incorporates three dams, three weirs, three water treatment plants, over 50 reservoirs and more than 2,200 kilometres of pipelines. Every day, we supply around 80 million litres of water to about 120,000 properties.

The water comes from local rivers, creeks and dams. Council moves water from these catchment areas to our filtration plants at Somersby and Mardi, where it is filtered and disinfected to ensure it is safe to drink. Low levels of chlorine are added for your health to disinfect the water as it travels through the system to your home. Our water supply is considered soft or moderately soft. It is also fluoridated in line with the NSW Department of Health's recommendations.

Drinking water quality

Regular tests are performed by Council and independent National Association of Testing Authorities (NATA) registered laboratories to ensure our water is safe for human consumption and complies with the water quality guideline values provided in the Australian Drinking Water Guidelines.

View the 2022-2023 Annual Drinking Water Quality report.

Understanding your drinking water

As with all water supplies, our drinking water contains small amounts of naturally occurring minerals, such as calcium, magnesium, iron and manganese. Without these substances, the water would taste bland.

However some of these substances can impact water quality when a change in demand or temperature occurs. Most of the water quality concerns reported by customers to Council are related to its appearance, taste or odour.

Discoloured water

Although town drinking water supplies are generally colourless, from time to time the water's appearance can change.

Sometimes it can take on a yellow or reddish/brown tint to almost being black, while at other times it can appear milky white or blue. This change can occur for a number of reasons.

Yellow, reddish/brown, or black water is usually caused by natural minerals such as iron and manganese. Milky or white water can occur when air becomes trapped in water pipes. Blue stains is common if your hot water cylinder is made from copper.

Discoloured water is more commonly experienced during summer and periods of daily or seasonally higher demand, in low lying areas, dead end streets and streets that normally experience low flow velocities

Prior to undertaking any works, Council performs a risk assessment and takes any necessary action to prevent or mitigate discoloured water. We notify residents in advance of planned water supply works via hand delivered notices, advertisements and our website.

Report drinking water quality issues to Council on 02 4306 7900.

Taste and odour

The taste and odour of water can vary from tap to tap and can be similarly impacted by naturally occurring minerals, water treatment processes and internal plumbing. An individual’s personal likes and dislikes can also influence their perception of taste and odour.

Some of the most common taste and odour complaints are listed below.

Chlorine taste and/or smell

Council adds chlorine to the water supply to remove harmful bacteria. A small residual of chlorine is required to be present in water coming from your taps and, from time to time, a slight chlorine taste or smell may be present.

Seasonal changes in demand, the distance from the water filtration plant and unavoidable changes to system operation, can impact the amount of chlorine residual in your water. The taste and smell of chlorine can be eliminated by placing some water in a covered jug in the refrigerator. It is recommended this water be consumed within 24 hours. Domestic water filters or jug filters are also useful.

Musty, mouldy or earthy tastes or odours

Musty tastes and odours in drinking water can be caused by organic growth inside water pipes when certain jointing compounds are used or when cold water pipes pass closely to uninsulated hot water pipes. Water pipes in areas of the supply system with low flow rates can also create an environment for deposit of organic matter.

Rusty or metallic taste

Drinking water with a rusty or metallic taste generally contains excessive iron or manganese. When these materials are present in high levels there will also be a change in the colour of the water.

In spite of our thorough treatment processes water may pick up material from unlined or corroding pipes. When a house’s internal plumbing is corroded, water may appear clear at first but then turn rusty or black in a few minutes.

Rotten egg smell or taste

A rotten egg smell or taste in water indicates that it most likely contains hydrogen sulfide. This is typically caused by decay of organic matter or chemical reactions in the plumbing or bacteria which change naturally occurring sulfates into hydrogen sulfide.

If the smell only comes from a hot water tap, there may be a problem with the hot water system. If the smell is strong from both the hot and cold water taps when they are first turned on contact Council on 02 4306 7900.

Managing drinking water quality at home

The quality of drinking water can change once it leaves our distribution system and enters the plumbing on private property. To help you keep your drinking water quality in good condition, we've listed below some common causes for water quality deterioration and tips to prevent it.

Check your internal plumbing

All plumbing from the meter to the property is the responsibility of the property owner.

