The Vaucluse and Diamond Bay sewage catchment is the last remaining non-treated ocean outfall in the Sydney Water service area. Whilst the sewage flow is relatively small and the receiving environment ideal, Sydney Water saw the need to reduce impacts on the receiving waters and bring this system up to contemporary standards.

The challenges of this project included:

• The area is densely urban, has steep slopes and restricted vehicle access which makes construction technologies more difficult
• The system is a gravity system, therefore many of the pump stations and transfer mains are on the sensitive harbour’s edge
• The outfall is in a location that is neither visible nor near popular swimming areas so public awareness of the system and its problems is low.

Manidis Roberts was part of a small interdisciplinary project team that included members from Sydney Water and our long-term partners, MWH. The integrated team was responsible for the project planning and management to determine a preferred option for consideration by the board of Sydney Water. We specifically undertook the community and stakeholder engagement processes.