MOD 11 - water management during MPPS outages

- This mod is critical to support the long term energy supply to NSW
- This mod helps provide ongoing job security for Centennial Coal mine workers in the Lithgow region
- Centennial has a long history of continual improvement in managing water in the region

• Centennial has gone to significant effort and invested in industry best infrastructure to ensure discharged water quality is as good as reasonably practicable
• Centennial has a long history of continual improvement in improving water quality
• The MOD is critical for long term energy supply to MPPS

Centennial has gone to significant effort and invested in industry best infrastructure to ensure discharged water quality is as good as reasonably practicable.
Centennial has a long history of continual improvement in improving water quality.
The MOD is critical for long term energy supply to MPPS.

I am a current employee of Angus Place and have direct experience with the SWTP. The MOD 11 is required to ensure that water levels at the Mine Site remains at acceptable levels. Reduction in water transfer to SWTP will result in substantial increase in underground water levels resulting in Centennial to expend large amounts of monies to ensure it protects its assets and future coal reserves. This is required to ensure the ability of the company to remain solvent and supply coal to the domestic power industry. I am also confident that this modification with not damage or harm the environment in any way shape or fashion.

• Centennial has gone to significant effort and invested in industry best infrastructure to ensure discharged water quality is as good as reasonably practicable
• Centennial has a long history of continual improvement in improving water quality
• The MOD is critical for long term energy supply to MPPS

I am writing to express my strong support for Centennial Springvale’s project modification (MOD11) to enable increased water bypass to Thompsons Creek Reservoir during the planned outage at Mount Piper Power Station (MPPS).

The upcoming outage, expected to last for 30 days, presents significant challenges to Centennial’s ability to manage underground water storage, transfer, and discharge at both Springvale and Angus Place mines. Without this temporary modification, Centennial will face substantial operational strain in maintaining safe water levels, which could have both immediate and long-term impacts on water management and the broader energy supply.

Centennial has consistently demonstrated a commitment to best-practice water management, investing in industry-leading infrastructure to ensure that discharged water quality meets or exceeds reasonable environmental standards. The company has also maintained a strong track record of continuous improvement in water quality management. Approving MOD11 is a crucial step in safeguarding these efforts and ensuring operational continuity.

Furthermore, the viability of the Centennial Angus Place West (APW) project depends on a reliable and sustainable approach to water management. Any disruption caused by the MPPS outage threatens not only Centennial’s operations but also the long-term stability of energy supply linked to MPPS.

I urge the NSW Department of Planning, Housing and Infrastructure to approve MOD11, recognising its necessity in mitigating the risks associated with the MPPS outage while upholding Centennial’s ongoing commitment to environmental responsibility.

Thank you for your time and consideration.

Dear DPHI,

I am writing to express my full support for Centennial Springvale’s project modification (MOD11) request, which aims to enable increased water bypass to Thompsons Creek Reservoir during the upcoming outage at the Mount Piper Power Station (MPPS). The planned 30-day outage poses significant challenges for Centennial Springvale, particularly in its ability to manage underground water storage, transfer, and discharge effectively at both Springvale and Angus Place mines.

This modification is vital not only for ensuring continued operations at the mines, but also for maintaining safe underground water levels, which are critical for the viability of the Centennial APW project in the long term. The increased bypass will help mitigate these challenges and ensure a stable water supply to Centennial’s treatment facilities during this period.

I would like to commend Centennial’s efforts in establishing industry-leading infrastructure that guarantees the discharge of water with the highest possible quality, and their ongoing commitment to continuous improvement in water management. This dedication not only benefits the local environment but also supports the long-term sustainability of the region’s energy supply, especially given the role MPPS plays in energy generation.

Supporting this project modification is essential for the resilience of both Centennial's operations and the broader energy infrastructure. I strongly urge approval of MOD11 to safeguard water levels and operations during the MPPS outage.

Thank you for considering this important modification. Please feel free to contact me should you require further information.

Centennial has consistently demonstrated a commitment to industry best practices by investing in advanced infrastructure to ensure discharged water quality is as good as reasonably practicable. With a long-standing history of continuous improvement in water management, Centennial has proactively enhanced water quality over time. This modification is critical to securing the long-term energy supply to MPPS, ensuring operational stability while maintaining environmental responsibility.

