SYDNEY'S DEEP OCEAN OUTFALL

Click the photograph for a enlarged view

General Description

Malabar, North Head and Bondi outfalls collectively discharge more than eighty percent of Sydney’s sewage effluent (EPA 1996a). They have been the subject of a series of intensive studies (EPA 1996a, Krogh et al 1997) and will not be treated with detail in this report. [Interested readers are referred to the Final Report Series from the Environmental Monitoring Program (EPA 1996a-g) and references therein, and to the follow up study on soft bottom benthic communities conducted by Krogh et al 1997].

Sewerage Catchment:

- North Head outfall is the discharge point for the North Head STP which serves most of the suburbs east of Blacktown between the Parramatta and Hawkesbury Rivers, as well as the western suburbs south of the Parramatta River including Parramatta, Fairfield and Prospect. The Bondi outfall is the discharge point for the Bondi STP which services the City of Sydney, and the municipalities of Leichhardt, Marrickville, Randwick, Waverley and Woollahra. The Malabar outfall is the discharge point for the Malabar STP which receives sewage from most of the suburbs between Parramatta and the Georges River west to Campbelltown

Sewage Treatment:

- North Head, Bondi and Malabar STPs are high rate primary treatment plants

Outfall:

- A deepwater ocean outfall that now services North Head STP was commissioned in December 1990. The deepwater outfall consists of a 3.5 m diameter tunnel approximately 3500 m long with a diffuser zone 765 m long and is located in an average water depth of 60 m.

- A deepwater ocean outfall that now services Bondi STP was commissioned in August 1991. The deepwater outfall consists of a 2.3 m diameter tunnel approximately 1700 m long with a diffuser zone 510 m long and is located in an average water depth of 60 m.

- A deepwater ocean outfall that now services Malabar STP was commissioned in September 1990. The deepwater outfall consists of a 3.5 m diameter tunnel approximately 4100 m long with a diffuser zone 720 m long and is located in an average water depth of 80 m.

Sydney's Deep Ocean Outfalls

(Deep3_2) Last updated June 2000