September 28, 2018

EnergyAustralia, one of the country’s leading energy retailers, today said it has committed $2 million toward new measures to manage underground water at the Mt Piper power station in the central west of New South Wales.

Ross Edwards, EnergyAustralia Executive - Energy, said the spend was part of a broader program to provide the community, workers and customers with certainty about the future of the power station, which has an operating life until 2043. Works already underway at Mt Piper include a $200 million water treatment plant and pipeline project, assessment of a waste-to-energy project and a rail development to expand sources of long-term coal supply.

The new "groundwater" investment is in addition to the $11.5 million already spent each year at Mt Piper on managing water at the site.

"In 2016 a study at Mt Piper confirmed readings of elevated chloride in the groundwater beneath the ash repository, and ongoing monitoring has now given us a good indication of the source. It showed chloride from ash was making its way through the soil and rock and into groundwater beneath the repository," Mr Edwards said.

"If we’re planning for Mt Piper to be part of the energy system for a long time to come, then groundwater is one of the potential impacts we have to manage and get right. Owners of big power stations have an obligation to make sure their operations are environmentally and socially acceptable," he said.

EnergyAustralia acquired the Mt Piper and now-closed Wallerawang power stations from the New South Wales government in 2013.

Ash is a by-product of generating electricity from coal. It’s stored on site in large, specially-designed pits or repositories. The ash is mixed with salt water from the power station’s cooling system.

"Chloride is basically salt. It occurs naturally in water and isn’t harmful to humans, except in extremely high doses," Mr Edwards said. "But if left to make its way into water courses and streams the salt residue can impact the local ecology, and we can’t let that happen."

The power station has an existing network of 18 bores to monitor and test the quality of water below ground. To manage groundwater over the long term, EnergyAustralia has built three, new 20-mega-litre double-lined water retention ponds with leak detection systems. It is investing in a groundwater and surface water assessment program that includes the installation of 14 new groundwater monitoring bores.

The company is also developing an updated groundwater model to help predict flows and guide ongoing water management and remedial works, if they’re needed.

Meanwhile, EnergyAustralia recently announced it had applied to build a rail coal unloader as part of plans to expand Mt Piper’s potential sources of supply. The company is also assessing the potential for energy recovery, which would allow the power station to generate power to meet the electricity needs of around 40,000 typical homes in New South Wales without having to burn additional coal.

Mt Piper fast facts:

  •  On average, Mt Piper’s operations use approximately 40 megalitres of water per day
  •  The site has complex water treatment facilities that ensure all process water is reused up to six times within the site; it’s not released directly into the local environment
  •  Mt Piper already commits around $11.5 million to water management including $200 million in a water treatment plant and an additional $2 million in groundwater management
  •  Mt Piper is responsible for the controlled release of water from Lake Lyell into the Coxs River to Warragamba Dam (Sydney’s drinking water catchment)
  •  Mt Piper was built in two stages; unit two was commissioned in 1992 followed by unit 1 in 1993. The site has an operational life until 2043