In support of the project it is critical to know that
• Centennial has gone to significant effort and invested in industry best infrastructure to ensure discharged water quality is as good as reasonably practicable
• Centennial has a long history of continual improvement in improving water quality
• The MOD is critical for long term energy supply to MPPS

Centennial’s underground coal mining has damaged groundwater flows under the Gardens of Stone State Conservation Area. Not only has this been responsible for draining of peat moss swamps and cracking the iconic pagoda rock formations, it also has created a problem with groundwater flowing into the coal mines.
Now Centennial wants to be able to remove this excess water by pumping it into Thompsons Creek that flows into the Coxs River and then into Sydney’s water catchment. Large proportion of this water is polluted but Centennial wants to release this water without treatment to remove heavy metals and salts. This goes against the zero release system they proposed when the water treatment plant was originally approved
This proposal is unacceptable and must not be approved. I am concerned that the quality of Sydney’s drinking water will be reduced and/or greater expenditure will be required by Sydney Water and us taxpayers in purifying the water. The ecological value of the World Heritage Blue Mountains and its wildlife will be damaged.
How much will the volume of water entering the creek be increased? The release of this groundwater is not a natural flow. Its natural form is to remain underground. The additional flow plus the polluted water will harm aquatic life.
I understand that the discharges will occur when the Mount Piper power station is offline. The power station is expected to continue to operate until 2040. As the power station ages it is likely that there will be longer periods required for maintenance when power station will be offline. This makes the discharge situation even worse as time goes on.
The planning department must require Centennial to significantly reduce the mining intensity at its underground coal mines to protect the natural environment and to reduce the volume of wastewater sent to Mount Piper power station.

I wish to lodge my strong objection to Centennial Coal's proposed modification to their consent to release wastewater into the environment of our World Heritage listed National Park and ultimately into Sydney's water catchment. Centennial should be required to treat mine water to ensure that any discharge fully removes contaminants like heavy metals, salt and brine and deliver the zero release system they proposed when the water treatment plant was approved. Anything less threatens the safety of Sydney’s drinking water supply and water dependent ecosystems, including endangered and threatened species. If Centennial is unable to do this, Springvale mine must be closed and alternative coal supplies found for Mount Piper power station. I do not think it is good enough for Centennial to self-monitor the level of contaminants as they have proposed. Centennial has already been found to have breached its environmental licence more than 1400 times across 7 coal mine sites in the Greater Blue Mountains region. If Centennial is unable to prevent the polluting of our waterways, then Angus Place Colliery and Springvale Colliery operations should be closed. Let Mount Piper find an alternative coal source (and let the mines flood if necessary), but do not discharge into Cox's River or its tributaries. The planning department should require Centennial to at least significantly reduce the mining intensity at its underground coal mines to protect the natural environment and to reduce the volume of wastewater sent to Mount Piper power station. The government should commission a public inquiry into mine wastewater produced by Centennial’s underground coal mines in the Gardens of Stone region. Centennial seeking to discharge megalitres of mine waste would result in a huge increase in pollution, via an unacceptable heavy metal and salinity load into the receiving environment. The modifications they seek could discharge combinations of treated and untreated mine waste totalling up to 68.5ML/day of water directly and indirectly (via Thompsons Creek Reservoir) into the catchment for Sydney’s drinking water supply. This is an outrageous proposition that should not be permitted by this Government. This vast volume of polluted mine waste water is a problem of their own creation because Centennial’s underground coal mining has damaged groundwater aquifers under the Gardens of Stone State Conservation Area. To drain the resulting influx of groundwater into underground coal mines, Centennial removes more than 20 billion litres of groundwater every year, interrupting groundwater supply and drying out peat swamps. Therefore I call on the NSW Government to curtail these damaging mining operations to prevent further degradation of our precious natural environment.

See attachment

I support MOD 11. If the modification is not approved and the water cannot be discharged as specified in the application when MPPS has an outage, I believe this will put a significant risk on the continuity of mining operations at Springvale and the future of Angus Place, especially as outages are relatively routine for operating a power station, and negatively affect the livelihoods of employees and the economic and community participation benefits that the Lithgow community and council currently receive.

