Sydney Water is proposing a new wastewater treatment facility at Camellia-Rosehill in Sydney's west that would discharge 70 million litres of treated effluent into the Parramatta River every day through an outlet at Meadowbank Park, according to a report published 6 September 2026 by ABC News & Headlines – Australian Broadcasting Corporation. The project, which would be built if approved, is being assessed as a state significant development application by the NSW Department of Planning, Housing and Infrastructure, and Sydney Water must still obtain an environmental protection licence from the NSW EPA before any discharge can begin.
Key takeaways
- Sydney Water is proposing a 70 million litre per day treated-wastewater discharge to Parramatta River at Meadowbank, connected by a 5.3 km largely tunnelled pipeline to a new plant at Camellia-Rosehill (ABC News & Headlines – Australian Broadcasting Corporation).
- Construction is targeted to begin in 2028 and complete in 2032, with existing Northern Suburbs Ocean Outfall Sewer and North Head Water Resource Recovery Facility capacity forecast to be reached by 2031 (ABC News & Headlines – Australian Broadcasting Corporation).
- The facility is sized to serve an additional 230,000 people forecast for the catchment over 30 years, on top of the 1.7 million people currently served (ABC News & Headlines – Australian Broadcasting Corporation).
- More than 400 public submissions have been lodged, with most raising environmental and wildlife concerns around the Meadowbank discharge zone (ABC News & Headlines – Australian Broadcasting Corporation).
What happened
The proposal would add a second major wastewater resource recovery node in western Sydney, sitting downstream of the Northern Suburbs Ocean Outfall Sewer and the North Head Water Resource Recovery Facility, which together process effluent for around 1.7 million residents in the city's western and northern suburbs and are forecast to reach capacity by 2031, according to ABC News & Headlines – Australian Broadcasting Corporation. Sydney Water says the Camellia-Rosehill plant is needed to accommodate an additional 230,000 people forecast for the area over the next 30 years.
Project delivery lead Caine Mertens told the ABC that the treated water would be cleaner than the current river water and would improve local water quality, with the design relying on multiple safeguards and redundancy: "Water in this project will be treated to a very high level with lots of safeguards, lots of redundancy," he said, as reported by ABC News & Headlines – Australian Broadcasting Corporation. Mertens added that any off-spec water can be returned to the existing system and that only high-quality water would be sent to Meadowbank, although a water-quality fallback still relies on a manual override by operators.
The discharge point sits in an ecologically sensitive stretch of the river. According to ABC News & Headlines – Australian Broadcasting Corporation, the riverside banks at Meadowbank host endangered migratory birds, mangroves and wetlands still recovering from decades of industrialisation, and the proposed outlet is several kilometres upstream of two newly opened swimming sites at Bedlam Bay in Gladesville, which opened in November 2025, and Putney Beach, which opened in January 2025. The NSW government spent $1.26 million opening those two sites, the same source reports.
Independent water science researcher Ian Wright, an associate professor at Western Sydney University and a former Sydney Water scientist of 18 years, questioned the reliability of the treatment train. "Pumps break, filters block. All kinds of things can happen, so you may be able to achieve high quality most of the time, probably not all the time," he said, according to ABC News & Headlines – Australian Broadcasting Corporation. Local resident Andrew Yeung raised similar concerns about the area's recreational intensity, citing three downstream swimming areas, a junior sailing club and three boat ramps near the outlet.
Next steps are gating rather than groundbreaking. The Department of Planning, Housing and Infrastructure is assessing the state significant development application, and Sydney Water must still hold an environmental protection licence issued by the NSW EPA before any water is released, as reported by ABC News & Headlines – Australian Broadcasting Corporation. If approval and licensing land on the project's current schedule, construction would begin in 2028 and the plant would be commissioned in 2032.
Specification read
The headline figure of 70 million litres per day converts to 70,000 m³/day, or 70 megalitres per day (MLD), of treated effluent routed to a single surface-water discharge point — a flow envelope that, in a project of this size, is normally handled by a full secondary-plus-tertiary train: screening and grit removal, primary clarification, a biological stage (typically A2O, MBR, MBBR or SBR depending on footprint and effluent targets), tertiary filtration and disinfection (often UV plus chlorine or chloramine for river-outlet reuse), with on-site buffer volume and a manual-override diversion back to the existing sewer for off-spec flows (ABC News & Headlines – Australian Broadcasting Corporation). This event bears principally on the tertiary and disinfection stage, because the discharge is going into a river that is also being marketed as swimmable, which is exactly where nutrient limits, pathogen log-reduction targets and the manual-override control philosophy are set. The 5.3 km largely tunnelled pipeline to Meadowbank, the 230,000-person growth assumption and the 2028-2032 delivery window together describe a greenfield build rather than a retrofit (ABC News & Headlines – Australian Broadcasting Corporation).
| Parameter | Reported value |
|---|---|
| Average treated discharge | 70 ML/day (70,000 m³/day) |
| Additional population served | 230,000 over 30 years |
| Current population served by existing assets | ~1.7 million |
| Existing-asset capacity year | 2031 |
| Pipeline length to outlet | 5.3 km, largely tunnelled |
| Construction start (if approved) | 2028 |
| Target completion | 2032 |
If your plant sits in the 20-100 MLD range, discharges to a river or estuary that is also used for recreation, and is being asked to meet a swimmable-water or nutrient-stripping consent, this is a class-of-project that turns on the tertiary and disinfection envelope and the buffer/divert-to-sewer philosophy rather than on the biological reactor choice — the engineering case studies on our Municipal and Industries We Serve pages cover that envelope, and a recent capital-cost benchmark for a comparable ocean-outfall upgrade is captured in our write-up of the Surrey Connect puts North Shore Wastewater Plant cost at $5.5B, September 2026 project, while a buyer's view of solids-separation selection for a heavy-industry feed is laid out in DAF vs Clarifier for Mining/Metals Wastewater in Zahl, ND: 2026 Factory Buyer's Guide.
FAQ
What flow rate is the proposed Camellia-Rosehill plant designed to discharge?
The reported design figure is 70 million litres per day, or 70,000 m³/day, routed to a single outlet at Meadowbank Park, according to ABC News & Headlines – Australian Broadcasting Corporation. In buyer terms, that is a 70 MLD greenfield facility with a 5.3 km tunnelled transfer main.
What approvals does Sydney Water still need before discharge can begin?
It must clear a state significant development application assessed by the NSW Department of Planning, Housing and Infrastructure, and then hold an environmental protection licence issued by the NSW EPA, as reported by ABC News & Headlines – Australian Broadcasting Corporation. Construction is targeted to start in 2028 and complete in 2032 if approval and licensing land on schedule.
What is the indicative capital cost of the project?
The source does not report a capital figure for the new plant or pipeline. For a recent municipal benchmark, see our write-up of the Surrey Connect puts North Shore Wastewater Plant cost at $5.5B, September 2026 project, and treat any rule-of-thumb range for a 70 MLD tertiary-plus-disinfection greenfield as a general industry range, not from the sources.
What is the main engineering risk buyers should focus on?
The independent reviewer flagged the reliability of treating raw effluent to a high bar and the fact that the water-quality fallback still requires a manual operator override, as reported by ABC News & Headlines – Australian Broadcasting Corporation. For buyers, the practical question is how much on-site buffer volume and automatic diversion to the existing sewer is locked into the control philosophy before any river discharge is permitted.
