More than 200 million tonnes of coal ash waste is currently dumped in unlined sites across NSW, with more than half of the material stored in the Hunter and Central Coast regions, a parliamentary inquiry has heard.
The inquiry into the costs for remediation of sites containing coal ash repositories was told on Tuesday that the amount of the waste product is growing by 3.8 million tonnes a year.
Several environment and community organisations raised concerns about the impact of the material on surrounding residents and the environment, in particular the potential for heavy metals and other pollutants to contaminate waterways, soil and air.
The NSW Nature Conservation Council has called for the state government to introduce ash dam regulations consistent with international best practice and to apply the regulations to both active and inactive ash dams.
It also wants all ash dams to be lined and made leach proof and for the ash dams at Vales Point and Eraring power stations to be decontaminated and reconstructed.
"For both the Eraring and Vales Point power stations the government is liable for pre-sale contamination of their coal ash dams. The government should reflect on the international coal ash disasters and ensure they take every possible measure to mitigate this risk," Nature Conservation Council climate and energy campaigner Liz Hadjia said.
Environmental Justice Australia has called on the government to pause the assessment process for a coal ash dump expansion at AGL's Bayswater power station until the outcomes of the coal ash inquiry are known.
The group argued the company's proposal to expand ash recycling by one million tonnes per year and establish a waste disposal site for salt cake ignored hazards and failed to comply with NSW law.
"Not only is the approval of the Bayswater coal ash dam expansion going ahead before the coal ash inquiry has begun, there are serious gaps in AGL's proposal that could put the local community and environment at risk from things like groundwater contamination," Bronya Lipski, lawyer with Environmental Justice Australia, said.
"To protect the community, NSW Environment Minister, Matt Kean, must stop this proposal in its tracks until the recommendations from the coal ash inquiry are known."
Representatives from Delta, Origin and AGL defended their management of coal ash waste and said they were keen to increase the amount of the material that was recycled.
Origin, which operates Eraring Power Station, said it has already constructed a private haul road paved with a pavement product with an ash content of 92 per cent.
Assessments conducted by independent laboratories found that the road exceed performance standards over a 25-year period.
The company is in discussions with Lake Macquarie Council to construct another road with the product in the local government area.
The inquiry's second hearing will be held at Lake Macquarie on October 6.
The majority of the submissions received by the inquiry raised concerns about heavy metal contamination leaching into the water, dust pollution, and the low rate of coal ash reuse in Australia.