Check out our News and research section to find out more about exciting developments at Sydney Water. 

You can find more information on our Reports & publications webpage. 

We must monitor chemical, biological and physical properties of water - its water quality. This is to ensure we meet our core objectives to protect public health and the environment. 

We manage and monitor water quality at many points through out our drinking water system in a 'multi-barrier approach'. You can find out more on our drinking water quality and filtration webpage.

We're also protecting the environment by treating wastewater and managing water in the environment. We treat and monitor wastewater for reuse as recycled water or to safely discharged into the environment. 

No matter the source of water - we treat, monitor and manage water so it is 'fit-for-purpose' - right for the job and environment it end up in. 

Why not try our Make mock water samples fact sheet to replicate sources of water and see how water quality can change.

Wastewater is a complex mixture and needs to go through multiple treatment processes to make recycled water. You can read more about wastewater treatment and water recycling here.

Washing detergents have multiple components that are removed in different steps. Many of the naturally available components, including nutrients like phosphates and nitrates, are broken down and removed in secondary or biological treatment using microbes. 

Fine particles, remaining chemicals and excess nutrients require chemical mixing in tertiary treatment. This includes coagulation and flocculation which pull together the tiny particles to form larger solids that can then be removed using processes like sedimentation and filtration. 

We recommend using eco-friendly washing detergents at home. Detergents low in phosphates and unscented require less chemicals and energy to remove from wastewater.

There are range of different chemicals that we use in water treatment to protect public health and the environment.  

The chemicals we use are fit-for-purpose, meaning that at each site we choose chemicals that are appropriate for the job and the end use for the water. 

We carefully follow regulations and recommendations of authorities like NSW Health and take into consideration variables like the quality of the raw or incoming water, equipment available and the end purpose of the water. 

Some of the classes of chemicals include: 

• Coagulants: are added to water to neutralise the charges on suspended solids to help with their removal. One or combinations coagulants can be used at a plant. 
• Flocculants: are added to water to cause a physical reaction making solids clump  together (aggregate). This can be used with coagulants to help separate solid particles. Flocculants can include polymers, that can be non-ionic, contain charged groups (polyelectrolytes). 
• Oxidants and disinfectants: can be used to manage aesthetic water quality needs (the way water looks, smells and tastes). Oxidation reactions are used for colour removal, such as precipitation of manganese or iron ions. They can also be used for disinfection purposes such as applying chlorine or ozone. 
• Acids and bases: are used for pH regulation, cleaning and to create a suitable environment for other chemical reactions.   

You can check out our Natural buffers in water treatment video for more information. 

Head to our HSC Chemistry page for more fact sheets, videos and information. 

You can also see our technical data sheets located on treatment plant pages such as for specific examples. 

There are multiple ways we use polymers in water treatment. 

• We use a polymer in a process called flocculation. It is used to stick fine particles together to help remove them. Watch Polymers in water treatment to find out more.

• We also use polymers in membrane filtration such as reverse osmosis. we use this process to remove dissolved salts, nutrients and particles <0.0005 μM! This purifies the water in a process called advanced water recycling. 

Both of these uses of polymers are important to help us:

• remove fine particles from water making sure it's cleaned for its intended use
• to recover solids for beneficial reuse such as biosolids, a safe fertiliser. 

You can read more fact sheets on the uses and properties of specific polymers on our HSC Chemistry web page.