The Castlemaine Water Reclamation Plant has been treating used water from sinks, toilets, and drains across Castlemaine and surrounding towns for around 100 years.

Funded by the customers it serves, the plant is a critical piece of infrastructure for our health and our community's growth and success.

Climate change, ageing infrastructure, and a growing population mean the plant requires vital upgrades to keep pace with demand. So, we're making plans to carry out the most significant upgrade of the plant in a generation.

These works will take several years. When complete the plant will be modern, sustainable, efficient, and deliver a range of community and environmental benefits.

The upgraded plant will meet the needs of the local community for the next 30 years.

About our plant

Aerial view of Castlemaine Water Reclamation Plant

About the upgrades

Planned upgrades to the Castlemaine Water Reclamation Plant will be carried out in stages, including the construction of:

  • A new Water Reclamation Facility
  • A new Biosolids Handling Treatment Facility

The upgrades will ensure the plant can support forecast population growth.

We are also consulting key stakeholders, including local Council, state and federal government representatives, and others to ensure the upgrades will support economic growth and regional development and the needs of key employers, including Don KR Castlemaine, the Loddon Prison Precinct, and Castlemaine Health.

All upgrades will be underpinned by our commitment to reduce our carbon footprint as we target net zero emissions by 2030, and to deliver more recycled water and biosolids for community and environmental benefit.

Project benefits

  • Increased treatment capacity and more resilient sewerage services, designed for our growing population and uncertain environmental conditions.
  • Reduced likelihood of odour and noise emitted from the plant.
  • Increased biosolids and recycled water available for community use.

Environmental benefits

  • Recycled water to maintain flows to Campbells Creek.
  • In conjunction with 'Friends of Campbells Creek' an enhanced environmental space for native flora, fauna, and community enjoyment.
  • Reduced carbon emissions.

Concept, approvals and planning

Current stage

Our focus is to gain a comprehensive understanding of the existing site conditions through investigations and engagement.

With our partners we will be undertaking assessments of key factors that will help guide us through this concept stage including:

  • Site assessments: existing infrastructure, topography, geology.
  • Environmental assessments: noise, water, biodiversity and habitat considerations.
  • Cultural and community assessments: key stakeholder engagement, local business, government.

Construction

To commence 2026

We will provide additional detail when available.

Frequently asked questions

About our upgrade plans

We are in the early stages of project planning, with a number of key approvals to gain as the project progresses. At present we are gaining a comprehensive understanding of existing site conditions through investigations and assessments.

We hope to construct the plant in coming years with a view to completion by 2030.

Our existing plant continues to treat wastewater for Castlemaine, Campbells Creek, Maldon, Chewton, Harcourt and Newstead.

As this is an ageing asset, and we continue to face the challenges of climate change and a growing population, we are designing a new plant that will be modern, sustainable and deliver a range of community and environmental benefits, including potential for increased use of recycled water.

This upgrade will sustain the needs of these communities for the next 25-30 years.

As part of this once-in-a-generation upgrade, we are planning to build a completely new water reclamation plant, including a new biosolids handling facility. This is subject to a number of key approvals.

The proposed new plant will meet best practice by reducing the overall carbon footprint, reducing noise and odour and delivering environmental benefits for the nearby Campbells Creek.

The upgrades will remain within the boundaries of the existing Coliban Water-owned land on Langslow Street. These will allow the plant to align with the best available treatment standards and technology.

You can see our proposed plans on the right hand side of this webapage.

Yes. A new modernised plant will feature an improved treatment process for solids handling compared with the existing process. The current process, and broader plant, are aging and this means new technology has superceded what is currently in place.

Solids processed at the new plant will be more ‘stable’ – which means the resulting biosolids production will have increased reliability. The new process will also include ‘dewatering’ which is not part of the current process. This means biosolids will be drier before they leave the plant, and will be closer to being ready for beneficial reuse on agricultural land.

Once treated, the solids become biosolids – a product rich in nutrients that looks and smells like soil when dried. The proposed plant would see biosolids stored onsite in fully enclosed and ventilated containers, until they are removed by truck, and transported to a biosolids base for drying.

For more information on biosolids visit our page here.

We encourage anyone with questions to ring us on 1300 363 200, and a member of our project team can return your call and speak with you one-to-one.

