The NSW Environment Protection Authority is investigating a fish kill event in the Hunter River at Mount Thorley, following reports of hundreds of dead fish along a stretch of the river.
EPA officers were called to the site on Friday 20 March, where they collected water and fish samples for laboratory analysis. Locals reported seeing dead fish across an estimated two‑kilometre section of the river.
At this stage, the cause of the fish kill is unknown. EPA Director of Operations David Gathercole said the Hunter River at Mount Thorley receives inputs from a range of sources, including industrial estates, agricultural runoff and mining activities.
Mr Gathercole said the EPA is contacting licenced facilities in the area with known discharge points to ensure they are operating normally and to determine whether a pollution incident has occurred. He said the EPA would also work with other government agencies to monitor water quality.
As a precaution, the EPA is advising anyone swimming in the river to follow NSW Health advice and avoid drinking untreated water. Downstream users are also being encouraged to delay water extraction where possible until water quality is confirmed as safe.
Water sample analysis results are expected within the next week, while fish sample testing could take up to three weeks.
