Delta Electricity found guilty over 2022 fish kill near its Vales Point Power Station

The New South Wales Land and Environment Court has ruled power company Delta Electricity is guilty of an environmental offence over a 2022 fish kill near its Vales Point coal-fired power station, south of Newcastle.

The NSW Environment Protection Authority (EPA) launched legal action in September 2023 over the second of two fish kills that occurred in 2022 in waters near the plant which operates on the shores of Lake Macquarie.

The EPA concluded the first kill, which occurred in August 2022, was likely due to natural causes.

But the authority alleged the second kill, which occurred a month later, was due to a valve maintenance failure which led to sodium hypochlorite being discharged into the water.

Hundreds of fish were killed in the second event, with a court hearing in March that "five to ten large bags" of fish were collected, while a large group of dead fish were seen on the foreshore of Wyee Bay.

In her written judgement, Judge Sarah Pritchard said Delta Electricity was charged with contravening the conditions of an environmental protection licence it holds.

She said the company "failed to maintain the chlorine dosing plant in a proper and efficient condition".

"[Delta Electricity failed to maintain] the chlorine dosing plant in a physical state that enabled sodium hypochlorite to be dosed to the cooling water system at the premises (cooling water system) in a controlled manner and in a manner that avoided or minimised the risk of uncontrolled discharge of sodium hypochlorite into the environment," the judgement read.

"On or about 6 September 2022, the condition of the chlorine dosing plant was such that it failed to control the dosing of sodium hypochlorite to the cooling water system, as a consequence of which uncontrolled sodium hypochlorite was discharged to the environment."

Separate incidents

The judgement discussed the first fish kill event in August 2022 and referenced evidence that was submitted by the EPA, concluding that it was likely a natural event.

"[EPA documents] in relation to the [August] incident recorded that the EPA had obtained no evidence suggesting a pollution incident from the Vales Point Power Station "causing or contributing to the fish kill," the judgement read.

"[The August event was] likely caused by natural events related to a sediment turnover incident caused by preceding low temperatures and wind direction change and speed and exacerbated by the warmer temperatures of Wyee Bay related to the Vales Point cooling discharge."

Judge Pritchard later noted the company undertook a "detailed investigation of its systems" following the August incident, but concluded Delta Electricity failed to maintain the system in advance of the September incident despite that.

A hearing has been scheduled for February 6, 2026, ahead of Judge Pritchard handing down a sentence to Delta Electricity.