Odour management

Odour control is carried out by capturing and treating odour produced during the wastewater treatment process. The proposed upgrade will improve the onsite treatment process for solids handling and mean less odour.

This is because the new plant will be better equipped to capture odour and will have increased ability to treat odourous air. This will be achieved by covering odourous areas, ventilating them well and using best practice odour treatment.

Several of the treatment stages are naturally odour-generating, including the inlet works where wastewater arrives at the plant. We manage our plant in line with our Environment Protection Authority Victoria (EPA) operating licence and we have a range of measures in place to minimise and treat odour.

From time-to-time odour can increase due to weather conditions or plant maintenance activities. If we are aware of upcoming maintenance that will generate odour, we will notify neighbours beforehand in addition to other mitigation measures, such as misting systems.

About our recycled water

The plant produces about 1,400 megalitres of recycled water each year.

About 50 megalitres of recycled water is currently reused in Castlemaine, including at the Castlemaine Golf Club during the warmer months. About 1,350 megalitres of recycled water is released to Campbells Creek each year.

Recycled water is a reliable and sustainable water supply. We are always looking for new opportunities to see our recycled water used in the community.

For more information on recycled water visit our page here.

The Castlemaine plant produces Class C recycled water. Our recycled water is subject to stringent monitoring and testing that aligns with our current Environment Protection Authority operating licence.

We are licensed to discharge up to 5.5ML per day. We release water as required by plant operations.

About our environmental impact

Proposed upgrades will see the quality of the recycled water we produce improved. We continue to work with various community groups to support native flora and fauna. We acknowledge the important role this recycled water plays in sustaining a healthy eco-system in Campbells Creek and intend to see that continue.

We’re seeking to strike the right balance between appropriate community access and the safety of our community to allow the plant to operate. We will install fencing around the plant to protect our assets and ensure a safe environment for staff and visitors to the site.

We’ll continue conversations with the community about what long-term public access to Campbells Creek from Langslow Street may look like.

The platypus population in Campbells Creek benefit from the recycled water discharge from our plant. These discharges sustain their habitat and we recognise the value of platypus to the community.

Research conducted in 2021 showed the only platypuses detected during sampling were located directly downstream of the plant.


About trade waste

Our plant services the towns of Castlemaine, Chewton, Campbells Creek, Newstead, Maldon and Harcourt. From these towns, we receive a combination of domestic waste and trade waste which is processed by our plant.

The upgraded plant will cater for anticipated population and industry growth in the Mount Alexander Shire.

From 'waste' to 'great' for community benefit

Once upon a time, the water washed or flushed down Australia's drains and toilets was considered 'wastewater'.

But in a changing and drying climate, improving how we reclaim and reuse the by-products of our water use is important for future water security.

At Coliban Water, we haven't just named our wastewater plants Water Reclamation Plants, we've committed to embedding sustainable practices in every part of our business.

At the Castlemaine Water Reclamation Plant, the production of recycled water and biosolids help us contribute to a circular economy and deliver benefits to our customers, communities and the environment.

  • Biosolids

    Biosolids are the organic by-product of the sewage treatment process.

    Rich in nutrients and similar to the look and smell of soil once dried, they can be applied to maintain productive soils, boost crop growth, and fertilise parks and gardens.

    We're looking to boost the beneficial production of biosolids to return nutrients and carbon to local soils, reducing the need for additional fertilisation.

    Biosolids are managed and reused in accordance with regulatory guidelines set out by the EPA.

    Learn more about biosolids 

  • Recycled water

    You'll see recycled water from the Castlemaine Water Reclamation Plant at work across the region, including at the Castlemaine Golf Club.

    It is also released into Campbells Creek to maintain environmental flows that contribute to the health and biodiversity of this local waterway.

  • Thriving biodiversity

    The lagoons and treatment ponds at the plant provide a local habitat for thousands of birds, many of local and international conservation significance.

    While reclaimed water returned to Campbells Creek improves the health of this natural waterway.

    We're proud of our partnership with the Friends of Campbells Creek and continue to support their efforts to return more native species, including the Platypus, to a seven-kilometre long section of the creek.

    Meet the platypus that call Campbells Creek home