Drinking water

Did you know?

PFAS

What are PFAS?

Per- and poly-fluoroalkyl substances (PFAS) are human-made chemicals that have been widely used in everyday products since the mid-1900s. They are resistant to heat, stains, grease, and water, so they were often used in items like non-stick cookware, firefighting foams, water-repelling fabrics, cleaning products, and personal care products. However, PFAS do not easily break down, so they can remain in the environment for a long time. The NSW Environmental Protection Authority (EPA), is investigating PFAS at certain sites across the state, listed on the EPA website. Importantly, no sites in the Griffith City Council drinking water catchment area are under investigation for PFAS.

Find out how Council is responding here(PDF, 140KB)

Griffith Water Treatment Plant

The Griffith Water Treatment Plant (GWTP) was commissioned in 1988 and has the capacity to produce 60ML of drinking water per day.

Raw water is obtained from Murrumbidgee Irrigation’s main canal at the "Three Ways Bridge". The raw water is stored in a 300 megalitre (ML) off-channel dam (Hayes Lease Reservoir) and is pumped to the treatment plant when in operation.

Water treatment process

• Coagulant dosing and Flocculation - a polymer is added to the raw water at a rate determined by lab tests. The polymer reacts with suspended particles in the water which cause them to stick together and become larger (called floc)
• Dissolved Air Flotation (DAF) - water saturated with air is introduced to the bottom of the DAF tanks. As the tiny air bubbles are released and float to the top of the water surface, it takes the floc with it, floating the floc to the top
• Rapid Gravity Media Filtration - the water is then filtered through multimedia filters which remove any fine particles remaining in the water
• Disinfection - the filtered water is then transferred to the clear water tank where chlorine is added to ensure it is free of harmful bacteria
• Fluoridation - fluoride is added to assist with dental health
• pH correction - when required, pH adjustment is done by adding soda ash (sodium carbonate)
• Powdered Activated Carbon - can be dosed when raw water turbidity is high, and 'tastes' become noticeable. 

At this stage, the water will have a turbidity generally less than 0.4 NTU and pH between 7.5 to 8.2. Following this process, the water is considered fit for human consumption and is then pumped into the town's reticulation system and up to the reservoirs on Scenic Hill. There are three large tanks with a total volume of 53ML. These reservoirs feed potable (drinkable) water to consumers in Griffith and surrounding villages.

Yenda Water Treatment Plant

The 2.5ML per day Microfiltration plant at Yenda was officially opened in 2002.

The treatment processes are:

• Microfiltration
• Disinfection
• Fluoridation

Raw water is drawn from Murrumbidgee Irrigation's Main Canal upstream of the Yenda to Griffith bridge into two in-ground storages.

The raw water is pumped into a 1.75ML steel reservoir which is used for the Yenda raw reticulation and to feed the Filtration Plant. 

Yenda is also connected via a trunk main to the Griffith water supply system meaning water can be supplied to the township from either the Yenda or Griffith plants. Griffith drinking water can supply the Yenda reservoir, directly supply Yenda township, or directly supply the industries on the eastern part of the village.