Sydney Water is proposing to construct and operate a water resource recovery facility (WRRF) (link) and associated infrastructure at Camellia-Rosehill. The WRRF would divert wastewater from the Northern Suburbs Ocean Outfall Sewer (NSOOS) via the Camellia pumping station and produce advanced treated water which would be released to the Parramatta River at John Whitton Bridge, Meadowbank Park. Pipelines associated with the project run through Rydalmere, Camellia, Rosehill, Silverwater, Newington, Wentworth Park, Meadowbank Park and Memorial Park.
The Department of Planning, Housing and Infrastructure (DPHI) has received a State Significant Infrastructure (SSI) application from Sydney Water for the above-mentioned proposal. The application, Environmental Impact Statement (EIS) and accompanying documents are available to view at www.planningportal.nsw.gov.au/major-projects/projects/greater-parramatta-olympic-peninsula-water-cycle.
1. What were the alternative route options and why were they not chosen?
As part of the planning process, Sydney Water’s project team undertook a detailed optioneering process to evaluate multiple potential pipeline alignments. This assessment considered constructability, safety, environmental impacts, service conflicts, heritage constraints, traffic impacts and delay risks.
In 2024, Sydney Water prepared and publicly displayed the Scoping Report (link), which formed the first stage of this process. The Scoping Report, available on DPHI’s website, includes information around the various options considered for the project. The proposed design as shown in the EIS builds on the findings of the Scoping Report, and has been informed by further environmental assessments, site investigations and stakeholder engagement, including engagements with council, government departments, and community groups.
The preferred alignment was selected for the following reasons:
· Significantly less interface with an existing high-pressure fuel pipeline, below ground services and major utilities (on Holker Ave and Silverwater Road), therefore improving constructability
· Reducing traffic disruptions on high-volume arterial roads which service public transport, freight and emergency vehicles
· Reduced interface with private property and therefore less requirements for land acquisition, land easements and significant restrictions to access for construction
· Avoiding potential impacts to adjacent State Heritage Register-listed items, conservation areas along Holker Street and the Wilson Park Bioremediation site
· Avoiding conflicts with other major projects, including Stage 2 of Parramatta Light Rail, which will be carrying out construction on Hill Road and Holker Street.
Alternative options considered for the river release pipeline and more information about why they were not chosen can be seen in Chapter 2 of the EIS (link).
2. Did Sydney Water consider Holker Street?
As part of the optioneering process while planning the project, a route along Holker Street and Silverwater Road was considered, along with several alternatives.
Holker Street and Silverwater Road contain a large number of below-ground services, including high pressure fuel pipelines, major utilities and assets with strict protection / clearance requirements. Working around these services would require complex relocations, deep excavations, staging constraints with significant delays to delivering the work, and specialist approvals which greatly increase project delivery risks and construction duration.
Holker Street and Silverwater Road are also classified as high-volume arterial routes that carry substantial daily traffic, including public transport, freight and emergency vehicle movements. The optioneering process identified that trenching within these roads would create significant traffic disruptions. As these roads are regionally significant, even short-term lane closures would have major operational impacts that would introduce substantial construction delays and additional costs. In comparison to these arterial roads, Newington Boulevard and surrounding streets experience less traffic volumes, allowing for shorter construction duration.
In addition, Holker Street is located adjacent to State heritage curtilage and are within proximity to sensitive conservation areas.
Sydney Water is committed to working with all stakeholders to balance the delivery of growth-supporting infrastructure in the GPOP area. The proposed alignment has also been developed to avoid conflicting with other major projects, including Stage 2 of Parramatta Light Rail, which will be carrying out construction on Hill Road and Holker Street.
3. Did Sydney Water consider Millennium Parklands for Horizontal Directional Drilling (HDD) construction compounds?
The Millennium Parklands is a significant heritage site that features heritage-listed structures including the Newington Armory, a former Royal Australian Navy armament depot and Newington Nature Reserve under the National Parks and Wildlife Act 1974. The project also deliberately avoids the Nature Reserve which contains endangered ecological communities protected under both State and Commonwealth legislation.
The Millennium Parklands also includes substantial wetlands, saltmarsh, and mangrove habitats, many of which are protected ecological communities.
4. What will the impacts be on Newington Boulevard?
Traffic and transport related impacts to Newington Boulevard are described in Section 14.4.1 of the EIS (link), and throughout the Traffic and Transport Assessment (Appendix O) (link).
Should the project be approved, Sydney Water would continue to explore opportunities to stage construction to minimise impacts. This could include engaging with the community to explore the option of carrying out construction outside of standard daytime construction hours to avoid the morning and evening peak travel periods.
