Cassilis Sewer Treatment Plant

  • Project typeConstruction of Sewer System
  • Project value$9.7 Million
  • Project scheduleNot available
  • Contractor nameNot available
  • Completion Date31 December 2028
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Last updated: 9 December 2025

The Cassilis Sewer Treatment Plant Project will deliver long-overdue modern sewer infrastructure to the village of Cassilis, improving public health, environmental outcomes, and paving the way for more resilient services into the future.

This project responds to the critical need for a centralised sewage system in Cassilis, where ageing and often failing on-site septic systems have posed ongoing challenges. Once complete, the new system will serve residential properties, key community facilities and commercial sites, including those that support major local events like the Cassilis Rodeo and Campdraft.

Backed by the NSW Government’s Regional Water and Waste Water Backlog Program, the new sewer scheme includes a reticulated collection system, a purpose-built pump station, and a multi-stage sewage treatment plant with an effluent reuse system for pasture irrigation on Council-owned land.

Environmental safeguards have been embedded in every stage of the design, from pond-based treatment with extended detention times to a land-based irrigation system that avoids discharge to local waterways.

The project represents a major infrastructure investment in the future of Cassilis, enhancing liveability, supporting environmental protection, and enabling long-term sustainability for the local community.

Frequently Asked Questions

  1. What stage is the project at?

    A detailed design for the sewage system was developed by Cardno in 2021. Since funding was secured, the design is under review and approvals being sought prior to going to market for construction.
  2. What part of Cassilis is included?

    A site catchment map is shown below shows the part of town included in the scope (red outline). At this point in time, Thompsons Road is not included in the scope. This may be altered pending available funds.
    Cassilis-Sewer_Map.png


  3. How is the project funded?

    This project is funded by the Legacy Infrastructure Fund - Central West Orana Renewable Energy Zone (REZ) Community and Employment Benefit Program, with an overall funding of $9.7M. The Project includes all infrastructure and the connection of all households and businesses to the system. Including decommissioning  of old DSMS tanks
  4. What is the timetable?

    Work is expected to start onsite in the second half of 2026 and is forecast to be completed by the end of 2028.

  5. Will there be work on my land?

    Work will be required on each Lot that is to be connected to the system. New pipework will be installed from the current inlet of the septic system on site, to the nominated connection point on the sewer main.
    The design of the reticulated sewer collection system utilises public land wherever possible, such as the road reserve and laneways. In order to keep the system simple, using gravity as far as possible, some infrastructure will be required to be on private lands.
    Arrangements will be made with each affected landowner, with an easement to be created where required. Works will typically involve underground pipework, with inspection and service access holes at changes in direction. The treatment plant will be located on Council owned land off Cassilis Road.
  6. What will it cost me? (Connection provided, rates altered on completion)

    Council will connect each house/business to the new sewerage reticulation system up to a suitable location. Each connection will be designed and reviewed by Council and landholder prior to installation. For gravity sewer, Council will maintain up to sewer shaft. For pump out pressure sewers (Scott Street, north of Buccleugh St intersection) Council will maintain up to boundary kit.
    The project will fund all infrastructure and connection works. There is no installation costs for the property owner. Property owners will be charged maintenance through the sewer rates for each property. This is determined in the fees and charges.
  7. What if I don't want to participate?

    The system requires all connections to operate efficiently. Connecting at a later date will come at a cost due to the works then being considered private.

  8. What will be construction disruptions?

    Council will undertake consultation with each property owner when works are required on their land. Council and the contractor will aim to minimise disruptions.

  9. What happens if I have a structure (e.g. shed) that runs along my property boundary where the sewer line is going?

    At this point in time, the design has not identified going under sheds / property structures. As part of the design review, the site will be walked to ensure this is the case. Should it happen, it will be assessed on a case by case basis and we will look to minimise disruptions and return the surface back as close as possible to it's pre construction condition.
  10. What happens with my old septic tank?

    All existing septic tanks will be decommissioned, material removed and be cleaned out. A hole will be placed in the bottom of the tank and the lid modified to standard and filled with soil. Note: the tank will not be removed.

  11. What happens during a flood?

     Infiltration will be minimal as the new system is sufficiently scaled for minor flood events and will operate as normal.
    During major flood events, the system may be inundated and diluted.

  12. Will there be a smell from the plant?

    Response: Odour has been considered part of the detailed design report and can be found here.

Contact details

Upper Hunter Shire Council
02 6540 1100
council@upperhunter.nsw.gov.au
Customer Request Management Form

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