I believe Centennial has met all of their legislative requirements when submitting the modification and included thorough impact analyses and appreciate the level of stakeholder engagement they conduct.

This company has demonstrated a highly responsible commitment to improving discharge water quality. The impact of ongoing restrictions are jeopardising the future viability of providing coal supply to the (MPPS) power station. The quantity of bypass water requested in the submission for this modification is critical to maintain safe levels of stored water underground and not further risk this asset. Significant effort and engineering has been employed to ensure any risk to the environment is maintained as low as reasonably practicable throughout this planned outage of the power station as Centennial continue to demonstrate an exceptionally high standard in managing the water from the workings in a sustainable and responsible manner.

Water Management Proposal

I understand the proposal provides for Centennial to release an additional 42 million litres per day of mine waste water to Thompsons Creek Reservoir (for up to 111 days at a time) to cover Mount Piper outage periods. This will consist of up to 18 million litres per day of water through the water treatment plant and 24 million litres a day of untreated water. Removing sediment does not equate to treating water.

I object to this proposal because Thompsons Creek Reservoir discharges via tributaries of the Coxs River that flows through a World Heritage listed national park and ultimately to Warragamba Dam. It is vital to maintain the integrity (and safety) of urban water supplies- as we are experiencing with the fallout of PFAS contamination in the Blue Mountains water supply in and other regions.
I and many others enjoy the value of the Greater Blue Mountains World Heritage Area- providing bushland and creeks where citizens can walk and camp and relax away from the hot and crowded cities and suburbs. We know that our biodiversity is under threat and conservationists are working to restore habitat and waterways to support wildlife such as the platypus, koalas and native birds. These efforts and our diminishing natural bush areas will be compromised if this proposal be approved.

I understand that water experts have previously cautioned that blending or dilution of dirty water with treated water will exacerbate, rather than address, pollution of the Sydney drinking water catchment as the overall load of pollutants will drastically rise.
Further, I note two previous applications from Centennial seeking to discharge megalitres of mine waste into Wangcol Creek were withdrawn, and this ‘dilute and discharge’ approach would be far worse as it involves far more polluted water.
If this proposal is approved, it would result in a huge increase in pollution, heavy metal and salinity load into the receiving environment. Higher salinity means lower oxygen, which reduces food for platypus. I understand the elecro-receptors on their bill used to locate prey, are compromised by increased salinity and the platypus then can’t find food and starve to death.
As Mount Piper power station may remain open until the early 2040s, Centennial is seeking permission to dilute and discharge water from Thompsons Creek Reservoir during scheduled offline maintenance periods for the lifetime of the water treatment plant. This could mean up to or around 15 years of huge volumes of dirty water discharge for up to 111 days at a time.
I appreciate the need for Centennial to continue operations, but this should not be at the cost of our health and our native environment. Centennial should be required to treat mine water to ensure that any discharge has fully removed contaminants like heavy metals, salt and brine and delivers the zero release system they proposed when the water treatment plant was approved. Anything less threatens the safety of Sydney’s drinking water supply and water dependent ecosystems, including endangered and threatened species.
If Centennial is unable to do this, Springvale mine must be closed and alternative coal supplies found for Mount Piper power station.
It is clearly not good enough for Centennial to self-monitor the level of contaminants as they have proposed. Centennial has been found to have breached its environmental licence more than 1400 times across 7 coal mine sites in the Greater Blue Mountains region[2].
There appears to be no alternative plan to divert mine water if monitoring reveals higher than expected salinity levels.
To ensure the health and safety of citizens and the environment, the planning department must require Centennial to significantly reduce the mining intensity at its underground coal mines to protect the natural environment and to reduce the volume of wastewater sent to Mount Piper power station.
I urge the government to commission a public inquiry into mine wastewater produced by Centennial’s underground coal mines in the Gardens of Stone region. A treasured reserve and outstanding natural and tourist resource.

I trust you will give this submission and my concerns due consideration. Marion Brown

Please find attached a submission on behalf of Lithgow Environment Group Inc objecting to this proposal SSD-7592 (MOD 11) – SPRINGVALE WATER TREATMENT PLANT and MOUNT PIPER POWER STATION OUTAGES.

See attached submission that replaces my earlier submission of 26 Jan 2025.

Please find attached submission.