Galvanised pipes are made from steel or iron and coated in molten-zinc, and usually found in homes built prior to the mid-1960s. They have a tendency to rust internally with age. If a property is fitted with galvanised pipes or plumbing fixtures, the taste or odour may be affected by corrosion. Council recommends replacing old corroded pipes with new pipes made from an alternative material, such as copper, stainless steel or polyethylene. Although discoloured water of this type is not harmful to health, it does have a metallic taste.

A licensed plumber can provide advice on the type of pipes on your property.

The validity of a plumber's licence can be checked on the Department of Fair Trading's Website.

The Master Plumbers Association of NSW website also has a list of licensed plumbers.

Beware of backflow

A sudden loss of pressure in the water supply system (e.g. from a burst water main) can cause water to flow out of private property into the system.

This reverse flow—known as backflow—can suck back potentially contaminated water into a home's plumbing and the supply system servicing the community.

To eliminate the risk of contamination, backflow devices are installed on residential properties where a rainwater tank can be 'topped-up' from the water supply system.

Clean taps regularly

The tap in your kitchen can become contaminated with harmful bacteria from food or items washed in the sink. It is important taps used for drinking water are kept clean and that food is never allowed to come into contact with the outlet of the tap.

Maintain water filters

Some people use water filters in their homes. There are several different kinds of domestic water and jug filters available on the market, each designed to remove various compounds from drinking water.

Filters can create a perfect environment for bacteria to grow and pass through your taps into your drinking water. Council recommends changing filter cartridges regularly, in accordance with the manufacturer’s instructions. Water produced by filters should be treated as a perishable good, like food, and used as soon as possible. It is best stored in a refrigerator and should be discarded after 24 hours.

Help us help you

We want to hear from you! We would like to know if you experience drinking water quality issues and if you notice an improvement in the quality of your drinking water. Council can be contacted regarding water quality issues 24 hours a day on 02 4306 7900.

Special needs

Council understands that some people have special water supply needs due to medical conditions. If you have special health care needs, you can be placed on a dedicated stakeholder list by calling council during business hours.

Bogus callers

From time to time we hear from customers concerned about phone calls from people claiming to work for, or on behalf of, Central Coast Council. Bogus callers often call to discuss local drinking water quality, offer water quality tests and sell water filtration units. These individuals do not represent or act on behalf of Council and we do not endorse these companies or their products.

Maintaining water quality at work

If you own, manage or occupy a commercial or industrial property you need to take extra care to ensure the distribution and use of water inside your property does not impact drinking water quality. It is your responsibility to ensure that:

  • the connection design of a water service to your property is inspected and approved by Council prior to commencement of any related work
  • the installation and connection of any water service is carried out by a licensed plumber with appropriate/approved plumbing materials
  • your water service complies with the Plumbing Code of Australia (PCA)
  • the water service on your property remains in good condition and free from blockages or leaks.

Implement best management practices

It is important that you become informed of the best management practices appropriate to your business in areas such as:

  • hazardous material usage reduction
  • process or design changes
  • operational changes, including preventative system maintenance
  • employee training on business operations and its impact on drinking water quality
  • spill and/or leak response, notification and reporting procedures.

Certain property types pose a greater risk to public health if backflow occurs. These include:

  • chemical plants
  • pest controllers
  • market gardens
  • golf courses/sporting ovals
  • caravan parks
  • greywater treatment systems
  • metal processing plants
  • paint manufacturers
  • laundries, and
  • nurseries.

Prevent contamination

Good housekeeping practices can help to avoid contamination of the drinking water supply. These include:

  • changing water fountain filters regularly, as specified by the manufacturer, to remove accumulated impurities and reduce bacterial growth
  • frequent cleaning and replacing of tap aerators
  • keeping containers closed whilst not in use
  • replacing manual transfer operations with pumps to reduce spills and leaks, and
  • having a spill kit readily available so spills can be cleaned up quickly and properly.

Backflow prevention devices should be inspected and tested annually. Test results must be submitted to Council.

Carefully discharge trade waste

Trade waste is any liquid, and any substance contained in it, produced by a commercial or industrial activity at a business premises. If it is not managed properly, trade waste can contaminate the water supply.

If your business discharges trade waste into the town sewerage system, you must obtain approval from Council to do so. Council can also provide you with pre-treatment advice to help ensure that any trade waste discharged into the sewer meets council requirements.

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