Belmont Wastewater Treatment Works

Belmont wastewater treatment plant

The Belmont Wastewater Treatment Works serves the eastern side of Lake Macquarie, from Charlestown and Redhead in the north to Swansea in the south.

It currently treats 30 megalitres per day and can handle wastewater from a population of up to 100,000 people.


The Belmont Wastewater Treatment Works provides secondary treatment of the wastewater and is designed to remove nutrients (nitrogen and phosphorus). It works as follows:

  1. Sewage receives primary treatment consisting of screening with automatic step screens and de-gritting in a vortex grit removal system.
  2. Screenings are washed and compacted and the grit is washed and dewatered before being disposed of into industrial bins for disposal to landfill.
  3. A soil bed filter treats odours from the covered inlet works.
  4. Biological treatment occurs in aeration tanks fitted with diffused aeration followed by clarification.
  5. Waste activated sludge is thickened in a dissolved air flotation (DAF) unit and pumped to aerobic digesters for stabilisation. The stabilised sludge is dewatered with two centrifuges.

Recycling and reuse

All biosolids produced at the plant are beneficially used in mine site rehabilitation and pasture improvement projects.

The treated effluent is discharged to the Pacific Ocean through a 1.5km ocean outfall. The outfall outlet structure consists of 176 diffusers.

Environmental Licence Monitoring

Pollution monitoring data is collected by Hunter Water, as required under the Environment Protection Licences (EPL) issued by the NSW Environment Protection Authority (EPA).