Cessnock Wastewater Treatment Works

The Cessnock Wastewater Treatment Works serves the communities of Cessnock, Aberdare, Bellbird and Nulkaba.

It currently treats 5.8 megalitres per day and can handle wastewater from a population of up to 32,000 people.


The Cessnock Wastewater Treatment Works is designed to remove nutrients (nitrogen & phosphorus) and to provide a high level of disinfection.

It provides tertiary treatment of the wastewater by the following process:

  1. inlet works, including screening flow meter and grit removal
  2. soil bed biofilter for odour control
  3. two primary clarifiers
  4. four trickling filters
  5. a humus clarifier
  6. chemical dosing to remove phosphorus
  7. anaerobic digestion system for sludge stabilisation
  8. an onsite Centrifuge dewatering system
  9. a tertiary flotation plant to remove algal cells and other suspended solids
  10. a UV disinfection system after flotation.

Recycling and Reuse

All biosolids produced at the Cessnock Wastewater Treatment Works are beneficially used for mine site rehabilitation.

Recycled water is utilised for:

  • grit and screening washing
  • general wash down around the Wastewater Treatment Plant
  • ground irrigation.

A golf course also takes up to 50 megalitres per year of recycled water for irrigation.

The rest of the effluent is discharged to Black Creek. Downstream irrigators are also licensed to extract water from Black Creek, the flows of which are mainly sustained by treated effluent from Cessnock Wastewater Treatment Works.

Future upgrades

An upgrade to the Cessnock Wastewater Treatment Works is currently progressing so that we can provide additional future capacity and improve the quality of treated effluent.

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).