The northbound lanes of Newington Boulevard (between Comaneci Avenue and Avenue of Oceania) would be temporarily closed during construction works while pipeline construction is occurring. Proposed detours include:
· Newington Boulevard, Nurmi Avenue, Kosmala Close and Wenden Avenue to continue travelling northbound and southbound
· Louis Avenue onto Clarke Street.
Travel lanes would be sectioned off by barriers and fences to minimise construction hazards and prioritise safety. Traffic controllers would also be present on Fariola Street/ Comaneci Avenue/ Newington Boulevard/ Mockridge Avenue to guide other respective vehicles near the worksite. Residents and businesses along Fariola Street, Comaneci Avenue and Newington Boulevard would be notified in advance if driveway access is temporarily restricted during construction.
Construction vehicles are proposed to travel to compounds at Pierre De Coubertin Park using the following route:
· Parramatta Road/ Great Western Highway
· Hill Road
· Avenue of Oceania.
During open trenching works for the river release pipeline, a temporary closure of the shared path along Newington Boulevard may be required. Should this occur, a suitable alternative route for pedestrians and cyclists would be determined. The Traffic and Transport Impact Assessment (Appendix O) (link) has identified that suitable alternative routes are available in the area, including along Louise Savage Pathway.
Should the project be approved and closure of the shared path be required, Sydney Water would continue to work to assess suitable alternative routes. This would occur under a Construction Traffic Management Plan and would be subject to additional consultation and approval.
5. What are the impacts on Comaneci Avenue?
The installation of an open-trench to install the 1m diameter pipeline along Comaneci Avenue will require careful planning and mitigation due to the narrow street width and the established tree canopy.
We understand that street trees along Comaneci Avenue are predominately Corymbia Maculata (Spotted gum), with occasional Brachychiton Acerifolius (Illawara Flame tree) and Lophostemon Confertus, and we recognise the value these trees provide to the local community and streetscape.
Given the constrained space, some level of vegetation impact may occur, however our primary objective is to minimise tree removal wherever feasible. Sydney Water will work closely with arborists to identify opportunities for trench realignment, narrowing of work zones where removal will only occur as a last resort, with any losses being offset through appropriate replacement planting in consultation with council and the community. Protective fencing and root-zone management will be implemented to ensure adjacent trees are not impacted by construction activities.
For continuous open-trench construction, short term disruptions will occur. To minimise these impacts to residents the following mitigation measures will be used:
· Noise controls will include restricted hours, use of modern low-noise machinery, and noise mitigating barriers where feasible
· Dust suppression will be maintained through regular water application, and ensuring vehicle movements are managed to avoid unnecessary dust generation
· Vibration-producing activities if required, will be monitored and controlled, and dilapidation reports will be conducted where required.
We also recognise that Comaneci Avenue is a residential street with limited space, so maintaining safe access for all residents is a priority. This will be managed by:
· Implementing staged construction so works can occur in short, manageable sections.
· Maintaining pedestrian and driveway access as a priority, and using steel road plates and/or temporary crossings where required.
· Ensuring traffic management personnel are on site to assist residents, service vehicles and emergency access where required.
6. Will the dog park and playground in Pierre De Coubertin park be demolished?
No, we are not planning to demolish or remove access to the dog park or the playground within Pierre de Coubertin Park during construction of the project.
The number of open space areas identified for use as potential compound sites are presented in the EIS as a worst case and Sydney Water may not need all compounds proposed. The number, size and location of compound sites required will be refined during the detailed design stage. In doing so, Sydney Water will determine options for construction that have the least impact on public space accessibility. This will include access solutions to the dog park, established public toilets and playgrounds during construction.
During construction (subject to project approval), Sydney Water would continue to liaise with local councils, communities and other relevant stakeholders to develop temporary solutions.
7. What impact will construction have on contaminated land in the area (including dust and leaching)?
Contamination
A Soil and Contaminated Land Assessment (Appendix J) was undertaken, which presents the outcomes of the soil and land contamination assessment, as well as mitigation and management measures for the safe handling and management of spoil. The assessment was reviewed by an EPA accredited Site Auditor. All spoil will be managed in accordance with the appropriate legislation and NSW Environment Protection Authority (EPA) guidelines. Should the project receive approval, Sydney Water will continue to carry out investigations to further understand the risk for residual contamination in the area.
