Tea Gardens water supply

Tea Gardens and Hawks Nest residents derive their water from a borefield to the north-west of Tea Gardens. These bores tap the aquifer between 17 and 20 metres from the surface and can yield up to 12 litres per second.

The borefield, which was developed in 1962, has been expanded and upgraded several times to meet the growing demands of the community.

MidCoast Water Services completed an $18 million project to upgrade the Tea Gardens Water Supply Scheme in 2013, to improve quality and to increase security of supply. The project saw the construction of a new water treatment plant, an 8.1 million litre reservoir, high lift pump station and associated pipeworks.

The new water treatment plant is capable of removing naturally occurring soluble metals in the groundwater, and will cater for the area's growing population. Groundwater is treated with chemicals prior to entering two large aeration towers. Lime is used to adjust pH (which is naturally acidic). ACH (aluminium chlorohydrate) is added as a coagulant to draw larger particles together to assist in their removal. Sodium hypochlorite (liquid chlorine) is added for the oxidisation of soluble metals, such as iron and aluminium, to help remove them in filters further down the treatment process.

The water travels through aeration towers to ensure it is well mixed and allows gases to escape. It then passes through a microfiltration system. There are two filter racks, each containing 34 modules. These filters are capable of treating eight million litres of water a day. Small particles are removed by the filters and the clear water passes through to the final stage of treatment.

Liquid chlorine is added for disinfection and fluoride for dental hygiene. Soda ash can be added for final pH adjustment if required. The clear, treated water is pumped to three reservoirs, which have a total capacity of 14 million litres. The scheme has about 37 kilometres of pipelines and serves over 2000 homes and businesses.

More information is available on the chemicals in the Tea Gardens water treatment process