Help protect Sydney’s drinking water from Centennial’s toxic mine waste by opposing their plans.
NCC Submission Guide: Centennial Coal Modification 11 to SSD-7592 (MOD 11)
One of NSW’s biggest mining companies, Centennial, has been storing wastewater from coal mine operations and has submitted a “modification” proposal to dump it in a reservoir at the headwaters of Sydney’s drinking water catchment.
The Nature Conservation Council of NSW (NCC) has put together this submission guide to assist those in our network to make their own submission, either as an organisation or an individual.
Original submissions are more impactful so where possible we recommend adding in your own thoughts and comments in addition to the information provided.
Key Information
- Submissions close on Thursday 6th February 2025.
- Click on “Make a Submission” here. Note you'll need to create a login in order to make a submission. Please stick with it! It only takes a few minutes and once you have a login the submission process is quick and easy.
- You can find Centennial’s proposal here.
In addition to making a submission, you can also sign the NCC petition to the EPA to do what it takes to make Centennial clean up its act.
Background
Where does the water come from?
- Centennial mining operations are adjacent to the Gardens of Stone State Conservation Area, a place with more than 80 rare and threatened species and 16 threatened ecological communities. Intensive mining methods have destroyed aquifers, resulting in drying out of endangered upland peat swamps.
- 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.
- Approximately 5,000,000,000 litres of mine wastewater is stored underground in Angus Place mine as well as Springvale mine. To continue mining, Centennial proposes to discharge this waste into Sydney’s drinking water catchment.
How does Mount Piper power station fit in?
- EnergyAustralia’s Mount Piper coal-fired power station takes in water from Centennial mines, and runs water needed for the power station cooling towers through the water treatment plant.
- But Mount Piper power station will be offline for maintenance for a period this year which means it does not need the water.
What is Centennial proposing?
- Centennial wants 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 (only sediment will be removed).
- Thompsons Creek Reservoir discharges via tributaries of the Coxs River that flows through a World Heritage listed national park and ultimately to Warragamba Dam.
- We also expect Centennial to submit a second mine waste proposal in the next couple of months to address stored wastewater. We understand they will apply to release up to 26.5 million litres per day into Wangcol Creek consisting of 16.5 million litres per day treated water via the water treatment plant and 10 million litres per day untreated water (only sediment will be removed) for up to 4 years.
- In total, the modifications will contemplate discharge of 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.
Key points for your submission
- Clearly express your opposition to this proposal and outline your concern that the health of Sydney’s drinking water and the ecological value of the Greater Blue Mountains World Heritage Area and wildlife such as the platypus will be compromised should this proposal be approved.
- Water experts have previously warned that blending or dilution of dirty water with treated water will exacerbate, rather than address, pollution of the Sydney drinking water catchment as overall load of pollutants will drastically rise[1].
- 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 first 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. Elecro-receptors on their bill locate prey, however salinity disrupts these, they 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.
- 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.
- It is 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 is no ‘plan B’ to divert mine water if monitoring reveals higher than expected salinity levels.
- 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.
- The government should commission a public inquiry into mine wastewater produced by Centennial’s underground coal mines in the Gardens of Stone region.
[1] Centennial Coal plan to release more water into Sydney catchment will make pollution worse, expert says - ABC News
[2] https://apps.epa.nsw.gov.au/prpoeoapp/