Key proposed mitigation measures for contamination include:
· implement best practice erosion and sediment control measures to avoid mobilisation of saline soils
· prepare and implement the following management plans and protocols:
o Unexpected Finds Protocol, to manage any unexpected contamination found during construction
o Asbestos Management Plan, which would detail asbestos locations on-site, management decisions including transport management, air monitoring requirements (if applicable)
o during construction, testing, disposal and encapsulation options, incident and emergency procedures.
o Soil and Water Management Plan (including a contamination sub-management plan) to manage the handling of soil, soil vapour, ground gases and groundwater contamination
o Dewatering Protocol, to outline procedures for removal of groundwater (including contaminated groundwater)
o Spill Response Procedure, to manage impacts and establish procedures for the unlikely event of a chemical spill
o Acid Sulfate Soils Management Plan, to establish the procedure for working in acid sulfate soils.
The full set of proposed mitigation measures for the project is included in Appendix E of the EIS (link).
Dust
Potential impacts from dust were assessed in:
· section 19.5.2, Chapter 19 of the EIS (Human Health)
· the Health Impact Assessment (Appendix T) (link)
· table 18-8, Chapter 18 of the EIS (Social Impacts)
· the Social Impact Assessment (Appendix S) (link).
The Human Health Assessment has concluded that with the implementation of the recommended mitigation measures in Appendix E (link), there would be negligible health impacts from construction activities. The Social Impact Assessment concluded that the risk for dust related impacts (relating to health and wellbeing) would be low, with the implementation of these mitigation measures.
Mitigation measure AQ03 (Appendix E) (link) would be implemented by the project and would involve including the following measures into the Construction Environmental Management Plan:
· Maintain equipment in good working order to comply with the Clean Air Regulations of the Protection of the Environment Operations Act 1997 (POEO Act), having appropriate exhaust pollution controls, and meeting Australian Standards for exhaust emissions
· Carry out dust suppression on exposed areas and stockpiles using a non-drinking water source, where possible
· Cover exposed areas or stockpiles when high wind conditions are expected and if expected to be left exposed for more than 20 days (for example with tarpaulins or geotextile fabric)
· Modify or cease dust-generating work in windy conditions, where possible
· Maximise distance of dust-generating activities from sensitive receivers, where possible.
8. What impact will construction have on the wetlands and native fauna?
Wetlands
Construction and route selection has been designed to avoid impacting any wetlands across the proposed alignment. Sydney Water is proposing to use trenchless construction methods (drilling up to 25m underground) to install pipes beneath wetlands. This avoids any need to trim or remove mangrove plants and critical root systems. The approach to avoiding wetlands is described in Chapter 3 of the EIS. An assessment of potential groundwater drawdown (lowering of the water level) impacts is included in Section 10.5 of the EIS, and in Appendix K (link) (Groundwater Impact Assessment).
With the implementation of mitigation measures, impacts to groundwater dependent ecosystems are unlikely to occur during construction.
Sydney Water would implement the mitigation measures proposed in Appendix E (link) of the EIS to manage other potential impacts to groundwater during construction.
These measures would include:
· Developing and implementing a Dewatering Protocol to manage dewatering during the works. Works would be monitored as needed over the course of construction in accordance with the terms of the Protocol.
· Implementing sheet piling and concrete encasement to minimise groundwater flows into excavated areas and avoid groundwater drawdown impacts
· Implementing a Drilling Fluid Management Protocol to avoid the loss of drilling fluid and groundwater seepage during trenchless construction
· Develop and implement a groundwater monitoring plan to inform detailed design and allow monitoring of water quality indicators during construction work.
Native fauna and flora
Similar to avoiding impacts to wetlands, Sydney Water has surveyed native fauna and flora within the project study area, and the design has been refined to avoid areas of threatened ecological communities and high biodiversity value, where feasible. Potential residual impacts to native flora and fauna are described in Section 11.5 and Section 11.6 of the EIS, as well as in the Biodiversity Development Assessment Report (BDAR) (Appendix L) (link).
The BDAR has been prepared by a qualified consultant. The assessment assumes a worst-case scenario, with the assumption that all native vegetation within the impact area will be cleared except where vegetation has definitively been avoided using trenchless construction methods. This methodology is best practice and is in line with the current guidelines and policies for biodiversity assessments. However, Sydney Water will seek to avoid direct impacts on native vegetation wherever feasible.
Along Fariola Street and Comaneci Avenue in Newington, street trees are strongly dominated by Corymbia maculata (Spotted Gum), with occasional Brachychiton acerifolius (Illawarra Flame Tree) and L. confertus. Sydney Water will make every effort to avoid removing trees during the detailed design phase and will endeavour to use minimal trimming where necessary to carry out works.
The BDAR concluded that in Pierre de Coubertin Park, impacts to planted native vegetation from the project are likely to be minimal. It is not intended to clear native trees within parks or to negatively impact ornamental plantings. Sydney Water will make every effort to avoid removing park trees and will endeavour to minimise trimming necessary to carry out works.
Appendix E (link) outlines detailed mitigation measures to minimise impacts on native fauna and flora during construction.
